Associations of loneliness with poor physical health, poor mental health and health risk behaviours among a nationally representative community dwelling sample of middle-aged and older adults in India

Abstract

Objectives:

Loneliness may negatively impact on health outcomes. The study aimed to estimate the associations between loneliness and poor physical health, poor mental health, and health risk behaviours in middle-aged and older adults in a national population survey in India.

Methods:

The sample included 72,262 middle-aged and older adults from a cross-sectional national community dwelling survey in India in 2017–2018.

Results:

Results indicate that the prevalence of moderate loneliness was 20.5%, and severe loneliness was 13.3%. In the adjusted logistic regression analysis, moderate and/or severe loneliness was significantly positively associated with fair or poor self-rated health status, and significantly negatively associated with life satisfaction and cognitive functioning. Furthermore, loneliness was associated with stroke, angina, physical injury, difficulty of Activities of Daily Living (ADL), difficulties of Instrumental Activities of Daily Living (IADL), and multimorbidity. Loneliness increased the odds of major depressive disorder and insomnia symptoms. The associations between loneliness and current tobacco use and Body Mass Index (BMI) were negative and between loneliness and physical inactivity and underweight were positive.

Conclusions:

Loneliness is associated with poor physical health, poor mental health and health risk behaviour (physical inactivity), emphasising the need to consider loneliness in various physical and mental health contexts.

1. INTRODUCTION

Loneliness is a “distressing feeling that accompanies the perception that one’s social needs are not being met by the quantity or especially the quality of one’s social relationships,”¹ and may increase with ageing because of changes in the quantity and quality of social relationships.^2–4

The prevalence of loneliness is common among older adults, e.g., in 11 European countries, loneliness ranged from 10% in France and Norway to more than 30% in Bulgaria.⁵ In a middle-income country, South Africa, the prevalence of self-reported loneliness was among older adults (≥50 years) 9.9%,⁶ in Malaysia, 32.5% of older adults (≥60 years) reported sometimes feeling lonely, and 20.9% always feeling lonely,⁷ and in a national study among older adults (≥50 years) in India in 2007, the prevalence of loneliness was 18%.⁸

Loneliness and social isolation can negatively impact on both psychological and physical health in old age.^9,10 Loneliness has been found associated with poor self-rated health,^11–15 low life satisfaction,¹⁵ lower subjective well-being,¹⁰ and poor cognitive functioning.^15–18 Strong associations have been found between loneliness and psychological distress,^12,13 depression,^12,15,19,20 and insomnia, sleep problems, and diminished sleep.^{10,13,15,18,21,22} Loneliness has also been associated with various chronic conditions, ¹² such as lower body mass index (BMI),¹⁵ obesity,²³ underweight,²⁴ heart disease, hypertension, stroke, lung disease,²⁵ diabetes,¹² high cholesterol,¹² and multimorbidity.^11,15 Several studies have shown that loneliness increased the odds of limiting physical ability,¹¹ and functional limitations.¹⁹ Various studies showed associations between loneliness and health risk behaviours, including current smokers/tobacco use,^12,13,15,18 binge drinking,¹³ alcohol use,¹⁰ physical inactivity,^12,15 and poor nutrition,¹⁰ such as inadequate fruit and vegetable intake¹² and soft drink consumption.¹⁵

Most studies investigating the relationship between loneliness and detrimental effects on health in older age have been conducted in high-income countries, and we lack information on this relationship in low- and middle-income countries, such as in India. India has a rapidly ageing society,²⁶ accompanied by rapid urbanization, changing family structure and lifestyles, interpersonal relationship patterns, and power structures, reducing social cohesion and support, eroding kinship ties (relationship strain, support, family cohesion),^27–29 thereby elevating the risk for loneliness. Majority of studies showed a lower prevalence of loneliness in collectivist countries, such as India, than in individualistic cultures,³⁰ but rapid socio-cultural changes in India may increase individualistic elements in Indian culture and thereby possibly increasing levels of loneliness, and possibly loneliness having an increasingly stronger impact on various health outcomes. The older population in India is affected by non-communicable diseases, including chronic lung conditions, cardiovascular diseases, stroke, cancer, multiple disabilities, vision and hearing problems, mental health problems, and cognitive impairment, which are exacerbated by poor socioeconomic conditions, gender, place of residence, etc.³¹ Based on the cited research, we hypothesize that loneliness is associated with poor physical health, poor mental health and health risk behaviours in middle-aged and older adults in India. The study aimed to estimate the associations between feeling alone or loneliness and poor physical health, poor mental health and health risk behaviours in middle-aged and older adults in a national population survey in India in 2017–2018.

