BOSTON -- Shift work and its associated sleep disorders may significantly impact a man's sexual and urologic health, researchers said here.
Non-standard shift workers with shift work sleep disorders (SWSD) were more likely to have lower urinary tract symptoms (LUTS), reported John Sigalos, a medical student at Baylor College of Medicine in Houston, and colleagues.
The study included 2,487 men who completed questionnaires that assessed their work schedules, SWSD risk, and LUTS, as determined by an International Prostate Symptom Score (IPSS). The effect of non-standard shift work and SWSD on LUTS was assessed using linear regression and analysis of variance (ANOVA).
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- Note that these studies were published as abstracts and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Of these men, 30.8% reported working non-standard shifts, and of those, 36.8% were diagnosed with SWSD, which was defined as a primary circadian rhythm disorder characterized by excessive daytime sleepiness and/or difficulty sleeping, the authors said in a presentation at the American Urological Association (AUA) annual meeting.
One of the questions the researchers wanted to answer was whether there was something inherent in shift work itself, or the presence of a sleep disorder, that causes these LUTS.
They found that when controlling for age, testosterone, and comorbidities, "there was no difference that shift work had on the IPSS score," Sigalos said. "So, there was nothing inherent in shift work that we found that would cause someone to have increased lower urinary tract symptoms."
However, non-standard shift workers who were diagnosed with SWSD had IPSS scores that were 3.1 points higher than those non-standard shift workers without the sleep disorder, which was an increase Sigalos said was clinically significant.
"Patients at risk for this circadian rhythm disorder should be counseled regarding these risks and screened for lower urinary tract symptoms as part of their ongoing care and management," he said. "Modification of work and sleep schedules may reduce the risk for shift work sleep disorder and subsequent lower urinary tract symptoms."
In another AUA study, Will Kirby, MD, also at Baylor, and colleagues looked at hypogonadal symptoms in non-standard shift workers with SWSD.
"Non-standard shifts have been shown to be associated with increased risk of hypogonadal symptoms and sexual dysfunction," Kirby said. "And these same patients are at risk for the sleep disorder which is this unique entity among non-standard workers. So we were curious to see whether or not it was the shift work sleep disorder cohort that was at a particularly high risk for hypogonadal symptoms."
They used same methodology as the previous study, with the exception that the men in this study completed quantitative Androgen Deficiency in the Aging Male (qAdam) questionnaires assessing their hypogonadal symptoms.
Controlling for age, comorbidities, and testosterone levels, non-standard shift workers had qAdam scores 0.8 points lower than daytime workers, while a subgroup analysis of the non-standard shift workers showed that those with SWSD had qAdam scores 3.9 points lower than in those workers without SWSD. Additionally, SWSD was individually associated with lower testosterone levels.
"These findings suggest that it is these specific poor sleep symptoms that may be contributing to the more severe hypogonadal symptoms that we see in the non-standard shift workers," Kirby stated.
In a third AUA presentation, Taylor Kohn, also a medical student at Baylor, and colleagues examined the impact of non-standard shift work on semen parameters and reproductive hormones in infertile men.
Study participants were men who presented at an academic andrology clinic, and completed shift work and sleep quality surveys, semen analysis, and hormone testing. The infertile group consisted of men who were unable to achieve pregnancy within 12 months and had no known genetic or obstructive causes of infertility, while the control group consisted of fertile men who had fathered a child within the past 5 years.
Kohn reported that non-standard shift workers had lower levels of sperm density, total motile count, and testosterone. In addition, infertile shift workers had worse semen parameters than non-shift workers.
Kohn also noted that sleep quality influences total motile count, but that the relationship followed an inverse U shape "where too much or too little sleep impacts total motile count."
"That was a surprising finding for us. We believed the total motile count would decrease with less sleep," he said.
AUA session moderator , of the Stony Brook School of Medicine in Stony Brook, N.Y., said the studies highlight the importance of ongoing research on patients with sleep disorders.
"When I was in training, there was data that came out that many men deemed to have wetting symptoms had prostate procedures with no improvement in symptoms," Adler recalled. "And I bet if people were to go back and look they would see there were a lot of other things going on."
"Identifying this early, getting the appropriate evaluation in terms of sleep assessment, sleep apnea, or something else that is going on, and working with the primary care provider and educating them on this literature will streamline the process, makes the evaluation more efficient and lead to answers sooner for the patients," Adler added.
Disclosures
Sigalos, Kirby, Kohn, and co-authors disclosed no relevant relationships with industry.
Primary Source
American Urological Association
Lipshultz L, et al "Shift workers with shift work sleep disorder have increased lower urinary tract symptoms" AUA 2017; Abstract MP13-12.
Secondary Source
American Urological Association
Lipshultz L, et al "Increased risk of hypogonadal symptoms in shift workers with shift work sleep disorder" AUA 2017; Abstract MP91-06.
Additional Source
American Urological Association
Lipshultz L, et al "Shift work is associated with altered semen parameters in infertile men" AUA 2017; Abstract PD13-08.