Osteoporosis and symptomatic knee osteoarthritis in postmenopausal women: A case-control study

Background: Postmenopausal women with symptomatic knee osteoarthritis (AKO) may be at increased risk of bone loss due to reduced physical activity. However, data in this setting are conflicting and the current study was designed to determine the association between symptomatic AKO and bone mineral density in postmenopausal women. Methods: Postmenopausal women with symptomatic AKO were recruited from patients attending a rheumatology clinic. Diagnosis of AKO was made according to ACR criteria. Age-matched subjects without clinical AKO served as controls. French bone mineral density (BMD) at the femoral neck (CF) and lumbar spine (LHR) was determined by dual X-ray absorptiometry (DXA). Osteoporosis was diagnosed based on a BMD T-score < 2.5 at CF or RHL. Student's t test and chi-square test with multiple regression analysis were used to determine associations. SPSS software version was used for statistical analysis. Results: Thirty-five patients and 35 controls with a mean age of 61.9±8.69 and 58.8±6.8 (P = 0.67) years, respectively, were studied. In univariate analysis, the values ​​of all BMD parameters at the femoral neck and lumbosacral regions were similar and the differences did not reach statistical significance. In multiple regression analysis, symptomatic KOA was not significantly associated with an increased risk of osteoporosis, and obesity was significantly associated with a decreased risk of osteoporosis by adjusted OR = 3.14 (95% CI, 0.60-16.2) and OR = 0.23 (0.058-0.945), respectively. Conclusion: These results suggest that there is no association between symptomatic knee osteoarthritis and osteoporosis in postmenopausal women. However, this question requires further long-term studies with large samples.