Obstructive sleep apnea and osteoporosis: A bidirectional two-sample mendelian randomization analysis.

Background: Previous epidemiological studies have explored the association between obstructive sleep apnea (OSA) and osteoporosis (OP), with inconclusive results due to various biases. Herein, we sought to determine the causal association between OSA and OP through bidirectional two-sample Mendelian randomization analysis.

Methods: Summary-level data for OSA were acquired from the FinnGen consortium, while data for fractures and BMDs (FA-BMD, FN-BMD, LS-BMD and eBMD) were derived from the UKBB and GEFOS. The inverse variance weighted (IVW) method was conducted as the main method, and several supplementary methods were further utilized for sensitivity analysis to strengthen the reliability of our findings.

Results: The study findings strongly suggest a causal association between OSA and FA-BMD based on the IVW method (BETA = 0.404; 95 % CI = 0.208, 0.599; p = 5.28 × 10). However, OSA showed no significant causal relationship with eBMD (BETA = 0.052; 95 % CI = -0.018, 0.123; p = 0.145), FN-BMD (BETA = 0.095; 95 % CI = -0.009, 0.2; p = 0.073), LS-BMD (BETA = 0.021; 95 % CI = -0.082, 0.124; p = 0.695), and fractures (OR = 0.998; 95 % CI = 0.907, 1.098; p = 0.971). The conclusions from other analytical strategies were generally aligned with those of the IVW. No definitive causal effect of OP on OSA was observed in reverse analysis.

Conclusion: This research provided clear evidence of a causal association between OSA and FA-BMD, shedding light on the potential impact of OSA on bone metabolism.