Summary
Objective
The aim of this study was to explore the impact of body weight change following intentional weight loss on measures of physical performance in adults with diabetes.
Design and methods
Four hundred fifty individuals with type 2 diabetes (age, 59.0 ± 6.9 years; body mass index, 35.5 ± 5.9 kg/m2) who participated in the Look AHEAD Movement and Memory Study and lost weight 1 year after being randomized to an intensive lifestyle intervention were assessed. Body weight was measured annually, and participants were categorized as continued losers/maintainers, regainers, or cyclers based on a ±5% annual change in weight. Objective measures of physical performance were measured at the year 8/9 visit.
Results
Forty‐four percent, 38% and 18% of participants were classified as regainers, cyclers, and continued losers/maintainers, respectively. In women, weight cycling and regain were associated with worse follow‐up expanded physical performance battery score (1.46 ± 0.07 and 1.48 ± 0.07 vs. 1.63 ± 0.07, both p ≤ 0.02) and slower 20‐m walking speed (1.10 ± 0.04 and 1.08 ± 0.04 vs. 1.17 ± 0.04 m/s, both p < 0.05) compared with continued or maintained weight loss. Male cyclers presented with weaker grip strength compared with regainers or continued losers/maintainers (30.12 ± 2.21 vs. 34.46 ± 2.04 and 37.39 ± 2.26 kg; both p < 0.01).
Conclusions
Weight cycling and regain following intentional weight loss in older adults with diabetes were associated with worse physical function in women and grip strength in men.
Keywords: Physical performance, type 2 diabetes mellitus, weight cycling, weight loss
Introduction
The prevalence of disability increases with age and is accelerated in the presence of diabetes 1, 2. Physical disability contributes to loss of independence, premature mortality and increased healthcare spending 3, 4 and is consistently predicted by poor performance on several objective measures of physical function and strength 5, 6, 7. As older adults make up an increasingly larger proportion of the diabetic population 8, identification and treatment of risk factors for diabetes‐related disability are emerging as a significant public health research priority.
Obesity is closely associated with diabetes and is a well‐characterized, modifiable predictor of functional decline in older adults 9, 10, 11, 12, 13. Treatments for obesity, such as diet and exercise interventions, that result in significant weight loss frequently yield immediate improvement in risk factors for diabetes progression 14 and physical performance 15, 16, 17. However, for most individuals, stable, long‐term, weight loss maintenance is unlikely 18, 19, 20, and data assessing the impact of weight fluctuation following intentional weight loss on physical performance in older adults, particularly those at increased risk for disability, are limited.
Some insight into this question is provided from three prospective epidemiologic studies, with data suggesting weight loss and weight cycling are associated with increased risk of mobility disability in middle‐aged and older adults 21, 22, 23. However, these studies did not assess objective measures of physical function and strength, and only one 23 controlled for self‐reported intentionality of weight change. To the best of our knowledge, the long‐term impact of body weight change following an intentional, structured weight loss programme on objective measures of physical performance in older adults with diabetes has yet to be assessed. Results are necessary to comprehensively evaluate the long‐term benefits and risks of intentional weight loss in this population.
The purpose of this study is to explore the associations of weight change following intentional weight loss (i.e. weight pattern classification of weight loss maintainers, continued losers, regainers or cyclers based on a ±5% annual change in weight) on objective measures of physical function and strength, including expanded physical performance battery (PPB) score, 20‐ and 400‐m walk tests, and grip and knee strength, measured in the Action for Health in Diabetes (Look AHEAD) Movement and Memory (M&M) ancillary study. We hypothesize that individuals who experience weight cycling or weight regain following intentional weight loss will perform worse on measures of physical function and strength compared with individuals who continue to lose weight or maintain their weight loss.
Methods and procedures
Look AHEAD study design
The design and methods of the Look AHEAD trial have been published previously 24. In brief, Look AHEAD recruited individuals with type 2 diabetes who were 45–76 years of age and had a body mass index (BMI) >25 kg/m2 (>27 kg/m2 in participants on insulin), glycosylated haemoglobin (HbA1c) <11%, systolic blood pressure <160 mmHg, diastolic blood pressure <100 mmHg and triglycerides <600 mg/dL. Participants were randomized to a usual care condition (i.e. diabetes support and education) or to an intensive lifestyle intervention (ILI), with a goal in the ILI arm of inducing a loss of 7% or more of initial weight and increasing physical activity to 175 min or more per week 25.
The Look AHEAD M&M ancillary study enrolled Look AHEAD participants at four clinical centres to assess physical and cognitive function at either their year 8 or 9 Look AHEAD clinical examination. Only Look AHEAD participants who were currently active (i.e. had not been lost to follow‐up or refused further Look AHEAD activity) at the Baton Rouge, Denver, Memphis and Pittsburgh clinics and who provided separate informed consent were eligible to enrol. The Look AHEAD M&M protocol and consent forms were approved by local institutional review boards prior to use. Primary outcome papers, including recruitment and retention details, were published with modest treatment effects observed for physical, but not cognitive, function endpoints 26, 27.
Study population
Because this analysis examines the effect of changing weight dynamics following intentional weight loss on physical performance, only individuals in the ILI arm were included. A total of 2570 Look AHEAD participants were randomized to the ILI arm, of which 499 participated in the Look AHEAD M&M ancillary study and had a clinic visit during the year 8/9 exam. Ninety‐one percent of this subgroup lost at least 0.1% of their baseline weight at the year 1 visit and had at least two additional annual weights (n = 455). Participants lacking pertinent covariates [n = 5; 3 missing diabetes duration and 2 missing Short Form‐36 Health Survey {SF‐36}] were further excluded, yielding a final analysis sample of 450 participants (197 men and 253 women).
Weight pattern classifications
Certified clinic staff, masked to intervention assignment, collected annual measures of weight, using a Tanita BWB 800 digital scale (Tanita Corp., Arlington Heights, IL), throughout the Look AHEAD trial. Longitudinal measures of body weight were used to classify individuals into three weight pattern categories, (i) continued losers or maintainers, (ii) regainers and (iii) cyclers, utilizing definitions previously employed in the Cardiovascular Health Study 22. Briefly, a 5% weight change from year to year was used to define weight patterns, as a change ≥5% is considered clinically significant 28, and the participant year 1 (i.e. post‐intensive weight loss or post Phase I 25) weight served as the referent point. Weight at follow‐up visits during years 2–8 were first compared with both the referent point and weight from previous year to categorize each follow‐up visit into one of the three weight pattern categories. Then, weight pattern category at each follow‐up visit was compared with other follow‐up visit categories to yield an overall weight pattern category across the 8‐year follow‐up period.
