The influence of sex and gonadal hormones on sleep disorders

Sleep disorders such as insomnia, sleep-related breathing disorders, circadian rhythm disorders, and sleep-related movement disorders are a significant public health issue, affecting approximately 40 million people in the US each year. Sleep disturbances are observed in both men and women, though prevalence rates often differ between the sexes. In general, research suggests that women more frequently report subjective complaints of insomnia, yet show better sleep than men when evaluated on objective measures of sleep. Men are more likely to be diagnosed with obstructive sleep apnea than women, though rates of obstructive sleep apnea increase after menopause and may be generally underdiagnosed in women. Although circadian rhythm disorders are equally prevalent in men and women, studies find that women typically have earlier bedtimes and exhibit altered temperature and melatonin rhythms relative to men. Lastly, movement disorders appear to be more prevalent in women than men, presumably due to higher rates of anemia and increased risks associated with pregnancy in women. Although gonadal hormones would be expected to play a significant role in the development and/or exacerbation of sleep disturbances, no causal link between these factors has been clearly established. In large part, the impact of hormones on sleep disturbances is significantly confounded by factors such as psychiatric, physical, and lifestyle concerns, which may play an equal or greater role in the development and/or exacerbation of sleep disturbances than do hormonal factors. Current standard of care for persons with sleep disorders includes use of psychological, pharmacologic, and/or medical device supported interventions. Hormonal-based treatments are not typically recommended given the potential for long-term adverse health effects. In sum, there is a sub- stantial need for more comprehensive studies focused on elucidating the impact of hormones on sleep. Such studies should reveal sex-specific differences in sleep, which could lead to enhanced interventions for sex-specific sleep disturbances.