We need to keep in mind that angioplasty and bypass surgery have some significant adverse outcomes, including heart attacks, stroke and death. These invasive procedures only attempt to treat a small segment of the diseased heart, usually with only a temporary benefit. The patients treated with angioplasty and bypass will continue to experience progressive disability and most often die a premature death as a result of their heart disease.
Although medication can help extend the lives of men with chronic heart failure, several factors associated with this disease can interfere with a person's ability to engage in and enjoy sexual activities. Fatigue, depression, medication side effects and the fear of damaging the heart can cause people with chronic heart failure to lose interest in sex or wonder whether this activity is safe for them.
Oral medications (Viagra™, Cialis™, Levitra™ and Stendra™) are a common first step to treat ED, but they don’t work for everyone – especially men with heart disease. Men taking nitrates for heart disease or those taking alpha blocking agents for blood pressure are generally not candidates for oral ED medication.13 In addition, some medications simply do not work for certain men. When ED medication is not the answer, there are other options.
Alprostadil self-injection. With this method, you use a fine needle to inject alprostadil (Caverject Impulse, Edex) into the base or side of your penis. In some cases, medications generally used for other conditions are used for penile injections on their own or in combination. Examples include papaverine, alprostadil and phentolamine. Often these combination medications are known as bimix (if two medications are included) or trimix (if three are included).
Heart disease and erectile dysfunction can be related. In fact, ED and heart disease are considered two signs of the same disease process. The smaller arteries in the penis are affected by atherosclerosis sooner, perhaps three or more years before they cause heart disease symptoms.11 A large international study found that men with ED were more likely to die from heart causes; have a heart attack, stroke or be admitted to the hospital with heart failure than men with no or mild ED.12
Arterial hypertension is a major risk factor for cardiovascular disease and affects approximately one third of the adult population worldwide. The vascular origin of erectile dysfunction is now widely accepted in the vast majority of cases. Erectile dysfunction is frequently encountered in patients with arterial hypertension and greatly affects their quality of life of hypertensive patients and their sexual partners. Therefore, the management of erectile dysfunction in hypertensive patients is of paramount importance. Unfortunately, erectile dysfunction remains under-reported, under-recognized, and under-treated in hypertensive patients, mainly due to the lack of familiarity with this clinical entity by treating physicians. This review aims to discuss the more frequent problems in the management of hypertensive patients with erectile dysfunction and propose ways to overcome these problems in everyday clinical practice.
Sexual dysfunction refers to a problem during any phase of the sexual response cycle that prevents the individual or couple from experiencing satisfaction from the sexual activity. The sexual response cycle has four phases: excitement, plateau, orgasm, and resolution. Sexual dysfunction can be caused by physical and emotional factors, or a combination of both. The side effects of some medications also can lead to sexual dysfunction.
DHEA is a hormone made by the human body. It’s a building block for testosterone. According to a study published in Urology, this supplement may be able to help men whose ED is related to having low testosterone. However, there’s no definitive evidence of this benefit. It’s clear that DHEA can cause various side effects, including liver damage and acne. Long-term use of DHEA can also cause hormonal imbalances.
PubMed | Google ScholarSee all References However, other studies have noted that, when blood pressure levels are monitored after initiation of antihypertensive therapy, changes in blood pressure level are not correlated with sexual function.38x38Rosen, RC, Kostis, JB, Jekelis, A, and Taska, LS. Sexual sequelae of antihypertensive drugs: treatment effects on self-report and physiological measures in middle-aged male hypertensives. Arch Sex Behav. 1994; 23: 135–152
In another study, 60 patients underwent stress exercise cardiovascular testing and Doppler ultrasonography for measurement of their cavernosal artery peak systolic velocity (PSV).17x17Kawanishi, Y, Lee, KS, Kimura, K et al. Screening of ischemic heart disease with cavernous artery blood flow in erectile dysfunctional patients. Int J Impot Res. 2001; 13: 100–103
As ED has become more prevalent among the U.S. population, entrepreneurs have set out to serve this patient population by introducing a variety of non-invasive devices to help correct the condition. There’s the penis pump, which includes a plastic tube that fits over the penis and a hand or battery-powered pump attached to the tube, and a band that circles the base of the penis when it becomes erect.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (124) | Google ScholarSee all References This was a doubleblind, single-dose crossover study involving 41 men with stable coronary artery disease characterized by reproducible stable exertional angina. After taking either 10 mg of vardenafil or placebo, these men underwent treadmill exercise tolerance testing to 5 to 10 METs. Compared with placebo, vardenafil use did not result in a change in exercise treadmill time or time to first awareness of angina but significantly increased the time to ischemic threshold. At peak exercise levels, vardenafil did not cause a change in either heart rate or blood pressure level. This study concluded that 10 mg of vardenafil did not impair the ability of men with stable coronary artery disease to exercise at levels consistent with the exertion associated with sexual intercourse.
