Associations of lifestyles and frailty status with survival among older adults in China: a nationwide, community-based, prospective cohort study
摘要
No studies have examined whether lifestyles mediate the association between frailty status and survival among older adults in China, and research exploring the interactions and joint associations of frailty status and lifestyles on survival is also limited. Therefore, we conducted this study to address these critical gaps in a nationwide, community-based, prospective cohort of older adults in China.
MethodsA total of 17,476 participants (median age: 87.0 [IQR: 80.0–95.0], males: 61.5%) from the Chinese Longitudinal Healthy Longevity Survey conducted between 1998 and 2014 were included, with follow-up until 2018. Frailty index assessed frailty status: robustness, pre-frailty, and frailty. Four lifestyle factors were examined: cigarette smoking, alcohol consumption, physical activity, and diet. The study outcome was overall survival. We performed a mediation analysis of lifestyles on the association between frailty status and survival. Additionally, we assessed the interactions and joint associations of frailty status and lifestyles on survival.
ResultsDuring a median follow-up of 3.4 years, 13,008 deaths (74.4%) were recorded. Compared to robust participants, those with pre-frailty had a 16.0% shorter overall survival (adjusted time ratio [TR]: 0.84, 95% confidence interval [CI]: 0.82–0.86), with lifestyles mediating 11.9% of this difference (95% CI: 9.2%–15.3%); frail participants experienced a 41.0% reduction in survival (adjusted TR: 0.59, 95% CI: 0.57–0.62), with lifestyles mediating 11.1% (95% CI: 9.2%–13.3%). Additionally, more healthy lifestyle factors were associated with longer survival across different frailty levels (pinteraction=0.090). Furthermore, frail participants with no or one healthy lifestyle factor had a 53.0% shorter survival (adjusted TR: 0.47, 95% CI: 0.44–0.51) compared to robust participants with four healthy lifestyle factors; at the age of 65 years, the former group experienced a reduction in life expectancy of 8.6 years (95% CI: 5.2–12.1) compared to that of the latter group.
ConclusionsAmong older adults in China, lifestyles only mediate a small proportion of frailty disparities in overall survival; consequently, without direct interventions for frailty or additional favorable measures, promoting healthy lifestyles alone is insufficient to significantly reduce frailty disparities in survival. Furthermore, individuals of frailty and unhealthy lifestyles experience significantly shorter survival, highlighting the urgent need for targeted interventions for this population.