Overweight or underweight and the risk of decline in activities of daily living in a 22-year cohort study of a Japanese sample

Aim: The present study aimed to clarify the association between body mass index (BMI) and the activities of daily living (ADL). Although BMI is likely to be concerned regarding the relationship with specific diseases or mortality, few studies have focused on the relationship of BMI and ADL. Methods: A total of 3353 Japanese participants of a 22-year cohort study from 1990 to 2012 aged 45–74 years at baseline were divided into four groups according to their BMI levels: ≤18.5, 18.5–21.9 (reference), 22.0–24.9 and ≥25.0 kg/m ² . Outcomes were becoming dependent in ADL (including death after ADL decline) and death without observation of ADL decline as a competing risk. Sex-specific multinomial logistic regression analysis was carried out in 2017 to estimate the odds ratios (OR) after adjusting for age, smoking, alcohol drinking, hypertension, hypercholesterolemia, diabetes and serum albumin. Results: After multivariable adjustment, though the relationship between BMI and risk of ADL decline was U-shaped among women, only those with BMI ≥25.0 showed a higher risk for ADL decline (OR 1.39, 95% CI 1.01–1.92) compared with the reference. The OR for death without observation of ADL decline was significantly lower for men with BMI ≥25.0 (OR 0.70, 95% CI 0.50–0.98). Conclusions: This study suggests being overweight is a good predictor of future decline in ADL for women, whereas men with BMI 22.0–24.9 had lower risks of ADL decline. Appropriate management of weight in older women could prevent disabilities. Geriatr Gerontol Int 2018; 18: 799–805.