Hypogonadism in men with obstructive sleep apnea and its related risk factors

Abstract

Background Sleep-related breathing disorders, including obstructive sleep apnea (OSA), have been linked to altered hypothalamic–pituitary–gonadal axis. Hypoxia, sleep fragmentation. and decreased deep sleep time in patients with OSA affect the hypothalamic–pituitary–gonadal axis, including serum luteinizing hormone (LH) and testosterone levels. Purpose To study serum levels of LH and testosterone in men with OSA and to investigate the possible risk factors that could affect their levels. Patients and methods This was a prospective cohort case–control study. The case group included 16 adult patients diagnosed with OSA confirmed by polysomnography. The control group included 16 matched healthy participants. Both groups were subjected to history taking, clinical examination, and investigations, including the Epworth sleepiness scale, BMI, neck circumference measurement, and serum levels of LH and testosterone. Results Patients with OSA had significantly higher mean levels of serum LH compared with healthy controls (P=0.031). The mean serum level of testosterone was lower in the OSA group compared with the matched controls; however, this difference was statistically insignificant (P=0.192). Among the studied risk factors for altered hormonal levels in patients with OSA, there was a significant positive correlation between desaturation index and serum LH levels (P=0.046) and a significant negative correlation between Epworth sleepiness scale and serum testosterone levels (P=0.025). Conclusion Our findings suggest that OSA in men is associated with a dysfunction in the hypothalamic–pituitary–gonadal axis, represented as high levels of serum LH. Although serum levels of testosterone were lower in patients with OSA, the study was underpowered to show a statistically significant difference.