Abstract P348: Association Between Sleep Apnea and Blood Pressure Control Among African-Americans, the Jackson Heart Study

Abstract

Background: African-Americans have the highest prevalence of elevated blood pressure (BP) and poorer BP control than other racial/ethnic groups in the US. Untreated sleep apnea, common among minority populations, may explain the high prevalence of uncontrolled BP. We studied the association of objective measurements of sleep apnea severity with resistant hypertension and uncontrolled BP among African-Americans in the Jackson Heart Study (JHS) Sleep Ancillary study. Methods: Between 2012 and 2016, JHS participants (N=913) underwent an in-home sleep apnea study (measuring nasal pressure, abdominal and thoracic inductance plethysmography, oximetry, position, ECG); resting blood pressure; anthropometry; and completed questionnaires. Sleep apnea was defined as an apnea-hypopnea index > 15 and nocturnal hypoxemia was quantified as % sleep time <90% oxyhemoglobin saturation (%Sat<90%). Elevated BP was defined as systolic BP ≥ 140 mmHg or diastolic BP > 90mmHg. Controlled BP was defined as systolic BP <140mmHg or diastolic BP <90mmHg. Uncontrolled BP was defined as having elevated BP with use of < 2 antihypertensive medications. Resistant hypertension was defined as having elevated BP while on 3-4 antihypertensive medications with one being a diuretic; or use of > 4 antihypertensive medications. The study sample was limited to individuals with prevalent hypertension (N=613). Multinomial models were fit to determine the association between sleep apnea severity and resistant hypertension or uncontrolled BP (vs. controlled BP) adjusted for age, sex, education, smoking status, obesity (body mass index>30) and diabetes. Results: The study sample had a mean age of 54.8 years, were predominately female (69.8%), obese (57.8%), and college educated (52.7%). Approximately 40.5% had sleep apnea, which was untreated in 95% of individuals. Among the sample, 25.4% had uncontrolled BP and 4.9% were classified as resistant hypertension. After adjustment for confounders, individuals with sleep apnea had a 2.6-fold higher odds of resistant hypertension (95% confidence interval: 1.1, 5.9). A standard deviation higher %Sat<90% was associated with a 41% higher odds (1.1, 1.8) of resistant hypertension after adjustment for covariates. Sleep apnea and %Sat<90% were not related to uncontrolled BP. Conclusion: Among our sample of African-Americans in the JHS, sleep apnea was related to resistant hypertension but not uncontrolled BP. The study identifies the high burden of untreated sleep apnea in African-Americans and its association with resistant hypertension, a significant risk factor for stroke and heart disease. Research is needed on the impact of treating sleep apnea as a strategy for decreasing resistant hypertension, and thus, narrowing cardiovascular health disparities.