2. METHODS

2.1. Sample and procedures

This cross-sectional study was conducted in a nationally representative sample of community-dwelling middle-aged and older adults in India in 2017–2018; “the overall household response rate was 96%, and the overall individual response rate was 87%.”³² In a household survey, “interview, physical measurement and biomarker data were collected from individuals aged 45 and above and their spouses, regardless of age;” specific details on the sampling approach are found elsewhere.³² The study was approved by the Indian Council of Medical Research (ICMR) Ethics Committee and written or oral informed consent was obtained from the participants.³²

2.2. Measures

Health indicator outcome variables

Self-rated health status was sourced from the question, “In general, would you say your health is excellent, very good, good, fair, or poor?” Responses were coded as “1=poor, 2=fair, 3=good, 4=very good, and 5=excellent.”³² Self-rated health has in particular high predictive validity for mortality.³³

Life satisfaction was measured with the 5-item Satisfaction With Life Scale (SWLS).³⁴ Total scores ranged from 5–35, with higher scores indicating higher life satisfaction.³⁴ Cronbach’s alpha for the SWLS in this study was 0.86. The SWLS has been shown to be valid and reliable and suited for use with different populations and age groups.³⁵

Cognitive functioning were assessed with tests for immediate and delayed word recall, serial 7s, and orientation based on the Mini-Mental State Exam.³⁶ A composite score of 0–32 was computed with a higher score representing better cognitive functioning.

Hypertension or raised blood pressure (BP) was defined as “systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg (based on the last two averaged of three readings) or where the participant is currently on antihypertensive medication.”³⁷

Angina was assessed with the “World Health Organization’s Rose angina questionnaire”,³⁸ defined on the basis of “discomfort at walking uphill or hurrying, or at an ordinary pace on level ground. Furthermore, the pain should be located at the sternum or in the left chest and arm, causing the patient to stop or slow down, and the pain should resolve within 10 minutes when the patient stops or slows down.”³⁹ Rose Angina Questionnaire was found to have moderate sensitivity but high specificity to detect coronary heart disease in a study in Bangladesh and found valid for use in population surveys.⁴⁰

Insomnia symptoms were assessed with four questions adapted from the Jenkins Sleep Scale (JSS-4):⁴¹ “How often do you have trouble falling asleep?” 2) “How often do you have trouble with waking up during the night?” 3) “How often do you have trouble with waking up too early and not being able to fall asleep again?” 4) “How often did you feel unrested during the day, no matter how many hours of sleep you had?” Response options were “never, rarely (1–2 nights per week), occasionally (3–4 nights per week), and frequently (5 or more nights per week)”(item 4 was reverse coded). Insomnia problems were “coded as ‘frequently’ for any of the four symptoms as one.”⁴² The “JSS-4 proved excellent reliability and it demonstrated good construct validity.”⁴³ Internal consistency of the JSS-4 was 0.88 in this study.

Major depressive disorder in the past 12 months was assessed with the Health and Retirement Study (HRS) Composite International Diagnostic Interview short form (CIDI-SF),⁴⁴ using criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).⁴⁵ Study respondents were required to “endorse either anhedonia or depressed mood for most of the day for most of a 2-week period or more,” and those who fulfilled this criterion “completed an additional seven symptoms: lost interest, feeling tired, change in weight, trouble with sleep, trouble concentrating, feeling down, and thoughts of death.”⁴⁶ “Those with a score ≥3 were considered to meet the criteria for having MDD in the previous 12 months;^46,47 MDD symptomology scores ranged from 0 to 7.”⁴⁶ The scale has been validated in general population surveys.⁴⁸

Current tobacco use included, 1) “Do you currently smoke any tobacco products (cigarettes, bidis, cigars, hookah, cheroot, etc.)? and/or 2) Do you use smokeless tobacco (such as chewing tobacco, gutka, pan masala, etc.)?”³²

Heavy episodic alcohol use was assessed with the question, “In the last 3 months, how frequently on average, have you had at least 5 or more drinks on one occasion?”³² and defined as “one to three days per month, one to four days per week, five or more days per week, or daily.”

