Erectile Dysfunction
Erectile dysfunction (ED), also referred to as impotence, is the inability to attain and/or maintain an erection sufficient for satisfactory sexual intercourse. Sexual dysfunction is a more general term that also includes disorders of libido (sexual urge), orgasmic dysfunction, and ejaculatory dysfunction in addition to the inability to attain or maintain penile erection. A survey showed that 52% of men between the ages of 40 and 70 were affected by erectile dysfunction of some degree.
Population based studies indicate that the best predictors of the risk of ED are age, history of diabetes mellitus, hypertension, medication use, and cardiovascular disease.Advancing age is an important risk factor for ED in men: less than 10% of men younger than 40 years and more than 50% of men older than 70 years have ED.
Among the chronic diseases associated with ED, diabetes mellitus is the most important risk factor. The age-adjusted risk of complete ED was three times higher in men with a history of diabetes mellitus than in those without a history of diabetes mellitus. Fifty percent of men with diabetes mellitus will experience ED at some time during the course of their illness.
Heart disease, hypertension, and hyperlipidemia were associated with significantly increased risk of ED. Cardiovascular disorders, including hypertension, stroke, coronary artery disease, and peripheral vascular disease, are all associated with increased risk of ED. Physical activity is associated with reduced risk of ED.
Several reviews have emphasized the relationship of prescription medications and the occurrence of ED. IThiazide diuretics and psychotropic drugs used to treat depression may be the most common drugs associated with ED simply because of the high prevalence of their use. However, a variety of drugs, including almost all antihypertensives, digoxin, H2-receptor antagonists, anticholinergics, cytotoxic agents, and androgen antagonists, have been implicated in the pathophysiology of ED.
Recent surveys have revealed an association of lower urinary tract symptoms with erectile dysfunction, even after adjusting for age and other risk factors. The presence and severity of lower urinary tract symptoms is an independent predictor of ED. There is growing evidence that the two conditions may be mechanistically linked, because the biochemical mechanisms that regulate bladder detrusor and cavernosal smooth muscle function share many similarities.
The diagnostic evaluation of a man with ED usually includes measurements of hemoglobin, white blood count, blood glucose, blood urea nitrogen (BUN) and creatinine, plasma lipids, and testosterone levels.
If the history, physical exam, and ED questionnaire do not identify any obvious medical concerns needing further workup, then a cost-effective approach is to prescribe a trial of oral PDE5 inhibitor provided there are no contraindications (e.g., nitrate use).
Male Infertility
The World Health Organization (WHO) has defined infertility as the inability of a sexually active couple to achieve pregnancy despite unprotected intercourse during the fertile phase of the menstrual cycle for a period of greater than 12 months. The percentage of couples seeking medical treatment for infertility is estimated at 4% to 17%.
The estimates of prevalence rates of infertility and subfertility depend crucially upon the method used to define these conditions. The WHO definition was based on studies that used time to pregnancy estimations and found the probability of conception to be 20% per cycle or ∼85% to 90% per year. Even among couples who do not conceive within 12 months, 55% have a live birth within the next 36 months. When the duration of infertility exceeds 4 years, the conception rate per month drops to 1.5%.
In 20% of infertile couples, the primary problem resides in the male partner; in an additional 26%, problems reside in both the male and the female partner; thus, the male partner contributes to infertility in about half the couples. The occurrence of infertility substantially affects a couple’s relationship, quality of life, and health care expenditures.
COMMON DIAGNOSES IN MEN BEING EVALUATED FOR INFERTILITY
Correctable or treatable causes of infertility, such as gonadotropin deficiency and obstruction, are present in only a small number of men, but it is important to recognize them because effective treatment modalities are available. Varicoceles are present in 10% to 30% of men with infertility; their role, if any, in the pathophysiology of male infertility remains unclear. An increasing number of genetic disorders are being implicated in specific abnormalities of germ cell development; in addition, a number of systemic disorders nonspecifically affect spermatogenesis. Of these, Klinefelter’s syndrome and Y chromosome microdeletions are the most prevalent disorders, together accounting for 10% to 20% of patients . Although the prevalence of antisperm antibodies in infertile men is higher than that in fertile men, the mechanisms by which antisperm antibodies cause infertility are unclear.