Association between obesity and osteoarthritis in the South Korean older population: A nationwide population-based study.

There are few studies on the association between obesity and radiologically-confirmed osteoarthritis (OA) in the South Korean older population. We investigated the association between obesity and radiologically-confirmed OA in a nationally-representative sample of the South Korean older population. The study population comprised 5811 participants (2530 men and 3281 women) aged ≥60 years selected from the 2010 to 2012 Korea National Health and Nutrition Examination Survey. Radiographic OA was defined as Kellgren-Lawrence grade ≥ 2 on either the knee or hip area in radiographic images. The odds ratios and 95% confidence intervals for OA were determined using multiple logistic regression analyses after adjusting for confounding factors. Overall, 7.9% and 29.6% of older men and women had OA, respectively. A U-shaped curve with the nadir in the appropriate body weight (body mass index 18.5-23 kg/m2) revealed that 9.0%, 6.8%, 8.1%, and 9.1% of older men and 24.5%, 21.6%, 27.1%, and 38.4% of older women who were underweight, normal weight, overweight, and obese, respectively, had OA. Compared with normal-weight people, the odds ratios (95% confidence intervals) for OA in obese subjects were 1.73 (1.13-2.64) and 2.76 (2.13-3.56) for older men and women, respectively, after adjusting for age, comorbidities, lifestyle behaviors, and socioeconomic status. Obesity was significantly associated with an increased risk of OA in the South Korean older population. This finding suggests that efforts to maintain appropriate body weight and reduce excessive body weight should be considered to reduce the risk of OA in older adults.