Physical inactivity was defined as hardly ever or never engaging in vigorous or moderate physical activity.

Activities of Daily Living (ADL) were assessed with 6 items and Instrumental Activities of Daily Living (IADL) with 7 items (Yes, No).^49,50 Cronbach alpha was 0.87 for ADL and 0.90 for IADL in this study. Responses were dichotomized into 0 and ≥1 ADL and IADL items. ADL and IADL measures have been found to have acceptable validity with reference to Indian geriatric population.⁵¹

Anthropometry: “Height and weight of adults were measured using the Seca 803 digital scale.” Body Mass Index=BMI was calculated and underweight defined as underweight (<18.5 kg/m²).³²

Self-reported health care provider diagnosed chronic conditions included: 1) “ Hypertension or high blood pressure (Yes/No); 2) Diabetes or high blood sugar (Yes/No); 3) Cancer or malignant tumor (Yes/No); 4) Chronic lung disease such as asthma, chronic obstructive pulmonary disease/Chronic bronchitis or other chronic lung problems (Yes/No); 5) Chronic heart diseases such as Coronary heart disease (heart attack or Myocardial Infarction), congestive heart failure, or other chronic heart problems (Yes/No); 6) Stroke (Yes/No); 7) Arthritis or rheumatism, Osteoporosis or other bone/joint diseases (Yes/No); 8) Any neurological, or psychiatric problems such as depression, Alzheimer’s/Dementia, unipolar/bipolar disorders, convulsions, Parkinson’s etc. (Yes/No); and 9) High cholesterol (Yes/No).”³² Multimorbidity was based on ≥2 chronic conditions.

Exposure variable

The loneliness question used for this analysis comes from the Center for Epidemiologic Studies Depression Scale (CES-D-10)⁵²: “How often did you feel alone in the past week?” Response options were coded into not feeling alone: 1=rarely or none of the time (<1 day), moderate feeling alone: 2=sometimes or 1–2 days/week and severe feeling alone: 3=occasionally or all the time or 3–7 days/week).

Covariates

Sociodemographic variables consisted of education (none and ≥1 years), age, sex (male, female), marital status (currently married vs. widowed/divorced/separated/deserted/live-in relationship/never married), urban and rural residence. Subjective socioeconomic status was assessed with the question, “Please imagine a ten-step ladder, where at the bottom are the people who are the worst off – who have the least money, least education, and the worst jobs or no jobs, and at the top of the ladder are the people who are the best off – those who have the most money, most education, and best jobs. Please indicate the number (1–10) on the rung on the ladder where you would place yourself.”³² Steps 1 to 3 on the socioeconomic ladder were defined as low, 4–5 as medium, and 6–10 as high.

Intrinsic religiosity was measured with four items from the Daily Spiritual Experience Scale (DSES)⁵³, 1) “Do you think that you have a feeling of deep inner peace?” 2) “Do you think that you are spiritually touched by the beauty of creation?” 3) “Do you think that you are thankful for whatever you received in your life?” and 4) “Do you think that you are selflessly caring for others?” Responses ranged from 1=never to 5=every day in a week, and the summed scores were trichotomized to 4–7=low, 8–11=medium, and 12–20=high. Cronbach’s alpha for the DSES in this study was 0.86. The DSES has shown good reliability across several studies.⁵³

Organizational religiosity was assessed with the question, “In the past year, how often have you attended religious services (at a temple/mosque/church, etc.)?” Response options were grouped into 1 (low)=not at all, 2 (medium)=1–3 times a month or 1 or more times a year, and 3(high)=once a week or more than once a week or every day.³²

Social participation was measured with 8 items, e.g., “Eat-out-of-house (restaurant/hotel)”, from the Health and Retirement Study, that has been found reliable and predictive validity to measure social participation in older adults.⁵⁴ Responses were coded 1= daily to at least once a month and 0=rarely/once a year or never (Cronbach’s alpha 0.67).

