Association of life satisfaction with disability-free survival: role of chronic diseases and healthy lifestyle

Abstract

Background this article investigates the association between life satisfaction and disability-free survival, and explores the roles of chronic diseases and healthy lifestyle in this association. Method a cohort of 2,116 functionally independent adults aged ≥60 was followed up to 12 years. At baseline, life satisfaction was assessed with the Life Satisfaction Index A (LSI-A). Disability-free survival was defined as the survival till the first occurrence of either death, dementia or physical disability. Information on lifestyle factors was collected via questionnaire. Chronic diseases were ascertained through clinical examinations at baseline and each follow-up. Data were analysed using Cox proportional hazard regression models and Laplace regression. Results over follow-up, 1,121 participants died, developed dementia, or became disabled. High LSI-A versus Low LSI-A had a lower risk of death, dementia and physical disability (hazard ratio [HR] 0.79, 95% confidence intervals [CI] 0.67–0.94), and had a longer disability-free period by 1.73 (95% CI 0.18–3.32) years. In mediation analysis, accumulation of chronic diseases mediated 17.8% of the association between LSI-A and disability-free survival. In joint effect analysis, participants with high LSI-A and a favourable lifestyle profile had a HR of 0.53 (95% CI 0.41–0.69) for the composite endpoint, and lived 3.2 (95% CI 1.35–5.11) disability-free years longer than those with low life satisfaction and an unfavourable lifestyle profile. Discussion high life satisfaction is independently associated with longer disability-free survival. This association is partially mediated by a lower burden of chronic diseases and is reinforced by healthy lifestyle.

Mental distress and incident functional disability among a rural ageing population in South Africa

“…Poor sleep quality, PTSD symptoms, restless sleep and loneliness were not significantly associated with incident functional disability. The findings appear to confirm previous results 11 , 12 , 13 , 14 , 15 , 21 of an association between depressive symptoms, lower life satisfaction, and incident functional disability, extending previous knowledge on the relationship between depressive symptoms, lower life satisfaction, and disability onset in an African ageing population. Several mechanisms for the development of functional disability from depressive symptoms include the continuous presence of somatic depressive symptoms, poorer management of chronic medical conditions, and increased health risk behaviours, all of which can contribute directly or indirectly to the decline in ADL disability.…”

“…Poor sleep quality, PTSD symptoms, restless sleep and loneliness were not significantly associated with incident functional disability. The findings appear to confirm previous results [11][12][13][14][15]21 of an association between depressive symptoms, lower life satisfaction, and incident functional disability, extending previous knowledge on the relationship between depressive symptoms, lower life satisfaction, and disability onset in an African ageing population.…”

“…20 In China, high life satisfaction was "independently associated with longer disability-free survival older adults." 21 In cross-sectional studies in Africa, higher depression scores and major depressive disorder were associated with functional disability among older adults in Nigeria, 22,23 and among middle-aged and older adults in Ghana, loneliness was associated with physical functioning impairment, 24 and among middle-aged and older South Africans, lower quality of life was associated with functional disability. 4 None of the longitudinal studies reviewed were conducted in African countries, and it is unclear to what extent the associations of mental symptoms with functional disability apply to African populations.…”

“… 10 In the USA, among people aged 24–75 years, “chronic sleep problems predicted a higher risk of onset and increases in functional limitations 9–10 years later,” 18 non‐disabled older adults with more sleep complaints had higher odds of developing ADL disability in the USA, 19 while among older adults in Japan, long sleep duration and excessive sleepiness during the day were associated incident disability. 20 In China, high life satisfaction was “independently associated with longer disability‐free survival older adults.” 21 …”

Adverse childhood experiences affect the health of middle-aged and older people in China: The multiple mediating roles of sleep duration and life satisfaction

“…Second, our results show that ACEs are positively associated with a decline in health through a decrease in life satisfaction, which is consistent with several recent studies. The study of Hughes et al ( 46 ) found that early adversity was negatively correlated with life satisfaction, and the OR value of low life satisfaction increased with the number of ACEs, while low satisfaction was significantly correlated with an increase in the number of chronic diseases per year ( 47 ). One possible explanation for the above results is that life satisfaction is a type of cognition and evaluation of subjective wellbeing, which generates positive emotions.…”