Aim: To fill the knowledge gap regarding weight change and the onset of disability in community-dwelling Japanese older adults, we investigated the potential effects of rapid weight change on disability risk as defined by Japan's long-term care insurance (LTCI) system.
Methods: We analyzed data from a longitudinal study of 10 375 community-dwelling older Japanese adults (≥65 years) who were not LTCI needs certified at baseline and joined the study from 2002 to 2005. Weight change (percentage) was calculated by subtracting participants' weight in the previous year from that measured during a physical examination at study commencement. The five weight-change categories ranged from sizable weight loss (≤ -8.0%) to sizable weight gain (≥ +8.0%). Disability was defined according to LTCI certifications at follow-up. Hazard ratios (HRs) and 95% confidence intervals were calculated for new-onset disability using a Cox proportional hazards model that fitted the proportional subdistribution hazards regression model with weights for competing risks of death.
Results: During the mean 10.5-year follow-up, 2994 participants developed a disability. Sizable weight loss (HR [95% confidence intervals], 1.41 [1.17-1.71]) and weight loss (1.20 [1.05-1.36]) were significant predictors of disability onset. Sizable weight gain (1.45 [1.07-1.97]) corresponded to severe disability. Stratified analyses by lifestyle and initial body mass index categories revealed more pronounced associations between weight change and disability risk in the unhealthy lifestyle and below initial normal body mass index groups.
Conclusions: Rapid and sizable weight gain could be additional criteria for disability risk in older adults. Geriatr Gerontol Int 2023; 23: 809-816.
Keywords: disability; long-term care insurance system; rapid weight change; weight gain; weight loss.
© 2023 Japan Geriatrics Society.