For over 25 years, Dr. Fuhrman has shown that it is possible to achieve sustainable weight loss and reverse heart disease, diabetes and many other illnesses using smart nutrition. In his medical practice, and through his books and PBS television specials, he continues to bring this life-saving message to hundreds of thousands of people around the world.
Three FDA-approved oral medications, sildenafil, tadalafil, and vardenafil are available. These drugs are phosphodiesterase type 5 (PDE-5) inhibitors that can prolong levels of cGMP in tissue allowing improved smooth muscle relaxation, thus facilitating an erection. PDE-5 inhibitor drugs are effective in 56-63% of diabetic men with ED. More stringent glycemic control can improve these results. Men with testosterone deficiency may benefit from a combination of oral ED medication and testosterone supplementation.
* Low-risk patients include those with complete revascularization (eg, via coronary artery bypass grafting, stenting, or angioplasty), patients with asymptomatic controlled hypertension, those with mild valvular disease, and patients with left ventricular dysfunction/heart failure (NYHA classes I and II) who achieved 5 metabolic equivalents of the task METS without ischemia on recent exercise testing.
Crucial to the understanding of the relationship between ED and CVD and the management of ED patients within the context of the (potential) CVD were the consecutive Princeton Consensus Recommendations (I: 2000, II: 2005, and III: 2012). The reader is strongly encouraged to refer to the most recent, third (2012) Princeton Consensus.30 Key notions in the assessment and management of the patient with organic ED are that (i) he should be considered at increased CVD risk until recommended checks suggest otherwise, and (ii) ED identifies increased CVD risk in the presence or absence of CVD symptoms or history.
Physical and emotional stress — whether over-exercising, under-sleeping or just dealing with everyday stressors like work and a busy schedule — causes an increase in “stress hormones,” including cortisol and adrenaline. Stress can lower desire for sex. This is because stress can contribute to fatigue or preoccupation with other tasks. It can also significantly affect blood flow by increasing inflammation.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References However, if optimally treated with β-blockers, lipid-lowering agents, and aspirin, these patients have no significantly increased cardiovascular risk associated with sexual activity, although they should receive appropriate risk information.88x88Jackson, G. The use of sildenafil in heart disease [editorial]. Hosp Med. 2000; 61: 526–527
The links between hypertension and ED are increasingly recognized and the 2009 re-appraisal of European guidelines includes relevant statements.35,47 Erectile dysfunction is almost twice as frequent in hypertensive as in normotensive individuals and appears to be of higher severity. The relative risk of developing ED in hypertensive patients compared with normotensive individuals ranges from 1.3 to 6.9. Regarding pathophysiology, hypertension appears to cause ED per se, through a multitude of mechanisms that include prolonged exposure to elevated levels of systemic blood pressure, endothelial dysfunction, and circulation of vasoactive substance (with a pivotal role of angiotensin II) that lead to structural and functional alterations in the penile arteries. The largely unfounded (see earlier paragraph) notoriety of antihypertensive treatment for causing ED is one of the most predominant causes for non-adherence and discontinuation of antihypertensive therapy, and therefore, patients should be properly informed by physicians. Phosphodiesterase type 5 inhibitors are effective in hypertensive patients with ED and they can safely be co-administered with antihypertensive medication.39 Specifically for alpha-blockers, low starting doses of PDE5 inhibitors are preferred in patients already on alpha-blocker treatment, and likewise, low starting doses of alpha-blockers are encouraged in patients taking PDE5 inhibitors. Of clinical significance is that hypertensive men with ED are more likely to comply with their antihypertensive medication when under PDE5 inhibitors.
