Fixed-pressure CPAP versus auto-adjusting CPAP: comparison of efficacy on blood pressure in obstructive sleep apnoea, a randomised clinical trial

Abstract

NCT01090297.

Efficacy of CPAP modalities in lowering blood pressure in OSA: does the method used to measure blood pressure matter?

“…It is important to note that in the study by Patruno et al 8 the patients started with a significantly higher level of BP than the study by Pepin et al (mean BP 143/87 vs 132.5/80 mm Hg, respectively). Moreover, 65% of the participants in the study by Pepin et al 7 were hypertensive at baseline. Although the number of subjects with hypertension was equally distributed between FP-CPAP and auto-CPAP groups, it is not clear whether equal numbers of patients in each group were on antihypertensive medications.…”

“…Pepin et al 7 conducted the largest double-blind randomised-controlled trial (RCT) to date comparing the efficacy of 4 months of therapy with fixed-pressure CPAP (FP-CPAP, n=161) versus auto-adjusting CPAP (auto-CPAP, n=161) in reducing BP in patients with moderate-to-severe obstructive sleep apnoea (OSA). In an intention-to-treat analysis, there was no difference in the primary outcome of change in office systolic BP between FP-CPAP and auto-CPAP groups.…”

“…Pepin et al 7 estimated their sample size and set their a priori primary end point of office BP based on a prior smaller RCT by Patruno et al, 8 which found a significant change in office BP with FP-CPAP but not with auto-CPAP after 3 months of therapy. It is important to note that in the study by Patruno et al 8 the patients started with a significantly higher level of BP than the study by Pepin et al (mean BP 143/87 vs 132.5/80 mm Hg, respectively).…”

Effects of sleep apnoea therapy on blood pressure and metabolism: a CPAP sex gap?

“…Although the minimum threshold of CPAP adherence needed to obtain a clinically significant blood pressure reduction is unknown, improving CPAP compliance may contribute to improving blood pressure control, especially by avoiding residual rapid eye movement-related sleep disordered breathing at the end of the night [22]. The superiority of fixed pressure CPAP over auto-CPAP in reducing 24-h blood pressure might also be of particular interest in OSA patients with poorly controlled or resistant hypertension [17]. Considering the multifactorial pathophysiology of OSA-associated hypertension, the combination of CPAP therapy, antihypertensive drugs and weight-loss interventions appears to be the most promising strategy to improve blood pressure control in OSA patients [18].…”

“…Among included patients, 31% satisfied the hypertension criteria at baseline and 55% were on antihypertensive medication. The study has a number of important strengths including a large sample size, a multicentre design, the use of fixed pressure CPAP (which has been found to be more effective than auto-CPAP in reducing 24 h diastolic BP [17]) and a relatively high rate of CPAP compliance with 75% of participants using the device for at least 4 h per night. The main limitation of the study is the use of office rather than 24-h ambulatory blood pressure monitoring, which is considered the reference standard for the diagnosis of hypertension, particularly in OSA patients in whom hypertension is predominantly nocturnal [8].…”