CPAP Lowered Heart Rate in Prediabetics with Sleep Apnea

— Magnitude of reductions in comparable to beta-blockers, researchers say

MedicalToday

SAN DIEGO -- Treating sleep apnea aggressively in patients who also showed early signs of diabetes appeared to lower cardiovascular disease risk, researchers reported here.

Mean daytime resting heart rate profiles were significantly lower in pre-diabetic obstructive sleep apnea (OSA) patients treated with continuous-positive airway pressure (CPAP) versus treatment with placebo (P=0.04), with the largest differences during the second week of treatment, according to Esra Tasali, MD, of the Sleep Research Center at the University of Chicago, and colleagues.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Similar effects of CPAP were also observed during nighttime (P=0.002), they reported at the American Thoracic Society annual meeting.

The effect observed in the preliminary study was similar to that seen in patients taking beta blockers, the researchers added.

"OSA is exceedingly common among individuals with abnormal glucose tolerance," Tasali said.

His group previously reported that CPAP treatment improved glucose metabolism and reduced plasma norephinephine levels in a randomized trial involving the of 39 prediabetic patients with OSA.

In the current study, they assessed the impact of all-night CPAP on resting heart rate during 14 consecutive days and nights.

In an effort to control for the effects of physical activity on heart rate, the researchers analyzed daytime data from rest periods only. Nighttime data (bedtimes 11 p.m. to 7 a.m.) included only the sleep period excluding all wake epochs.

Mixed-effects linear modelling was used to determine the impact of CPAP versus placebo over 14 consecutive treatment days on activity and resting heart rate, while adjusting for baseline values and gender.

Physical activity and heart rate were monitored for 24-hours before CPAP or placebo use (baseline) and during 14 consecutive treatment days using an ambulatory device consisting of tri-axial accelerometer and one-lead ECG.

The participants were randomized to either CPAP (n=26) or placebo tablet (n=13). Daytime activity counts at rest were not significantly different between groups (P=0.77).

"Our study is a first step in demonstrating that optimal treatment of sleep apnea reduces cardiovascular risk in those with prediabetes," Tasali said.

Primary Source

American Thoracic Society

Pamidi S, et al "All-Night CPAP Treatment Reduces 24-Hour Resting Heart Rate in Prediabetes: A Randomized Placebo-Controlled Study" ATS 2018; Abstract 13808.