Yohimbine is an indole alkaloid derived from the bark of the African yohimbe tree (33). Yohimbine has been noted to treat fatigue, depression, diabetes, and sexual dysfunction. A meta-analysis of seven placebo-controlled trials (34) deemed yohimbine superior to placebo for the treatment of ED with rare adverse events. The proposed mechanism of action (35) is via the inhibition of central alpha-2-adrenergic receptors, decreasing central inhibition of arousal, and increasing penile nerve stimulation resulting in increased NO. Common side effects include headache, sweating, agitation, hypertension and insomnia. Contraindications include patients on tricyclic antidepressants, anti-hypertensives and central nervous system stimulants.
Get your diabetes under control. According to Dr. Nehra, the most important number you need to stay on top of is your A1C, which is a blood test that lets you know how well your blood sugar has been controlled for the past few months. Lifestyle changes can help and so can medications. Diabetes medications do not add to your risk for erectile dysfunction, says Nehra.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (328) | Google ScholarSee all References Their mean resting systolic and diastolic blood pressure levels decreased by 6% and 11%, respectively, compared with baseline. These patients also experienced a mild decrease in mean resting right atrial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, and cardiac output. However, the hemodynamic response to exercise was preserved. Phase 2 and 3 trials showed no difference in the rate of adverse events between sildenafil and placebo in patients being treated with antihypertensive medications. The effects of sildenafil on blood pressure level were similar in patients who were taking antihypertensive medications compared with those who were not. In healthy volunteers, no consistent or significant doserelated electrocardiographic (ECG) changes were noted at 1 and 2 hours after doses of sildenafil ranging from 1.25 to 200 mg.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
Abstract | Full Text | Full Text PDF | PubMed | Scopus (30) | Google ScholarSee all References Increased cGMP levels cause intracellular calcium levels to decrease, resulting in relaxation of the corporeal smooth muscle, active dilatation of the penile arteries, arterioles, and sinusoids, and finally, increased arterial inflow and passive compression of penile venous outflow.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
The physical exam should focus on femoral and peripheral pulses, femoral bruits (vascular abnormalities), visual field defects (prolactinoma or pituitary mass), breast exam (hyperprolactinemia), penile strictures (Peyronie’s disease), testicle atrophy (testosterone deficiency), and asymmetry or masses (hypogonadism). A rectal exam allows for assessment of both the prostate and sphincter tone, abnormalities that are associated with autonomic dysfunction. Sacral and perineal neurological exam will help in assessing autonomic function.
Low testosterone levels have been observed inconsistently in STZ-induced diabetic and BB rats.18 Androgen deficiency in rats is associated with downregulation of the neuronal isoforms of nitric oxide synthase, suggesting a trophic effect of testosterone on peripheral erectile tissues. In humans, androgens play a larger role in sexual interest and motivation (libido) than in erectile capacity itself; penile erection is more resistant to androgen withdrawal than is sexual desire.19,20
The connection between diabetes and ED is related to your circulation and nervous system. Poorly controlled blood sugar levels can damage small blood vessels and nerves. Damage to the nerves that control sexual stimulation and response can impede a man’s ability to achieve an erection firm enough to have sexual intercourse. Reduced blood flow from damaged blood vessels can also contribute to ED.
Deer velvet is a covering found on the growing bone and cartilage of deer’s antlers. In Eastern medicine, deer velvet is sought after for its Chinese medicinal properties which include boosting one’s endurance and improving one’s immunity. People have also used deer velvet as an aphrodisiac or to treat ED. The randomized double-blind placebo-controlled study on deer velvet by Conaglen et al. (31), no benefit but this study was underpowered involving healthy participants with no sexual dysfunction.
Physical and sexual activity can trigger acute cardiac events. In a recent meta-analysis, a significant association between acute cardiac events and episodic physical (relative risk 3.45 for myocardial infarction and 4.98 for sudden cardiac death) and sexual activity (relative risk 2.7 for myocardial infarction) was demonstrated.32 This association was attenuated among individuals with high levels of habitual physical activity (for every additional time per week the relative risk for myocardial infarction decreased by ∼45%, and the relative risk for sudden cardiac death decreased by 30%). The physical demands of sexual activity have been identified as follows. Studies conducted primarily in young married men showed that sexual activity with a person's usual partner is comparable with mild-to-moderate physical activity in the range of 3–4 metabolic equivalents of the task (METS).30,33 The heart rate rarely exceeds 130 b.p.m. and systolic blood pressure rarely exceeds 170 mmHg in normotensive individuals. Accordingly, demands during sexual activity correspond to walking 1.5 km (or 1 mile) on the flat in 20 min or briskly climbing two flights of stairs in 10 s. Generalization, however, may not characterize all individuals (especially those who are older, are less physically fit, or have CVD) or sexual activity circumstances (e.g. extramarital, unfamiliar setting, excessive food and alcohol consumption). Therefore, completing 4 min of the standard Bruce treadmill protocol (5–6 METS) without symptoms, ST segment changes, arrhythmias, or a fall in systolic BP identifies the safety of sexual activity.30,33
The cardiovascular effects of sildenafil during exercise in patients with known or probable cardiovascular disease were studied in a randomized placebo-controlled trial of 105 men with a mean age of 66 years.63x63Arruda-Olson, AM, Mahoney, DW, Nehra, A, Leckel, M, and Pellikka, PA. Cardiovascular effects of sildenafil during exercise in men with known or probable coronary artery disease: a randomized crossover trial. JAMA. 2002; 287: 719–725
A substantial body of literature documents the prevalence of ED in men with diabetes. Unfortunately, the majority of these studies do not distinguish between type 1 and type 2 disease, and, therefore, it is difficult to determine if prevalence rates between the two forms of diabetes differ significantly. Acknowledging this limitation in the literature, prevalence estimates of ED in cross-sectional studies of diabetic populations range from 20 to 71% (Table 1). Most of these studies did not control for severity of disease, duration of disease, or control of hyperglycemia.
