PURPOSE: Obstructive sleep apnea (OSA) is commonly associated with hypertension. Purpose of our study was to compare occurrence of OSA in patients with resistant hypertension and in those with optimally controlled hypertension.
METHODS: DESIGN: Case-control study. SETTING: Referral sleep laboratory and hypertension clinic at Government Medical College and Hospital, Chandigarh, India. DURATION: 13 months. PATIENTS: Out of 86 referred hypertensive patients, 37 patients of resistant hypertension [BP ≥ 140/90 mm of Hg despite using at least three antihypertensive drugs, including a diuretic] and 30 patients with controlled hypertension receiving antihypertensive medications, were included in the study. MEASUREMENTS: Overnight polysomnography was done in all selected patients. Obstructive sleep apnea was defined as apnea-hypopnea index of more than 5.
RESULTS: Twenty out of 37 (54.05%) patients of resistant hypertension and 5 out of 30 (16.67%) patients of controlled hypertension had OSA (p < 0.005). Among patients of resistant hypertension, 10 out of 15 (66.67%) men and 10 out of 22 (45.45%) women had OSA (P =0.20).
CONCLUSION: To best of our knowledge, this is the first study of its kind in a sleep laboratory setting which concluded that OSA was significantly higher in patients of resistant hypertension than in those with controlled hypertension. However, there was no statistically significant gender difference for OSA amongst resistant hypertension patients.
CLINICAL IMPLICATIONS: The patients of resistant hypertension should preferably be evaluated for OSA.
DISCLOSURE: Anup Singh, No Financial Disclosure Information; No Product/Research Disclosure Information