Causal relationship between serum creatinine levels and bone mineral density: A Mendelian randomization study

To study serum creatinine (Scr) levels and bone mineral density (BMD), we used Mendelian randomization (MR) to investigate the causal relationship between them. The genetic association data of Scr levels and total body BMD across age groups were retrieved from the genome-wide association studies, and the causal relationship between Scr levels and BMD was analyzed using the inverse-variance weighting method, MR-Egger regression method, weighted median estimation method, simple mode, and weighted mode. The results of the inverse-variance weighted method indicated that the creatinine level might be a protective factor for the 45 to 60 age group (P = .005, odds ratio = 1.176, 95% confidence interval = 1.049-1.318). All error lines in the sensitivity analysis graph of the retention method were on the right side of 0, suggesting that the results were highly stable and that the MR results were stable, and no association was found in other age groups. Scr levels exhibited a causal relationship with BMD. As a standard proxy indicator for skeletal muscle mass, Scr levels are correlated with BMD. Reduced Scr levels may indicate sarcopenia, which adversely affects skeletal health. Consequently, monitoring Scr could enable the early identification of individuals at risk of low BMD.