Yuan S, Wan ZH, Cheng SL, et al. - Researchers performed a Mendelian randomization study to evaluate the correlations of serum insulin-like growth factor-1 (IGF-1) levels with estimated bone mineral density (eBMD) and fracture. Genetic instruments for IGF-1 were chosen at the genome-wide significance level from a genome-wide association study involving 358,072 people of European ancestry. From the UK Biobank study, summary-level data for eBMD (426,824 individuals) and fracture (53,184 fracture cases and 373,611 noncases) were collected. The change of eBMD levels was 0.04 g/cm² and the odds ratio of fracture was 0.94 for 1-SD increase in IGF-1. The present study supports IGF-1's role in fracture prevention, possibly and partly mediated by higher bone mineral density.