Associations of body mass index, lifestyle factors, and medical findings in midlife with frailty in older ages: A 15‐year longitudinal study

AIM: Preventing frailty is crucial; however, the current evidence is limited to findings from older adults and may not apply to earlier life stages. This study examined the associations between health screening findings, body mass index, lifestyle factors, and medical findings in midlife with frailty in older ages by longitudinal analysis and the associations between them in older ages by cross-sectional analysis. METHODS: The study was conducted in a population-based cohort of the Circulatory Risk in Communities Study. We used the data of 1785 men and women aged 40-65 years (mean age: 54 years) who underwent health examinations between 2002 and 2004 in two Japanese communities. Among them, the frailty evaluation was conducted for 784 men and women aged 60 years or older (average age: 69 years) between 2017 and 2019. Multinomial logistic regression analysis was performed to calculate the multivariable odds ratios of pre-frailty and frailty compared with non-frailty, based on body mass index, lifestyle factors, and medical findings in midlife using longitudinal data, and based on these factors in older ages using cross-sectional data. RESULTS: We identified 351 non-frailty, 400 pre-frailty, and 33 frailty cases according to Fried's phenotype. Being overweight in middle age was associated with frailty in older ages in the longitudinal analysis, while being overweight in older ages was not in the cross-sectional analysis. A history of musculoskeletal disorders in both midlife and older ages was associated with frailty. In the cross-sectional analysis but not in the longitudinal analysis, the factors associated with pre-frailty or frailty included current smoking, current drinking, exercise, consumption of vegetables and soy products, and diabetes mellitus. CONCLUSIONS: Being overweight in midlife was associated with frailty in older ages, pointing to the importance of keeping an appropriate weight and lifestyle modifications in midlife to prevent frailty. Geriatr Gerontol Int 2025; 25: 889-896.