A randomized controlled study of CPAP effect on plasma aldosterone concentration in patients with resistant hypertension and obstructive sleep apnea

Abstract

Seventy-eight patients completed the follow-up (36 CPAP, 42 conventional treatment); 58 had true resistant hypertension (74.3%), whereas 20 had white-coat resistant hypertension (25.6%). Most patients were men (70.7%), age 58.3 ± 9.4 years, and the mean apnea-hypopnea index was 50.1 ± 21.6. In patients with true resistant hypertension, CPAP achieved a significant decrease in most 24-h BP measurements and a nonsignificant decrease in PAC (25 ± 8.7 vs. 22.7 ± 9 ng/dl; P < 0.182). In patients with white-coat resistant hypertension, CPAP achieved a significant decrease in PAC (26.1 ± 11.2 vs. 18.9 ± 10.1 ng/dl; P < 0.041) and in night-time DBP. After adjustment, a weak but significant association was found between cumulative time spent with SaO2 below 90% (CT90%) and baseline PAC (P < 0.047, R 0.019), and between changes in PAC and changes in office DBP (P < 0.020, R 0.083) CONCLUSIONS:: Night-time hypoxemia and changes in DBP showed an association with baseline and changes in PAC, respectively. CPAP achieved a significant reduction in PAC only in patients with white-coat resistant hypertension, although the CPAP effect on BP was highest in patients with true resistant hypertension.

Obstructive sleep apnoea during REM sleep and incident non-dipping of nocturnal blood pressure: a longitudinal analysis of the Wisconsin Sleep Cohort

“…Although several cross-sectional studies have reported a higher prevalence of non-dipping in moderate to severe OSA,12 24 only one longitudinal population-based study has reported an association between OSA and incident non-dipping of systolic BP 11. The direction of causality is further strengthened by studies that have shown CPAP therapy to lower night-time BP more than daytime BP,13 25–27 particularly in patients with resistant hypertension who are adherent to CPAP therapy 28 29. We previously reported that in the Wisconsin Sleep Cohort, total AHI severity was associated with nocturnal systolic, but not diastolic, dipping; however, that study did not attempt to differentiate between REM and NREM AHI 11.…”

Obstructive sleep apnea syndrome, continuous positive airway pressure and treatment of hypertension

“…Several randomized trials of therapeutic CPAP of up to 6 months in duration have been conducted (30,(95)(96)(97) and their collective findings presented in recent meta-analyses (98,99). The authors of a Spanish trial in which a subset (41 patients) had ambulatory monitoring confirmed drug-resistant hypertension reported a significant 10/7 mm Hg reduction in 24 hour blood pressure, a 6 mm Hg reduction in daytime diastolic blood pressure, and a greater prevalence of a 'dipping' pattern of blood pressure at night but only if CPAP was used for more than 5.8 hours nightly (97).…”

“…Reductions in all representations of blood pressure were proportionate to CPAP use. Lloberes et al(95) allocated randomly 102 patients with both drugresistant hypertension and an AHI > 15 events/hour to CPAP or no CPAP. Of these 78 completed a 3 month follow-up.…”

Obstructive Sleep Apnoea and Vascular Disease in Patients with Type 2 Diabetes

“…18 However, not all studies showed similar results; in recent RCTs 3-6 months of CPAP had no impact on BP in patients with moderate to severe OSA and resistant hypertension. 19,20 Furthermore, in an 8-week RCT with a crossover design, both CPAP and valsartan resulted in a significant reduction in mean 24-hour BP but valsartan was superior to CPAP (−7.0 mm Hg, 95 % CI −10.9 to −3.1 mm Hg; p<0.001). 21 The impact of CPAP on incident hypertension was assessed in one RCT, in which 723 patients with AHI ≥20 and ESS ≤10 were randomised to CPAP versus no CPAP.…”