Participants were classified as ‘maintainers’ if their weight changed by <5% from the prior year and from the year 1 weight. Participants were classified as ‘regainers’ if they gained ≥5% from the prior year and the year 1 weight and ‘continued losers’ if they lost ≥5% from the prior year and the year 1 weight. Once a participant was categorized as a regainer or continued loser, they remained in that group unless weight changed sufficiently in the opposite direction to qualify them as a ‘cycler’. For example, if a participant lost ≥5% weight in comparison with year 1, yet gained in comparison with the previous year, they would be categorized as a cycler for that follow‐up year and would remain a cycler for the overall weight pattern category. Similarly, having a combination of ‘loser’ and ‘gainer’ across yearly categories would result in an overall cycler categorization. Due to the relatively small number of participants classified as either continued losers (n = 49) or maintainers (n = 35), these categories were combined for subsequent analyses.
Physical function and strength assessments
The Look AHEAD M&M study assessed objective measures of physical function and strength using certified staff who were masked to intervention assignment during a clinic exam at the eighth or ninth year of Look AHEAD follow‐up 27. The expanded physical performance battery (expanded PPB; 5, 29) consists of standing balance tasks, time to complete five repeated chair stands and a 4‐m walk to assess usual gait speed. Performance on these tasks is converted to a continuous score, ranging from 0 to 3, with higher scores indicative of better performance (n = 445). Usual walking speed over 20 m and walking endurance over 400 m were also measured 30 (n = 430 and 413 for the 20‐ and 400‐m walk tests, respectively). Grip strength (kg) was measured twice in each hand using an isometric Hydraulic Hand Dynamometer (Jamar, Bolingbrook, IL). The maximum force from two trials for the stronger hand was used in the analyses (n = 425). Maximum knee extensor muscle strength (lb; one repetition maximum) was assessed on a Nautilus One™ Leg Extension machine (n = 328). The right leg was tested unless there was a contraindication (e.g. prior knee surgery). If participants experienced knee pain during the test and there were no contraindications to test the other leg, the other leg was tested.
Potential risk factors for physical limitations
All baseline physical performance risk factor measurements were obtained by certified staff. Self‐reported characteristics (i.e. age, gender, race, education and smoking status) and medical history were captured using standardized questionnaires. Participants brought current prescription medications to update medication records. Subscales of the SF‐36 were used as measures of self‐reported bodily pain and physical functioning status, with higher scores indicative of better functioning or well‐being 31. Depressive symptoms were assessed using the Beck Depression Inventory (BDI). Total scores on the BDI range from 0 to 63, with higher scores indicating more symptoms of depression 32.
Height was measured in duplicate using a stadiometer, and BMI was calculated as weight in kilograms divided by height in square meters. Blood specimens were collected after at least a 12‐h fast and were analysed by the Central Biochemistry Laboratory (Northwest Lipid Research Laboratories, University of Washington, Seattle, WA) using standardized laboratory procedures for measuring HbA1c. A maximal graded exercise test was administered at baseline, with results recorded as metabolic equivalents (METS). Lastly, total length of hospital stays prior to the ancillary visit was assessed based on participant medical records.
Statistical analysis
Due to a significant association between gender and weight pattern classification, all results are presented stratified by gender and were initially analysed using descriptive statistics. Comparisons between groups were carried out using chi‐square tests for proportions and t‐tests or anova procedures for continuous variables. The Wilcoxon rank sum test was used for BDI due to non‐normality. Analysis of covariance models was used to compare all outcome measures. Three sets of models were fitted for each outcome measure: a minimal model including age, gender, race, education and clinic site as covariates (model 1), a further adjusted model that also included baseline insulin use, hypertension, cardiovascular disease (CVD) history, smoking status, BMI, HbA1c, self‐reported diabetes duration, baseline fitness (METS), SF‐36 physical functioning and pain subscales, and BDI score (<11 or ≥11); interim hospitalizations (model 2); and a third model that also adjusted for year 1 weight change from baseline (model 3). Additional sensitivity analyses were performed, including (i) stratification of analyses by achievement of the study weight loss goal (≥7%) at year 1 and (ii) separation of the weight cyclers into single or multiple cycler categories resulting in a four‐category weight pattern variable. All analyses were performed in SAS 9.3 (Cary, NC), and a two‐sided α level of 0.05 was considered significant.
Results
Participant characteristics
Average age of the study sample (n = 450) was 59.0 ± 6.9 years, 56% were women and 20% were African–American. Baseline BMI was 35.5 ± 5.9 kg/m2, and average percent weight loss at the year 1 visit was 10.2 ± 6.5%, with men reporting greater losses than women (−11.1 ± 6.1% vs. −9.5 ± 6.7%; p = 0.01). Compared with other ILI participants at the Look AHEAD M&M clinics (n = 221), participants included in our analyses were more likely to have a college or graduate education (p < 0.01), not have had a hospital stay during follow‐up (p < 0.01) and have lower baseline HbA1c (0.23%; p = 0.01).
Characteristics of men and women at baseline, by weight pattern category, are shown in Table 1. Overall, the majority of participants were categorized as regainers (44%), followed by weight cyclers (38%) and then continued losers/maintainers (18%), with women more likely to be classified as weight cyclers and men more likely to be classified as regainers (p < 0.01). No difference in weight pattern category was seen by age, education, diabetes duration and control, chronic disease (diabetes‐related variables, hypertension or CVD), depression, smoking status, fitness or self‐reported pain at baseline for either gender, although marginally significant group differences in baseline hypertension and depression, and total length of hospital stays prior to the ancillary visit were seen in men. Both men and women classified as regainers or weight cyclers were more likely to be White than continued loser/maintainers (who were more likely to be African–American/Black). Men classified as weight cyclers were also more likely to have a higher weight/BMI and worse self‐reported physical functioning at baseline than continued losers/maintainers or regainers.
Table 1.
