Obstructive sleep apnea severity and morning hypertension in children: Age-stratified associations across...

Obstructive sleep apnea (OSA) is common in children and has been linked to cardiovascular dysregulation, including elevated blood pressure (BP). This study examined whether OSA severity is independently associated with morning hypertension in a pediatric clinical cohort, and whether associations vary by developmental stage and sex. We retrospectively analyzed 806 children aged 1 to 18 years (55.2% Male) who underwent overnight polysomnography (PSG) and had BP recorded before and after the PSG at the University of Louisville and Norton Pediatric Sleep Center. OSA was categorized based on the total apnea hypopnea index (AHI) and severity was categorized based on the obstructive apnea hypopnea index (OAHI) the cohort was stratified as: normal/snoring (OAHI < 1 event/hr, n = 318), mild OSA (OAHI 1-4.9 events/hr, n = 205), moderate OSA (OAHI 5-9.9 events/hr, n = 103), and severe OSA (OAHI ≥ 10 events/hr, n = 180). Evening and morning blood pressures were recorded and classified per American Academy of Pediatrics guidelines. ANOVA/ANCOVA, linear regression, and multivariable logistic regression examined associations between the total AHI and blood pressure, with adjustment for age, sex, body mass index (BMI) z-score, and comorbidities. Morning systolic blood pressure (SBP) rose from 108 ± 13 mmHg in non-OSA children to 118 ± 15 mmHg in severe OSA. Severe OSA more than doubled the odds of morning hypertension across all adjusted models (OR 2.35; 95% CI 1.57-3.52, p < 0.001). Each 1-unit increase in AHI was associated with a 0.137 mmHg rise in morning SBP after adjustment (p < 0.001). Moderate OSA's association was attenuated after BMI adjustment, while BMI z-score itself was an independent predictor of BP grade (OR 1.52; 95% CI 1.27-1.82; p < 0.001). Participants were categorized by developmental age. Subgroup analyses found the strongest association between AHI and systolic blood pressure in preschool children, while the link with diastolic blood pressure appeared only in older groups. Sex-stratified analyses showed similar AHI-blood pressure associations in both males and females, with no significant interaction. Severe OSA independently increased the risk of morning hypertension in children, regardless of obesity status, sex, or developmental stage. Routine BP monitoring is warranted across the full OSA severity spectrum.