Abstract:
Obesity is a risk factor for osteoarthritis (OA) and both are steadily increasing among older adults. Nevertheless, empirical examinations of the associations of body mass index (BMI) with depressive symptomatology, pain, and disability in OA remain limited. Few studies have described and differentiated functional disability in necessary tasks (basic and instrumental activities of daily living; ADL/IADLs) from discretionary, leisure activities among symptomatic normal, overweight, and obese adults. Therefore, here, associations of BMI with pain, depressive symptoms, and measures of disability among older adults with knee osteoarthritis were examined. A key focus was how BMI influences the form functional disability takes in terms of limiting necessary vs. discretionary activities. Data were collected from a sample of community-dwelling older adults with physician-confirmed knee osteoarthritis (N =353). BMI predicted significant variance in psychological and functional impairment in osteoarthritis, including pain, depressive symptoms, and three functional outcomes measures (specifically, ADL/IADL disability, discretionary activity, and activity limitation). Effects of BMI depended on level and were differentially mediated through pain. For adults with low BMI, engagement in more discretionary activities was associated with fewer depressive symptoms. This research confirms the association of BMI with disability related osteoarthritis, identifying it as a rich intervention target in a comprehensive treatment of OA to interrupt its cycle of excessive weight gain, pain, depressive symptoms, and disability particularly among older adults.
