Changes in physical activity and all-cause mortality in the oldest old population: Findings from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

Background: Insufficient or decreasing physical activity is common in older adults. Most studies on physical activity changes and mortality were conducted in adults younger than 80 years old in developed countries. We aimed to investigate the relationship between changes in physical activity and longevity in the oldest old (80 years or older) population using the Chinese Longitudinal Healthy Longevity Survey.

Methods: Participants aged 80 or older at baseline were categorized into four groups: 1) remaining physically inactive (n = 14,287), 2) remaining physically active (n = 5411), 3) shifting from being inactive to active (n = 1364), and 4) shifting from being active to inactive (n = 1401). We fitted accelerated failure time Weibull survival regression models, adjusting for baseline sociodemographics, lifestyle factors and disease status. We further examined whether the associations differed by subgroups.

Results: A total of 15,707 participants died during follow-up (median duration of follow-up = 3.0 years). Compared with participants who remained physically inactive, those who remained active (fully adjusted event time ratio (ETR): 1.14, 95%CI: 1.11-1.17) or shifted from being inactive to active (fully adjusted ETR: 1.14, 95%CI: 1.08-1.20) had statistically significant longer survival time. No significant association was observed between remaining physically inactive and shifting from being active to inactive. Subgroup analyses showed consistent associations in nearly all strata.

Conclusion: Maintaining frequent physical activity or shifting from being physically inactive to active was consistently associated with longer survival time in the oldest old population. Our findings provide evidence for encouraging older adults to regularly engage in physical activity to gain longevity benefits.