A recent study from the University of Louisville may have pinpointed the cause of erectile dysfunction (ED) that OSA patients sometimes experience. The researchers believe the ED may be linked to the chronic intermittent hypoxia (CIH) that OSA patients experience during an apnea event.

The study, performed on mice, showed a 55% decline in daily spontaneous erections after only 1 week of exposure to CIH similar to that which an OSA patient would experience. After 5 weeks of exposure to the same levels of CIH, the average interval between mounting a mate—the “latency to mount” period—increased 60-fold.

“Even relatively short periods of CIH … are associated with significant effects on sexual activity and erectile function,” says David Gozal, MD, professor of pediatrics at the University of Louisville.

The mice recovered only 74% after 6 weeks of recovery time following 1 week of CIH exposure. However, when the mice were administered tadalafil, which increases the availability of nitric oxide through PDE5, the CIH-exposed mice experienced improved erectile and sexual functioning to near-normal levels.

“The effects of tadalafil were not limited to the erectile tissue but extended to behavioral components, suggesting a possible role for PDE5 in central nervous system mechanisms that control sexual behavior,” says Gozal.

“Further studies are needed to explore the effects of sleep disruption and episodic hypoxia during sleep on the central nervous system that mediates sexual drive. Exploration of alternative interventions aiming at preventing and treating this infrequently spoken of, yet extremely frequent, complication of OSA will certainly require improved understanding of the complex mechanisms affecting sexual activity and how they are affected by diseases such as sleep apnea,” says Gozal.