Sex Differences in The Association Between Clinically Diagnosed Sleep Apnea & All-Cause Mortality: Findings From A National Veterans Database.

INTRODUCTION: Sex differences exist in the clinical presentation and outcomes of sleep apnea (SA), yet sex-specific associations between SA severity and mortality remain inconsistent. We examined sex- and age-specific associations between severe SA and all-cause mortality in a large national cohort of Veterans referred to Veterans Health Administration (VHA) sleep disorder centers. METHODS: This retrospective cohort study used Veterans Health Administration records (1999-2022). A validated natural language processing pipeline extracted Apnea-Hypopnea Index (AHI) values from electronic medical records. Severe SA (s-SA, AHI ≥30) was compared with no SA (n-SA, AHI <5). Age was stratified as Young (≤40 years), Middle-aged (40-65 years), and Older adults (≥65 years). Multivariable logistic regression estimated odds ratios (ORs) for all-cause mortality, with sequential adjustment for demographic and clinical variables. RESULTS: Among 146,145 Veterans (13.2% female; mean age 52.2 years), s-SA was associated with higher unadjusted odds of mortality compared to n-SA in both sexes, which reversed after full adjustment in females (aOR:0.64, 95%CI: 0.54,0.76 and males (aOR:0.56, 95%CI: 0.54,0.58). Age-stratified analyses demonstrated no significant associations among young adults. In Middle-aged females and males, s-SA was associated with reduced mortality (aOR:0.78, 95%CI: 0.64,0.95 and 0.63, 95%CI: 0.6,0.67, respectively). This reduction in mortality was most pronounced in older adults of both sexes (females: aOR:0.28, 95%CI: 0.19-0.42; males: aOR:0.44, 95%CI: 0.42,0.47). CONCLUSION: In this large clinical cohort of Veterans referred for sleep studies at VHA centers, severe clinically diagnosed SA was associated with lower adjusted all-cause mortality in middle-aged and older adults, with similar patterns in females and males. Further research is needed to clarify underlying mechanisms and the role of treatment.