People tend to have more severe sleep apnea—the disorder that interrupts breathing during sleep—in winter than they do in warmer months, suggests a Brazilian study. Researchers reviewed the records of 7,523 patients who sought help for a sleep disorder at one sleep clinic over 10 years. They found that patients tested in the colder months had more breaks in breathing than those tested in warm weather.

Although the study couldn't establish a direct causal link to worsening apnea in winter, the authors think part of the reason may be due to seasonal factors such as winter-related upper-airway problems and fumes from wood burning to heat homes.

They also found an association between the increase in sleep apnea severity and atmospheric pressure, air humidity and carbon monoxide levels.

Source: Chest, published online June 2012; Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at

Published: 21 Jul 2013

Last Modified: 27 Feb 2015