Background and objective: Both low and high body mass index (BMI) have been associated with greater mortality in older adults. This study evaluated the trajectory of BMI in the final years of life.
Design: Population-based cohort study.
Setting: Community-dwelling adults in the English Longitudinal Study of Ageing between 1998 and 2012.
Measurements: Body mass index, years before death and all-cause mortality. Analyses were adjusted for age, gender, educational level, housing tenure and social class.
Results: Data were analysed for 16,924 participants with 31,857 BMI records; mean age at study start, 61.6 (SD 10.9) years; mean BMI, 27.5 (4.7) Kg/m2. There were 3,686 participants (4,794 BMI records) who died and 13,238 participants (27,063 BMI records) who were alive at last follow-up. Mean BMI increased with age to 60-69 years but then declined, but the age-related decline was more rapid in decedents. At ages 80-89 years, mean BMI in decedents was 26.1 (4.7) compared with 27.1 (4.4) Kg/m2 in survivors. After adjusting for age and covariates, mean BMI declined in the five years before death. From 9 to 5 years before death or end of study, adjusted mean BMI was 0.51 (95% confidence interval 0.24 to 0.78) Kg/m2 lower for decedents than survivors; and from four to zero years before death, 1.55 (1.26 to 1.84) Kg/m2 lower in decedents.
Conclusions: In community-dwelling older adults, mean body mass index enters an accelerating decline during five years before death. Reverse causation may account for the association of lower BMI with mortality.
Associations Between Body Mass Index and Foot Joint Pain in Middle-Aged and Older Women: A Longitudinal Population-Based Cohort Study
