Abstract
Background
Social isolation is a pervasive and debilitating condition that has adverse prognostic impacts. This condition often co-occurs with other geriatric syndromes, further exacerbating negative health outcomes. Given these considerations, the present study aims to elucidate the roles of social isolation in older adults with anorexia of aging and/or sarcopenia with respect to long-term mortality using a nationally representative cohort study.
Methods
Data were obtained from the Taiwan Longitudinal Study on Aging (TLSA), with a sample size of 3,762 study participants aged 50 years and older. Data from 1999 (wave 4) to 2015 (wave 9) were analyzed. The TLSA questionnaire was used to define social isolation, anorexia, and sarcopenia. Logistic regressions were employed to explore the associations between social isolation, anorexia, and sarcopenia. The Cox proportional hazard model was utilized to examine the synergistic effects of social isolation and anorexia or sarcopenia on 16-year all-cause mortality.
Results
After controlling for demographic information and comorbidities, older adults with social isolation were significantly associated with anorexia (adjusted odds ratio [aOR] 1.46 [95% confidence interval: 1.00–2.12, p=0.0475]) and sarcopenia (aOR 1.35 [95% CI: 1.12–1.64, p=0.0021]). Furthermore, the synergistic effects of social isolation with anorexia (aOR 1.65 [95% CI: 1.25–2.18, p=0.0004]) or sarcopenia (aOR 1.65 [95% CI: 1.42–1.92, p<0.0001]) were both significantly associated with higher risks of all-cause mortality, while social isolation alone revealed borderline statistical significance.
Conclusions
Our findings indicate that social isolation is closely linked to anorexia and sarcopenia among middle-aged and older adults. Additionally, social isolation significantly exacerbates the long-term mortality risk associated with anorexia of aging and sarcopenia. However, social isolation alone appears to have borderline long-term mortality risk in this cohort. These findings underscore the importance of addressing social isolation in older adults with anorexia and/or sarcopenia to optimize their health outcomes and mitigate long-term mortality risk.
Key words: Social isolation, anorexia, anorexia ofaging, sarcopenia, mortality, Taiwan Longitudinal Study on Aging
Introduction
Social isolation has become a prominent and escalating concern in most developed countries (1), and is typified by limited social engagement and a dearth of familial and social contacts (2). Recent estimates suggest that the global prevalence of social isolation has reached a staggering 25% (3, 4), with the COVID-19 pandemic exacerbating its severity even further (5, 6). Studies have demonstrated that social isolation is linked to a host of adverse health outcomes, including poor psychological well-being, depression (7), cognitive decline (7, 8), and diminished quality of life (9) among middle-aged and older individuals. Epidemiological investigations have also identified associations between social isolation and a range of unfavorable physical outcomes, such as stroke, cardiovascular disease, and dementia (7, 10, 11, 12, 13). Notably, social isolation has been found to significantly increase the risk of hospitalizations and severity of anorexia nervosa among young individuals during the pandemic (14, 15), while people living alone were also reported to be at-risk of anorexia of aging (16). Furthermore, social isolation may synergistically act with other health risks to worsen the outcomes of older adults. In light of these findings, addressing social isolation in vulnerable populations is crucial for promoting health and well-being.
Anorexia of aging is a widely observed phenomenon among older adults, characterized by a decrease in appetite and/or food intake (17, 18, 19, 20), that affects more than 10% of older individuals living in the community (21). The regulation of appetite and dietary intake is a complex process that may be influenced by a range of factors throughout the lifespan (22). Additionally, physiological changes such as gustatory function degeneration or alterations in gastrointestinal motility and metabolic factors (e.g., hormones, inflammatory mediators, and gut dysbiosis) may contribute to reduced food intake (23, 24, 25, 26). Prior research has established a link between anorexia of aging and negative health outcomes, including inferior quality of life, sarcopenia, and reduced survival (17). Moreover, diminished dietary intake may result in decreased physical activity and muscle mass, leading to complications such as sarcopenia, frailty, and mortality (16, 17, 21, 27, 28). On the other hand, sarcopenia, characterized by the loss of skeletal muscle and muscle strength and/or reduced physical performance (29, 30), has emerged as a major public health challenge in rapidly aging societies (31, 32). The prevalence of sarcopenia ranges from 7.3% to 12.0% (29) in different settings, and it significantly increased the risk for mortality (33), falls (34), functional declines, and healthcare utilization (35, 36, 37).
Prior research has highlighted the association between social isolation and all-cause mortality (2, 38); however, given that social isolation frequently co-occurs with other geriatric conditions such as anorexia or sarcopenia, a more comprehensive approach is necessary to disentangle the complex interplay between these factors. To address this gap in knowledge, the present study employs a nationally representative 16-year cohort design to examine the associations between social isolation and anorexia of aging or sarcopenia, as well as the potential synergistic effects of these conditions on the long-term risk of all-cause mortality rates among community-dwelling middle-aged and older adults.
Materials and Methods
Participants
Data of this study were retrieved from the Taiwan Longitudinal Study of Aging (TLSA), an ongoing nationally representative survey initiated by the Health Promotion Administration (HPA), Ministry of Health and Welfare (MOHW), Taiwan. The TLSA, which was first conducted in 1989 with follow-up interviews every 3–4 years, provides a comprehensive assessment of physical, functional, and mental health, as well as demographic and household information via face-to-face household interviews. Originally designed for adults aged 65 and above, the TLSA expanded its sample to include adults aged 50 and above in 1996 to better capture the aging process. Detailed designs of the TLSA are described on the website of the HPA (39) and in previously published studies (40, 41, 42).
The present study drew its sample from the 1999 survey of the TLSA, comprising both the original and refresh samples of the study initiated in 1989. Participants with incomplete demographic information (n=41), missing data on social isolation (n=48), or inadequate measurements of anorexia of aging or sarcopenia (n=276) were excluded. Additionally, those with alternative respondents (n=313) were also excluded. Following the exclusion criteria, a total of 3,762 participants were included in our final study cohort. A schematic depiction of the study subject selection process is presented in Figure 1.
Figure 1.
Study flowchart
Assessment of social isolation
The determination of social isolation status in our study was established based on the Steptoe social isolation index (2, 43), a well-established metric employed in previous studies (2, 38, 43, 44). The Steptoe social isolation index captures five domains of social isolation, including 1) marital status or cohabitation, 2) frequency of contact with children, 3) frequency of contact with other family members, 4) frequency of contact with friends, and 5) participation in social clubs or groups, and the responses were obtained from the TLSA questionnaires. For each item, participants who reported marriage status other than married or cohabiting, contacts with children and grandchildren/family/friends less than 1 time per month, or no participation in any clubs or groups were scored 0, and the remaining participants were scored 1. The total score of social isolation ranged from 0 to 5, and those who scored 2 points or more (the top quintile) were categorized as socially isolated.
