Association of severe obstructive sleep apnea and elevated blood pressure despite antihypertensive medication use.
Level 4 - case-series / case-control
Cross-sectional observational analysis of baseline data from a randomized trial cohort
PubMed 25126027 · doi:10.5664/jcsm.3946
What was done
Baseline data from 284 participants in the Heart Biomarker Evaluation in Apnea Treatment (HeartBEAT) randomized controlled trial were analyzed. Participants had high cardiovascular disease risk, hypertension, and moderate-to-severe obstructive sleep apnea (OSA, apnea-hypopnea index [AHI] 15–50). Intensive antihypertensive regimen (IAR) was defined as ≥ 3 antihypertensives including a diuretic. Blood pressure (BP) control was categorized as controlled (BP < 130/80 mm Hg), uncontrolled elevated (BP ≥ 130/80 mm Hg without IAR), or resistant elevated (BP ≥ 130/80 mm Hg despite IAR). Associations between untreated severe OSA (AHI ≥ 30) and BP categories were analyzed using multivariable logistic regression adjusted for age, sex, race, body mass index, smoking status, diabetes, and cardiovascular disease.
What was found
Among the 284 participants (mean age 63.1 ± 7.2 years, 23.6% with severe OSA), 61.6% had controlled BP, 28.5% had uncontrolled elevated BP, and 9.9% had resistant elevated BP. Among participants prescribed IAR, resistant elevated BP was significantly more prevalent in those with severe compared to moderate OSA (58.3% vs. 28.6%, p = 0.01). Severe OSA was associated with higher adjusted odds of resistant elevated BP (OR 4.1, 95% CI: 1.7–10.2), an association not observed in participants not taking IAR.
Why it matters
This study demonstrates that severe OSA is strongly associated with resistant hypertension in cardiology patients, highlighting sleep apnea as a major potential contributor to poor blood pressure control despite multi-drug therapy.
Limits
The cross-sectional baseline design precludes establishing causal or temporal relationships. The sample size was modest (n = 284) with only 9.9% meeting criteria for resistant elevated BP, resulting in wide confidence intervals. Medication adherence was not evaluated in the abstract. Results from high-cardiovascular-risk patients recruited from cardiology practices may not generalize to broader populations.
Cited by
- supports Severe sleep apnea is defined clinically as 30 or more respiratory events per hour.