Relationships among Obesity, Sarcopenia, and Osteoarthritis in the Elderly.

Background: The present study examined the correlations between obesity, sarcopenia, and osteoarthritis in Korea's elderly population.

Methods: A cross-sectional analysis of 1,865 and 1,769 respondents with knee osteoarthritis and lumbar spondylosis, respectively, was performed by using data from the 2010 and 2011 Korea National Health and Nutrition Examination Survey. Obesity was defined as a body mass index of ≥25 kg/m; osteoarthritis, as a Kellgren/Lawrence grade of ≥2; and sarcopenia, as an appendicular skeletal muscle mass (ASM; ASM/weight ×100) on dual-energy X-ray absorptiometry of two standard deviations below the mean reference value.

Results: The unadjusted and age-adjusted risks of knee osteoarthritis were as follows: 1.88 and 1.92 times greater, respectively, for male subjects with sarcopenic obesity; 6.03 and 7.64 times greater, respectively, for female subjects with non-sarcopenic obesity; and 1.97 and 2.43 times greater, respectively, for female subjects with sarcopenic obesity. The age-and-waist circumference-adjusted risks were 5.88 and 1.80 times greater for the female subjects with non-sarcopenic and sarcopenic obesities, respectively. No statistically significant finding was obtained for lumbar spondylosis.

Conclusion: Obesity and sarcopenia were associated with knee osteoarthritis in the elderly subjects. The risk of knee osteoarthritis was greater in the male subjects with sarcopenic obesity than in the male subjects with non-sarcopenic obesity. In the female subjects, the risk of knee osteoarthritis was high in both obesity groups. Further research to explain the sex-related difference in knee osteoarthritis risk based on body composition will be beneficial.