Anorexia of aging
Anorexia of aging (17, 18, 19, 20), a prevalent condition affecting older adults, has been defined as a decline in either appetite or food intake. To assess this condition, the nutrition section of the TLSA 1999 questionnaire utilized two self-reported items. To evaluate appetite, participants were asked, “Generally speaking, what do you think about your appetite?” with response options of “good,” “on and off,” or “bad.” Similarly, to evaluate food intake, participants were asked, “Has your food intake increased or decreased significantly recently?” with response options of “no change,” “increase significantly,” or “decrease significantly.” Participants who responded with “bad” for appetite or “decrease significantly” for food intake were classified as having anorexia of aging.
Sarcopenia
The SARC-CalF (≥ 11 points) (45), which combines the SARC-F questionnaire with calf circumference measurements (45, 46), was adopted in this study to define sarcopenia. Each of the five items from SARC-F was rated on a scale of 0, 1, or 2, based on the level of difficulty experienced by the participant. In addition, a calf circumference below the cut-off (female: ≤33 cm, male: ≤34 cm) was scored as 10, whereas a circumference above the cut-off (female: >33 cm, male: >34 cm) was scored as 0. In this study, we replaced two elements in the original SARC-CalF questionnaire with questions available in the TLSA1999. Specifically, for muscle strength, “lifting and carrying 10 pounds (about 4.5 kilograms)” was substituted with “lifting and carrying 1.2 kilograms”, while for climbing stairs, “climbing a flight of 10 stairs” was replaced with “climbing to the 2nd or 3rd floor”. The total score of SARC-CalF ranged from 0 to 20, and a score of ≥11 points was used to identify sarcopenia in this study.
All-cause mortality
The survival status of study subjects was retrieved from the mortality database of TLSA, which was linked to the Household Registration and Conscription Information System of the Ministry of Interiors (MOI) and the death certificate report system of MOHW. All TLSA participants were recorded as 1) alive, 2) deceased, and 3) survival status unknown or emigration in the database and updated concurrently in each follow-up survey. In the event that a subject's survival status was unknown in 2015, the latest record of being alive was considered the censored time.
Sociodemographic variables and comorbidities
Sociodemographic variables including age (stratified as 50–64, 65–74, 75–84, 85+ years), gender, marital status (married/cohabiting, widowed, divorced/separated/never married), education level (illiterate, primary, junior/senior high/college), residence area (large city, small city/township, country/rural area), current smoking, current alcohol use, and physical activity were collected from the questionnaires for each participant. Self-reported chronic conditions, including hypertension, diabetes mellitus, heart disease, stroke, cancer/malignant tumor, arthritis/rheumatism, gastric ulcer/stomach ailment, liver/gallbladder disease, and renal disease, were meticulously recorded, and the cumulative number of self-reported conditions was subsequently calculated. Frailty was also captured and defined according to the Fried criteria. Individuals who exhibited at least three of five traits (i.e. weight loss, exhaustion, low physical activity, slowness, and weakness) were considered frail. Individuals meeting only one or two of the five traits of the Fried frailty criteria were regarded as prefrail (47).
Statistical analysis
In the initial phase of this investigation, the baseline sociodemographic variables and comorbidities were compared between subjects with and without social isolation using the Chi-square test. The study then employed multivariate logistic regression models to explore the associations between social isolation and anorexia of aging or sarcopenia, respectively, after adjusting for relevant confounding factors, such as age, sex, education level, residence area, smoking behavior, drinking behavior, and self-reported chronic conditions. Both unadjusted and adjusted odds ratios (ORs) were presented with 95% confidence intervals (CIs).
Subsequently, in the second stage, the Kaplan-Meier method with log-rank tests was applied to assess the all-cause mortality in the 16-year follow-up period, examining the individual or synergistic effects of social isolation and either anorexia of aging or sarcopenia. This involved examining various combinations of social isolation and anorexia of aging (i.e., social isolation (−)/anorexia of aging (−); social isolation (+)/ anorexia of aging (−); social isolation (−)/anorexia of aging (+); social isolation (+)/anorexia of aging (+)) or sarcopenia (i.e., social isolation (−)/sarcopenia (−); social isolation (+)/sarcopenia (−); social isolation (−)/sarcopenia (+); social isolation (+)/ sarcopenia (+)). Finally, multivariate logistic regression models were utilized to examine these associations while adjusting for the relevant variables. Model 1 only considered age and gender, while model 2 included all covariates except for marital status and physical activity. In addition, we undertaken analyses to look into the impacts of different combinations of social isolation, anorexia of aging, and sarcopenia on mortality.
The study employed a two-tailed p-value <0.05 as the level of statistical significance for all analyses. All the data processing and statistical analysis were carried out using SAS, version 9.4 (SAS Institute, Inc., Cary, NC).
Results
Baseline characteristics
A total of 3,762 study subjects (53.1% males) were included that 1442 (38.3%) of them were categorized as social isolation. Table 1 summarizes the sociodemographic variables and self-reported chronic conditions of our study subjects, stratified by social isolation status. Subjects with social isolation were older than those without social isolation. Compared to those without social isolation, those with social isolation were older (aged 65+, 74.8 vs. 54.7%), more likely to be women (54.6 vs. 42.1%), illiterate (35.0 vs. 26.7%), living in urban communities (35.5 vs. 21.6%), no marriage or cohabiting partners (59.0 vs. 12.7%), having hypertension (35.4 vs. 30.5%), heart disease (19.1 vs. 15.6%), stroke (6.0 vs. 3.3%), or more chronic conditions (3+, 17.8 vs. 13.9%), and more likely to be frail (30.3 vs. 14.6%). Moreover, study subjects with social isolation were less likely to be current smokers (21.2 vs. 26.2%), alcohol users (20.5 vs. 28.1%), and to do physical activities (57.8 vs. 61.9%).
Table 1.
