Continuous positive airway pressure efficiency in apnoeic patients with resistant hypertension. Results from the randomised controlled RHOOSAS study

Objective Most of patients suffering from resistant hypertension (RH) have obstructive sleep apnea (OSA). However, little is known about the metabolic profile of these patients as well as the efficacy of continuous positive airway pressure (CPAP) in RH. Methods We performed a multicentre, comparative (presence or not of OSA), randomized, simple blind study in 62 patients with essential RH (24-hour daytime systolic BP (SBP) / diastolic BP (DBP): 145±13 / 85±10 mmHg, 3.7 antihypertensive drugs).OSA patients (AHI:37.6 [25.4; 51.8]/h(median [25 th ; 75 th percentiles]), n=37) were randomized to receive either sham CPAP (3-months,n=18)followed by active CPAP (6 months) or only 6 months of active CPAP (n=19). The primary endpoint was the influence of OSA on blood leptin level in patients with RH. The influence of OSA on BP and the impact of CPAP treatment were also studied. Results The 37 OSA patients with RH (60% of the 62 included patients) were predominantly men (87 vs 64% in non-OSA patients, p=0.038), with metabolic syndrome (84 vs 60%, p=0.036). Their blood leptin level was significantly lower than in non-OSA patients (9 [6; 15] vs 17 [6; 29] ng/mL, p =0.041).In intention to treat analysis, 3 months of CPAP decreased significantly nighttime SBP by 6.4 mmHg (p=0.033) and HR by 6.0 mmHg (p=0.010), compared to sham CPAP effect. Six months under effective CPAP also decreased nighttime BP and improved dipper profile. Conclusions It is important to investigate OSA in RH and to start CPAP treatment since besides its interest on sleepiness, CPAP is efficient to decrease nighttime BP in apneic patients suffering from RH.