CPAP Treatment Benefits Blood Pressure

Researchers from Spain have found that 12 weeks of continuous positive airway pressure (CPAP) treatment is associated with a decrease in 24-hour mean and diastolic blood pressure and an improvement in nocturnal blood pressure pattern in individuals with obstructive sleep apnea (OSA) and resistant hypertension. OSA has been shown to be a contributor to poor blood pressure control and is very common individuals with resistant hypertension, defined as hypertension that is not reduced despite the use of at least three antihypertensive drugs at optimal doses. “The results of the study are very important since more than 70-80% of resistant hypertension patients have sleep apnea,” said lead researcher Miguel-Angel Martínez-García, MD, PhD, Respiratory Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain. According to Martínez-García, theirs is the largest randomized clinical trial examining the effect of CPAP, the treatment of choice for OSA, in patients with resistant hypertension. The authors collected data on 194 patients with resistant hypertension and an apnea-hypopnea index of ≥15 from 2009 to 2011. Participants were randomly assigned to receive CPAP (n=98) or no CPAP (n=96) for 12 weeks. Their usual blood pressure control medications were maintained throughout the study. Compared with the control group, the CPAP group had a 3.1 mm Hg greater reduction in 24-hour mean blood pressure and a 3.2 mm Hg greater reduction in 24-hour diastolic blood pressure. There were no statistically significant differences in 24-hour systolic blood pressure between the groups. Martínez-García and colleagues also found that a nocturnal blood pressure dipper pattern was more common at the 12-week follow-up among those in the CPAP group than in the control group. A significant positive correlation was detected between hours of CPAP use and the decrease in 24-hour mean blood pressure and diastolic blood pressure. According to Martínez-García, the main message of the study is that all patients with resistant hypertension should undergo a sleep study to rule out a significant OSA. He explained that if the patient has sleep apnea, then treatment with CPAP could significantly reduce his or her blood pressure levels. He also pointed out that other studies have demonstrated CPAP’s protective effect of cardiovascular events. “Taken into account that most resistant hypertension patients will have at least one cardiovascular event during their lives, this highlights the importance of performing a sleep study in these patients and the treatment with CPAP when adequate,” he said. The authors concluded that further research is needed to assess longer-term health outcomes. Martínez-García noted that they are currently designing a study that will answer the following questions: • What are the effects of long-term CPAP treatment in patients with resistant hypertension? • Could the number of antihypertensive drugs that are taken by these patients be reduced with CPAP? • Is there a reduction in the number of future cardiovascular events in these patients with the use of CPAP? • What is the adherence to CPAP treatment in patients with resistant hypertension? The current study is available in JAMA. -Meredith Edwards White Reference Martinez-Garcia MA, Capote F, Campos-Rodriguez F, et al; Spanish Sleep Network. Effect of CPAP on blood pressure in patients with obstructive sleep apnea and resistant hypertension: the HIPARCO randomized clinical trial. JAMA. 2013 Dec 11;310(22):2407-15. doi: 10.1001/jama.2013.281250.