Baseline characteristics; stratified by status of social isolation
| Without Social Isolation | With Social Isolation | p-value | |
|---|---|---|---|
| N | 2320 (61.67) | 1442 (38.33) | |
| Age | |||
| 50-64 | 1051 (45.30) | 363 (25.17) | <.0001 |
| 65-74 | 849 (36.59) | 525 (36.41) | |
| 75-84 | 387 (16.68) | 469 (32.52) | |
| 85+ | 33 (1.42) | 85 (5.89) | |
| Sex | |||
| Male | 1344 (57.93) | 655 (45.42) | <.0001 |
| Female | 976 (42.07) | 787 (54.58) | |
| Marital | |||
| Married or cohabiting | 2026 (87.33) | 591 (40.98) | <.0001 |
| Widowed | 280 (12.07) | 679 (47.09) | |
| Divorced / separated / never married | 14 (0.60) | 172 (11.93) | |
| Education | |||
| Illiterate | 620 (26.72) | 505 (35.02) | <.0001 |
| Primary | 1130 (48.71) | 621 (43.07) | |
| Junior / senior high / college | 570 (24.57) | 316 (21.91) | |
| Residence area | |||
| Large city | 500 (21.55) | 512 (35.51) | <.0001 |
| Small city / township | 1013 (43.66) | 596 (41.33) | |
| Country / rural area | 807 (34.78) | 334 (23.16) | |
| Lifestyle behaviors | |||
| Current smoker | 607 (26.16) | 305 (21.15) | 0.0005 |
| Current alcohol use | 652 (28.10) | 296 (20.53) | <.0001 |
| Physical activity | 1437 (61.94) | 834 (57.84) | 0.0124 |
| Self-reported chronic conditions | |||
| Hypertension | 708 (30.52) | 510 (35.37) | 0.0020 |
| Diabetes | 293 (12.63) | 210 (14.56) | 0.0902 |
| Heart disease | 362 (15.60) | 275 (19.07) | 0.0058 |
| Stroke | 77 (3.32) | 87 (6.03) | <.0001 |
| Cancer or malignant tumor | 62 (2.67) | 39 (2.70) | 0.9527 |
| Arthritis or rheumatism | 457 (19.70) | 277 (19.21) | 0.7130 |
| Gastric ulcer or stomach ailment | 441 (19.01) | 282 (19.56) | 0.6786 |
| Liver or gall bladder disease | 170 (7.33) | 114 (7.91) | 0.5140 |
| Renal disease | 182 (7.84) | 111 (7.70) | 0.8699 |
| Number of self-reported chronic conditions | |||
| 0 | 817 (35.22) | 473 (32.80) | 0.0101 |
| 1 | 733 (31.59) | 429 (29.75) | |
| 2 | 447 (19.27) | 283 (19.63) | |
| 3+ | 323 (13.92) | 257 (17.82) | |
| Frailty | |||
| 0 (fit) | 694 (29.91) | 239 (16.57) | <.0001 |
| 1 (pre-frail) | 924 (39.83) | 449 (31.14) | |
| 2 (pre-frail) | 342 (14.74) | 300 (20.80) | |
| 3+ (frail) | 338 (14.57) | 437 (30.31) | |
* Data were shown as number (percentage), and the Chi-square test was used for comparisons between groups
Associations between social isolation and anorexia of aging and sarcopenia
The associations between social isolation and anorexia of aging analyzed by multivariate logistic regressions were presented in Table 2. In the unadjusted model, participants with social isolation were significantly associated with anorexia of aging (OR 1.80 [1.28–2.53]). After adjusting for covariates, both the model 1 (considering only age and gender) and model 2 (all covariates except for marital status and physical activity) indicated that social isolation was associated with a 40% increase in risk of anorexia of aging (aOR 1.44 [1.00–2.06] and 1.46 [1.00–2.12]). Similar results were found in the the associations between social isolation and sarcopenia (Table 2). The logistic regression model revealed social isolation was significantly associated with sarcopenia in the unadjusted model (OR 2.13 [1.81–2.52]), as well as adjusted models (model 1: aOR 1.28 [1.07-1.54], model 2: aOR 1.35 [1.12–1.64]).
Table 2.
The associations of social isolation with anorexia of aging or sarcopenia
| Ref.: Without social isolation | OR (95% CI) | p-value |
|---|---|---|
| Anorexia of aging | ||
| Unadjusted model | 1.80 (1.28–2.53) | 0.0008 |
| Adjusted model 1 (age, gender) | 1.44 (1.00–2.06) | 0.0482 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.46 (1.00–2.12) | 0.0475 |
| Sarcopenia | ||
| Unadjusted model | 2.13 (1.81–2.52) | <.0001 |
| Adjusted model 1 (age, gender) | 1.28 (1.07–1.54) | 0.0083 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.35 (1.12–1.64) | 0.0021 |
# Education level, residence area, current smoker, current alcohol use; ❡ Hypertension, diabetes, heart disease, stroke, cancer or malignant tumor, arthritis or rheumatism, gastric ulcer or stomach ailment, liver or gall bladder disease, renal disease
Social isolation, and/or anorexia of aging on mortality at 16-year of follow-up
The present study further classified participants into two-by-two groups based on their social isolation and anorexia of aging status. Specifically, among all subjects, 2255 (59.9%) were categorized as «Neither» and were used as the reference group. Additionally, the remaining participants were divided into three other groups: «Only social isolation» (1371, 36.4%), «Only anorexia of aging» (65, 1.7%), and «Both (social isolation (+)/ anorexia of aging (+))» (71, 1.9%). Kaplan-Meier survival curves for each group were presented in Figure 2, and the corresponding odds ratios for all-cause mortality were reported in Table 3.
Figure 2.
16-year survival probability among groups of social isolation and anorexia of aging
Table 3.
16-year all-cause mortality risk among groups of social isolation and anorexia of aging
| Ref.: Social isolation (-) / Anorexia of aging (-) (N=2255) | OR (95% CI) | p-value |
|---|---|---|
| Social isolation (+) / Anorexia of aging (−) (N=1371) | ||
| Unadjusted model | 1.51 (1.38–1.65) | <.0001 |
| Adjusted model 1 (age, gender) | 1.10 (1.00–1.21) | 0.0491 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.12 (1.01–1.23) | 0.0261 |
| Social isolation (−) / Anorexia of aging (+) (N=65) | ||
| Unadjusted model | 1.84 (1.35–2.51) | 0.0001 |
| Adjusted model 1 (age, gender) | 1.73 (1.27–2.37) | 0.0006 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.77 (1.29–2.42) | 0.0004 |
| Social isolation (+) / Anorexia of aging (+) (N=71) | ||
| Unadjusted model | 2.87 (2.19–3.75) | <.0001 |
| Adjusted model 1 (age, gender) | 1.87 (1.42–2.46) | <.0001 |
| 1 Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.65 (1.25–2.18) | 0.0004 |
# Education level, residence area, current smoker, current alcohol use; ❡ Hypertension, diabetes, heart disease, stroke, cancer or malignant tumor, arthritis or rheumatism, gastric ulcer or stomach ailment, liver or gall bladder disease, renal disease
In comparison to the «Neither» group, all groups exhibited noteworthy correlations with all-cause mortality, both before and after adjustments. Specifically, in Model 2 (as shown in Table 3), the «Only social isolation» group (aOR 1.12 [1.01–1.23]) displayed a higher risk of all-cause mortality than the «Neither» group but a lower risk than the other groups. Moreover, anorexia of aging was significantly associated with increased risks of all-cause mortality, regardless of the presence of social isolation («Only anorexia of aging»: aOR 1.77 [1.29–2.42], «Both social isolation and anorexia of aging»: aOR 1.65 [1.25–2.18]) (Table 3).
Social isolation, and/or sarcopenia on mortality at 16-year of follow-up
Within the study population, 1996 (53.1%) were identified as not having social isolation and sarcopenia, designated as the «Neither» group. Of the remaining participants, 1071 (28.5%) exhibited social isolation without sarcopenia and were categorized as «Only social isolation», while 324 (8.6%) presented with sarcopenia without social isolation and were classified as «Only sarcopenia». The remaining 371 (9.9%) participants exhibited both social isolation and sarcopenia, labeled as the «Both» group. The 16-year all-cause mortality rates for each group were presented in Figure 3.
