Gender differences in sleep disordered breathing: implications for therapy

Abstract

There are gender differences in the upper airway function and respiratory stability in obstructive sleep apnea (OSA). Hormones are implicated in some gender-related differences, and these differences between men and women appear to mitigate as age increases. In addition, changes in the airway and lung function during pregnancy can contribute to snoring and OSA that might have an adverse effect on the mother and fetus. The limited data available suggest that although the prevalence and severity of OSA may be lower in women, the consequences of the disease are similar, if not worse. Women with OSA may have greater risk for hypertension and endothelial dysfunction, be more likely to develop comorbid conditions such as anxiety and depression and have increased mortality. Therefore, treatment options specifically targeting female presentations and pathophysiology of sleep-disordered breathing (SDB) are expected to result in improved outcomes in women.

Keywords:

• gender
• positive airway pressure
• sleep apnea
• sleep-disordered breathing
• women

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• It has been suggested that discrepancies in obstructive sleep apnea (OSA) prevalence between men and women may arise from misdiagnosis or underdiagnosis of the disorder in women. More than 90% of women with OSA may not be clinically diagnosed. Reasons for this may include gender-related differences in presenting symptoms such as women being less likely to present with snoring or witnessed apneas, which may make the diagnosis more challenging in women.

• Women with SDB have different polysomnographic abnormalities. Women have greater proportion of REM AHI compared with men, and therefore may be at greater risk for hypertension. REM AHI has been recently shown to be a stronger predictor of hypertension than overall or NREM AHI. In those with NREM AHI ≤5, a twofold increase in REM AHI was associated with 24% greater odds of hypertension.

• OSA is more than threefold prevalent in postmenopausal than in premenopausal women. In the Wisconsin Sleep Cohort Study, the prevalence of SDB (defined by AHI ≥5) was 10.8, 18.4 and 29.1% in premenopausal, perimenopausal and postmenopausal women, respectively. The prevalence of SDB (defined by an AHI ≥10) was 5.5% in postmenopausal women not on HRT, compared with 1.1% in postmenopausal women on HRT.

• The prevalence of SDB in women increases with age, and by age 50 years, male predominance decreases and the incidence rates among men and women are similar. The OR for increased AHI per 10-year age increase is 2.41 in women (CI: 1.78–3.26) and 1.15 in men (CI: 0.78–1.68). The male to female OR decreases from 5.04 (CI: 2.19–11.6) at age 30 years to 0.54 (CI: 0.15–1.99) at age 60 years.

• Several physiologic changes during pregnancy place women at risk for SDB. OSA has been associated with increased risk for preeclampsia, gestational diabetes and unplanned Caesarean deliveries.

• Women with SDB had 2.44 greater risk of death compared with men with SDB even when being treated with PAP. However, whether PAP therapy improves cardiovascular and noncardiovascular outcomes in patients with SDB may be in part affected by baseline gender differences in the risks posed by SDB.

• Women with OSA who were nonadherent to PAP therapy (using <4 h/day) showed a greater incidence rate of the stroke or coronary heart disease compared with women without OSA. Regular PAP use (>4 h nightly) reduced risk and incident rates were comparable with those without OSA.

• Women with severe OSA and who used PAP >4 h/day had improved cardiovascular mortality compared with women who did not adhere with PAP therapy. PAP-treated women had morality rates comparable with women without OSA. The adjusted hazard ratio for cardiovascular mortality in those with untreated severe OSA was 3.50 (CI: 1.23–9.98) compared with women without OSA. There was no increase in cardiovascular mortality in untreated women with mild to moderate OSA (1.60; CI: 0.52–4.90).

• There are few studies evaluating the impact of gender on responsiveness to alternative therapies such as oral appliance, surgery, weight loss and nasal resistors. Currently, these interventions are considered on an individual basis with consideration of many variables that may or may not be gender specific.

• There are only a few studies evaluating the role of HRT for treatment of SDB in postmenopausal women. Medroxyprogesterone does not seem to have an effect, whereas estrogen monotherapy has been shown to improve AHI in some women. More studies are required before HRT is recommended as an alternative therapy for SDB in women.

Notes