| Objective To evaluate the causal relationship between bone mineral density (BMD) and knee osteoarthritis(KOA). Methods Data from gene-wide association studies were used for analysis, the exposure factor was BMD, including total body BMD, lumbar BMD, femoral neck BMD, heel BMD, ultradistal forearm BMD, and forearm BMD. The outcome variable was KOA. Mendelian randomization(MR) analysis was performed by IVW method, MR-Egger method, WM method, Simple Mode method and Weighted Mode method, and heterogeneity test, sensitivity analysis and pleiotropy test were performed. Results IVW method results showed that the whole body BMD OR was 1.08 (1.02 to 1.14), lumbar spine BMD OR was 1.09 (1.01 to 1.18), femoral neck BMD OR was 1.15 (1.04 to 1.28), heel BMD OR (95% CI) was 1.04 (0.99 to 1.08), distal forearm BMD OR (95% CI) was 1.07 (1.00 to 1.15), and OR (95% CI) for forearm BMD was 0.97 (0.86 to 1.10). Total body BMD, lumbar BMD, femoral neck BMD were no abnormal variables in the heterogeneity test, and the sensitivity analysis was robust, and no pleiotropy was found. Conclusion Total BMD, lumbar BMD, and femoral neck BMD are causally related to KOA, while heel BMD, ultradistal forearm BMD, and forearm BMD are not causally related to KOA. |