2.3. Data analysis

Considering the clustered study design, data analyses were conducted with “STATA software version 15.0 (Stata Corporation, College Station, TX, USA).” Unadjusted and adjusted logistic regression analyses were used to calculate associations between moderate and severe loneliness and 19 health outcome variables. The multivariable models were adjusted for age group, sex, education, marital status, subjective socioeconomic status, area of residence, social participation, intrinsic and organised religiosity. Covariates were selected based on previous literature review.^{6,9,11–13,15,10} P-values of below 0.05 were accepted as significant and missing values were excluded from the analysis.

3. RESULTS

3.1. Sample and loneliness prevalence characteristics

The sample included 72,262 middle-aged and older adults (45 years and older, M= 58.57, SD=11.82), 58.0% were female and 42.0% male. Almost half of participants (49.5%) had no formal education, 75.6% were married, and 68.2% were residing in rural areas. More than one third of participants (34.9%) had high intrinsic religiosity, 27.6% attended at least weekly religious services, and 30.6% had a high social participation. Furthermore, health indictor characteristics are shown in Table 1. The prevalence of moderate (sometimes) feeling alone or loneliness was 20.5%, and severe (often or most or all time) feeling alone or loneliness 13.3% (see Table 1).

Table 1:

Sample characteristics among middle-aged and older adults in India, 2017–2018 (N=72262)

Variable	Variable specification	% or M (SD)
Social and demographic factors
Age in years	45–59 60 or more	54.1 45.9
Sex	Female Male	58.0 42.0
Education	Some None	50.5 49.5
Subjective socioeconomic status	Low Medium High	37.2 38.7 24.1
Marital status	Not married Married	24.4 75.6
Residence	Rural Urban	68.2 31.8
Intrinsic religiosity	Low (4–7) Medium (8–11) High (12–20)	31.3 33.8 34.9
Organised religiosity (Attendance of religious services)	Not at all 1–3 times/month or ≥1 times/year ≥1/week or every day	25.5 46.9 27.6
Social participation	Low Medium High	39.7 29.7 30.6
Health indicators
Self-rated health status	Fair or poor	39.7
Life satisfaction	Scale (5–35): M (SD)	18.7 (5.1)
Cognitive functioning	Scale (0–32): M (SD)	23.7 (7.5)
Hypertension	Yes	40.4
Stroke	Yes	1.8
Angina	Yes	8.6
Diabetes	Yes	11.6
Major injury	Yes	12.9
Insomnia symptoms	Yes	12.7
Major depressive disorder	Yes	7.6
Chronic lung disease	Yes	6.3
Current tobacco use	Yes	30.4
Heavy episodic drinking	Yes	2.9
Physical inactivity	Yes	23.7
ADL one or more	Yes	15.9
IADL one or more	Yes	36.1
Body mass index (BMI)	Scale: M (SD)	22.6 (4.8)
BMI underweight	Yes	20.8
Multimorbidity	Yes	18.1
Feeling alone or loneliness in the past week	Rarely or never (<1 day) Sometimes (1 or 2 days) Often (3 or 4 days) Most or all of the time (5–7 days)	66.1 20.5 8.8 4.4

ADL: Activities of Daily Living; IADL: Instrumental Activities of Daily Living

3.2. Associations of moderate and severe loneliness with health outcome indicators

In the adjusted logistic regression analysis, moderate and/or severe loneliness was significantly positively associated with fair or poor self-rated health status, and significantly negatively associated with life satisfaction and cognitive functioning. Furthermore, loneliness was associated with stroke, angina, and physical injury. High odds were found between loneliness and major depressive disorder and insomnia symptoms. Furthermore, loneliness was associated with difficulty of ADL and IADL and multimorbidity. The association between loneliness and current tobacco and BMI use were negative and between loneliness and physical inactivity and underweight positive (see Table 2).