Hyperlipidemia has been implicated in the development of ED by several different mechanisms. Hyperlipidemia is associated with development of atherosclerotic blood vessel disease, thus contributing to vasculogenic impotence. Penile vascular changes have been noted in impotent patients with elevated serum lipids.7x7Virag, R, Bouilly, P, and Frydman, D. Is impotence an arterial disorder? a study of arterial risk factors in 440 impotent men. Lancet. 1985; 1: 181–184
Erectile dysfunction (ED) is commonly called impotence. It’s a condition in which a man can’t achieve or maintain an erection during sexual performance. Symptoms may also include reduced sexual desire or libido. Your doctor is likely to diagnose you with ED if the condition lasts for more than a few weeks or months. ED affects as many as 30 million men in the United States.
Higher consumption of fiber-rich vegetables, fruits and beans helps to keep blood pressure in the favorable range.10 Beans, nuts and seeds have unique cholesterol-lowering capabilities.11-13 Berries and the flavonoids they contain have a blood pressure-lowering effect, plus berries and pomegranate have potent antioxidant and anti-inflammatory effects that protect against the development of heart disease.14-18
PubMed | Google ScholarSee all References Postulated mechanisms of effect on sexual function with these centrally acting medications have included increased prolactin levels and a direct effect on α2-adrenergic receptors in the central nervous system.36x36Wein, AJ and Van Arsdalen, KN. Drug-induced male sexual dysfunction. Urol Clin North Am. 1988; 15: 23–31
Finally, prevalence rates will be affected by whether the study population is accrued from a single hospital/clinic setting or from a more general population of men with diabetes. For example, Siu et al.4 studied 500 Chinese diabetic men (of which 97% had type 2 disease) seen at a single medical clinic in Hong Kong during 1999 and found the overall prevalence of ED to be 63.6%. Contrast this to Fedele et al.,5 who studied 9,756 diabetic men accrued from 178 diabetes centers in Italy. Among the 8,373 men with type 2 diabetes, only 37% reported ED, considerably less than in the Chinese study.
Control your blood sugar through your diet. Eating a diabetes-friendly diet will help you better control your blood sugar levels and lessen the amount of damage to your blood vessels and nerves. A proper diet geared at keeping your blood sugar levels in check can also improve your energy levels and mood, both of which can help reduce the risk of erectile dysfunction. You may consider working with a dietitian who is also a certified diabetes educator to help adjust your eating style.
The prevalence of erectile dysfunction is approximately 2-fold higher in hypertensive patients compared to normotensive individuals. However, erectile dysfunction remains under-reported, under-recognized, and under-treated in hypertensive patients. Hypertension per se and antihypertensive drug therapy may contribute to the development of erectile dysfunction in patients with arterial hypertension. The management of erectile dysfunction in hypertensive patients is tricky and should take into account the different effects of antihypertensive drug categories on erectile function. Lifestyle modification should be the mainstay of treating erectile dysfunction in patients with untreated hypertension. Switching antihypertensive therapy should be considered in treated hypertensive patients, unless administered drugs are absolutely indicated for the individual patient. Otherwise, PDE-5 inhibitors should be used, since they are both effective and safe in hypertensive patients. Finally, erectile dysfunction offers the opportunity to recognize asymptomatic cardiovascular disease and better characterize the relevant risk with obvious benefits for cardiovascular disease prevention.
Diuretics: Diuretics are also referred to as water pills. They can make the flow of blood to your penis less intense. This makes getting an erection difficult. Diuretics are also known to lower zinc levels, which can decrease the amount of testosterone your body makes. In turn, this can decrease your sex drive. It may also affect your muscle contraction.
