Severe elder obesity and 1-year diminished lower extremity physical performance in homebound older adults

OBJECTIVES: To determine whether severe obesity in older people is independently associated with diminished lower extremity physical performance (LEP) in a random sample of homebound older adults that were considered ambulatory. DESIGN: Prospective cohort with 1 year of follow-up (2000-02). SETTING: In-home assessments of homebound older adults in four North Carolina counties. PARTICIPANTS: Random sample of 282 home-delivered meal recipients aged 60 and older who completed both in-home assessments (n=253) or were nursing home residents (n=29) at the 1-year follow-up assessment of the Nutrition and Function Study. MEASUREMENTS: Objective measures were selected for baseline and 1-year LEP (timed walking, static and dynamic balance, and chair rise) and baseline body mass index (BMI, based on measured weight and knee height). BMI was categorized as underweight/normal (< 25.0 kg/m(2)), overweight (25.0-29.9 kg/m(2)), moderately obese (30.0-34.9 kg/m(2)), and severely obese (>= 35.0 kg/m(2)). Based on summary scores, overall LEP was categorized as poor, intermediate, or good. Sample characteristics included depressive symptomatology, fear of falling, medical conditions, and medication use. MEASUREMENTS: Almost 23% of participants were moderately obese and 15% severely obese. Only severe obesity independently increased the odds (odds ratio 2.9-7.0) for diminished performance at 1 year in individual tests and in overall LEP performance. Severe obesity was independently associated with poor LEP at both assessments or with decline in LEP at 1 year. CONCLUSIONS: These results highlight the need to distinguish between moderate and severe obesity in older people in terms of relationships with key functional outcomes. The findings identify severe obesity in older people as an important target for future interventions. In particular, this calls for greater understanding of intervention goals, whether to primarily target weight reduction or improvement in physical performance.