Women with lower levels of two sex hormones may be at increased risk of experiencing obstructive sleep apnea (OSA) in middle age, according to a new study.
The findings, published June 22 in PLOS ONE, showed that postmenopausal women with double the average estrogen concentration had as much as a 23% decrease in the odds of snoring. Women with double the average progesterone concentration had a 9% decrease in the odds of snoring.
"Our study is important, as it is another building block on the way to individualized hormone substitution for postmenopausal women," said Kai Triebner, PhD, postdoctoral fellow at the University of Bergen, Norway, and senior author of the article. "The observed associations had already been suspected by smaller studies, and now we finally were able to prove them in a large population-based cohort with very precise measurements of their hormone status."
OSA is marked by snoring, irregular breathing, and/or gasping. The condition can lead to poor sleep quality and is associated with an increased risk of cardiovascular conditions, including ischemic heart disease and stroke.
Previous studies have shown that estrogen and progesterone mitigate the symptoms of OSA. Triebner and his colleagues sought to evaluate the protective association between hormones and sleep on a population level.
The new study included 774 women (age, 40–67 years) from the 2010–2012 European Community Respiratory Health Survey. The women responded to two questionnaires about respiratory health and sleep and gave blood for hormone analysis of progesterone and three types of estrogen: 17β-estradiol, estrone, and estrone 3-sulfate.
Women with hormonal irregularities, such as endometriosis, and those taking exogenous sex hormones through replacement therapy or contraception were excluded from the study.
Among the total group, 551 reported snoring. Of those, 411 had additional symptoms of OSA, such as irregular breathing, gasping, or a disturbing snore. Triebner and his colleagues determined the average estrogen and progesterone concentrations of all women in the study. Women with double the average estrogen concentration had a 19% decrease in odds of snoring.
With regard to individual forms of estrogen, women with double the average serum concentration of 17β-estradiol, estrone, and estrone 3-sulfate had a 17% to 23% decrease in odds of breathing irregularity. Women with double the average serum concentration of progesterone had a 9% decrease in the odds of snoring and a 12% decrease in the odds of waking up with a choking or gasping sensation.
"By adjusting our model for BMI [body mass index] and alcohol consumption, we found that the results of the study [the effect of hormones on the risk of OSA] were not influenced," Triebner told Medscape Medical News.
Triebner's team did not give women exogenous estrogen or progesterone to observe individual changes in sleep behavior.
"The path to a good hormone replacement therapy is not yet paved," Triebner said. "What may be beneficial for one woman might be actually harmful to the other. The next steps are considerably more research on how to properly administer an individualized hormone therapy to women."
Vincent Joseph, PhD, a sleep researcher at Laval University, Quebec, Canada, said the findings were unsurprising.
"The mechanisms have been addressed, at least partially, in animal studies, showing effects on key structures in the brain and elements of the peripheral nervous system that are involved in the control of respiration," Joseph, who was not involved in the study, told Medscape.
However, the results provide a much stronger case to support the link between the variation of hormone levels and sleep apnea in women, Joseph added.
Triebner and Joseph reported no relevant financial relationships.
PLoS One. Published online June 22, 2022. Full text
Arianna Sarjoo is an intern at Medscape and a biology major at Boston University.
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Cite this: Lower Hormone Levels Linked to Risk of Sleep Apnea - Medscape - Jul 01, 2022.