Gender differences in obesity hypoventilation syndrome

Sleep-disordered breathing (SDB) is a group of sleep-related breathing disorders which includes obstructive sleep apnea (OSA), central sleep apnea (CSA), and obesity hypoventilation syndrome (OHS). OHS is characterized by a combination of obesity, daytime hypercapnia and hypoxemia, and sleep-disordered breathing without other known hypoventilation causes, such as severe obstructive or restrictive parenchymal lung disease, kyphoscoliosis, severe hypothyroidism, neu-romuscular disease, or congenital central hypoventilation syndrome. Four hundred ninety potentially eligible references were identified; of these, 462 abstracts or full texts were excluded because they did not fulfil inclusion criteria. We reviewed the full text of the remaining 38 papers which fulfilled the inclusion criteria. The role of gender in SDB and par-ticularly in OHS is not well known. In general, the diseases are under-recognized in women and only a few studies have reported the impact of gender on clinical presentation and treatment outcome. On the other hand, there is often a delay in diagnosing these diseases in women as compared to men; therefore, they are often more advanced when diagnosed in women. Better understanding and clinical awareness of the higher OHS prevalence in postmenopausal women may lead to earlier diagnosis and a more timely and appropriate treatment. Further studies are needed to assess the prevalence of OHS in women, the effect of menopause on OHS, and the increased risk of OHS, which will hopefully lead to optimizing OHS patient care.