Change in body size associated with all-cause mortality in an older Chinese population

Objective

Evidence of an association between a change in body size and the risk of all-cause mortality is limited among older populations. We explored the association of a change in body size over three years with the risk of all-cause mortality in an older Chinese population.

Methods

A total of 5134 participants from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were recruited. Cox proportional-hazards models were used to assess the association of changes in body mass index (BMI) and body fat percentage (BF%) with risk of all-cause mortality, using hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Of the 5134 participants (median age, 81 years; 2716 women [52.90%]), 1494 deaths were observed over a median of 4.08 years of follow-up. Compared with participants with stable body size (change within 5%), those with more than a 10% decrease in BMI or BF% had 36% and 46% higher risks, respectively, of all-cause mortality (HR = 1.36, 95% CI: 1.17–1.59; and HR = 1.46, 95% CI: 1.25–1.72); also, those with more than a 10% increase in BMI or BF% had 22% and 17% higher risks of all-cause mortality (HR = 1.22, 95% CI: 1.05–1.41; and HR = 1.17, 95% CI: 1.02–1.35).

Conclusions

This prospective cohort study of older adults suggests that a dramatic change in body size was positively associated with a higher risk of all-cause mortality. More attention should be paid to the effects of a dramatic change in body size, particularly a dramatic decrease in body size, among the Chinese population.