Table 2:

Associations between moderate and severe loneliness and health indicators

Outcome variables		Loneliness	Model 1: unadjusted odds ratio or exp (Coef.) (95% CI)	Model : adjusted odds ratio or exp (Coef.) (95% CI)a
Fair or poor self-rated health status	No Yes	No Moderate Severe	1 Reference 1.33 (1.23, 1.43)*** 1.40 (1.24, 1,58)***	1 Reference 1.21 (1.13, 1.30)*** 1.28 (1.15, 1.43)***
Life satisfaction	Scale	No Moderate Severe	1 Reference 0.10 (0.08, 0.14)*** 0.03 (0.02, 0.05)***	1 Reference 0.16 (0.13, 0.21)*** 0.06 (0.04, 0.10)***
Cognitive functioning	Scale	No Moderate Severe	1 Reference 0.36 (0.30, 0.43)*** 0.33 (0.24, 0.47)***	1 Reference 0.73 (0.64, 0.84)*** 0.67 (0.53, 0.84)***
Hypertension	No Yes	No Moderate Severe	1 Reference 1.03 (0.96, 1.10) 1.18 (1.03, 1.35)*	1 Reference 0.99 (0.92, 1.06) 1.08 (0.94, 1.22)
Stroke	No Yes	No Moderate Severe	1 Reference 1.33 (1.07, 1.65)** 2.03 (1.44, 2.87)***	1 Reference 1.32 (1.06, 1.64)* 2.02 (1.40, 2.92)***
Angina	No Yes	No Moderate Severe	1 Reference 1.32 (1.19, 1.47)*** 1.35 (1.16, 1.56)***	1 Reference 1.27 (1.15, 1.41)*** 1.31 (1.14, 1.52)***
Diabetes	No Yes	No Moderate Severe	1 Reference 1.14 (0.95, 1.37) 1.22 (0.92, 1.61)	---
Major injury	No Yes	No Moderate Severe	1 Reference 1.16 (1.05, 1.29)** 1.32 (1.14, 1.52)***	1 Reference 1.09 (0.98,1.21) 1.22 (1.04, 1.42)*
Insomnia symptoms	No Yes	No Moderate Severe	1 Reference 1.50 (1.36, 1.64)*** 2.26 (2.02, 2.53)***	1 Reference 1.42 (1.30, 1.56)*** 2.16 (1.93, 2.41)***
Major depressive disorder	No Yes	No Moderate Severe	1 Reference 2.43 (2.03, 2.93)*** 3.42 (2.99, 3.90)***	1 Reference 2.26 (1.88, 2.72)*** 3.17 (2.77, 3.62)***
Chronic lung disease	No Yes	No Moderate Severe	1 Reference 1.10 (0.94, 1.30) 1.18 (0.97, 1.49)	---
Current tobacco use	No Yes	No Moderate Severe	1.01 (0.94, 1.08) 0.83 (0.75, 0.92)***	0.96 (0.88, 1.04) 0.85 (0.77, 0.94)***
Heavy episodic drinking	No Yes	No Moderate Severe	1 Reference 1.04 (0.88, 1.24) 1.22 (0.87, 1.70)	---
Physical inactivity	No Yes	No Moderate Severe	1 Reference 1.32 (1.22, 1.42)*** 1.50 (1.35, 1.66)***	1 Reference 1.27 (1.18, 1.37)*** 1.43 (1.28, 1.59)***
ADL one or more	No Yes	No Moderate Severe	1 Reference 1.81 (1.61, 2.05)*** 2.01 (1.78, 2.27)***	1 Reference 1.69 (1.48, 1.92)*** 1.81 (1.60, 2.04)***
IADL one or more	No Yes	No Moderate Severe	1 Reference 1.56 (1.44, 1.69)*** 1.71 (1.51, 1.93)***	1 Reference 1.39 (1.27, 1.53)*** 1.45 (1.29, 1.64)***
Body mass index (BMI)	Scale	No Moderate Severe	1 Reference 0.52 (0.43,0.64)*** 0.63 (0.43, 0.92)*	1 Reference 0.78 (0.65, 0.92)** 0.81 (0.62, 1.06)
BMI underweight	No Yes	No Moderate Severe	1 Reference 1.30 (1.19, 1.41)*** 1.26 (1.12, 1.41)***	1 Reference 1.12 (1.02, 1.22)* 1.09 (0.96, 1.22)
Multimorbidity	No Yes	No Moderate Severe	1 Reference 1.25 (1.10, 1.42)*** 1.53 (1.28, 1.83)***	1 Reference 1.27 (1.11, 1.46)*** 1.48 (1.26, 1.74)***

^aAdjusted for age group, sex, education, marital status, subjective socioeconomic status, area of residence, social participation, intrinsic and organised religiosity

^***p<0.001

^**p<0.01

^*p<0.05

ADL: Activities of Daily Living; CI: Confidence Interval; IADL: Instrumental Activities of Daily Living; The N ranged from 70061 to 70129 for nonphysical measures and from 64588 to 65263 for physical measures.