Descriptive baseline characteristics by gender and weight cycling category
| Male | Female | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Overall | Weight pattern category* | Overall | Weight pattern category* | |||||||
| Losers/maintainers | Regainers | Cyclers | p ** | Losers/maintainers | Regainers | Cyclers | p ** | |||
| N or Mean ± SD | N (%) or Mean ± SD | N (%) or Mean ± SD | N (%) or Mean ± SD | N or Mean ± SD | N (%) or Mean ± SD | N (%) or Mean ± SD | N (%) or Mean ± SD | |||
| Total | 197 | 32 | 108 | 57 | 253 | 48 | 90 | 115 | ||
| Age (years) | 60.12 ± 6.64 | 60.72 ± 6.92 | 59.78 ± 6.69 | 60.44 ± 6.49 | 0.71 | 58.09 ± 6.96 | 58.50 ± 7.04 | 58.01 ± 6.82 | 57.98 ± 7.08 | 0.90 |
| <60 | 97 | 17 (53.13) | 53 (49.07) | 27 (47.37) | 0.87 | 150 | 26 (54.17) | 55 (61.11) | 69 (60.00) | 0.72 |
| ≥60 | 100 | 15 (46.88) | 55 (50.93) | 30 (52.63) | 103 | 22 (45.83) | 35 (38.89) | 46 (40.00) | ||
| Race | <0.01 | 0.08 | ||||||||
| African–American/Black | 21 | 8 (25.00) | 9 (8.33) | 4 (7.02) | 71 | 21 (43.75) | 20 (22.22) | 30 (26.09) | ||
| White | 164 | 21 (65.63) | 97 (89.81) | 46 (80.70) | 163 | 23 (47.92) | 64 (71.11) | 76 (66.09) | ||
| Other/mixed | 12 | 3 (9.38) | 2 (1.85) | 7 (12.28) | 19 | 4 (8.33) | 6 (6.67) | 9 (7.83) | ||
| Education | 0.46 | 0.52 | ||||||||
| High school or less | 15 | 2 (6.25) | 10 (9.26) | 3 (5.26) | 54 | 12 (25.00) | 15 (16.67) | 27 (23.48) | ||
| Post high school | 67 | 8 (25.00) | 41 (37.96) | 18 (31.58) | 104 | 22 (45.83) | 38 (42.22) | 44 (38.26) | ||
| College/graduate | 115 | 22 (68.75) | 57 (52.78) | 36 (63.16) | 95 | 14 (29.17) | 37 (41.11) | 44 (38.26) | ||
| Body mass index (kg/m2) | 34.55 ± 5.26 | 33.93 ± 6.20 | 33.63 ± 4.64 | 36.65 ± 5.30 | <0.01 | 36.19 ± 6.20 | 37.36 ± 6.33 | 35.39 ± 5.89 | 36.32 ± 6.35 | 0.20 |
| Weight (kg) | 108.6 ± 18.66 | 106.1 ± 21.97 | 106.2 ± 16.43 | 114.4 ± 19.68 | 0.02 | 96.39 ± 17.41 | 99.49 ± 17.14 | 94.11 ± 16.04 | 96.88 ± 18.44 | 0.21 |
| Year 1 percent weight change*** | ‐11.1 ± 6.14 | ‐6.92 ± 4.68 | ‐13.6 ± 5.98 | ‐8.57 ± 4.77 | <0.01 | ‐9.52 ± 6.69 | ‐5.58 ± 3.48 | ‐10.9 ± 6.13 | ‐10.1 ± 7.50 | <0.01 |
| HbA1c (%) | 7.15 ± 1.16 | 7.08 ± 0.81 | 7.08 ± 1.17 | 7.32 ± 1.31 | 0.42 | 7.17 ± 1.07 | 7.25 ± 1.10 | 7.08 ± 1.07 | 7.21 ± 1.05 | 0.60 |
| Any insulin use (% yes) | 30 | 5 (15.63) | 16 (14.81) | 9 (15.79) | 0.98 | 43 | 13 (27.08) | 15 (16.67) | 15 (13.04) | 0.09 |
| Diabetes duration (years) | 6.92 ± 6.24 | 6.75 ± 3.60 | 6.66 ± 6.59 | 7.51 ± 6.77 | 0.70 | 5.64 ± 6.04 | 5.08 ± 5.45 | 5.92 ± 7.18 | 5.65 ± 5.28 | 0.74 |
| Hypertension (% yes) | 165 | 24 (75.00) | 88 (81.48) | 53 (92.98) | 0.06 | 210 | 43 (89.58) | 71 (78.89) | 96 (83.48) | 0.28 |
| Cardiovascular disease history (% yes) | 42 | 9 (28.13) | 21 (19.44) | 12 (21.05) | 0.57 | 28 | 8 (16.67) | 6 (6.67) | 14 (12.17) | 0.18 |
| Beck Depression Inventory**** | 4.07 ± 3.88 | 4.22 ± 3.87 | 3.49 ± 3.27 | 5.07 ± 4.71 | 0.14 | 5.89 ± 4.86 | 7.13 ± 6.27 | 5.96 ± 4.45 | 5.33 ± 4.43 | 0.27 |
| <11 | 182 | 28 (87.50) | 104 (96.30) | 50 (87.72) | 0.07 | 219 | 38 (79.17) | 80 (88.89) | 101 (87.83) | 0.24 |
| ≥11 | 15 | 7 (12.28) | 4 (3.70) | 4 (12.50) | 34 | 10 (20.83) | 10 (11.11) | 14 (12.17) | ||
| Smoking status | 0.65 | 0.88 | ||||||||
| Never | 67 | 13 (40.63) | 39 (36.11) | 15 (26.32) | 153 | 26 (54.17) | 57 (63.33) | 70 (60.87) | ||
| Former | 122 | 18 (56.25) | 65 (60.19) | 39 (68.42) | 88 | 19 (39.58) | 29 (32.22) | 40 (34.78) | ||
| Current | 8 | 1 (3.13) | 4 (3.70) | 3 (5.26) | 12 | 3 (6.25) | 4 (4.44) | 5 (4.35) | ||
| Fitness (METs) | 8.27 ± 2.03 | 8.39 ± 2.14 | 8.48 ± 1.84 | 7.81 ± 2.25 | 0.12 | 6.76 ± 1.65 | 6.45 ± 1.42 | 6.84 ± 1.69 | 6.81 ± 1.71 | 0.36 |
| Short Form‐36 Health Survey | ||||||||||
| Bodily pain | 51.28 ± 8.87 | 52.73 ± 8.65 | 51.57 ± 8.59 | 49.92 ± 9.47 | 0.32 | 49.70 ± 8.54 | 48.15 ± 9.38 | 50.17 ± 7.74 | 49.97 ± 8.77 | 0.38 |
| Physical functioning | 49.44 ± 7.22 | 50.32 ± 6.06 | 50.49 ± 6.80 | 46.95 ± 8.06 | <0.01 | 47.33 ± 8.26 | 45.85 ± 8.05 | 48.05 ± 7.98 | 47.39 ± 8.56 | 0.33 |
| Total length of hospital stays prior to ancillary visit (days) | 0.07 | 0.71 | ||||||||
| 0 | 81 | 12 (37.50) | 50 (46.30) | 19 (33.33) | 100 | 19 (39.58) | 40 (44.44) | 41 (35.65) | ||
| 1–7 | 75 | 14 (43.75) | 42 (38.89) | 19 (33.33) | 88 | 18 (37.50) | 27 (30.00) | 43 (37.39) | ||
| >7 | 41 | 6 (18.75) | 16 (14.81) | 19 (33.33) | 65 | 11 (22.92) | 23 (25.56) | 31 (26.96) | ||
Weight pattern categories defined based on ±5% change in annual weight.
