ED: Is It All in My Head?
The MMAS study also showed an inverse correlation between ED risk and high-density lipoprotein cholesterol levels but no effect from elevated total cholesterol levels. Another study involving male subjects aged 45-54 years found a correlation with abnormal high-density lipoprotein cholesterol levels but also found a correlation with elevated total cholesterol levels. The MMAS study had a preponderance of older men.
Vascular diseases account for nearly half of all cases of ED in men older than 50 years. Vascular diseases include atherosclerosis, peripheral vascular disease, myocardial infarction, and arterial hypertension.
Vascular damage may accompany radiation therapy to the pelvis and prostate in the treatment of prostatic cancer. In this situation, both the blood vessels and the nerves to the penis may be affected. Radiation damage to the crura of the penis, which are quite susceptible to radiation damage, can induce ED. The radiation oncologist must take precautions to avoid treating this area. Data indicate that 50% of men undergoing radiation therapy lose erectile function within 5 years after completing therapy. Fortunately, some of these men tend to respond to one of the PDE-5 inhibitors.
Prostatic surgery for benign prostatic hyperplasia has been documented to be associated with ED in 10-20% of men. This is thought to be related to nerve damage from cautery. Newer procedures such as microwave, laser, or radiofrequency ablation have rarely been associated with ED.
Radical prostatectomy for the treatment of prostate cancer poses a significant risk of ED. A number of factors are associated with the chance of preserving erectile function. If both nerves that course on the lateral edges of the prostate can be saved, the chance of maintaining erectile function is reasonable. This depends on the age of the patient. Men younger than 60 years have a 75-80% chance of preserving potency, but men older than 70 years have only a 10-15% chance. Sural nerve grafts are used by some surgeons. Following surgery, one of the PDE-5 inhibitors, such as sildenafil, vardenafil, or tadalafil, is frequently used to assist in the recovery of erectile function.
Trauma to the pelvic blood vessels and nerves is another potential etiologic factor in the development of ED. Bicycle riding for long periods has been implicated as an etiologic factor by causing vascular and nerve injury. Some of the newer bicycle seats have been designed to diminish pressure on the perineum.