Abstract 15486: Spironolactone Reduces Severity of Obstructive Sleep Apnea in Resistant Hypertension
Purpose: Plasma aldosterone levels are positively correlated with obstructive sleep apnea (OSA) severity in patients with resistant HTN but not in normotensive patients. This suggests a mechanistic interaction between OSA and aldosterone excess in resistant HTN patients. We hypothesized that aldosterone excess in resistant HTN patients worsens OSA. If true, the use of a mineralocorticoid antagonist like spironolactone would reduce OSA severity in patients with resistant HTN, and thereby enhance the treatment of OSA.
Methods: Adults with resistant HTN defined as an office BP > 140/90 mm Hg on 3 or more antihypertensive medications and symptoms of OSA were identified in a referral HTN clinic. Participants with an apnea-hypopnea index (AHI) ≥ 15 events/hr during a full-night diagnostic polysomnogram were enrolled. Sixteen subjects were randomized in open-label fashion to either spironolactone 25-50 mg daily or routine care (addition/titration of antihypertensive medications). Office BP, 24 hour ambulatory BP monitoring, and a diagnostic polysomnogram were performed at baseline and at 3 months.
Results: Baseline characteristics were similar between the 8 control patients and the 8 patients receiving spironolactone. Control and spironolactone group mean baseline values include: body mass index of 36.8 and 35.7 (kg/m2), 24 hour urine aldosterone of 12.9 and 12.9 (mcg), ambulatory systolic BP of 149.6 and 143.3 (mm Hg), and AHI of 31.1 and 42.8 (events/hr), respectively. Differences in baseline and 3 month office BP, ambulatory BP, and AHI were not statistically different in the control group. In the group receiving spironolactone statistically significant mean differences were seen with AHI (18.3 events/hr, p 0.015) by the paired t-test (Figure 1).
Conclusions:Treatment with spironolactone reduces the severity of OSA in patients with resistant HTN, supporting the hypothesis that aldosterone excess worsens OSA.
- © 2012 by American Heart Association, Inc.