The bidirectional association between body weight and mobility disability : A population-based cohort

Abstract Background Obesity is more common in people with mobility disability than in non-disabled individuals, but less is known about the longitudinal effects leading to this health state. Objective To explore the potential bidirectional association between mobility disability and obesity. Methods Participants were identified in the population-based Stockholm Public Health Cohort (2002–2010, n  = 17 945). Observations with schizophrenia, depression, eating disorder, or cancer within 5 years during and prior to baseline were excluded. Mobility disability and height and weight to calculate BMI (kg/m 2 ) were self-reported. We used multivariate-adjusted regression models to estimate relative risks (RRs) and 95% confidence intervals (CI) based on new cases of mobility disability in cohorts that were obese, overweight or normal weight at baseline, and increases in BMI over time by mobility disability status. Results Obesity at baseline was associated with incident mobility disability. The highest risk was observed in middle-aged women (RR = 3.95, CI = 2.35–6.65). Young men and middle-aged women with long-term mobility disability increased more in BMI (men: 1.55 kg/m 2 , 0.61–2.49; women: 0.38, 0.01–0.75), as well as young and middle-aged people with incident mobility disability (young men: 0.68 kg/m 2 , 0.10–1.27; middle-aged men: 0.49, 0.20–0.77; young women: 1.41, 0.94–1.87; middle-aged women: 0.64, 0.36–0.93) compared to the groups without any mobility disability. Conclusions In this paper, we demonstrated the bidirectional and longitudinal associations between body weight and mobility disability and thus the increased risk of developing the combination over time from either condition. Effective health-promotion and prevention strategies are needed to prevent worse health for these vulnerable groups in society.