Montorsi P, Ravagnani PM, Galli S, Rotatori F, Veglia F, Briganti A, Salonia A, Dehò F, Rigatti P, Montorsi F, Fiorentini C. Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement: the COBRA trial, Eur Heart J , 2006, vol. 27 (pg. 2632-2639)https://doi.org/10.1093/eurheartj/ehl142
The truth is medication or psychosexual counselling are the first treatments a doctor will suggest because they’ve been proven to work. If a doctor has approved a medication for you then it’s safe. If you would still like to see if herbal supplements work for you, then there is a list below of supplements thought to work for erectile dysfunction. Just before you invest your money in them, remember they aren’t proven to work:
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Phosphodiesterase type 5 is found predominantly in the smooth muscle of the corpora cavernosa but can be found in smaller quantities in platelets and other vascular smooth muscle.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
Montorsi F, Briganti A, Salonia A, Rigatti P, Margonato A, Macchi A, Galli S, Ravagnani PM, Montorsi P. Erectile dysfunction prevalence, time of onset and association with risk factors in 300 consecutive patients with acute chest pain and angiographically documented coronary artery disease, Eur Urol , 2003, vol. 44 (pg. 360-364)https://doi.org/10.1016/S0302-2838(03)00305-1
A sexually competent male must have a series of events occur and multiple mechanisms intact for normal erectile function. He must 1) have desire for his sexual partner (libido), 2) be able to divert blood from the iliac artery into the corpora cavernosae to achieve penile tumescence and rigidity (erection) adequate for penetration, 3) discharge sperm and prostatic/seminal fluid through his urethra (ejaculation), and 4) experience a sense of pleasure (orgasm). A man is considered to have ED if he cannot achieve or sustain an erection of sufficient rigidity for sexual intercourse. Most men, at one time or another during their life, experience periodic or isolated sexual failures. However, the term “impotent” is reserved for those men who experience erectile failure during attempted intercourse more than 75% of the time.
Erectile dysfunction (ED) is highly prevalent affecting at least 50 % of men with diabetes mellitus (DM). DM may cause ED through a number of pathophysiological pathways. These include neuropathy, endothelial dysfunction, cavernosal smooth muscle structural/functional changes, and hormonal changes. Lifestyle changes, diabetes control, and treatment of hypogonadism are important as the first step in ED management since there is no curative treatment for ED. Phosphodiesterase type 5 inhibitors (PDE5i) are the first-line treatment option. Intracavernous administration of vasoactive drugs is commonly used as a second-line medical treatment when PDE5i have failed. Alprostadil is the most widely used drug in this second-line setting. The combination of papaverine, phentolamine, and alprostadil represents the most efficacious intracavernous pharmacologic treatment option that may save non-responders to alprostadil. Penile prosthesis implantation can be considered in treatment refractory cases, with excellent functional and safety results in the properly informed patients.
Relaxation of erectile tissue requires nitric oxide from nonadrenergic-noncholinergic neurons and the endothelium.21 Penile tissue from diabetic men with ED demonstrates impaired neurogenic and endothelium-mediated relaxation of smooth muscle,22 increased accumulation of advanced glycation end products (AGEs),23 and upregulation arginase, a competitor with nitric oxide synthase for its substrate L-arginine.24 Normal responses to direct smooth muscle relaxants in most of these studies implies that the impairments are due to decreased synthesis, release, or activity of nitric oxide. The fundamental mechanisms mediating these changes are thought to be the same as for other diabetic complications: increased polyol pathway flux, intracellular accumulation of AGEs, activation of protein kinase C, and increased flux through the hexosamine pathway.25
Ginseng is the most common ingredient among top-selling supplements for men’s sexual health (36). The English word ginseng derives from the Chinese term renshen. Ren means “person” and shen means “plant root”. This plant has been named in this manner as its roots resemble the lower limbs of a human, Traditionally, ginseng has been used to restore and enhance the normal well-being of the body. The effects are due to ginseng’s reactions with the central nervous system, metabolism, immune function and cardiovascular system. The principal active compounds are triterpene saponins known as ginsenosides. Animal studies have suggested that specific ginsenosides may be responsible for ginseng-mediated effects on copulatory behavior (37). Ginsenoside induces smooth muscle relaxation by hyperpolarizing the smooth muscle membrane via activation of large-conductance KCa channels (38).
