Evidence suggests an increasing apnea−hypopnea index (AHI) with aging. However, the effect of aging on sleep-related metrics, especially AHI, has been less frequently investigated within different gender-specific subpopulations by taking prominent confounding factors, e.g., obstructive sleep apnea (OSA)-related comorbidities and body mass index (BMI) into account. Therefore, we retrospectively analyzed 186 first-time polysomnographic (PSG) recordings and medical files of all patients presented to a tertiary university sleep center during a 1-year period. Six groups were formed based on age (over vs. under 55 years) and gender: PSG-related parameters (AHI, apnea-index, and hypopnea-index) were significantly higher in the older mixed-gender cohort (p = 0.0001, p = 0.0011, and p = 0.0015, respectively), and the older female cohort (p = 0.0005, p = 0.0027, and p = 0.001, respectively). Within the older male cohort, the AHI and apnea-index were significantly higher (p = 0.0067, and p = 0.0135, respectively). Inter-group comparison of the BMI showed no significant difference in any subpopulation. Within the older male cohort there were significantly more patients with arterial hypertension, diabetes mellitus, cardiovascular diseases, and chronic mental health disorders (p < 0.0001, p = 0.001, p = 0.0181, and p = 0.0454, respectively). Contrarily, within the female subpopulation there were no significant differences for the aforementioned comorbidities. In conclusion, all investigated sleep PSG-parameters increased among the older subpopulations. We suggest that Osa severity may increase with age due to the increasing accumulation of comorbidities in males, but not in females.
Keywords: age; apnea index; apnea–hypopnea index; hypopnea index; obstructive sleep apnea; obstructive sleep apnea and age.