Relationship of Bone Mineral Density and Knee Osteoarthritis (Kellgren-Lawrence Grade):Fifth Korea National Health and Nutrition Examination Survey

ABSTRACT

Background@#Osteoarthritis (OA) and osteoporosis (OP) are the 2 most common bone disorders associated with aging. We can simply assume that older patients have a higher incidence of OA and OP with more severity. Although several papers have conducted studies on the relationship between OA and OP, none of them has demonstrated a conclusive link. In this study, we used radiological knee OA and bone mineral density (BMD; T-score of the total hip and lumbar spine) to analyze the incidence of OA and OP in a large population. We aimed to determine the relationship between OA and OP and investigate the associated risk factors. @*Methods@#This cross-sectional study used data extracted from the 2010–2012 Korea National Health and Nutrition Examination Survey. We evaluated a total of 4,250 participants aged ≥ 50 years who underwent knee radiography and dual-energy X-ray absorptiometry and their laboratory results. The relationship between radiological knee OA and BMD was assessed. The generalized linear model was used to evaluate the relationship between BMD and Kellgren-Lawrence (KL) grade. @*Results@#The higher KL grade was associated with older age, higher body mass index (BMI), female sex, and lower hemoglobin level (p 0.05). After adjusting for confounding factors (age, BMI, diabetes, hypertension, smoking, and alcohol consumption), the average T-scores of total hip and lumbar spine were the highest in the mild OA group with KL grade 2 (–0.22 ± 1.08 and –0.89 ± 1.46, respectively,p < 0.001). The average T-scores of the total hip and lumbar spine significantly decreased as OA progressed from moderate (KL grade 3; –0.49 ± 1.05 and –1.33 ± 1.38, respectively, p < 0.001) to severe (KL grade 4; –0.73 ± 1.13 and –1.74 ± 1.75, respectively, p < 0.001). T-scores of the moderate-to-severe OA group were significantly lower than those of the non-OA group (KL grades 0 and 1, p < 0.001). @*Conclusions@#Compared with the non-OA group, BMD (T-scores of the total hip and lumbar spine) was higher in the mild OA group and lower in the moderate-to-severe OA group.