Penile erection is largely a vascular process, and the penile endothelium and smooth muscle tissue are very sensitive to functional and structural changes. Vasculogenic ED results from an impairment of endothelial dependent or independent smooth muscle relaxation (functional vascular ED, initial stages), occlusion of the cavernosal arteries by atherosclerosis (structural vascular ED, late stages), or a combination of these.3 Current data support a complex interplay between endothelial dysfunction, subclinical inflammation, and androgen deficiency (Figure 1). The relationship between ED and CAD at the clinical level is supported by this common pathophysiological basis. The ‘artery size’ hypothesis explains why patients with CAD frequently report ED before CAD detection.10 According to this hypothesis, for a given atherosclerotic burden, the smaller penile arteries suffer obstruction earlier than the larger coronary arteries (Figure 2). The same concept holds also true in the case of non-obstructing atherosclerosis: since the smaller penile artery have a greater endothelial surface and erection requires a large degree of vasodilation to occur when compared with arteries in other organs, the same degree of endothelial dysfunction will be symptomatic in these smaller vessels but subclinical in the larger ones (i.e. coronaries). In the same context, accelerated arterial ageing (as indicated by increased arterial stiffening that also affects large arteries of ED patients) may be a common background.11,12 Erectile dysfunction is associated with an incremental inflammatory and endothelial-pro-thrombotic activation.13 Interestingly, this activation is equal to that found in CAD patients with no ED, while when these two conditions are combined the burden is additive. Androgen deficiency may be also implicated in the common pathogenetic pathways of ED and CVD; however, this warrants further substantiation.2
Like all diabetic complications, ED can occur even when you have followed your doctor’s advice and carefully managed your diabetes. Also like all diabetes complications, ED is less likely to occur with good blood sugar control. Poorly controlled diabetes and high cholesterol increase the chances of vascular complications, which may lead to ED or other circulatory problems. In addition, regular smoking and alcohol use can contribute to ED.
Crossref | PubMed | Scopus (53) | Google ScholarSee all References This study found that, although hypertensive patients had more coronary artery disease, no direct evidence supported an association between hypertension and arteriogenic impotence, as measured by the PBI, peak systolic velocity, and resistive index, in patients with mild to moderate hypertension.
In a prospective human phase 1 open-label and single-arm study reported by Haahr et al. (27), 17 men with refractory post radical prostatectomy ED were given a single intracavernosal injection of autologous adipose-derived regenerative cells (ADRCs) freshly isolated after a liposuction. The procedures were well-tolerated and over a 6-month follow-up period, 8 of 17 men showed improvement of their erectile function.
Relative risk and 95% confidence interval for erectile dysfunction and clinical events. Relative risk and 95% confidence interval for erectile dysfunction and total cardiovascular events (A), cardiovascular mortality (B), myocardial infarction (C), cerebrovascular events (D), and all-cause mortality (E). Studies are listed alphabetically. Boxes represent the relative risk and lines represent the 95% confidence interval for individual studies. The diamonds and their width represent the pooled relative risks and the 95% confidence interval, respectively. CVD, cardiovascular disease; DM, diabetes mellitus; HF, heart failure; GEN, general population. Numbers in brackets are the number of references in the text—and references with S are from Supplementary material online. With permission from Vlachopoulos et al.5
Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Vision changes are described most frequently as an increased perception of bright lights, a blue-green tinge to observed colors, or blurred vision. Sildenafil has no direct effect on platelet function but potentiates the inhibitory effect of sodium nitroprusside on adenosine diphosphate–induced platelet aggregation ex vivo.56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In another study from ExCEED, Penson et al.38 compared erectile function and disease-specific quality of life of men with ED and diabetes to those of men with ED without diabetes. They found that those with diabetes reported significantly worse erectile function (P = 0.004) and intercourse satisfaction (P = 0.04) than those without diabetes. Importantly, the diabetic patients also reported that ED had a significantly worse psychological impact on their overall emotional life than did their nondiabetic counterparts (P = 0.01). Interestingly, no differences were noted between the two groups in the psychological impact of ED on the sexual experience.