Erectile Dysfunction caused by Sleep Apnoea

Erectile dysfunction (ED) and obstructive sleep apnoea (OSA) have been consistently correlated in a scientific manner. The literature on this topic involves the review of early studies by Sir Edmund Hilary and his scientific team in the Himalayan expedition up to recent mice experiments performed in the lab.

In the first model to address this possibility experimentally, researchers from the University of Louisville found that after one week of being exposed to chonic intermittent hypoxemia (CIH) similar to that which a human with sleep apnoea would experience, mice showed a 55 percent decline in their daily spontaneous erections. After five weeks of CIH exposure, the "latency to mount" period— the average interval between mounting a mate— increased 60-fold.

Interestingly after six weeks' recovery time with standard oxygen levels, mice exposed to CIH for as little as one week only recovered 74 percent of their original erectile function. "This could suggest either chronic residual deficits after CIH or that full recovery would require longer periods," wrote Dr. Gozal, principal author of the research study. It appears that SDB and ED are implicated in more than one way creating difficulties identifying the leading and major pathway. Vasculogenic (blood flow), neurogenic (nerve impulses), hormonal, and psychogenic pathways as well as the effects of drugs and others factors have their roles in the development of ED.

Since the majority of physicians who treat ED are unlikely to have expertise in SDB, and similarly those who treat SDB generally have little expertise in diagnosing or treating ED, the potential impact each of these conditions may have on the other is considered to be greatly underestimated. “These findings add sexual dysfunction to a long list of disorders associated with – and probably caused by OSA," agrees Dr Andrew Scott, Sleep Physician. "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."

“All patients with libido or erectile dysfunction should have a screening diagnostic sleep study as part of their routine workup” recommends Dr Andrew Scott. A recent study in the journal Sleep (January, 2010)showed that erectile dysfunction was more common in older men with restless leg syndrome (RLS) than in those without RLS, and the magnitude of this association increased with a higher frequency of RLS symptoms. Results show that erectile dysfunction was 16 percent more likely in men with RLS symptoms that occur five to 14 times per month (odds ratio of 1.16) and 78 percent more likely in men whose RLS symptoms occur 15 or more times a month (OR=1.78). The associations were independent of age, body mass index, use of antidepressants, anxiety and other possible risk factors for RLS.

Fifty-three percent of RLS patients and 40 percent of participants without RLS reported having erectile dysfunction, which was defined as a poor or very poor ability to have and maintain an erection sufficient for intercourse. The results suggest it is likely that the two disorders share common mechanisms, said lead author Xiang Gao, MD, PhD, instructor at Harvard Medical School. The mechanisms underlying the association between RLS and erectile dysfunction could be caused by hypofunctioning of dopamine in the central nervous system, which is associated with both conditions.

Data were collected from 23,119 men, aged 56- 91 years, who participated in the Health Professionals Follow-up study, a large ongoing U.S. cohort of male dentists, optometrists, osteopaths, podiatrists, pharmacists and veterinarians. To reduce possible misclassification of RLS, participants with diabetes and arthritis were excluded. Participants were questioned about RLS diagnosis and severity based on the International RLS study group criteria. RLS was defined as having unpleasant leg sensations combined with restlessness and an urge to move; with symptoms appearing only at rest, improving with movement, worsening in the evening or at night compared with the morning, and occurring five or more times per month.

About four percent of participants had RLS (944 of 23,119 men), and about 41 percent (9,433 men) had erectile dysfunction. Men with RLS were older and were more likely to be Caucasian. The prevalence of erectile dysfunction also increased with age. The authors noted that the association between RLS and erectile dysfunction also could be related in part to other sleep disorders that co-occur with RLS. For example, obstructive sleep apnea and sleep deprivation may decrease circulating testosterone levels.

New studies also demonstrate that up to 75% of OSAS patients with ED treated with nasal CPAP showed remission at one-month follow-up, resulting in significant improvement in quality of life. A recent Asian study showed that both sildenafil and CPAP, used separately, had a positive therapeutic impact, but sildenafil was superior. Under sildenafil, 128 of 249 (51.4%) intercourse attempts were successful; under CPAP, 51 of 193 (26.9%) attempts were successful . Erectile function was improved in both groups.

Patients and their partners were more satisfied with sildenafil for the treatment of ED. Fifty percent of patients treated with sildenafil and 25% with CPAP were satisfied with the treatment, and their partners were equally satisfied. Further studies are currently underway looking at combination therapy with CPAP and sildenafil.

Find Out More:
Erectile Dysfunction, Obstructive SLeep Apnoea Syndrome and nasal CPAP Treatment
Sildenafil versus Continuous Positive Airway Pressure for Erectile Dysfunction in Men