A face mask used to treat a nighttime breathing disorder called obstructive sleep apnea can reduce a patient’s blood pressure, cholesterol and stomach fat, potentially improving their heart health, researchers found.
The condition affects as many as 18 million Americans, primarily men, and is often first recognized by the patient’s partner. It is marked by a brief collapse of the airway, which leads the patient to stop breathing for a few seconds until the brain sends a signal to wake up. The result is a fractured night’s sleep, daytime drowsiness and a host of health issues.
Standard treatment is a mask attached to a continuous positive airway pressure, or CPAP, machine. The machines can be cumbersome, leading many to quit using them within a year. The results should help persuade patients to stick with the therapy, said Surendra Sharma, lead author of the study released today by the New England Journal of Medicine.
“These patients need to be properly counseled for regular use of CPAP machines,” because compliance is associated with greater benefits, said Sharma, head of the department of internal medicine at the All India Institute of Medical Sciences in New Delhi, in an e-mailed response to questions. “In a real-life situation, the machine will be used for a longer period and more benefits will be observed.”
Pfizer Inc. funded the trial through an investigator-initiated research grant. The New York-based company, the world’s largest drugmaker, doesn’t manufacture or sell devices for sleep apnea and wasn’t involved in the design, conduct or analysis of the study, the researchers said.
The global market to diagnose and treat patients with sleep apnea is about $2.9 billion and growing, with CPAP devices accounting for about one-third of the total, according to Global Industry Analysts Inc., a market research firm based in San Jose, California. Amsterdam-based Royal Philips Electronics NV, ResMed Inc. of Poway, California, and Fisher & Paykel Healthcare Corp. of Auckland, dominate the industry.
The study involved 86 patients recruited from the sleep laboratory at the All India Institute of Medical Sciences. They were treated with either a legitimate CPAP machine or a doctored device that included an airflow-restricting connector and tiny escape holes. Patients used each of the machines, which looked the same, for three months, with a one-month break between treatment.
After treatment, patients’ systolic blood pressure, measured during heart contractions, dropped an average of 3.9 millimeters of mercury or mmHg, while their diastolic blood pressure, when the heart fills with blood, fell by 2.5 mmHg. Previous studies of drug treatment found a 5 mmHg decline cut heart disease risk by 15 percent and strokes by 42 percent.
The CPAP machines also reduced total cholesterol by 13.3 mg per deciliter and artery-clogging bad cholesterol by 9.6 mg per deciliter, the study found. Benefits also were seen in abdominal fat content, weight loss and improved hemoglobin levels, the researchers said.
A constellation of heart risk factors, known as the metabolic syndrome, also appeared to reverse in 11 of the 86 patients after CPAP treatment. Those who were most adherent to the therapy showed a reduction in plaque buildup in the walls of the arteries leading to the brain, the study found.
“These results suggest a significant clinical benefit that will lead to a reduction in cardiovascular risk,” the investigators concluded.