Written by Joyce Smith, BS. This study found an inverse U-shaped association between sleep duration and total number of sperm with high DNA stainability (HDS), suggesting a complex association between sleep duration and male reproductive health.
Existing evidence points to sleep duration, whether excessive or deficient, as a contributor to increased risk of obesity, diabetes, hypertension and ulcerative colitis 1-3. However, the effect of sleep on semen quality is a new area of research. A recent study has shown that sleep deprivation decreases sperm motility and viability and may play an important role in male reproductive health 4. While chromatin has been considered an independent predictor of male infertility 5, recent studies have implicated an association between sleep duration and chromatin integrity and attributed the association to the chromatin damaging effects of increasing reactive oxygen species (ROS) which occurs during restrictive sleep 6.
To validate a potential association between sleep duration and sperm chromatin integrity, researchers 7 used data from The Male Reproductive Health in the Chongqing College Students (MARHCS) study, which was established to investigate the effect of environmental factors and socio-psycho-behavioral factors on male reproductive health. The study, conducted from 2013 to 2015, consisted of a three-phase panel of 796 male volunteers. The baseline survey began in June of 2013 and was followed up with two additional surveys in (May–June) of 2014 and 2015. At each visit, the volunteers were asked to provide semen samples, undergo a physical examination and complete a questionnaire that included sleep-related issues. Sleep duration was measured using a modified Munich Chronotype Questionnaire. Sperm DNA integrity was examined via Sperm Chromatin Structure Assay and Comet assay.
In their data analysis, researcher found that subjects with sleep duration between 7 and 7.5 hours per day had the highest proportion of chromatin-abnormal sperm. Using 7-7.5 hours per day of sleep duration as a reference point or index, the baseline data analysis revealed an inverse U-shaped association between high DNA stainability (HDS) and sleep duration. Both longer and shorter sleep duration (greater or less that 7-7.5 hours per day) were negatively associated with high HDS (P = 0.009), reflecting the proportion of immature sperm that had abnormal chromatin. Chromatin is a complex of DNA and proteins that form chromosomes. Participants who received greater than 9 hours of sleep per day and those who received 6.5 or less hours of sleep per day had 40.7% and 30.3% lower sperm DNA stainability than participants who received 7–7.5 hours of daily sleep. Researchers found no association between sleep duration and DNA fragmentation index or Comet assay parameters. After performing analysis that integrated the individual results of all 3 surveys, researchers saw similar results in that for each hour of increased or decreased sleep there was a decrease of 8.2% in high density staining (P=0.009)
While the mechanism of the sleep–sperm quality association remains unclear, researchers suggest that the circadian clock may be a player in this association. Existing in both brain and peripheral tissues, circadian genes (which are influenced by sleep), could be disrupted by inadequate sleep, and adversely affect the male reproductive system. Although the study suggests that altering sleep duration can affect the integrity of sperm chromatin, other studies have also found an indirect effect on sperm quality that is mediated through multiple pathways, some of which are reversible with vitamin C. 8 More studies are needed to validate these findings and to further investigate the mechanisms underlying this association.
Source: Wang, Xiaogang, Qing Chen, Peng Zou, Taixiu Liu, Min Mo, Huan Yang, Niya Zhou et al. “Sleep duration is associated with sperm chromatin integrity among young men in Chongqing, China.” Journal of sleep research 27, no. 4 (2018): e12615.
© 2017 European Sleep Research Society
Posted November 9, 2020.
Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.
References:
- Ananthakrishnan AN, Khalili H, Konijeti GG, et al. Sleep duration affects risk for ulcerative colitis: a prospective cohort study. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. 2014;12(11):1879-1886.
- Cappuccio FP, Taggart FM, Kandala NB, et al. Meta-analysis of short sleep duration and obesity in children and adults. Sleep. 2008;31(5):619-626.
- Liu Y, Wheaton AG, Chapman DP, Croft JB. Sleep duration and chronic diseases among U.S. adults age 45 years and older: evidence from the 2010 Behavioral Risk Factor Surveillance System. Sleep. 2013;36(10):1421-1427.
- Choi JH, Lee SH, Bae JH, et al. Effect of Sleep Deprivation on the Male Reproductive System in Rats. J Korean Med Sci. 2016;31(10):1624-1630.
- Bungum M, Bungum L, Lynch KF, Wedlund L, Humaidan P, Giwercman A. Spermatozoa DNA damage measured by sperm chromatin structure assay (SCSA) and birth characteristics in children conceived by IVF and ICSI. Int J Androl. 2012;35(4):485-490.
- Alvarenga TA, Hirotsu C, Mazaro-Costa R, Tufik S, Andersen ML. Impairment of male reproductive function after sleep deprivation. Fertil Steril. 2015;103(5):1355-1362.e1351.
- Wang X, Chen Q, Zou P, et al. Sleep duration is associated with sperm chromatin integrity among young men in Chongqing, China. J Sleep Res. 2018;27(4):e12615.
- Mangoli E, Talebi AR, Anvari M, et al. Vitamin C attenuates negative effects of vitrification on sperm parameters, chromatin quality, apoptosis and acrosome reaction in neat and prepared normozoospermic samples. Taiwanese journal of obstetrics & gynecology. 2018;57(2):200-204.
