Associations Between Fat Mass, Lean Mass, and Knee Osteoarthritis: The Fifth Korean National Health and Nutrition Examination Survey (KNHANES V)

摘要

As little is known about the associations between body composition (fat mass and lean mass) and knee OA, especially regarding body parts (upper body and lower limbs), the purpose of this study was to identify the association between the former and the prevalence of the latter according to body parts. This study was designed as a cross-sectional analysis, with 4194 people (1801 men and 2393 women) from the fifth Korean National Health and Nutrition Examination Survey (KNHANES V, 2010-2011) included. Body composition (fat mass and lean mass) was measured by using dual-energy X-ray absorptiometry, and knee OA was diagnosed based on the level of Kellgren-Lawrence grade. In multivariate logistic regression analysis, upper body composition was not significantly correlated with radiographic knee OA (P > 0.05), while participants with higher lean mass of lower limbs were less likely to have radiographic knee OA (aOR 0.57; 95 % CI 0.32-0.99). In stratified analysis, participants with higher lean mass of lower limbs were less likely to have a radiographic knee OA in 40-54 kg (P for trend = 0.05) and 55-70 kg stratum (P for trend = 0.03), while this trend slightly attenuated in 70-85 kg stratum (P for trend = 0.15). In conclusion, the increase in lean mass of lower limbs is inversely related to the prevalence of knee OA while upper body composition is not. This study suggests that the lean mass of lower limbs might be associated with reduction in the risk of knee OA.