Chi‐square for categorical variables and anova F‐test for continuous.
Compared with baseline.
p‐value is from Wilcoxon rank sum test.
HbA1c = glycosylated haemoglobin; METS = metabolic equivalents; SD, standard deviation.
Change in weight by weight pattern category
Year 1 percent weight change differed among weight pattern categories for both genders. Interestingly, both men and women who achieved the 7% weight loss goal at year 1 had 2.91 (1.68–5.06) and 7.82 (4.38–13.96) times the odds of being classified as a cycler or regainer than a continued loser/maintainer, respectively, compared with participants who did not meet the 7% weight loss goal at year 1. By the year 8 visit, on average, regainers gained (mean ± SD) 9.6 ± 6.7 kg (10.3 ± 6.9 and 8.7 ± 6.3 kg for men and women, respectively), weight cyclers gained 1.4 ± 10.4 kg (1.2 ± 9.5 and 1.5 ± 10.9 kg for men and women, respectively) and continued losers/maintainers lost 4.9 ± 7.5 kg (−2.7 ± 3.9 and −6.3 ± 8.9 kg for men and women, respectively) from the year 1 visit weight (Figure 1).
Figure 1.
Graphical depiction of weight loss trends for each weight pattern category for men (A) and women (B).
Associations between physical performance and weight pattern category
Performance on physical function and strength tests at the year 8/9 visit, by weight pattern category and gender, is presented in Table 2. Overall, mean gait speed was faster than 1.0 m/s for both the 20‐ and 400‐m walk. Expanded PPB score was 1.68 ± 0.40, and men had greater grip and knee strength than women. In unadjusted analyses, weight pattern category was found to be predictive of expanded PPB score, gait speed and grip strength in men. Weight cyclers consistently performed worse on select measures of physical performance and strength (compared with regainers for PPB and gait speed, and both losers/maintainers and regainers for grip strength; Table 2). Conversely, in unadjusted analyses, weight pattern category did not appear to be predictive of follow‐up physical performance or strength in women.
Table 2.
Physical performance measures at Look AHEAD Y8/Y9 Memory and Movement ancillary visit by gender and weight cycling category
| Weight pattern category | ||||||
|---|---|---|---|---|---|---|
| Overall | Losers/maintainers | Regainers | Cyclers | |||
| Physical performance measures | N | Mean ± SD | Mean ± SD | Mean ± SD | Mean ± SD | p * |
| Expanded PPB score (range 0–3) | ||||||
| Male | 195 | 1.73 ± 0.40 | 1.69 ± 0.43 | 1.81 ± 0.33 | 1.61 ± 0.46 | 0.02 |
| Female | 250 | 1.64 ± 0.40 | 1.67 ± 0.35 | 1.64 ± 0.43 | 1.63 ± 0.39 | 0.94 |
| 20‐m gait speed (m/s) | ||||||
| Male | 189 | 1.21 ± 0.20 | 1.22 ± 0.22 | 1.25 ± 0.18 | 1.15 ± 0.23 | 0.02 |
| Female | 241 | 1.12 ± 0.22 | 1.14 ± 0.20 | 1.14 ± 0.25 | 1.10 ± 0.21 | 0.63 |
| 400‐m gait speed (m/s) | ||||||
| Male | 185 | 1.12 ± 0.19 | 1.13 ± 0.19 | 1.15 ± 0.17 | 1.06 ± 0.21 | 0.04 |
| Female | 228 | 1.03 ± 0.17 | 1.02 ± 0.15 | 1.04 ± 0.19 | 1.03 ± 0.17 | 0.93 |
| Grip strength (kg) | ||||||
| Male | 189 | 39.08 ± 8.72 | 42.10 ± 8.82 | 39.82 ± 7.91 | 35.99 ± 9.34 | <0.01 |
| Female | 236 | 24.80 ± 5.96 | 24.02 ± 5.58 | 25.61 ± 6.40 | 24.54 ± 5.78 | 0.94 |
| Knee extensor strength (lb) | ||||||
| Male | 164 | 70.40 ± 22.88 | 63.78 ± 22.42 | 73.69 ± 21.60 | 67.07 ± 25.13 | 0.08 |
| Female | 164 | 32.79 ± 12.54 | 29.19 ± 10.38 | 33.63 ± 13.62 | 33.62 ± 12.36 | 0.21 |
From unadjusted anova F‐test.
PPB = physical performance battery.
Table 3 presents adjusted anova results of physical performance measures by weight cycling category for men and women, respectively. Interestingly, in minimally adjusted models (model 1), weight cycling was associated with a lower score on the expanded PPB, slower walking speed and weaker grip strength in men. After further covariate adjustment (model 2), however, only grip strength in men was associated with weight pattern category (p < 0.01). Specifically, weight cyclers had lower grip strength at the year 8/9 visit when compared with weight regainers or continued losers/maintainers (30.12 ± 2.21 vs. 34.46 ± 2.04 and 37.39 ± 2.26 kg, respectively). Additional adjustment for year 1 percent weight change did not significantly alter effect size estimates; however, a trend was observed for weaker knee extensor strength in the continued losers/maintainer category compared with regainer or cycler categories (model 3; p = 0.08). When absolute knee extensor strength was divided by weight (to yield relative knee strength), this association was further attenuated.
Table 3.
