Long-term impact of PM2.5 exposure on frailty, chronic diseases, and multimorbidity among middle-aged and older adults: insights from a national population-based longitudinal study.

Particulate Matter 2.5 (PM2.5) is a significant risk factor for frailty and chronic diseases. Studies on the associations between PM2.5 and frailty, chronic diseases, and multimorbidity are scarce, especially from large cohort studies. We aimed to explore the potential association between PM2.5 exposure and the risk of frailty, chronic diseases, and multimorbidity. We collected data from a national cohort (CHARLS) with a follow-up period of 11-18 years, totaling 13,366 participants. We obtained PM2.5 concentration data from the Atmospheric Composition Analysis Group at Dalhousie University. PM2.5 exposure is based on the average annual concentration in the prefecture-level city where residents live. We define frailty as the comprehensive manifestation of declining various body functions, characterized by a frailty index of 0.25 or greater, and multimorbidity as the presence of at least two or more chronic conditions. Cox proportional hazards regression was used to estimate the hazard ratio (HR) with its 95% confidence interval (95%CI). A 10-µg/m3 increase for PM2.5 was significantly associated with an increased risk of frailty (HR = 1.289, 95%CI = 1.257-1.322, P < 0.001). A 10-µg/m3 increase for PM2.5 was significantly associated with the elevated risk for most chronic diseases. Compared to those with no morbidity or only single morbidity, a 10-µg/m3 increase for PM2.5 was significantly associated with the elevated risk for multimorbidity (HR = 1.220, 95%CI = 1.181-1.260, P < 0.001). Ambient PM2.5 exposure is a significant risk factor for frailty, chronic diseases, and multimorbidity, and some measures need to be taken to reduce PM2.5 concentration and prevent frailty and chronic diseases.

Frailty index trajectories in Chinese older adults with diverse levels of social participation: findings from a national population-based longitudinal study.

BACKGROUND: Aging and frailty pose significant challenges globally, placing a substantial burden on healthcare and social services due to their adverse consequences. AIM: The primary objective of this study was to investigate the relationship between social participation and development of frailty transition and trajectory. METHODS: This study utilized data from the CLHLS Cohort, a 10-year follow-up study involving 6713 participants, to investigate the association between social participation and development of frailty. Frailty reflects a comprehensive decline in various body functions. The study employed a group-based trajectory model to analyze the development trajectory of the frailty index and used logistic regression to assess the odds ratio (OR) of frailty risk. RESULTS: We identified two distinct groups of frailty progression trajectories: the "stable development group" and the "rapid growth group." Individuals who engaged in social activities at least once a month, but not daily, exhibited a significant association with an increased risk of transitioning into the "rapid growth group" (OR 1.305, 95% CI 1.032-1.649). Those with social participation less than once a month had an even greater risk (OR 1.872, 95% CI 1.423-2.463). Moreover, low social participation frequency (occasionally/never) has a more pronounced impact on frailty progression in males. CONCLUSION: A higher frequency of social participation is associated with a lower risk of being classified into the "rapid growth group" and a slower rate of frailty index progression. Preventing the progression of frailty can contribute to enhanced support for healthy aging among older adults.