Sleep apnea gets worse in colder months, study says

NEW YORK - Reuters

Changes in weight an seasonal allergies can affect sleep apnea, according to new study. Hürriyet Photo

Respiration problems in sleep apnea, which causes people to momentarily stop breathing multiple times throughout the night, for seconds to minutes at a time, appear to worsen during the colder months of the year, according to a study from Brazil.

Changes in weight and seasonal allergies can affect sleep apnea, and researchers writing in the journal Chest wanted to see if weather changes might also have an impact.

“More sleep disordered breathing events were recorded in wintertime than in other seasons,” wrote study leader Cristiane Maria Cassol from the Universidade Federal do Rio Grande do Sul.

Winter-related problems

Cassol and her team said it could be due to several causes, including winter-related upper-airway problems that intensify the severity of symptoms and the use of burning wood to heat homes during the winter.

The team utilized data from sleep clinic patients and looked at how many times their rest was disturbed by breaks in breathing. The study included one night of sleep for more than 7,500 patients over a 10-year-period. Researchers then compared the severity of the patients’ apnea to the weather conditions at the time, including humidity, temperature and air pollution.

Patients who came in during colder months had more nighttime breaks in breathing than those who sought treatment during warmer months. During the winter, patients stopped breathing an average of 18 times an hour compared to 15 times an hour during the summer.

30 times an hour

Similarly, the sleep clinic was more likely to see the most severe cases, people who stopped breathing more than 30 times an hour, during the colder months.

About 34 percent of patients who came in during cold weather had severe apnea, compared to 28 percent of patients during warmer weather.

The team found that certain weather conditions, such as high atmospheric pressure and humidity and high levels of the air pollutant carbon monoxide were tied to worse cases of apnea.