Adjusted anova results of testing physical performance measures with weight cycling category from gender stratified analyses
| Weight pattern category | ||||
|---|---|---|---|---|
| Losers/maintainers | Regainers | Cyclers | ||
| Physical performance measures | LSMean ± SE | LSMean ± SE | LSMean ± SE | Weight cycling p‐value |
| Expanded PPB score (range 0–3) | ||||
| Male | ||||
| Model 1 | 1.69 ± 0.07 | 1.78 ± 0.06 | 1.59 ± 0.06 | <0.01 |
| Model 2 | 1.73 ± 0.09 | 1.80 ± 0.08 | 1.71 ± 0.08 | 0.26 |
| Model 3 | 1.74 ± 0.09 | 1.80 ± 0.08 | 1.72 ± 0.09 | 0.44 |
| Female | ||||
| Model 1 | 1.69 ± 0.06 | 1.62 ± 0.05 | 1.61 ± 0.04 | 0.52 |
| Model 2 | 1.57 ± 0.07 | 1.45 ± 0.07 | 1.46 ± −0.07 | 0.13 |
| Model 3 | 1.63 ± 0.07 | 1.46 ± 0.07 | 1.48 ± 0.07 | 0.02 |
| 20‐m gait speed (m/s) | ||||
| Male | ||||
| Model 1 | 1.21 ± 0.04 | 1.26 ± 0.03 | 1.16 ± 0.04 | <0.01 |
| Model 2 | 1.20 ± 0.05 | 1.23 ± 0.05 | 1.19 ± 0.05 | 0.41 |
| Model 3 | 1.23 ± 0.05 | 1.23 ± 0.05 | 1.21 ± 0.05 | 0.87 |
| Female | ||||
| Model 1 | 1.16 ± 0.03 | 1.14 ± 0.03 | 1.11 ± 0.03 | 0.31 |
| Model 2 | 1.14 ± 0.04 | 1.09 ± 0.04 | 1.07 ± 0.04 | 0.11 |
| Model 3 | 1.17 ± 0.04 | 1.10 ± 0.04 | 1.08 ± 0.04 | 0.03 |
| 400‐m gait speed (m/s) | ||||
| Male | ||||
| Model 1 | 1.13 ± 0.04 | 1.17 ± 0.03 | 1.08 ± 0.04 | <0.01 |
| Model 2 | 1.11 ± 0.05 | 1.14 ± 0.04 | 1.10 ± 0.05 | 0.37 |
| Model 3 | 1.13 ± 0.05 | 1.14 ± 0.04 | 1.12 ± 0.05 | 0.80 |
| Female | ||||
| Model 1 | 1.03 ± 0.03 | 1.03 ± 0.02 | 1.03 ± 0.02 | 0.98 |
| Model 2 | 1.00 ± 0.03 | 0.97 ± 0.03 | 0.98 ± 0.03 | 0.52 |
| Model 3 | 1.02 ± 0.03 | 0.97 ± 0.03 | 0.98 ± 0.03 | 0.27 |
| Grip strength (kg) | ||||
| Male | ||||
| Model 1 | 41.43 ± 1.74 | 37.86 ± 1.37 | 34.03 ± 1.46 | <0.01 |
| Model 2 | 38.07 ± 2.19 | 34.36 ± 2.05 | 30.75 ± 2.16 | <0.01 |
| Model 3 | 37.39 ± 2.26 | 34.46 ± 2.04 | 30.12 ± 2.21 | <0.01 |
| Female | ||||
| Model 1 | 22.69 ± 0.93 | 24.55 ± 0.78 | 23.34 ± 0.68 | 0.17 |
| Model 2 | 22.67 ± 1.25 | 24.45 ± 1.26 | 23.27 ± 1.18 | 0.21 |
| Model 3 | 22.98 ± 1.30 | 24.49 ± 1.27 | 23.36 ± 1.19 | 0.30 |
| Knee extensor strength (lb) | ||||
| Male | ||||
| Model 1 | 63.47 ± 4.79 | 72.54 ± 3.80 | 67.99 ± 4.30 | 0.13 |
| Model 2 | 65.94 ± 6.00 | 75.86 ± 5.48 | 73.51 ± 5.94 | 0.11 |
| Model 3 | 64.71 ± 6.18 | 76.02 ± 5.49 | 72.22 ± 6.15 | 0.08 |
| Female | ||||
| Model 1 | 28.23 ± 2.49 | 34.07 ± 2.11 | 33.51 ± 1.90 | 0.08 |
| Model 2 | 27.53 ± 3.59 | 33.69 ± 3.42 | 34.00 ± 3.35 | 0.05 |
| Model 3 | 27.99 ± 3.70 | 33.72 ± 3.43 | 34.08 ± 3.36 | 0.08 |
Model 1 = age, gender, race, education and clinic. Model 2 = Model 1 + baseline insulin use, hypertension, cardiovascular disease history, smoking status, body mass index, glycosylated haemoglobin %, self‐reported diabetes duration, baseline fitness, Short Form‐36 Health Survey physical functioning and pain subscales, Beck Depression Inventory (<11 or ≥11) and interim hospitalizations. Model 3 = Model 2 + year 1 weight change from baseline.
PPB = physical performance battery.
A nearly opposite pattern was observed in women, with associations produced in models 1 and 2 suggestive of no effect of weight pattern classification on follow‐up physical performance. However, after further adjustment for year 1 weight change from baseline (model 3), weight regain and cycling were associated with lower PPB score (p = 0.02) and slower 20‐m gait speed (p = 0.03) compared with a pattern of weight maintenance or continued weight loss. Interestingly, for both genders, the association between slower gait speed and lower grip strength estimates did not differ by bouts of weight cycling (all pairwise comparisons between one weight cycle and multiple cycles, p > 0.10).
Lastly, because year 1 percent weight change appeared to be such an influential covariate to model results, analytic models 1 and 2 were stratified by achievement of the study‐wide weight loss goal at year 1 (7% of baseline weight). Stratification did not affect results in women; however, the association between weight cycling and low grip strength remained only for men who lost ≥7% of their baseline weight at year 1 (p = 0.04). Additionally, in minimally adjusted models (model 1), cycling men who lost ≥7% of baseline weight at year 1 also had significantly lower expanded PPB scores (p = 0.01), and slower 20‐m (p = 0.03) and 400‐m (p = 0.02) gait speed than loser/maintainer or regainer groups, although these findings were attenuated to non‐significance after adjustment for additional covariates (data not shown).
Discussion
This study is the first to assess the effect of weight pattern dynamics following intentional weight loss on objective measures of physical function and strength in a well‐functioning sample of older adults with diabetes. Differential classification of weight pattern status following weight loss by gender was observed, with women more likely to be classified as weight cyclers and continued losers/maintainers than men over the 7 years of follow‐up. Women categorized as weight cyclers and regainers presented with worse expanded PPB score and slower 20‐m gait speed at the year 8/9 clinic visit compared with women categorized as continued losers/maintainers. Similarly, men categorized as weight cyclers presented with weaker follow‐up grip strength compared with men in the regainer or continued loser/maintainer categories. Importantly, effect size differences observed between weight pattern categories (i.e. expanded PPB score, 0.16; gait speed, 0.08 m/s; grip strength, 6 kg) are considered clinically meaningful 33, 34. Thus, clinicians promoting weight loss in this population should emphasize stable weight loss maintenance for prolonged functional independence.
