An interesting study suggests that the reason men with sleep apnea may have a higher rate of ED is that they have atherosclerosis – sometimes called “hardening of the arteries” – a condition in which plaque forms on the arteries. What is fascinating about this study is that they demonstrated the treatment for sleep apnea – called CPAP (continuous positive airway pressure) actually can REDUCE atherosclerosis in men with sleep apnea.
Whether this is true for men with ED was not tested, but it may explain why some studies have shown that CPAP can reduce ED in men with sleep apnea.

Here is a link to the study: LINK HERE