Figure 3.
16-year survival probability among groups of social isolation and sarcopenia
Table 4 outlined the associations between each group and all-cause mortality in comparison to the « Neither» group, which served as the reference category. All groups were linked to a higher risk of all-cause mortality prior to adjustments. After adjustments in model 2, participants classified under «Only social isolation» displayed an insignificant effect on the risk of mortality (aOR 1.09 [0.97–1.21]). However, those with sarcopenia only and those with co-existing social isolation and sarcopenia were significantly associated with all-cause mortality (aOR: «Only sarcopenia»: 1.40 [1.20–1.63], «Both»: 1.65 [1.42–1.92]).
Table 4.
16-year all-cause mortality risk among groups of social isolation and sarcopenia
| Ref.: Social isolation (−) / Sarcopenia (−) (N=1996) | OR (95% CI) | p-value |
|---|---|---|
| Social isolation (+) /Sarcopenia (−) (N=1071) | ||
| Unadjusted model | 1.44 (1.30–1.60) | <.0001 |
| Adjusted model 1 (age, gender) | 1.08 (0.97–1.20) | 0.1664 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.09 (0.97–1.21) | 0.1352 |
| Social isolation (−) / Sarcopenia (+) (N=324) | ||
| Unadjusted model | 1.93 (1.67–2.24) | <.0001 |
| Adjusted model 1 (age, gender) | 1.48 (1.27–1.72) | <.0001 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.40 (1.20–1.63) | <.0001 |
| Social isolation (+) / Sarcopenia (+) (N=371) | ||
| Unadjusted model | 2.73 (2.38–3.12) | <.0001 |
| Adjusted model 1 (age, gender) | 1.74 (1.50–2.02) | <.0001 |
| Adjusted model 2 (age, gender, demographic#, comorbidities❡) | 1.65 (1.42–1.92) | <.0001 |
# Education level, residence area, current smoker, current alcohol use; ❡ Hypertension, diabetes, heart disease, stroke, cancer or malignant tumor, arthritis or rheumatism, gastric ulcer or stomach ailment, liver or gall bladder disease, renal disease
Combinations of social isolation, anorexia of aging, and sarcopenia with the impacts on mortality at 16-year of follow-up
We further classified participants into different combinations (Table 5). People with all three conditions have a highly increased risk of mortality (aOR 2.21 [95% CI 1.49–3.28], compared with no such conditions). Those with only sarcopenia (1.32 [1.12–1.55]) have a moderate increase in mortality, while those with only anorexia of aging (1.20 [0.73–1.97]) or only social isolation (1.07 [0.96–1.20]) showed insignificant results. However, those with both anorexia of aging and sarcopenia but without social isolation (3.00 [1.99–4.50]) have the highest mortality risk.
Table 5.
16-year all-cause mortality risk among combinations of social isolation, anorexia of aging, and sarcopenia
| Ref.: Without any conditions (N=1965) | OR (95% CI) | p-value |
|---|---|---|
| Social isolation only (N=1031) | 1.07 (0.96–1.20) | 0.2183 |
| Anorexia of aging only (N=31) | 1.20 (0.73–1.97) | 0.4754 |
| Sarcopenia only (N=290) | 1.32 (1.12–1.55) | 0.0009 |
| Social isolation + Anorexia of aging (N=40) | 1.56 (1.07–2.27) | 0.0209 |
| Social isolation + Sarcopenia (N=340) | 1.62 (1.39–1.90) | <.0001 |
| Anorexia of aging + Sarcopenia (N=34) | 3.00 (1.99–4.50) | <.0001 |
| Social isolation + Anorexia of aging + Sarcopenia (N=31) | 2.21 (1.49–3.28) | <.0001 |
Adjusted by age, gender, demographic (education level, residence area, current smoker, current alcohol use) and comorbidities (hypertension, diabetes, heart disease, stroke, cancer or malignant tumor, arthritis or rheumatism, gastric ulcer or stomach ailment, liver or gall bladder disease, renal disease)
Discussion
To our knowledge, this is the first study to report significant associations between social isolation and both anorexia of aging and sarcopenia in adults aged 50 and above in Taiwan. Additionally, we have identified potential synergistic effects of social isolation and anorexia of aging or sarcopenia on long-term (16-year) risk of mortality. Overall, our study provides valuable insights into the complex interplay between social isolation, anorexia of aging, sarcopenia, and long-term mortality in older adults, which has not been well explored previously.
Previous studies have reported associations between social isolation and mortality risks, albeit limited to younger population (14, 15). For instance, a study including adults above 50 years in the English Longitudinal Study of Ageing (ELSA) (2) indicated that social isolation was associated with a higher risk of all-cause mortality (aOR 1.26 [95% CI: 1.07–1.48, p=0.005]), even after adjustments with demographics and comorbidities. A study of older adults aged ≥60 years in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) also showed similar results (aOR 1.22 [95% CI: 1.18–1.25, p<0.01]). However, in our study, we found that social isolation was significantly associated with anorexia of aging and sarcopenia, in addition to being a risk factor for long-term mortality among middle-aged and older adults. It is worth noting that in the present study, the mean score of social isolation was 1.32±1.13, which was lower than that from the ELSA (1.6±1.4) (43). In this study, 38.3% of the study subjects were categorized as social isolation, and the high prevalence of social isolation was assumed to be affected by the socio-cultural context of Taiwan. In particular, as high as 51.0% of participants in our study reported no social participation (such as clubs or religious groups) and the distribution of scores thus became positively skewed.
Previous research has demonstrated that anorexia of aging (or poor appetite) is associated with reduced dietary intake and diversity, as well as an increased risk of sarcopenia, frailty (17, 21, 27, 28, 48, 49) or even mortality (50). Identifying anorexia of aging is therefore crucial for healthy aging, but the lack of a standardized tool for evaluation remains a challenge (51). The definition of anorexia of aging (50, 52, 53) currently utilizes the 4-item Simplified Nutritional Appetite Questionnaire (SNAQ) (54), with a score of ≤13 indicating anorexia of aging. The SNAQ was derived from the 8-item Council of Nutrition appetite questionnaire (CNAQ) and designed to identify individuals at high risk of significant weight loss (i.e., at least 5% weight loss within 6 months). A study (55) of healthy, community-dwelling older adults suggested a higher cutoff of SNAQ ≤15 to increase the sensitivity for anorexia detection and proposed a two-factor structure of the SNAQ, including the first two factors of 1) appetite and 2) satiety and intake. In our study, we employed 2 items from the TLSA questionnaires (appetite and food intake) to define anorexia of aging. Notably, the prevalence of anorexia of aging in our study was 3.6%, which was lower compared to a Japanese study among community-dwelling older people (9.8%) (21). This difference may be attributed to distinct algorithms for anorexia of aging definition and differences in the general health status of study participants. Our study defined anorexia of aging as a decrease in either appetite or dietary intake (17, 18, 19, 20) while the Japanese study adopted the algorithm of SNAQ score ≤13 to define anorexia of aging. Nevertheless, the ICFSR task force report (56) summarized distinct tools to assess appetite in older adults that could be useful under different circumstances. Multiple nutritional strategies against malnutrition were also recommended (i.e. modifying diet prescription, nutritional supplements, eating behaviors, culinary nutrition education programs or progressive resistance training) (16, 57, 58, 59, 60).
