Association between air pollution and osteoporosis: A Mendelian randomization study

Osteoporosis (OP) is a significant disease in the aging society, which poses a threat to the physical well-being of older adults. Some studies suggest that air pollution may contribute to an increased incidence of OP; however, this causal relationship has not been firmly established. To address this gap, we conducted Mendelian randomization (MR) analysis to assess the potential causal association between air pollution (including nitrogen dioxide [N = 456,380], nitrogen oxides [N = 456,380], particulate matter [PM]2.5 [N = 423,796], and PM10 [N = 455,314]) and total-body bone mineral density (BMD) (N = 56,284). We utilized summary data from IEU Open GWAS on the database of genome-wide association studies (GWAS) and employed inverse variance weighting (IVW) as our primary analytical approach. The findings from our MR study in the European population using the IVW method indicated a potential causal link between nitrogen oxides: β = -0.59, confidence interval (CI) = (-1.03 to -0.16), P = 0.008; PM2.5: β = -0.60, CI = (-1.12 to -0.08), P = .025. These results suggest that there might be a causative relationship between nitrogen oxides, PM2.5, and BMD with regards to OP development among individuals exposed to air pollution. Importantly, the observed associations passed all statistical tests without any evidence of heterogeneity or pleiotropy. Furthermore, the presence of air pollution was found to be associated with an elevated risk of developing OP. This study provides compelling evidence for a causal connection between nitrogen oxides, PM2.5, and OP, suggesting that reducing air pollution could play a crucial role in preventing OP development.