Results presented here contribute to a growing body of literature assessing the effect of weight change on physical performance in at‐risk populations for future disability. Our findings support and extend reports generated from other large, observational studies, linking weight gain 35, 36 and variability 22, 23 in middle‐to‐late life with lower self‐reported functional status, particularly in women, by providing confirmatory data using objective measures of physical performance. Long‐term results (8–9 years) presented here are also in agreement with an emerging body of shorter‐term (12–18 months) randomized controlled trial data, suggesting that lifestyle‐based interventions resulting in intentional weight loss of 7–10% are associated with improved physical function and strength in older adults 16, 17, 37. It is interesting to note that the year 1 weight change was strongly related to weight pattern classification over the next 7 years [with achievement of the 7% weight loss goal at year 1 associated with increased odds of weight regain {women only} and cycling {men and women}] and may also exacerbate associations between body weight dynamics and physical performance.
Gender differences reported here are intriguing and may be explained by weight change associated changes in body composition. Longitudinal studies of body composition in older adults show a tendency towards a loss of lean and a gain of fat mass over time, which may be exaggerated during a cycle of weight regain 38, particularly in older women 39. Total body fat mass is more strongly associated with physical performance in women (compared with men) 40, and a relative increase in fat mass in women classified as regainers or weight cyclers in the current study may explain their worse follow‐up expanded PPB score and 20‐m gait speed. This line of thinking is only speculative, however, and should be the focus of future work as we do not specifically examine associations between change in body composition and physical performance. The negative association between cycling and grip strength in men is in general agreement with other findings linking weight fluctuation to increased risk of physical disability 22, 23; however, it is curious that this association was only observed in one outcome measure (of five). Overall, men are less likely to present with disability than women 41, and perhaps their physical performance is also less likely to be affected by changing weight dynamics.
Strengths of this study include the use of measured weights to assess changing weight dynamics following an intentional weight loss and adjustment for multiple covariates, which may confound our observed relationship between weight pattern classification and physical performance. This study is not without limitations, however. Because physical performance measures were only assessed at the year 8/9 visit, changes over time could not be assessed. A general limitation in this field of research is the lack of an operational definition for weight cycling. Although our choice of 5% weight change was used previously in a similarly designed study 22 and is consistent with clinically meaningful weight change 28, conclusions may differ by weight pattern definitions used. Varying definitions also make true cross‐study comparisons difficult; studies testing similar hypotheses varied in weight change thresholds used to construct their weight pattern categories from a relative 5% weight change 21, 22, to an absolute weight change of 5–30 lb 23, 36, to absolute change over time 35, and no other study assigned weight pattern categories following an intentional weight loss intervention (as was carried out in the present analysis). Lastly, extrapolation of results should be limited to similar populations, particularly with regard to age and disease status.
In sum, data presented here suggest that weight regain and cycling following intentional weight loss in middle‐aged and older adults with diabetes contribute to worse physical function in women and grip strength in men. Importantly, for weight cyclers, this was true despite a relatively small increase in absolute weight from the year 1 visit. Given the known immediate benefit of weight loss on physical performance measures, adoption of effective weight loss maintenance strategies may have the potential to maintain and preserve independent living in overweight and obese, middle‐aged and older adults with diabetes.
Conflicts of Interest Statements
The authors have no competing interests.
Clinical Sites
Pennington Biomedical Research Center George A. Bray, MD1; Kristi Rau2; Allison Strate, RN2; Frank L. Greenway, MD3; Donna H. Ryan, MD3; Donald Williamson, PhD3; Brandi Armand, LPN; Jennifer Arceneaux; Amy Bachand, MA; Michelle Begnaud, LDN, RD, CDE; Betsy Berhard; Elizabeth Caderette; Barbara Cerniauskas, LDN, RD, CDE; David Creel, MA; Diane Crow; Crystal Duncan; Helen Guay, LDN, LPC, RD; Carolyn Johnson, Lisa Jones; Nancy Kora; Kelly LaFleur; Kim Landry; Missy Lingle; Jennifer Perault; Cindy Puckett; Mandy Shipp, RD; Marisa Smith; Elizabeth Tucker
University of Colorado Health Sciences Center James O. Hill, PhD1; Marsha Miller, MS, RD2; Brent Van Dorsten, PhD3; Judith Regensteiner, PhD3; Ligia Coelho, BS; Paulette Cohrs, RN, BSN; Susan Green; April Hamilton, BS, CCRC; Jere Hamilton, BA; Eugene Leshchinskiy; Lindsey Munkwitz, BS; Loretta Rome, TRS; Terra Worley, BA; Kirstie Craul, RD, CDE; Sheila Smith, BS
The University of Tennessee Health Science Center University of Tennessee East. Karen C. Johnson, MD, MPH1; Carolyn Gresham, RN2; Stephanie Connelly, MD, MPH3; Amy Brewer, RD, MS; Mace Coday, PhD; Lisa Jones, RN; Lynne Lichtermann, RN, BSN; Shirley Vosburg, RD, MPH; and J. Lee Taylor, MEd, MBA. University of Tennessee Downtown. Abbas E. Kitabchi, PhD, MD1; Ebenezer Nyenwe, MD3; Helen Lambeth, RN, BSN2; Amy Brewer, MS, RD,LDN; Debra Clark, LPN; Andrea Crisler, MT; Debra Force, MS, RD, LDN; Donna Green, RN; Robert Kores, PhD
University of Pittsburgh John M. Jakicic, PhD1, David E. Kelley, MD1; Jacqueline Wesche‐Thobaben, RN, BSN, CDE2; Lewis H. Kuller, MD, DrPH3; Andrea Kriska, PhD3; Amy D. Otto, PhD, RD, LDN3, Lin Ewing, PhD, RN3, Mary Korytkowski, MD3, Daniel Edmundowicz, MD3; Monica E. Yamamoto, DrPH, RD, FADA 3; Rebecca Danchenko, BS; Barbara Elnyczky; David O. Garcia, MS; George A. Grove, MS; Patricia H. Harper, MS, RD, LDN; Susan Harrier, BS; Nicole L. Helbling, MS, RN; Diane Ives, MPH; Juliet Mancino, MS, RD, CDE, LDN; Anne Mathews, PhD, RD, LDN; Tracey Y. Murray, BS; Joan R. Ritchea; Susan Urda, BS, CTR; Donna L. Wolf, PhD
Coordinating Center
Wake Forest University Stephen B. Kritchevsky, PhD1; Denise K. Houston, PhD3; Jeff D. Williamson, MD3; Stephen R. Rapp, PhD3; Mark A. Espeland, PhD3; Xiaoyna (Iris) Leng, MD, PhD3; Gary Miller, PhD3; Kristen M. Beavers, PhD3, Amelia Hodges, BS, CCRP2; Michelle Gordon, MS; Jennifer Walker; Tara Beckner; Jason Griffin, BS; Lea Harvin, BS; Kathy Lane, BS; Rebecca H. Neiberg, MS
______________________________
1Principal investigator
2Program coordinator
3Co‐investigator
All other Look AHEAD staffs are listed alphabetically by site.
