Male participants in the study were aged 18 to 50, and some were diagnosed with obstructive sleep apnea using an overnight test at a sleep center.
Compared to those without sleep apnea, researchers found that those with sleep apnea had lower semen quality, independent of erectile function.
Participants in the sleep apnea group had roughly 10 percent fewer sperm capable of swimming forward and 10 percent fewer sperm capable of swimming at all.
During follow-up, 25 participants used a CPAP regularly for four hours or more per night on five or more nights a week.
One month later, researchers noticed that in men who used the CPAP machine, the percentage of progressively motile sperm increased from nearly 40 percent to 45 percent.
No significant reductions were reported in the four elevated inflammatory markers.
