Erectile dysfunction among sleep apnea sufferers is curable
Washington, September 13 : Experiments on mice conducted by American researchers have
suggested that erectile dysfunction among sufferers of obstructive sleep apnea syndrome
can be cured.
Dr. David Gozal, a professor of Paediatrics at the University of Louisville, says that
the link between the two conditions can be due to the chronic intermittent hypoxia
(CIH)-oxygen deprivation-that sleep apnea sufferers often exerience during episodes of
obstructed breathing.
He has revealed that mice exposed to CIH, similar to that which a human with PSAS would
experience, showed a 55 per cent decline in their daily spontaneous erections when studied
after one week.
"Even relatively short periods of CIH...are associated with significant effects on
sexual activity and erectile function," says Dr. Gozal.
After five weeks of CIFH exposure, the "latency to mount" period- the average interval
between mounting a mate- increased 60-fold, and latency to intromission increased by
40-fold. Latency to ejaculation was also severely affected.
In five out of seven mice tested, ejaculation did not occur at all, but in one mouse
and latency to ejaculation was eleven hours, while in control mice the median time to
ejaculation was "only a few minutes.
One mouse appeared to be unaffected in this respect.
"The disparity in responses among mice is very similar to the heterogeneity of the
magnitude of end-organ morbidity in sleep apnea among patients, and shows that not
everyone will be affected to the same extent," said Dr. Gozal.
In another experiment, the researchers treated the mice with tadalafil that increases
the availability of nitric oxide through PDE5, and the treatment improved erectile and
sexual functioning in CIH-exposed mice to near-normal levels in almost all cases.
"In the present study, tadalafil restored CIH-induced impairments of latencies to
mounts, intromissions and ejaculations, significantly improving performance during
spontaneous erections and during mating and non-contact activity. The effects of tadalafil
were not limited to the erectile tissue but extended to behavioural components, suggesting
a possible role for PDE5 in central nervous system mechanisms that control sexual
behaviour," wrote Dr. 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 it is affected
by diseases such as sleep apnea," said Dr. Gozal.
John Heffner, past president of the ATS, said: "These findings add sexual dysfunction
to a long list of disorders associated with - and probably caused by - OSA. Although this
study was performed in research animals, chronic intermittent hypoxia has profound effects
on multiple organ systems and a strong biologic plausibility exists that similar findings
will be observed in humans. Early identification and effective therapy of OSA is
critically important especially considering the high prevalence of this disorder."
The results have been published in the American Journal of Respiratory and Critical
Care Medicine, a publication of the American Thoracic Society.
--ANI