Funding and Support
This ancillary study is supported by the National Institute on Aging, National Institutes of Health, Department of Health and Human Services, R01 AG03308701. The Action for Health in Diabetes is supported through the following cooperative agreements from the National Institutes of Health: DK57136, DK57149, DK56990, DK57177, DK57171, DK57151, DK57182, DK57131, DK57002, DK57078, DK57154, DK57178, DK57219, DK57008, DK57135 and DK56992. The following federal agencies have contributed support: National Institute of Diabetes and Digestive and Kidney Diseases; National Heart, Lung, and Blood Institute; National Institute of Nursing Research; National Center on Minority Health and Health Disparities; Office of Research on Women's Health; the Centers for Disease Control and Prevention; and the Department of Veterans Affairs. This research was supported in part by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases. The Indian Health Service (IHS) provided personnel, medical oversight and use of facilities. The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the IHS or other funding sources.
Additional support was received from the University of Colorado Health Sciences Center General Clinical Research Center (M01RR00051) and Clinical Nutrition Research Unit (P30 DK48520); the University of Tennessee at Memphis General Clinical Research Center (M01RR0021140); and the University of Pittsburgh General Clinical Research Center (GCRC) (M01RR000056), the Clinical Translational Research Center (CTRC) funded by the Clinical & Translational Science Award (UL1 RR 024153) and NIH grant (DK 046204); and the Frederic C. Bartter General Clinical Research Center (M01RR01346).
The following organizations have committed to make major contributions to Look AHEAD: FedEx Corporation; Health Management Resources; LifeScan, Inc., a Johnson & Johnson Company; OPTIFAST® of Nestle HealthCare Nutrition, Inc.; Hoffmann‐La Roche Inc.; Abbott Nutrition; and Slim‐Fast Brand of Unilever North America.
Acknowledgements
GAB, JOH, DKH, JMJ, KCJ and SBK designed the research; RHN and KMB analysed data; KMB, GAB, JOH, DKH, JMJ, KCJ, RHN and SBK contributed to the writing of the article; KMB had primary responsibility for final content. All authors read and approved the final manuscript.
Additionally, we gratefully acknowledge all Look AHEAD M&M study team members and funding sources:
Beavers, K. M. , Neiberg, R. H. , Houston, D. K. , Bray, G. A. , Hill, J. O. , Jakicic, J. M. , Johnson, K. C. , Kritchevsky, S. B. , and for the Action for Health In Diabetes (Look AHEAD) Movement and Memory Ancillary Study Research Group (2015) Body weight dynamics following intentional weight loss and physical performance: the Look AHEAD Movement and Memory Study. Obesity Science & Practice 1: 12–22. doi: 10.1002/osp4.3.
ClinicalTrials.gov Identifier: NCT00017953; NCT01410097
References
- 1. Wray LA, Ofstedal MB, Langa KM, Blaum CS. The effect of diabetes on disability in middle‐aged and older adults. J Gerontol A Biol Sci Med Sci 2005; 60: 1206–1211. [DOI] [PubMed] [Google Scholar]
- 2. Gregg EW, Beckles GL, Williamson DF, et al. Diabetes and physical disability among older U.S. adults. Diabetes Care 2000; 23: 1272–1277. [DOI] [PubMed] [Google Scholar]
- 3. Guralnik JM, Fried LP, Salive ME. Disability as a public health outcome in the aging population. Annu Rev Public Health 1996; 17: 25–46. [DOI] [PubMed] [Google Scholar]
- 4. Fried LP, Guralnik JM. Disability in older adults: evidence regarding significance, etiology, and risk. J Am Geriatr Soc 1997; 45: 92–100. [DOI] [PubMed] [Google Scholar]
- 5. Guralnik JM, Simonsick EM, Ferrucci L, et al. A short physical performance battery assessing lower extremity function: association with self‐reported disability and prediction of mortality and nursing home admission. J Gerontol 1994; 49: M85–M94. [DOI] [PubMed] [Google Scholar]
- 6. Guralnik JM, Ferrucci L, Simonsick EM, Salive ME, Wallace RB. Lower‐extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med 1995; 332: 556–561. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7. von Bonsdorff M, Rantanen T, Laukkanen P, Suutama T, Heikkinen E. Mobility limitations and cognitive deficits as predictors of institutionalization among community‐dwelling older people. Gerontology 2006; 52: 359–365. [DOI] [PubMed] [Google Scholar]
- 8. Boyle JP, Honeycutt AA, Narayan KM, et al. Projection of diabetes burden through 2050: impact of changing demography and disease prevalence in the U.S. Diabetes Care 2001; 24: 1936–1940. [DOI] [PubMed] [Google Scholar]
- 9. Visser M, Langlois J, Guralnik JM, et al. High body fatness, but not low fat‐free mass, predicts disability in older men and women: the Cardiovascular Health Study. Am J Clin Nutr 1998; 68: 584–590. [DOI] [PubMed] [Google Scholar]
- 10. Zoico E, Di Francesco V, Mazzali G, et al. High baseline values of fat mass, independently of appendicular skeletal mass, predict 2‐year onset of disability in elderly subjects at the high end of the functional spectrum. Aging Clin Exp Res. 2007; 19: 154–159. [DOI] [PubMed] [Google Scholar]
- 11. Sharkey JR, Ory MG, Branch LG. Severe elder obesity and 1‐year diminished lower extremity physical performance in homebound older adults. J Am Geriatr Soc 2006; 54: 1407–1413. [DOI] [PubMed] [Google Scholar]
- 12. Ferraro KF, Su YP, Gretebeck RJ, Black DR, Badylak SF. Body mass index and disability in adulthood: a 20‐year panel study. Am J Public Health 2002; 92: 834–840. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13. Bannerman E, Miller MD, Daniels LA, et al. Anthropometric indices predict physical function and mobility in older Australians: the Australian Longitudinal Study of Ageing. Public Health Nutr 2002; 5: 655–662. [DOI] [PubMed] [Google Scholar]
- 14. Knowler WC, Barrett‐Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002; 346: 393–403. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. Messier SP, Loeser RF, Miller GD, et al. Exercise and dietary weight loss in overweight and obese older adults with knee osteoarthritis: the Arthritis, Diet, and Activity Promotion Trial. Arthritis Rheum 2004; 50: 1501–1510. [DOI] [PubMed] [Google Scholar]
