Sensitivity analyses showed similar results.
These causal effects still existed after adjusting for BMI.
Result from inverse variance weighting (IVW) method provided evidence schizophrenia increased the risk of fractures of skull and facial bones and femur, whereas, decreased the level of eBMD. Multivariable Mendelian randomization (MVMR) analysis was performed to minimize the confounding effect of body mass index (BMI). Two-sample MR was utilized, based on instrumental variables from large genome-wide association studies (GWAS) of schizophrenia as exposure, to identify the causal association of schizophrenia with mixed fractures, fractures at different body sites (including skull and facial bones, shoulder and upper arm, wrist and hand, and femur) and BMDs of forearm (FA), femoral neck (FN), lumbar spine (LS) and estimated BMD (eBMD). This study aimed to test the causal effects between schizophrenia and fractures as well as aberrant BMD by conducting Mendelian randomization (MR) analyses. Schizophrenia was clinically documented to co-occur with fractures and aberrant bone mineral density (BMD), but the potential causal relationship remained unclear.