In our study, we adopted the SARC-Calf to define sarcopenia using calf circumferences to surrogate the measurements of muscle mass (61, 62, 63). A study enrolling community-dwelling older adults in China demonstrated that SARC-Calf had high specificity (94.7%) and acceptable sensitivity (60.7%) when using the AWGS criteria as the reference standard (64). The present study utilized the SARC-CalF to define sarcopenia, revealing a prevalence of 18.5%, which was higher than that observed in healthy community-dwelling older adults (65), but lower than that from daycare centers (66). As the first investigation examining the synergistic effects of social isolation and sarcopenia on adverse health outcomes, the definition of sarcopenia based on SARC-CalF was deemed satisfactory to investigate the associations in this study.
In the current study, it has come to light that individuals with both anorexia of aging and sarcopenia had the most elevated long-term mortality risk. Intriguingly, individuals with these conditions but without social isolation (3.00 [1.99–4.50]) showed higher mortality risks than those with all three conditions (2.21 [1.49–3.28]). One conjecture emanating from this scenario is that the cohort with anorexia of aging and sarcopenia but having social connections might encompass a distinct subgroup of dependent elderly relying on the support of family members, and those dependent individuals may have poorer survivals. This also serves as a reminder and prompts us to pay attention to the potentially divergent prognostic implications of these social connections or isolation across different populations, necessitating further research exploration.
In this study, we have not only illuminated the intricate associations between social isolation, anorexia of aging, and sarcopenia but have also unveiled distinctive risks in all-cause mortality among groups categorized by social isolation and anorexia of aging or sarcopenia. Our approach was strengthened by utilizing a nationally representative population-based cohort, which enabled us to examine long-term outcomes over a follow-up period of 16 years. However, despite our best efforts, some limitations still exist. Firstly, the definitions of anorexia of aging and sarcopenia were modified based on the available items of the TLSA questionnaire, but this remains the most viable approach to investigate the complex interrelationships of these conditions. Similar approaches have been employed in previous studies. Secondly, the assessment of social isolation was based on self-reported items, which could be influenced by psychosocial factors or recall bias. Nevertheless, this is a common limitation in population-based studies that rely on questionnaires and surveys, and our design and results are consistent with those of previous studies. Thirdly, we only focused on all-cause mortality as a longitudinal outcome in this study, and a wider range of outcomes such as incident depressive symptoms, cognitive impairment, and disabilities could be included in future research.
Conclusions
The results of this study demonstrate a significant association between social isolation and both anorexia of aging and sarcopenia in middle-aged and older adults residing in the community. Furthermore, our findings indicate that social isolation synergistically elevates the risk of anorexia of aging and sarcopenia, resulting in an increased risk of long-term mortality. To confirm these associations and explore the potential to modify adverse outcomes, further investigations and intervention studies are necessary.
Contributor Information
Liang-Kung Chen, Email: lkchen2@vghtpe.gov.tw.
Fei-Yuan Hsiao, Email: fyshsiao@ntu.edu.tw.
Conflict of Interest:
The authors declare no conflicts of interest.
Ethical considerations:
This study was authorized by the institutional review board of the National Taiwan University Hospital (NTUH-IRB; No. 202204025RINA), following the guidelines of the Declaration of Helsinki for research involving human subjects.
Funding Sources:
This research was funded by the Taiwan Ministry of Science and Technology (MOST 110-2634-F-010-001), the Taiwan National Science and Technology Council (NSTC111-2622-8-A49-019-IE, NSTC112-2923-B-A49-002-MY2), and the Interdisciplinary Research Center for Healthy Longevity of National Yang Ming Chiao Tung University from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. The funding source had no role in conducting this study, including study design, data collection and analysis, manuscript preparation and review, and the decision to submit the manuscript for publication.
References
- 1.Nicholson NR., Jr. Social isolation in older adults: an evolutionary concept analysis. J Adv Nurs. 2009;65(6):1342–1352. doi: 10.1111/j.1365-2648.2008.04959.x. 10.1111/j.1365-2648.2008.04959.x PubMed PMID: 19291185. [DOI] [PubMed] [Google Scholar]
- 2.Steptoe A, Shankar A, Demakakos P, Wardle J. Social isolation, loneliness, and all-cause mortality in older men and women. Proc Natl Acad Sci. 2013;110(15):5797–5801. doi: 10.1073/pnas.1219686110. 10.1073/pnas.1219686110 PubMed PMID: 23530191; PMCID 3625264. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.National Academies of Sciences, Engineering, and Medicine. National Academies Press; 2020. Social Isolation and Loneliness in Older Adults: Opportunities for the Health Care System. 25663. [DOI] [PubMed] [Google Scholar]
- 4.Teo RH, Cheng WH, Cheng LJ, Lau Y, Lau ST. Global prevalence of social isolation among community-dwelling older adults: A systematic review and meta-analysis. Arch Gerontol Geriatr. 2023;107:104904. doi: 10.1016/j.archger.2022.104904. 10.1016/j.archger.2022.104904 PubMed PMID: 36563614. [DOI] [PubMed] [Google Scholar]
