Masked hypertension may remain undetected despite non-elevated office blood pressure (BP), particularly in populations at higher cardiovascular risk. A pooled analysis of two cohort studies published in the Journal of Hypertension assessed the relationship between obstructive sleep apnea (OSA) and masked hypertension in Black adults with office BP <140/90 mmHg.

Data were derived from 1,078 participants enrolled in the Jackson Heart Study and the Coronary Artery Risk Development in Young Adults (CARDIA) study who completed 24-hour ambulatory BP monitoring (ABPM). Masked hypertension was defined as elevated awake BP ≥135/85 mmHg, asleep BP ≥120/70 mmHg, or 24-hour BP ≥130/80 mmHg.

A high likelihood of OSA was determined using sleep questionnaires and physical measurements. Associations were evaluated using Poisson regression models adjusted for demographic, lifestyle, and clinical factors, with analyses stratified by antihypertensive medication use.

Among participants, 34% had a high likelihood of OSA, and 53.3% met criteria for masked hypertension. In participants not taking antihypertensive medication (n=505), OSA likelihood was associated with a higher prevalence of any masked hypertension (PR 1.31; 95% CI 1.06-1.61), asleep masked hypertension (PR 1.37; 95% CI 1.09-1.73), and 24-hour masked hypertension (PR 1.35; 95% CI 1.00-1.83). No significant associations were observed among participants taking antihypertensive medication (n=573).

A higher likelihood of OSA was associated with increased masked hypertension prevalence among untreated participants.