Obesity and falls in older people: mediating effects of disease, sedentary behavior, mood, pain and medication use.

Obesity has been associated with an increased risk of falls among older people. However, it is not certain whether factors commonly associated with falls and/or obesity mediate this risk. This research examines whether specific diseases, sedentary behavior, mood, pain, and medication use mediate the association between obesity and falls. A representative sample of community-living individuals aged 65+ years in New South Wales (NSW), Australia were surveyed regarding their experience of falls, height, weight, lifestyle and general health within a 12 month period. Intervening variable effects were examined using Freedman and Schatzkin's difference in coefficients tests and regression analyses were used to estimate relative risks. Obesity was associated with a 25% higher risk (95%confidence interval (CI) 1.11-1.41; p<0.0003) of having fallen in the previous 12 months compared to non-obese individuals. The strongest mediators of the association between obesity and falls were sleeping tablets (t=-5.452; p<0.0001), sitting for more than 8h per day on weekdays (t=5.178; p<0.0001), heart disease/angina (t=3.526; p<0.0001), anti-depressant use (t=3.102; p=0.002), moderate/extreme anxiety or depression (t=3.038; p=0.002), and diabetes (t=3.032; p=0.002). Sedentary behavior, chronic health conditions and medication use were identified as mediators for the association between obesity and falls in community living older people. Interventions aimed at weight reduction and increased activity may have benefits not only for fall prevention, but also for the mediating health, mood and lifestyle factors identified here.