Association of Weight at Different Ages and All-Cause Mortality Among Older Adults in the US.

Objective: Assess the association of BMI and BMI change with mortality. Methods: Using data from the Wisconsin Longitudinal Study (WLS) on participants born mainly in 1939 ( n =4922), we investigated the associations between various measures of BMI across the life course (age 54 BMI; age 65 BMI; age 72 BMI; lifetime maximum BMI; BMI change between ages 54 and 65; BMI change between ages 65 and 72) and mortality. We also assessed whether these associations are mediated by late life health. Results: BMI at age 54 was more strongly associated with late life mortality than BMI at older ages. The association between BMI change and mortality varied based on the timing of weight change. Health at age 72, particularly self-rated health, diabetes, and physical functioning, mediated the observed associations. Conclusion: Knowing older people's weight at midlife and how their weight has changed may be more important in assessing late life mortality risk than their current weight.