- 5.Wu B. Social isolation and loneliness among older adults in the context of COVID-19: a global challenge. Glob Health Res Policy. 2020;5(1):27. doi: 10.1186/s41256-020-00154-3. 10.1186/s41256-020-00154-3 PubMed PMID: 32514427; PMCID 7272234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Holt-Lunstad J. Loneliness and Social Isolation as Risk Factors: The Power of Social Connection in Prevention. Am J Lifestyle Med. 2021;15(5):567–573. doi: 10.1177/15598276211009454. 10.1177/15598276211009454 PubMed PMID: 34646109; PMCID 8504333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Loneliness and social isolation linked to serious health conditions. Centers for Disease Control and Prevention. Accessed November 18, 2022. https://www.cdc.gov/aging/publications/features/lonely-older-adults.html
- 8.Cacioppo JT, Cacioppo S. Older adults reporting social isolation or loneliness show poorer cognitive function 4 years later. Evid Based Nurs. 2014;17(2):59–60. doi: 10.1136/eb-2013-101379. 10.1136/eb-2013-101379 PubMed PMID: 23749730. [DOI] [PubMed] [Google Scholar]
- 9.Freak-Poli R, Ryan J, Tran T, et al. Social isolation, social support and loneliness as independent concepts, and their relationship with health-related quality of life among older women. Aging Ment Health. 2022;26(7):1335–1344. doi: 10.1080/13607863.2021.1940097. 10.1080/13607863.2021.1940097 PubMed PMID: 34219569. [DOI] [PubMed] [Google Scholar]
- 10.Golaszewski NM, LaCroix AZ, Godino JG, et al. Evaluation of Social Isolation, Loneliness, and Cardiovascular Disease Among Older Women in the US. JAMA Netw Open. 2022;5(2):e2146461. doi: 10.1001/jamanetworkopen.2021.46461. 10.1001/jamanetworkopen.2021.46461 PubMed PMID: 35107574; PMCID 8811637. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Barth J, Schneider S, von Känel R. Lack of Social Support in the Etiology and the Prognosis of Coronary Heart Disease: A Systematic Review and Meta-Analysis. Psychosom Med. 2010;72(3):229–238. doi: 10.1097/PSY.0b013e3181d01611. 10.1097/PSY.0b013e3181d01611 PubMed PMID: 20223926. [DOI] [PubMed] [Google Scholar]
- 12.Cohen S, Doyle WJ, Skoner DP, Rabin BS, Gwaltney JM. Social ties and susceptibility to the common cold. JAMA. 1997;277(24):1940–1944. 10.1001/jama.1997.03540480040036 PubMed PMID: 9200634. [PubMed] [Google Scholar]
- 13.Schrempft S, Jackowska M, Hamer M, Steptoe A. Associations between social isolation, loneliness, and objective physical activity in older men and women. BMC Public Health. 2019;19(1):74. doi: 10.1186/s12889-019-6424-y. 10.1186/s12889-019-6424-y PubMed PMID: 30651092; PMCID 6335852. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Agostino H, Burstein B, Moubayed D, et al. Trends in the Incidence of New-Onset Anorexia Nervosa and Atypical Anorexia Nervosa Among Youth During the COVID-19 Pandemic in Canada. JAMA Netw Open. 2021;4(12):e2137395. doi: 10.1001/jamanetworkopen.2021.37395. 10.1001/jamanetworkopen.2021.37395 PubMed PMID: 34874405; PMCID 8652595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Gilsbach S, Plana MT, Castro-Fornieles J, et al. Increase in admission rates and symptom severity of childhood and adolescent anorexia nervosa in Europe during the COVID-19 pandemic: data from specialized eating disorder units in different European countries. Child Adolesc Psychiatry Ment Health. 2022;16(1):46. doi: 10.1186/s13034-022-00482-x. 10.1186/s13034-022-00482-x PubMed PMID: 35725621; PMCID 9208345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.de Souto Barreto P, Cesari M, Morley JE, et al. Appetite Loss and Anorexia of Aging in Clinical Care: An ICFSR Task Force Report. J Frailty Aging. 2020 doi: 10.14283/jfa.2022.14. Published online. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Landi F, Calvani R, Tosato M, et al. Anorexia of Aging: Risk Factors, Consequences, and Potential Treatments. Nutrients. 2016;8(2):69. doi: 10.3390/nu8020069. 10.3390/nu8020069 PubMed PMID: 26828516; PMCID 4772033. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Morley JE. Anorexia, sarcopenia, and aging. Nutrition. 2001;17(7–8):660–663. doi: 10.1016/s0899-9007(01)00574-3. 10.1016/S0899-9007(01)00574-3 PubMed PMID: 11448592. [DOI] [PubMed] [Google Scholar]
- 19.Martone A, Onder G, Vetrano D, et al. Anorexia of Aging: A Modifiable Risk Factor for Frailty. Nutrients. 2013;5(10):4126–4133. doi: 10.3390/nu5104126. 10.3390/nu5104126 PubMed PMID: 24128975; PMCID 3820063. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Di Francesco V, Fantin F, Omizzolo F, et al. The Anorexia of Aging. Dig Dis. 2007;25(2):129–137. doi: 10.1159/000099477. 10.1159/000099477 PubMed PMID: 17468548. [DOI] [PubMed] [Google Scholar]
- 21.Tsutsumimoto K, Doi T, Makizako H, et al. Aging-related anorexia and its association with disability and frailty: Anorexia and disability. J Cachexia Sarcopenia Muscle. 2018;9(5):834–843. doi: 10.1002/jcsm.12330. 10.1002/jcsm.12330 PubMed PMID: 30109778; PMCID 6204590. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Sturm K, Parker B, Wishart J, et al. Energy intake and appetite are related to antral area in healthy young and older subjects. Am J Clin Nutr. 2004;80(3):656–667. doi: 10.1093/ajcn/80.3.656. 10.1093/ajcn/80.3.656 PubMed PMID: 15321806. [DOI] [PubMed] [Google Scholar]
- 23.Picca A, Calvani R, Coelho-Júnior HJ, Landi F, Marzetti E. Anorexia of Aging: Metabolic Changes and Biomarker Discovery. Clin Interv Aging. 2022;17:1761–1767. doi: 10.2147/CIA.S325008. 10.2147/CIA.S325008 PubMed PMID: 36483084; PMCID 9726216. 2022. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Morley JE, Silver AJ, Miller DK, Rubenstein LZ. The Anorexia of the Elderly. Ann N Y Acad Sci. 1989;575:50–59. doi: 10.1111/j.1749-6632.1989.tb53231.x. 10.1111/j.1749-6632.1989.tb53231.x PubMed PMID: 2699205. 1 The Psychobio. [DOI] [PubMed] [Google Scholar]
- 25.Morley JE, Thomas DR. Anorexia and aging: pathophysiology. Nutrition. 1999;15(6):499–503. doi: 10.1016/s0899-9007(99)00057-x. 10.1016/S0899-9007(99)00057-X PubMed PMID: 10378207. [DOI] [PubMed] [Google Scholar]
- 26.Amarya S, Singh K, Sabharwal M. Ageing Process and Physiological Changes. In: D'Onofrio G, Greco A, Sancarlo D, eds. Gerontology. InTech; 2018. 10.5772/intechopen.76249 [DOI]
- 27.Fried LP, Tangen CM, Walston J, et al. Frailty in Older Adults: Evidence for a Phenotype. J Gerontol A Biol Sci Med Sci. 2001;56(3):M146–M157. doi: 10.1093/gerona/56.3.m146. 10.1093/gerona/56.3.M146 PubMed PMID: 11253156. [DOI] [PubMed] [Google Scholar]
