The Diagnosis and Investigation of Erectile Dysfunction in the Older Man
Muammer Kendirci, MD, Tulane University, School of Medicine, Department of Urology, Section of Andrology and Male Infertility, New Orleans, LA, USA.
Wayne J. G. Hellstrom, MD, FACS, Tulane University, School of Medicine, Department of Urology, Section of Andrology and Male Infertility, New Orleans, LA, USA.
Sexual dysfunction in the older man is common and has a significant impact on quality of life. In the aging man, erectile dysfunction (ED) has been encountered frequently due not only to associated comorbidities such as heart disease, hypertension, medications, diabetes, smoking, and depression, but also as a result of the aging process itself. Aging may impair molecular and structural components of erectile function. The introduction of effective oral erectogenic drugs has led to increased awareness of sexual issues and advancement in the methods used by clinicians to diagnose ED. Over the last twenty years, the approach for identification and evaluation of ED has transformed from invasive techniques to patient self-reporting and minimally invasive office procedures.
Key words: erectile dysfunction, aging, diagnosis, evaluation.
Introduction
Erectile dysfunction (ED) has been defined as the consistent or recurring inability of a man to achieve and/or maintain an erection sufficient for satisfactory sexual performance or intercourse.1 The increasing incidence of ED with age was acknowledged by the NIH Consensus Conference in 1993. The Massachusetts Male Aging Study (MMAS) has also provided a detailed epidemiological report on ED, demonstrating the detrimental role of age on the mechanism of erection.2 In this evaluation, men between the ages of 40 and 70 years were asked to categorize their erectile function as totally, moderately, or minimally impotent or potent. Overall, 52% of the people reported certain degrees of ED. Between 40 and 70 years of age, the probability of complete ED tripled from 5.1% to 15%; moderate ED doubled from 17% to 34%; whereas minimal ED remained at 17%. By the age of 70 years, only 32% portrayed themselves as being free from ED.2 In aging men, a higher probability of ED has been directly correlated with heart disease, hypertension, diabetes, medications, smoking, and depression.2 However, ED may occur frequently in healthy older men around 70 years of age without major comorbidities, in whom an incidence of 25% has been reported.3
The effect of the normal aging process on erectile function is unknown and the cause of age-related dysfunction is likely to be multifactorial in origin.4 Alterations in blood vessels, hormonal changes, neurologic dysfunction, medications and associated systemic diseases seem to be the main causes. Although a multitude of factors contribute to ED associated with aging, the ultrastructural changes to the tunica albuginea and corpora cavernosa play an important role. Penile tissue is composed of smooth muscle cells resting on collagen and elastic fibres limited by the tunica albuginea. Changes in the smooth muscle cells, elastic fibre activity, or collagen fibre content with age may bring about mechanical alterations of the penis by reducing its elasticity and compliance, which prevent optimal function of the corporeal smooth muscle and interfere with the normal filling of the vascular spaces.5 In addition, the percentage of smooth muscle cells in the corpora cavernosa declines with age.6 These ultrastructural changes in aged men certainly contribute to a decreased cavernous arterial inflow.7
Evaluation of ED Patients
Sexual dysfunction in older men is common and has a significant impact on quality of life. The