DHEA. Testosterone is essential for a healthy libido and normal sexual function, and erectile dysfunction sufferers known to have low testosterone improve when placed on prescription testosterone replacement therapy. Similarly, studies have shown that taking over-the-counter supplements containing DHEA, a hormone that the body converts to testosterone and estrogen, can help alleviate some cases of ED. But DHEA can cause problems, including suppression of pituitary function, acne, hair loss and its long-term safety is unknown, says McCullough. For this reason, many experts discourage use of the supplements.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (37) | Google ScholarSee all References One MET is equal to a resting state, or 3.5 mL/kg per minute. The relative MET values of sexual activity compared with other forms of activity are shown in Table 3. In general, sexual activity is similar to mild or moderate activity for most patients either with or without coronary artery disease.51x51DeBusk, R, Drory, Y, Goldstein, I et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol. 2000; 86: 62F–68F
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Nitrates have only modest antianginal effects and offer no prognostic benefit for mild recurrent angina or unstable angina. Therefore, such anginal symptoms occurring after sildenafil use should be treated with other nonnitrate antianginal agents such as β-blockers.15x15Taylor, HA Jr. Sexual activity and the cardiovascular patient: guidelines. Am J Cardiol. 1999; 84: 6N–10N
Mechanical therapy is also effective and is especially well-accepted in men with stable partners. Vacuum-assisted erection devices are effective in creating erections in as much as 67% of cases. Vacuum pressure encourages increased arterial inflow, and occlusive tension rings discourage venous outflow from the penile corpus cavernosae. The penis placed inside the cylinder, a pump is used to produce a vacuum that pulls the blood into the penis. After the tension ring is slipped onto the base of the penis, the cylinder is removed. Erection lasts until the rings are removed. The one-time expense of this therapy is $120–300.
A disruption anywhere along the complex chain of events will impair the capacity to have an erection. Any man who has experienced the frustration of male impotence knows that the consequences extend beyond physical dissatisfaction to anxiety, tension, and embarrassment. A common reason for failure of the erectile apparatus is disruption of the path leading to nitric oxide production and blood flow control.
Erectile dysfunction (ED) can be treated by urologists or other specialists or even by your general practitioner. Your doctor may recommend medication that works by relaxing penis muscles and increasing blood flow into the penis. Other treatments include therapy, implants, surgery and lifestyle changes, like exercising regularly, losing weight and eating right.
The initial step in evaluating ED is a thorough sexual history and physical exam. The history can help in distinguishing between the primary and psychogenic causes. It is important to explore the onset, progression, and duration of the problem. If a man gives a history of “no sexual problems until one night,” the problem is most likely related to performance anxiety, disaffection, or an emotional problem. Aside from these causes, only radical prostatectomy or other overt genital tract trauma causes a sudden loss of male sexual function.
