Sex- and age-related heterogeneity in obstructive sleep apnea phenotypes in a predominantly Afro-Caribbean population

Obstructive sleep apnea (OSA) shows wide variability in clinical presentation. Sex-related differences in symptom expression are increasingly recognized, but the contribution of age and respiratory event composition remains insufficiently explored in underrepresented populations. To describe sex- and age-related heterogeneity in clinical and respiratory phenotypes of OSA in a predominantly Afro-Caribbean population referred to a tertiary sleep center. We conducted a cross-sectional study of consecutive adults evaluated for suspected OSA at a tertiary sleep center (July 2024-June 2025). Clinical characteristics, symptom profiles, and respiratory indices were compared by sex and age (< 65 vs ≥ 65 years). Multivariable models adjusting for BMI and age assessed whether sex differences were independent of these factors. Among 213 patients evaluated, 189 had OSA (women: 61.4%, n = 116). Women had a higher BMI than men (31.4 vs 27.6 kg·m −2 , p < 0.001) and a lower respiratory event burden, with a lower apnea index and oxygen desaturation index but a higher relative contribution of hypopneas to the AHI (all p ≤ 0.045). Women also reported more insomnia (68.1% vs 49.2%, p = 0.02) and higher fatigue scores ( p = 0.02), with no significant difference in daytime sleepiness. After adjustment for age and BMI, these sex differences in respiratory indices persisted (all p ≤ 0.002), while the fatigue association was attenuated ( p = 0.08). Age ≥ 65 years was independently associated with a higher AHI, apnea index and ODI, a lower hypopnea/AHI ratio, and lower odds of excessive daytime sleepiness (adjusted OR 0.32, p = 0.002), patterns masked in unadjusted comparisons. A sex × age interaction was significant only for insomnia ( p = 0.007): the sex difference was confined to patients ≥ 65 years (adjusted OR 9.12) and absent in younger patients (adjusted OR 1.20). OSA phenotypes in this Caribbean population show marked heterogeneity by sex and respiratory event composition, largely independent of BMI and age. Age modulated daytime sleepiness, respiratory composition, and the sex-related difference in insomnia, which was concentrated among older patients. Reliance on daytime sleepiness alone may underestimate OSA burden in women, older patients, and hypopnea-dominant phenotypes, supporting a more phenotype- and age-based approach to screening.