AIM: To analyze sex differences in age trajectories of supine positional obstructive sleep apnea (POSA). METHODS: We conducted retrospective analysis of polysomnography studies from 13,144 individuals aged from 2 to 103 years with at least 30 min of both supine and lateral sleep. We used generalized linear mixed-effects models to estimate position-specific mean apnea-hypopnea index (AHI) values and logistic regression to estimate the proportion with POSA or with exclusive POSA among individuals with obstructive sleep apnea (OSA). Predictors included sex, 5-y age group, sleep position, and their interactions. RESULTS: Supine AHI was higher than lateral AHI regardless of age or sex except under age 5 y. The ratio of supine AHI to lateral AHI reliably exceeded 2 after age 30-35 in males and age 50-55 in females. For both sexes, the proportion with POSA among individuals with OSA increased rapidly with age until 30-35 and then stabilized. The proportion with POSA among individuals with OSA was significantly higher in males than females for each age group between 40 and 75 (p <
0.03). Among individuals with OSA in those 20 and older, the proportion with POSA was 64.6% (95% CI: 62.7%, 66.5%) in males and 55.8% (95% CI: 53.6%, 57.8%) in females. The proportion of individuals showing exclusive POSA also increased with age and peaked near 41% at age 15-20 in males and at age 20-25 in females. CONCLUSION: POSA becomes more common with age in both sexes
in women, its prevalence is generally lower but continues to increase after age 65.