Erectile dysfunction
Erectile dysfunction, or ED, can be a total inability to achieve erection, an inconsistent ability to do so, or a tendency to sustain only brief erections. These variations make defining ED and estimating its incidence difficult. Estimates range from 15 million to 30 million, depending on the definition used. According to the National Ambulatory Medical Care Survey (NAMCS), for every 1,000 men in the United States, 7.7 physician office visits were made for ED in 1985. By 1999, that rate had nearly tripled to 22.3. The increase happened gradually, presumably as treatments such as vacuum devices and injectable drugs became more widely available and discussing erectile function became accepted. Perhaps the most publicized advance was the introduction of the oral drug sildenafil citrate (Viagra) in March 1998. NAMCS data on new drugs show an estimated 2.6 million mentions of Viagra at physician office visits in 1999, and one-third of those mentions occurred during visits for a diagnosis other than ED.
When erectile dysfunction proves to be a pattern or a persistent problem, it can interfere with a man's self-image as well as his and his partner's sexual life. Erectile dysfunction may also be a sign of a physical or emotional problem that requires treatment.
Physiology of Erection - The physiological process of erection begins in the brain and involves the nervous and vascular systems. Neurotransmitters in the brain (e.g., epinephrine, acetylcholine, nitric oxide) are some of the chemicals that initiate it. Physical or psychological stimulation (arousal) causes nerves to send messages to the vascular system, which results in significant blood flow to the penis. Two arteries in the penis supply blood to erectile tissue and the corpora cavernosa, which become engorged and expand as a result of increased blood flow and pressure.
The term "erectile dysfunction" can mean the inability to achieve erection, an inconsistent ability to do so, or the ability to achieve only brief erections. These various definitions make estimating the incidence of erectile dysfunction difficult. According to the National Institutes of Health in 2002, an estimated 15 million to 30 million men in the United States experience chronic erectile dysfunction.
According to the National Ambulatory Medical Care Survey (NAMCS), approximately 22 out of every 1000 men in the United States sought medical attention for ED in 1999.
Incidence of the disorder increases with age. Chronic ED affects about 5% of men in their 40s and 15–25% of men by the age of 65. Transient ED and inadequate erection affect as many as 50% of men between the ages of 40 and 70.
The etiology of ED is usually multifactorial. Organic, physiologic, endocrine, and psychogenic factors are involved in the ability to obtain and maintain erections. In general, ED is divided into organic and psychogenic impotence, but most men with organic etiologies usually have an associated psychogenic component. Almost any disease may affect erectile function by altering the nervous, vascular, or hormonal systems. Various diseases may produce changes in the smooth muscle tissue of the corpora cavernosa or influence the patient's psychologic mood and behavior. Pure psychogenic ED is an uncommon disorder, although most ED was once attributed to psychological factors.
Diabetes is a well-recognized risk factor, with approximately 50% of diabetic men experiencing ED. The etiology of ED in diabetic men probably involves both vascular and neurogenic mechanisms. Evidence indicates that establishing good glycemic control can minimize this risk.
Cigarette smoking has been shown to be an independent risk factor. In studies evaluating more than 6000 men, the risk of developing ED increased by a factor of 1.5
Mental health disorders, particularly depression, are likely to affect sexual performance. The MMAS data indicate an odds ratio of 1.82. Other associated factors, both cognitive and behavioral, may contribute. Also, ED alone can induce depression. The new oral agents have been shown to be effective for men who develop depression following prostatectomy.
Cosgrove et al have reported a higher rate of sexual dysfunction in veterans with posttraumatic stress syndrome than in those veterans who did not develop this problem. The domains on the IIEF questionnaire that demonstrated the most change included overall sexual satisfaction and erectile function. This study suggests that regardless of etiology, men with posttraumatic stress syndrome should be evaluated and treated if they have sexual dysfunction.
|
