Sleep and the testis

• Published in: Current opinion in endocrine and metabolic research Vol. 18; pp. 83 - 93
• Main Authors: O'Byrne, Nora A., Yuen, Fiona, Niaz, Warda, Liu, Peter Y.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2021
• Subjects: Androgen; Circadian; Fertility; Sleep; Sleep-disordered breathing; Sleep; Androgen; Circadian; Fertility; Sleep-disordered breathing; Sleep Disordered Breathing
• ISSN: 2451-9650; 2451-9650
• DOI: 10.1016/j.coemr.2021.03.002

Disordered sleep impairs neurocognitive performance, and is now recognized to cause metabolic ill-health. This review assesses the nascent relationship between insufficient, misaligned, and disrupted sleep with andrological health. High-quality cohort studies show a reduced sperm count in men with sleep disturbances. Well-designed interventional studies show a reduction in testosterone with sleep restriction. Studies of long-term shift workers show no effect of misaligned sleep on mean testosterone concentrations. Men with obstructive sleep apnea (OSA) and more severe hypoxemia have lower testosterone levels, although it is unknown if this relationship is entirely explained by concomitant obesity, or is reversible. Nevertheless, erectile dysfunction, which is common in men with OSA, is clinically improved when OSA is properly treated. Few studies manipulating sleep have been performed in older men, in whom the accumulation of sleep disturbances over decades of life may contribute to age-related illnesses. Improving sleep could ameliorate the development of these disorders. •The hypothalamic-pituitary-testicular axis is tightly regulated and maintains eugonadal systemic testosterone (T) exposure.•T supports libido, mood, muscle mass, adiposity, erectile function, and fertility in men.•The axis signaling requires pulsatile secretion of GnRH, LH and T, which underpins the diurnal hormone rhythm.•Restricting sleep decreases T in young and older men in a time-of-day dependent manner which may be regulated by LH.•Misaligned sleep does not seem to alter T, but available studies do not control for environmental and behavioral confounders.•Disrupted sleep from OSA is associated with reduced T, but this relationship may be due to concomitant obesity.