Low levels of female sex hormones increase risk for sleep apnea symptoms

Low levels of serum estrogen and progesterone in middle-aged women were linked to a higher risk for obstructive sleep apnea symptoms, according to a population-based study published in PLOS ONE.

“Considering that [obstructive sleep apnea (OSA)] may lead to cardiovascular conditions (ischemic heart disease and stroke), which are among the greatest contributors to mortality worldwide, gaining a broader understanding of the reasons for the increased propensity of postmenopausal women to develop OSA is important,” Kai Triebner, PhD, a postdoctoral researcher at the University of Bergen in Norway at the time of the study, and colleagues wrote.

Triebner and colleagues studied 774 women (age range, 40 to 67 years) who completed the second follow-up of the European Community Respiratory Health Survey from 2010 to 2012 to determine if female sex hormones were associated with the prevalence of sleep apnea symptoms in women their age. Participants came from 15 study centers across seven countries.

The researchers used a respiratory health and lifestyle factors questionnaire, a sleep questionnaire, blood samples for hormone analyses and anthropometric measurements to examine participants. Participants self-reported snoring if they had ever been told they snored. If participants reported snoring, the researchers asked follow-up questions on irregular breathing, gasping and disturbing snore.

Triebner and colleagues created logistic regression models to assess the effect of serum estrogens and progesterone on snoring and sleep apnea-related outcomes.

Overall, when serum concentrations of estrogen and progesterone were doubled, the odds of snoring were decreased by 19% and 9%, respectively.

Within the cohort, 551 women reported snoring, and 411 of those answered affirmatively to at least one of the follow-up OSA questions.

Among women who snored, doubling of estrogens and progesterone were also associated with decreased odds of OSA symptoms. Specifically, a doubling of 17B-estradiol, estrone and estrone 3-sulfate were linked to 18%, 23% and 17% decreased odds of irregular breathing, and a doubling of progesterone was linked to 12% decreased odds of waking up suddenly with a choking sensation or gasping. No statistically significant associations were found for disturbing snore.

Sensitivity analyses confirmed these associations, and mutually adjusted models showed findings similar to the main analyses.

Triebner and colleagues wrote that more longitudinal studies are “highly warranted.”

“It is crucial to develop strategies to decrease the high prevalence and associated morbidity of OSA and adjusting female sex hormones levels might be the key to accomplish this, but further longitudinal studies with repeated measures of sex hormones and objective characterization of OSA are required to confirm our findings in other settings,” Triebner and colleagues wrote.