More Sleep Apnea Patients Reverse Metabolic Syndrome with CPAP

May 19, 2020
Kevin Kunzmann

A six-month study shows the common OSA therapy could have long-term benefit for reducing eventual cardiovascular risk.

Patients with metabolic syndrome and obstructive sleep apnea (OSA) are more likely to reverse the former if they treat the latter with a continuous positive airway pressure (CPAP) device.

A new study planned for presentation at the American Thoracic Society (ATS) 2020 International Conference this year showed the commonly primary treatment of OSA could have a five-fold greater probability of reversing metabolic syndrome—a clinical achievement linked to decreased cardiovascular risk.

A team of investigators from cardiovascular, hypertension, and sleep units at the Sao Paulo Medical School in Brazil noted that OSA is a frequently diagnosed condition in patients with metabolic syndrome, and may even drive components of the disease. The team considered the value of directly treating one condition to better both.

“This investigation was aimed to evaluate whether OSA treatment with CPAP would modify metabolic syndrome and related metabolic/body composition status,” they wrote.

Investigators conducted the randomized, placebo-controlled trial in patients with National Cholesterol Education Program (NCEP) III-defined metabolic syndrome, as well as moderate to severe OSA—defined as apnea-hypopnea index (AHI) ≥15 events per hour by polysomnography. Qualified patients were additionally non-smokers without any current medication.

A pool of 100 patients underwent either 6 months of therapeutic CPAP or a control therapy of nasal strips. Prior to care, they were measured for anthropometric variables, blood pressure (BP), fasting blood glucose levels, lipid profile, body composition, physical activity, food intake, and visceral fat.

The team sought a primary endpoint of metabolic syndrome reversibility in patients with moderate to severe OSA. Secondary endpoints included CPAP’s impact on the syndrome, body composition, physical activity, food intake, and visceral fat.

Mean patient age was 48±9 years old, with a body mass index (BMI) of 33±4. Most patients were male (79%), and mean Epworth Sleepiness Scale scores at baseline were 13±5.

In the treatment group, mean adherence to CPAP was 5.7±1.5 hours per night. The device was associated with significant improvements in OSA severity, as well as hypoxemic parameters and daytime somnolence. Control patients only improved in daytime somnolence, investigators noted.

At 6 months, 18% of CPAP-treated patients reversed their metabolic syndrome, versus just 4% of control patients (OR, 5.27; 95% CI, 1.27-35.85; P = .04).

The mean number of metabolic syndrome components in treated patients dropped from 3.7±0.6 at baseline to 3.2±0.9 at 6 months—as opposed to the increase from 3.7±0.6 to 3.8±0.8 observed in the placebo group (P = .01).

Improvements to patient BP, investigators noted, largely drove this change in components. Systolic BP (-7±12mmHg vs -2±11mmHg; P = .03) and diastolic BP (-5.8±mmgHg vs -1±8mmHg; P = .01) changes were significantly better in CPAP-treated patients than control.

Neither group reported significant changes to mean BMI, food intake, physical activity, body composition, or visceral fat.

The association between cardiometabolic risk and OSA is a stressed topic at past and current ATS meetings. Last year, at ATS 2019 in Dallas, TX, Mount Sinai investigator Neomi Shah, MD, MPH explained to HCPLive® the distinction of sleep apnea as an independent risk factor for cardiovascular disease has been established for 2 decades now.

It’s been linked to lethal events including stroke, arrhythmias, sudden cardiac events, atrial fibrillation, and myocardial infarction.

“But unfortunately, in the recent few years, the clinical trials in that we're trying to treat the sleep apnea condition with CPAP, therapy did not reduce the occurrence of some of these events,” Shah said.

These new findings from Brazil show the common OSA therapy may at least benefit a closely associated condition.

“In patients with MS and OSA, 6 months of CPAP therapy is able to promote five-fold increase chance to reverse MS,” investigators concluded. “This effect was not explained by changes in weight, adiposity, physical activity or food intake.”

The study, "Effects of CPAP on Metabolic Syndrome in Patients with Obstructive Sleep Apnea: The TREATOSA-MS Randomized Controlled Trial," was published online by ATS.