Perk J, De Backer G, Gohlke H, Graham I, Reiner Z, Verschuren WM, Albus C, Benlian P, Boysen G, Cifkova R, Deaton C, Ebrahim S, Fisher M, Germano G, Hobbs R, Hoes A, Karadeniz S, Mezzani A, Prescott E, Ryden L, Scherer M, Syvänne M, Scholte Op Reimer WJ, Vrints C, Wood D, Zamorano JL, Zannad F. European Guidelines on cardiovascular disease prevention in clinical practice (version 2012). The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR), Eur Heart J , 2012, vol. 33 (pg. 1635-1701)https://doi.org/10.1093/eurheartj/ehs092
The initial event for normal erectile function is sexual stimulation. Subsequent to processing in the central nervous system neural impulses are conveyed along the spinal cord, exiting through the pelvic parasympathetic preganglionic nerves. These pelvic nerves form the pelvic plexus and send their message through first messenger, acetyl choline, to the cavernosal nerves. The cavernosal nerves enter erectile bodies (corpora cavernosa) (Figure 1). Here, their nerve endings release a second messenger, nitric oxide. Nitric oxide activates the enzyme guanylyl cyclase, which lyses guanosine triphosphate (GTP) to produce a third messenger, the intracellular cyclic guanosine monophosphate (cGMP). Ultimately, the result is a decrease of intracellular calcium and an opening of potassium channels with the resultant relaxation of vascular smooth muscle in the arteries, aterioles, and sinusoids of the corpora cavernosa. The sinusoids open and rapidly fill with blood. Finally, the distended sinusoids compress their drainage pathways (venules) against the fibroelastic covering of the cavernosal bodies (tunica albuginea) and trap the blood in cavernosal bodies. The combination of an increased inflow of blood into the penis and coincident markedly diminished outflow results in rapidly increasing intracavernosal pressure that ultimately approximates systolic pressure. At this pressure the penis has sufficient axial rigidity to permit vaginal penetration.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References Avoiding sexual activity between 6 AM and noon may be recommended to higher-risk patients because this is the time of peak incidence of most arrhythmias, myocardial ischemia, sudden cardiac death, and cerebrovascular accidents.1x1Muller, JE. Sexual activity as a trigger for cardiovascular events: what is the risk?. Am J Cardiol. 1999; 84: 2N–5N
Yohimbe A number of clinical trials have shown that the primary component of this bark from an African tree can improve sexual dysfunction associated with selective-serotonin reuptake inhibitors (SSRIs) used to treat depression. This herb has been linked to a number of side effects, including increased blood pressure, fast or irregular heartbeat, and anxiety. Yohimbe shouldn't be used without a doctor's supervision.
Crossref | PubMed | Google ScholarSee all References In the general population, the estimated relative risk of experiencing a myocardial infarction within 2 hours after sexual intercourse is approximately 2.5 times higher than the baseline infarction risk of that individual, which itself is extremely low8x8Muller, JE, Mittleman, A, Maclure, M, Sherwood, JB, Tofler, GH, and Determinants of Myocardial Infarction Onset Study Investigators. Triggering myocardial infarction by sexual activity: low absolute risk and prevention by regular physical exertion. JAMA. 1996; 275: 1405–1409
Ohlsson C, Barrett-Connor E, Bhasin S, Orwoll E, Labrie F, Karlsson MK, Ljunggren O, Vandenput L, Mellström D, Tivesten A. High serum testosterone is associated with reduced risk of cardiovascular events in elderly men. The MrOS (Osteoporotic Fractures in Men) study in Sweden, J Am Coll Cardiol , 2011, vol. 58 (pg. 1674-1681)https://doi.org/10.1016/j.jacc.2011.07.019
With early detection, doctors can suggest preventive measures like statins, blood pressure meds, revamping eating habits and getting more exercise. Try these two exercises that can cut your risk of heart disease in half. The study researchers told Science Daily, “Our study supports a more aggressive CVD risk assessment and management for persons with erectile dysfunction, including young men who may otherwise be categorized as low-risk due to their young ages.” Check out the sexual health conditions affecting millennial men.
Olsson et al. conducted a randomised, double-blind, placebo-controlled, parallel group, and flexible dose study in 224 men with ED and one CVD, including IHD (20 %) and hypertension (80 %). This study reported that the sildenafil-treated group showed 71 % improvement in ED compared with the placebo-controlled group (24 %).64 Furthermore, no treatment-related cardiovascular adverse events were reported.65 Conti et al. showed in an early study that sildenafil is an effective treatment for ED in patients with IHD; the majority of patients reported improvement in penile erection with it.66 Another double-blind, placebo-controlled study of patients with ED and stable CAD showed statistically significant improvement with sildenafil versus placebo in both the frequency of penetration and frequency of maintained erections after penetration.67
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.