Sleep apnea syndrome in women: what are the particularities?

Often unrecognized and under-diagnosed, particularly in women, sleep apnea syndrome is not without consequences for quality of life and cardiovascular function (1). The prevalence and severity of this syndrome are influenced by changes in hormone levels over the course of a woman's life.
Admittedly, sleep apnea syndrome (SAS) is less common in women than in men (49% in men and 23% in women) in the general population (2). However, after the menopause, the difference in prevalence between men and women decreases markedly, both because of the fall in female hormone levels and because of the weight gain often associated with it. During pregnancy, prevalence also increases, rising to 28% in the last trimester.
The difference between men and women is primarily anatomical. Women have a narrower air space in the upper airways, but with less collapsing and less fatty distribution in the pharynx. However, during pregnancy, the increase in estrogen causes edema in the upper airways, facilitating their closure, which is also favored by the destabilization of the respiratory centers due to progesterone impregnation. During pregnancy, especially in the final months, respiratory mechanics are further modified by the increase in uterine volume and the reduction in lung volumes due to diaphragm compression.
Clinical symptoms in women are often less typical than in men, and can be misleading, as there are few complaints of hypersomnia or snoring, even if these signs do exist. Instead, the signs are more general, such as fatigue, lack of energy, depressive tendencies, insomnia and nightmares. This diagnosis should be considered and evoked, especially in cases of overweight, metabolic syndrome or simple hypertension. Sleep apnoea syndrome is often more severe in post-menopausal women, probably due to weight gain, hormonal changes and greater collapsibility of the VAS.
Cardiovascular complications are frequent, with increased risk of hypertension, stroke and heart attack. Women at "high cardiovascular risk" present moderate to severe SAS 4 times more often than others, and should therefore be systematically screened for SAS. During pregnancy, sleep-disordered breathing considerably increases the risk of eclampsia and gestational diabetes. They also have a major impact on fetal blood supply, leading to intrauterine growth retardation and a high risk of prematurity.
Treatment of sleep apnea syndrome is therefore essential, given the morbidity and mortality associated with the condition, particularly cardiovascular, and the deterioration in quality of life. The treatment is based on a combination of healthy dietary habits, including weight loss and good sleep hygiene, and more specific treatment of respiratory disorders using either continuous positive airway pressure (CPAP) or a mandibular advancement orthosis (M.A.O.). The choice of these treatments is guided by both the severity of SAS (level of apnea-hypopnea index) and the anatomical configuration of the upper airways. In the case of pregnancy, treatment may in some cases be transient, as SAS may regress following delivery.

1- Drager LF et al. INCOSACT Initiative (International Collaboration of SLEEP Apnea Cardiovascular Trialist). Sleep apnea and cardiovascular disease: lessons from recent trial and need for team science. Circulation 2017;136 (19):1840-50
2- Heinze R et al. Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study. Lancet Repir Med 2015;3(4):310-8