Background: Our aim was to study the effects of high body mass index (BMI) and physical impairments in midlife on later life walking limitation.
Methods: Primarily middle-aged persons (aged 32-72 years) with no walking limitation at baseline (n = 840) were followed-up for 22 years as a part of the Mini-Finland Follow-up Survey. Incident walking limitation (walking speed < 1.2 m/s or difficulty in walking 0.5 km) was predicted by measured BMI, handgrip strength, squatting test, and self-reported running difficulties.
Results: Twenty-one percent of the participants developed walking limitation. After adjustment for multiple potential confounders, high BMI, low handgrip strength, impaired squatting, and running difficulties were significant predictors of incident walking limitation. The odds ratio (OR) of walking limitation was 4.55 (95% confidence interval [CI], 1.32-15.74) for squatting difficulties and 2.39 (95% CI, 1.26-4.55) for major running difficulties as compared to participants with no difficulties. The corresponding ORs for handgrip strength and BMI were 0.56 (95% CI, 0.38-0.81) and 1.39 (95% CI, 1.10-1.75) per an increment of 1 standard deviation. For persons in the highest BMI tertile who had two or more physical impairments, the adjusted risk of walking limitation was 4.5 times higher in comparison to normal weight persons with no physical impairments.
Conclusions: In primarily middle-aged persons, BMI and simple tests of physical impairment strongly predicted the development of walking limitation 22 years later. In addition, physical impairments coexisting with high BMI predisposed to later life walking limitation more than high BMI alone. Therefore, increasing physical fitness by physical activity and promoting weight loss in middle age may prevent mobility limitation and subsequent disability in old age.