4. DISCUSSION

The study aimed to estimate the associations between loneliness and poor physical health, poor mental health, and health risk behaviours in middle-aged and older adults in a national population survey in India in 2017–2018. Results show for the first time that loneliness is associated with 13 health indicators (fair or poor self-rated health status, low life satisfaction, poor cognitive functioning, stroke, angina, physical injury, insomnia symptoms, major depressive disorder, difficulty with ADL and IADL, underweight, physical inactivity, and multimorbidity) in India, which is consistent with previous research.^{10–15,17–20,22,24,25,55}

The study found a very high association between loneliness and major depressive disorder, which may be related to its comorbibity with depression and may occur both as a consequence and a risk factor of depressive symptoms.¹² Loneliness may produce anxiety-provoking thoughts reducing the ability to relax resulting in insomnia symptoms.¹⁶ The relationship between loneliness and physical inactivity may be explained by the process in which loneliness may reduce emotional self-regulation contributing to a lessor motivation to engage in physical activity.¹⁶ The link between loneliness and injury may come from loneliness initiating via an increase of insomnia symptoms that in turn may generate drowsiness, increasing the risk of physical injury.^56,57

Several mechanisms may explain the link between loneliness and health in older adults,⁹ such as neurobiological mechanisms generating cardiovascular and inflammatory stress responses.¹⁸ Ong et al.¹⁰ suggest that health risk behaviours, such as poor sleep, and negative social cognition, and regional brain activation to social in contrast to non-social stimuli may be responsible for the effects of loneliness on a wide range of poor health outcomes.

Some studies^12,13,25 found an association between loneliness and hypertension, lung disease, diabetes, and binge drinking, while this study did only find for hypertension such an association in unadjusted analysis and no significant associations were found for lung disease, diabetes, and heavy episodic drinking. The non-association between loneliness and diabetes may be related to the fact that only self-reported diabetes was assessed. Considering that 42% of the general adult population in India with diabetes are ‘undiagnosed’,⁵⁸ the tested diabetes prevalence may be almost double that of self-reported diabetes. On the other hand, loneliness was in unadjusted analysis significantly positively associated with measured hypertension, confirming results from previous studies.^59,60 Perhaps because of the high prevalence of hypertension (40.4%), the association between loneliness and hypertension became nonsignificant in the adjusted model. Contributing factors to the nonsignificant findings could be that only a very small proportion of the population engaged in heavy episodic drinking. A number of previous studies^{12,13,15,19,23} found a positive association between loneliness and tobacco use, while in this study severe loneliness was negatively associated with current tobacco use. This could mean that middle-aged and older adults in India do not engage in tobacco use in an attempt to cope with their loneliness and gain social acceptance.^13,61 In agreement with another study in a middle-income country (Indonesia),¹⁵ this study found that loneliness was negatively associated with BMI, while in a high-income country (Australia) loneliness was associated with higher BMI.²³ Having a higher BMI may be associated with greater affluence and thereby reducing loneliness in India. Overall, addressing loneliness or social isolation by tailoring interventions to suit the needs of individuals, specific groups or the degree of loneliness experienced⁶² may help in reducing mental and physical health problems.

Study limitations include the cross-sectional design, the assessment of some variables by self-report, and loneliness was only assessed with one item. However, some research seem to indicate “a high correlation between single-item and multi-item loneliness indices.”³² Some questions, e.g., on living status (living alone, etc.) and dietary behaviour, such as fruit and vegetable intake and soft drink consumption, were not included in this study and should be incorporated in further investigations.

5. CONCLUSION

The study largely extends existing evidence that has shown associations between loneliness and 13 health indicators (fair or poor self-rated health status, low life satisfaction, poor cognitive functioning, stroke, angina, physical injury, insomnia symptoms, major depressive disorder, difficulty with ADL and IADL, underweight, physical inactivity, and multimorbidity) in India. Longitudinal studies are needed to directly assess the effects of loneliness on health in this population.

DATA AVAILABILITY STATEMENT

The data are available at the Gateway to Global Aging Data (www.g2aging.org).