- 28.Tsutsumimoto K, Doi T, Nakakubo S, et al. Association between anorexia of ageing and sarcopenia among Japanese older adults. J Cachexia Sarcopenia Muscle. 2020;11(5):1250–1257. doi: 10.1002/jcsm.12571. 10.1002/jcsm.12571 PubMed PMID: 32190984; PMCID 7567148. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Chen LK, Woo J, Assantachai P, et al. Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment. J Am Med Dir Assoc. 2020;21(3):300–307.e2. doi: 10.1016/j.jamda.2019.12.012. 10.1016/j.jamda.2019.12.012 PubMed PMID: 32033882. [DOI] [PubMed] [Google Scholar]
- 30.Malafarina V, Úriz-Otano F, Iniesta R, Gil-Guerrero L. Sarcopenia in the elderly: Diagnosis, physiopathology and treatment. Maturitas. 2012;71(2):109–114. doi: 10.1016/j.maturitas.2011.11.012. 10.1016/j.maturitas.2011.11.012 PubMed PMID: 22153348. [DOI] [PubMed] [Google Scholar]
- 31.Chen LK, Arai H, Assantachai P, et al. Roles of nutrition in muscle health of community-dwelling older adults: evidence-based expert consensus from Asian Working Group for Sarcopenia. J Cachexia Sarcopenia Muscle. 2022;13(3):1653–1672. doi: 10.1002/jcsm.12981. 10.1002/jcsm.12981 PubMed PMID: 35307982; PMCID 9178363. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Wang T, Feng X, Zhou J, et al. Type 2 diabetes mellitus is associated with increased risks of sarcopenia and pre-sarcopenia in Chinese elderly. Sci Rep. 2016;6:38937. doi: 10.1038/srep38937. 10.1038/srep38937 PubMed PMID: 27958337; PMCID 5153616. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Kwon YE, Lee JS, Kim J, et al. Impact of sarcopenia and phase angle on mortality of the very elderly. J Cachexia Sarcopenia Muscle. 2022 doi: 10.1002/jcsm.13128. Published online November 16, 2022:jcsm.13128. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34.Tanimoto Y, Watanabe M, Sun W, et al. Sarcopenia and falls in community-dwelling elderly subjects in Japan: Defining sarcopenia according to criteria of the European Working Group on Sarcopenia in Older People. Arch Gerontol Geriatr. 2014;59(2):295–299. doi: 10.1016/j.archger.2014.04.016. 10.1016/j.archger.2014.04.016 PubMed PMID: 24852668. [DOI] [PubMed] [Google Scholar]
- 35.Beaudart C, Rizzoli R, Bruyère O, Reginster JY, Biver E. Sarcopenia: burden and challenges for public health. Arch Public Health Arch Belg Sante Publique. 2014;72(1):45. doi: 10.1186/2049-3258-72-45. 10.1186/2049-3258-72-45 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Guralnik JM, Ferrucci L, Pieper CF, et al. Lower Extremity Function and Subsequent Disability: Consistency Across Studies, Predictive Models, and Value of Gait Speed Alone Compared With the Short Physical Performance Battery. J Gerontol A Biol Sci Med Sci. 2000;55(4):M221–M231. doi: 10.1093/gerona/55.4.m221. 10.1093/gerona/55.4.M221 PubMed PMID: 10811152. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Tanimoto Y, Watanabe M, Sun W, et al. Association between sarcopenia and higher-level functional capacity in daily living in community-dwelling elderly subjects in Japan. Arch Gerontol Geriatr. 2012;55(2):e9–e13. doi: 10.1016/j.archger.2012.06.015. 10.1016/j.archger.2012.06.015 PubMed PMID: 22795189. [DOI] [PubMed] [Google Scholar]
- 38.Yu B, Steptoe A, Chen Y. Social isolation, loneliness, and all-cause mortality: A cohort study of 35,254 Chinese older adults. J Am Geriatr Soc. 2022;70(6):1717–1725. doi: 10.1111/jgs.17708. [DOI] [PubMed] [Google Scholar]
- 39.Taiwan Longitudinal Study on Aging (TLSA). Health Promotion Administration, Ministry of Health and Welfare. Accessed November 21, 2022. https://www.hpa.gov.tw/EngPages/Detail.aspx?nodeid=1077&pid=6197
- 40.Hwang AC, Lee WJ, Huang N, et al. Longitudinal changes of frailty in 8 years: comparisons between physical frailty and frailty index. BMC Geriatr. 2021;21(1):726. doi: 10.1186/s12877-021-02665-1. 10.1186/s12877-021-02665-1 PubMed PMID: 34922488; PMCID 8684153. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Hsiao FY, Peng LN, Lee WJ, Chen LK. Higher dietary diversity and better healthy aging: A 4-year study of community-dwelling middle-aged and older adults from the Taiwan Longitudinal Study of Aging. Exp Gerontol. 2022;168:111929. doi: 10.1016/j.exger.2022.111929. 10.1016/j.exger.2022.111929 PubMed PMID: 35977645. [DOI] [PubMed] [Google Scholar]
- 42.Lin MH, Chen LJ, Huang ST, et al. Age and sex differences in associations between self-reported health, physical function, mental function and mortality. Arch Gerontol Geriatr. 2022;98:104537. doi: 10.1016/j.archger.2021.104537. 10.1016/j.archger.2021.104537 PubMed PMID: 34649184. [DOI] [PubMed] [Google Scholar]
- 43.Shankar A, McMunn A, Banks J, Steptoe A. Loneliness, social isolation, and behavioral and biological health indicators in older adults. Health Psychol. 2011;30(4):377–385. doi: 10.1037/a0022826. 10.1037/a0022826 PubMed PMID: 21534675. [DOI] [PubMed] [Google Scholar]
- 44.Donovan NJ, Blazer D. Social Isolation and Loneliness in Older Adults: Review and Commentary of a National Academies Report. Am J Geriatr Psychiatry. 2020;28(12):1233–1244. doi: 10.1016/j.jagp.2020.08.005. 10.1016/j.jagp.2020.08.005 PubMed PMID: 32919873; PMCID 7437541. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Barbosa-Silva TG, Menezes AMB, Bielemann RM, Malmstrom TK, Gonzalez MC. Enhancing SARC-F: Improving Sarcopenia Screening in the Clinical Practice. J Am Med Dir Assoc. 2016;17(12):1136–1141. doi: 10.1016/j.jamda.2016.08.004. 10.1016/j.jamda.2016.08.004 PubMed PMID: 27650212. [DOI] [PubMed] [Google Scholar]
- 46.Mo Y, Dong X, Wang X. Screening Accuracy of SARC-F Combined With Calf Circumference for Sarcopenia in Older Adults: A Diagnostic Meta-Analysis. J Am Med Dir Assoc. 2020;21(2):288–289. doi: 10.1016/j.jamda.2019.09.002. 10.1016/j.jamda.2019.09.002 PubMed PMID: 31672568. [DOI] [PubMed] [Google Scholar]
