The aetiology and management of erectile, ejaculatory, and fertility problems in men with diabetes mellitus.

Erectile impotence is more common in the diabetic than the general population, occurs at a younger age, and is often associated with ejaculatory problems. For these, and possibly for other more subtle reasons, fertility may be a problem for men with diabetes. The symptoms of erectile and ejaculatory dysfunction are frequently not discussed between patient and doctor. Psychological factors are important but the vast majority of diabetic patients have an organic basis for their impotence. Both neurogenic and vascular factors are important in the pathogenesis of erectile failure. Autonomic neuropathy is almost certainly the cause of the ejaculatory failure that may be present in up to 40% of men with diabetes. The final biochemical mediator of erection within the penile erectile tissue is nitric oxide and a key enzyme in its degradation is phosphodiesterase (type V). Drugs that affect the metabolism of this enzyme are being developed to treat erectile failure. At present, the self injection of intra-cavernosal erectogenic agents (such as prostaglandin E1) provide the main form of therapy for erectile failure. Vacuum devices are a simple alternative and venous ligation surgery may be effective for a properly selected cohort of patients. Prosthetic implants are a final option for patients in whom all else has failed. Fertility problems, particularly when associated with ejaculatory failure can be overcome with modern assisted reproductive techniques. Nowadays, these will frequently involve gamete micro-manipulation.