- 16. Villareal DT, Chode S, Parimi N, et al. Weight loss, exercise, or both and physical function in obese older adults. N Engl J Med 2011; 364: 1218–1229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17. Rejeski WJ, Brubaker PH, Goff DC, Jr , et al. Translating weight loss and physical activity programs into the community to preserve mobility in older, obese adults in poor cardiovascular health. Arch Intern Med 2011; 171: 880–886. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. McGuire MT, Wing RR, Hill JO. The prevalence of weight loss maintenance among American adults. Int J Obes Relat Metab Disord 1999; 23: 1314–1319. [DOI] [PubMed] [Google Scholar]
- 19. Weiss EC, Galuska DA, Kettel KL, Gillespie C, Serdula MK. Weight regain in U.S. adults who experienced substantial weight loss, 1999–2002. Am J Prev Med 2007; 33: 34–40. [DOI] [PubMed] [Google Scholar]
- 20. Methods for voluntary weight loss and control. NIH Technology Assessment Conference Panel. Consensus Development Conference, 30 March to 1 April 1992. Ann Intern Med 1993; 119(7 Pt 2): 764–770. [PubMed] [Google Scholar]
- 21. Launer LJ, Harris T, Rumpel C, Madans J. Body mass index, weight change, and risk of mobility disability in middle‐aged and older women. The epidemiologic follow‐up study of NHANES I. JAMA 1994; 271: 1093–1098. [PubMed] [Google Scholar]
- 22. Arnold AM, Newman AB, Cushman M, Ding J, Kritchevsky S. Body weight dynamics and their association with physical function and mortality in older adults: the Cardiovascular Health Study. J Gerontol A Biol Sci Med Sci 2010; 65: 63–70. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Lee JS, Kritchevsky SB, Tylavsky F, et al. Weight change, weight change intention, and the incidence of mobility limitation in well‐functioning community‐dwelling older adults. J Gerontol A Biol Sci Med Sci 2005; 60: 1007–1012. [DOI] [PubMed] [Google Scholar]
- 24. Ryan DH, Espeland MA, Foster GD, et al. Look AHEAD (Action for Health in Diabetes): design and methods for a clinical trial of weight loss for the prevention of cardiovascular disease in type 2 diabetes. Control Clin Trials 2003; 24: 610–628. [DOI] [PubMed] [Google Scholar]
- 25. Wadden TA, West DS, Delahanty L, et al. The Look AHEAD study: a description of the lifestyle intervention and the evidence supporting it. Obesity (SilverSpring) 2006; 14: 737–752. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26. Espeland MA, Rapp SR, Bray GA, et al. Long‐term impact of behavioral weight loss intervention on cognitive function. J Gerontol A Biol Sci Med Sci 2014; 69: 1101–1108. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27. Houston DK, Leng X, Bray GA, et al. Long‐term intensive lifestyle intervention and physical function: The Look AHEAD Movement and Memory Study. Obesity (Silver Spring) 2015; 23: 77–84. doi: 10.1002/oby.20944. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28. Wallace JI, Schwartz RS. Epidemiology of weight loss in humans with special reference to wasting in the elderly. Int J Cardiol 2002; 85: 15–21. [DOI] [PubMed] [Google Scholar]
- 29. Simonsick EM, Newman AB, Nevitt MC, et al. Measuring higher level physical function in well‐functioning older adults: expanding familiar approaches in the Health ABC study. J Gerontol A Biol Sci Med Sci 2001; 56: M644–M649. [DOI] [PubMed] [Google Scholar]
- 30. Simonsick EM, Montgomery PS, Newman AB, Bauer DC, Harris T. Measuring fitness in healthy older adults: the Health ABC Long Distance Corridor Walk. J Am Geriatr Soc 2001; 49: 1544–1548. [DOI] [PubMed] [Google Scholar]
- 31. Ware JE, Jr. , Sherbourne CD. The MOS 36‐item short‐form health survey (SF‐36). I. Conceptual framework and item selection. Med Care 1992; 30: 473–483. [PubMed] [Google Scholar]
- 32. Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry 1961; 4: 561–571. [DOI] [PubMed] [Google Scholar]
- 33. Perera S, Mody SH, Woodman RC, Studenski SA. Meaningful change and responsiveness in common physical performance measures in older adults. J Am Geriatr Soc 2006; 54: 743–749. [DOI] [PubMed] [Google Scholar]
- 34. Nitschke JE, McMeeken JM, Burry HC, Matyas TA. When is a change a genuine change? A clinically meaningful interpretation of grip strength measurements in healthy and disabled women. J Hand Ther 1999; 12: 25–30. [PubMed] [Google Scholar]
- 35. Chen H, Bermudez OI, Tucker KL. Waist circumference and weight change are associated with disability among elderly Hispanics. J Gerontol A Biol Sci Med Sci 2002; 57: M19–M25. [DOI] [PubMed] [Google Scholar]
- 36. Houston DK, Stevens J, Cai J, Morey MC. Role of weight history on functional limitations and disability in late adulthood: the ARIC study. Obes Res 2005; 13: 1793–1802. [DOI] [PubMed] [Google Scholar]
- 37. Messier SP, Mihalko SL, Legault C, et al. Effects of intensive diet and exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee osteoarthritis: the IDEA randomized clinical trial. JAMA 2013; 310: 1263–1273. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38. Gallagher D, Ruts E, Visser M, et al. Weight stability masks sarcopenia in elderly men and women. Am J Physiol Endocrinol Metab 2000; 279: E366–E375. [DOI] [PubMed] [Google Scholar]
- 39. Beavers KM, Lyles MF, Davis CC, Wang X, Beavers DP, Nicklas BJ. Is lost lean mass from intentional weight loss recovered during weight regain in postmenopausal women? Am J Clin Nutr 2011; 94: 767–774. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40. Visser M, Kritchevsky SB, Goodpaster BH, et al. Leg muscle mass and composition in relation to lower extremity performance in men and women aged 70 to 79: the health, aging and body composition study. J Am Geriatr Soc 2002; 50: 897–904. [DOI] [PubMed] [Google Scholar]
- 41. Murtagh KN, Hubert HB. Gender differences in physical disability among an elderly cohort. Am J Public Health 2004; 94: 1406–1411. [DOI] [PMC free article] [PubMed] [Google Scholar]