- 47.Chu WM, Ho HE, Yeh CJ, et al. Self-rated health trajectory and frailty among community-dwelling older adults: evidence from the Taiwan Longitudinal Study on Aging (TLSA) BMJ Open. 2021;11(8):e049795. doi: 10.1136/bmjopen-2021-049795. 10.1136/bmjopen-2021-049795 PubMed PMID: 34362805; PMCID 8351513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 48.İlhan B, Bahat G, Erdoğan T, Kiliç C, Karan MA. Anorexia is Independently Associated with Decreased Muscle Mass and Strength in Community Dwelling Older Adults. J Nutr Health Aging. 2019;23(2):202–206. doi: 10.1007/s12603-018-1119-0. 10.1007/s12603-018-1119-0 PubMed PMID: 30697631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 49.Merchant RA, Woo J, Morley JE. Anorexia of Ageing: Pathway to Frailty and Sarcopenia. J Nutr Health Aging. 2022;26(1):3–5. doi: 10.1007/s12603-021-1703-6. 10.1007/s12603-021-1703-6 PubMed PMID: 35067696. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 50.Cox NJ, Lim SE, Howson F, et al. Poor Appetite Is Associated with Six Month Mortality in Hospitalised Older Men and Women. J Nutr Health Aging. 2020;24(10):1107–1110. doi: 10.1007/s12603-020-1442-0. 10.1007/s12603-020-1442-0 PubMed PMID: 33244568. [DOI] [PubMed] [Google Scholar]
- 51.Cox NJ, Morrison L, Ibrahim K, Robinson SM, Sayer AA, Roberts HC. New horizons in appetite and the anorexia of ageing. Age Ageing. 2020;49(4):526–534. doi: 10.1093/ageing/afaa014. 10.1093/ageing/afaa014 PubMed PMID: 32043144. [DOI] [PubMed] [Google Scholar]
- 52.Aprahamian I, Romanini CV, Lima NA, et al. The concept of anorexia of aging in late life depression: A cross-sectional analysis of a cohort study. Arch Gerontol Geriatr. 2021;95:104410. doi: 10.1016/j.archger.2021.104410. 10.1016/j.archger.2021.104410 PubMed PMID: 33823473. [DOI] [PubMed] [Google Scholar]
- 53.Jeong E, Kim JA, Kim BS, Lee CK, Kim M, Won CW. Functional Constipation and Anorexia in Community-Dwelling Older Adults: Korean Frailty and Aging Cohort Study (KFACS) Int J Environ Res Public Health. 2021;18(11):5754. doi: 10.3390/ijerph18115754. 10.3390/ijerph18115754 PubMed PMID: 34071957; PMCID 8198611. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 54.Wilson MMG, Thomas DR, Rubenstein LZ, et al. Appetite assessment: simple appetite questionnaire predicts weight loss in community-dwelling adults and nursing home residents. Am J Clin Nutr. 2005;82(5):1074–1081. doi: 10.1093/ajcn/82.5.1074. 10.1093/ajcn/82.5.1074 PubMed PMID: 16280441. [DOI] [PubMed] [Google Scholar]
- 55.Lau S, Pek K, Chew J, et al. The Simplified Nutritional Appetite Questionnaire (SNAQ) as a Screening Tool for Risk of Malnutrition: Optimal Cutoff, Factor Structure, and Validation in Healthy Community-Dwelling Older Adults. Nutrients. 2020;12(9):2885. doi: 10.3390/nu12092885. 10.3390/nu12092885 PubMed PMID: 32967354; PMCID 7551805. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 56.de Souto Barreto P, Cesari M, Morley JE, et al. Assessment and Management of Appetite Loss in Older Adults: An ICFSR Task Force Report. J Frailty Aging. 2022 doi: 10.14283/jfa.2022.64. Published online. [DOI] [PubMed] [Google Scholar]
- 57.de Souto Barreto P. Poor Appetite & Aging: The Role of Physical Activity under a Geroscience Perspective. J Nutr Health Aging. 2022;26(10):907–908. doi: 10.1007/s12603-022-1849-x. 10.1007/s12603-022-1849-x PubMed PMID: 36259578. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 58.Hidaka R, Masuda Y, Ogawa K, et al. Impact of the Comprehensive Awareness Modification of Mouth, Chewing and Meal (CAMCAM) Program on the Attitude and Behavior Towards Oral Health and Eating Habits as Well as the Condition of Oral Frailty: A Pilot Study. J Nutr Health Aging. 2023;27(5):340–347. doi: 10.1007/s12603-023-1913-1. 10.1007/s12603-023-1913-1 PubMed PMID: 37248757. [DOI] [PubMed] [Google Scholar]
- 59.Alghamdi MM, Burrows T, Barclay B, Baines S, Chojenta C. Culinary Nutrition Education Programs in Community-Dwelling Older Adults: A Scoping Review. J Nutr Health Aging. 2023;27(2):142–158. doi: 10.1007/s12603-022-1876-7. PubMed PMID: 36806869; PMCID 9872757. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 60.Ruiz JG. Non-pharmacological Interventions in Anorexia of Aging. J Nutr Health Aging. 2022;26(2):110–111. doi: 10.1007/s12603-022-1744-5. 10.1007/s12603-022-1744-5 PubMed PMID: 35166300; PMCID 8821833. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 61.Woo J, Leung J, Morley JE. Validating the SARC-F: A Suitable Community Screening Tool for Sarcopenia? J Am Med Dir Assoc. 2014;15(9):630–634. doi: 10.1016/j.jamda.2014.04.021. 10.1016/j.jamda.2014.04.021 PubMed PMID: 24947762. [DOI] [PubMed] [Google Scholar]
- 62.Parra-Rodríguez L, Szlejf C, García-González AI, Malmstrom TK, Cruz-Arenas E, Rosas-Carrasco O. Cross-Cultural Adaptation and Validation of the Spanish-Language Version of the SARC-F to Assess Sarcopenia in Mexican Community-Dwelling Older Adults. J Am Med Dir Assoc. 2016;17(12):1142–1146. doi: 10.1016/j.jamda.2016.09.008. 10.1016/j.jamda.2016.09.008 PubMed PMID: 27815111. [DOI] [PubMed] [Google Scholar]
- 63.Bahat G, Yilmaz O, Kiliç C, Oren MM, Karan MA. Performance of SARC-F in Regard to Sarcopenia Definitions, Muscle Mass and Functional Measures. J Nutr Health Aging. 2018;22(8):898–903. doi: 10.1007/s12603-018-1067-8. 10.1007/s12603-018-1067-8 PubMed PMID: 30272090. [DOI] [PubMed] [Google Scholar]
- 64.Yang M, Hu X, Xie L, et al. Screening Sarcopenia in Community-Dwelling Older Adults: SARC-F vs SARC-F Combined With Calf Circumference (SARC-CalF) J Am Med Dir Assoc. 2018;19(3):277.e1–277.e8. doi: 10.1016/j.jamda.2017.12.016. 10.1016/j.jamda.2017.12.016 PubMed PMID: 29477774. [DOI] [PubMed] [Google Scholar]
- 65.Wu LC, Kao HH, Chen HJ, Huang PF. Preliminary screening for sarcopenia and related risk factors among the elderly. Medicine (Baltimore). 2021;100(19):e25946. doi: 10.1097/MD.0000000000025946. 10.1097/MD.0000000000025946 PubMed PMID: 34106666; PMCID 8133124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 66.Chang CF, Yeh YL, Chang HY, Tsai SH, Wang JY. Prevalence and Risk Factors of Sarcopenia among Older Adults Aged >65 Years Admitted to Daycare Centers of Taiwan: Using AWGS 2019 Guidelines. Int J Environ Res Public Health. 2021;18(16):8299. doi: 10.3390/ijerph18168299. 10.3390/ijerph18168299 PubMed PMID: 34444047; PMCID 8392701. [DOI] [PMC free article] [PubMed] [Google Scholar]