Weight loss and functional decline in older Japanese people: A cohort study using large-scale claims data.

Background: The association between weight loss and subsequent functional decline is uncertain. The study aims to elucidate the association between weight loss over a year and subsequent functional decline requiring assistance in performing their activities of daily living in older individuals.

Methods: The study used data from the publicly funded Long-Term Care Insurance service in Japan, which provides coverage for long-term care services for individuals unable to perform activities of daily living due to physical or cognitive impairment. The study enrolled people born in or before 1949, who underwent health checkups in both 2014 and 2015. The participants were followed from 2015 to the worsening of functional decline requiring long-term care services, death, or February 28, 2019, whichever occurred first. The risk of subsequent functional decline in each weight loss category was estimated using a Cox regression model adjusted for age, sex, baseline body mass index, smoking, and Charlson comorbidity index.

Results: We identified 67,452 eligible individuals from the database. The median follow-up period was 1,284 days. The hazard ratios (95 % confidence interval) of functional decline for -1 %, -2 %, -3 %, -4 %, and ≤-5% weight change compared to 0 % weight change were 1.17 (1.03-1.32), 1.26 (1.11-1.43), 1.29 (1.12-1.49), 1.61 (1.39-1.87), and 1.79 (1.58-1.99), respectively.

Conclusions And Implications: Older people with weight loss of 1 % or more were at risk of functional decline. Close weight monitoring may serve as an easy and inexpensive means of identifying older individuals at risk of functional decline.