Testosterone and Disordered Sleep

Abstract

Disordered sleep may be insufficient, misaligned, or disrupted and is known to adversely impact cardiometabolic health. The effect of insufficient, misaligned, or disrupted sleep on andrological health – including hypogonadism and systemic testosterone exposure, fertility, and erectile function – is only now becoming recognized. Restricting sleep decreases overall mean 24-hour blood testosterone concentrations, and lower sleep duration is associated with smaller testicular volumes and reduced sperm concentrations. Misaligned sleep due to night shift work does not alter overall systemic testosterone levels, but it does shift the diurnal rise in testosterone to coincide with the timing of sleep irrespective of whether sleep occurs during the day or during the night. Accordingly, testosterone should be measured in blood soon after awakening, not necessarily in the early morning, to assess hypogonadism in shift workers. Disrupted sleep due to obstructive sleep apnea (OSA) is associated with low blood testosterone concentrations, symptoms of hypogonadism, and erectile dysfunction. Adherent continuous positive airway pressure (CPAP) treatment of OSA improves erectile function and some symptoms of hypogonadism and may also increase testosterone levels. On the other hand, testosterone therapy may induce or worsen OSA, but any possible effects are moderate in degree and these effects may not persist with longer term, more physiological replacement therapy. Longer-term interventional studies in larger cohorts are required to better understand the complex relationship between disordered sleep and andrological health, and to document its reversibility.