On average, humans spend one-third of their lives asleep. Sleep is a restorative physiologic state and is a vital factor in physical and mental health maintenance, memory consolidation, and immune defense enhancement (Ann N Y Acad Sci 2010; 1193:48–59). Although sleep quality is difficult to precisely evaluate, it is a widely used construct measured subjectively by validated questionnaires and objectively by polysomnography or actigraphy. Sleep duration is commonly used as a proxy for assessment of sleep health. Adults typically require 7 to 9 hours of sleep per night, but over 35% of adults report sleeping less than 7 hours per night, and nearly 30% sleep less than 6 hours (Sleep 2015; 38:829-32).
Poor sleep has been associated with a number of serious adverse health effects, including obesity, type 2 diabetes, cardiovascular disease, and mortality (Sleep 2010; 33:585–92). Recent evidence has further linked impaired sleep with urologic disease, notably erectile dysfunction (ED) and lower testosterone levels (table) (J Urol 2018; 199[4S]:e560, abs. PD27-08; World J Urol 2019; 37:1449-53). Nocturia has repeatedly been associated with poor sleep quality, and evidence suggests this relationship is bidirectional.
Targeted counseling regarding sleep hygiene improvements may positively affect several urologic disorders while also facilitating a host of overall health benefits. Here we discuss the significant impact of sleep on men with urologic disease.
Sleep and erectile function
The link between ED and sleep disorders is well established. Numerous studies have reported an increased incidence of ED in men with obstructive sleep apnea (OSA) ranging from 47% to 80% (World J Mens Health Aug 14, 2018 [Epub ahead of print]). Insomnia has been identified as an independent risk factor for sexual dysfunction in older men, theorized to be related to decreases in testosterone (World J Mens Health Aug 14, 2018 [Epub ahead of print]). In a recent study, men working nonstandard shifts who reported poor sleep quality had higher rates of erectile dysfunction than men who subjectively slept better (Urology 2017; 102:121-5).
Both restless legs syndrome and periodic limb movements are associated with an increased prevalence of ED (World J Mens Health Aug 14, 2018 [Epub ahead of print]), although as with other sleep disorders the underlying relationship remains unclear. Given the high incidence of poor sleep in the overall population, increased attention has recently turned to the impact of poor sleep on erectile function in men without specific sleep disorders.
In a survey study, 377 men with a mean age of 46 years completed validated sleep and erectile function questionnaires and were queried about comorbidities, smoking status, shift work status, and caffeine and medication use (J Urol 2018; 199[4S]:e560, abs. PD27-08). Multivariable regression analysis controlled for a number of dependent variables, including age, body mass index, and burden of comorbidity. The authors found that poor sleep quality was independently associated with worsening erectile function. Notably, erectile function in this same group improved after patients were given instructions on improving sleep hygiene.
Further research characterizing this association is needed, but it is apparent that sleep health is an essential consideration for optimizing sexual function in men.