Effect of 3-month CPAP treatment on blood pressure and serum aldosterone concentration in patients with resistant hypertension

Introduction: The role of the renin-angiotensin-aldosterone system (RAAS) on the association obstructive sleep apnea (OSA) and resistant hypertension (RH) is unclear. Aim: To analyze the effect of CPAP on 24-h blood pressure monitoring (ABPM) and on serum aldosterone in RH patients. Methods: 102 patients with an OSA15 and office-RH were randomized to CPAP (n=50) or to conventional treatment (n=52) for 3 months. 24-h ABPM and serum aldosterone were measured. 78 patients completed the follow-up (36 CPAP, 42 conventional treatment). Results: 66.7% were male, aged 58.27±9.3yrs and AHI 50.1±21.6, without significant differences between both groups. Serum aldosterone and AHI correlated significantly in patients with ABPM-confirmed RH (r= 0.25, p=0.02). CPAP achieved a significant decrease in serum aldosterone and 24-h BP decreased especially in those with ABPM-confirmed RH. Conclusion: The association between OSA and RH could be mediated at least in part by an effect on the RAAS.