Is ED Related to Diabetes? What the Research Shows

Online estimates range from half to three in four. The research explains the spread, the mechanism and what is known about reversing it.

Yes. Diabetes is one of the best-established causes of erectile dysfunction. A 2017 meta-analysis of 145 studies and 88,577 men found ED in about 52.5% of men with diabetes, and men with diabetes had roughly 3.6 times the odds of ED compared with healthy controls.¹ The NIH says the same thing in plainer terms: men with diabetes may develop ED 10 to 15 years earlier than men without it.²

The percentages quoted online vary widely, from "half" to "three in four." This article explains why the numbers differ, how diabetes damages erections, and what the trials show about treatment when blood sugar is high.

How common is ED in men with diabetes?

It depends on who is counted and how ED is measured. The 2017 meta-analysis pooled prevalence figures from studies of men with type 1 and type 2 diabetes (average age about 56) and reported these results:¹

Two things explain the spread. First, questionnaires differ: a study that counts any reduction in erection quality will find far more ED than one that asks only about severe ED. The 82.2% figure came from one specific questionnaire, not from a different kind of patient. Second, the men in these studies were middle-aged or older, and ED rises with age in everyone. The authors also noted that studies with more men with high blood pressure reported higher prevalence.¹

A large US cohort of 31,027 men aged 53 to 90 gives a more conservative view. After adjusting for age, men with diabetes had a relative risk of ED of 1.32 compared with men without diabetes. Men with type 1 diabetes had a relative risk of 3.0 and men with type 2 diabetes 1.3. Among men with type 2 diabetes, risk rose with time since diagnosis, reaching a relative risk of 1.7 in men diagnosed more than 20 years earlier.³ That study relied on self-reported erectile ability, so it measures something different from the clinic-based surveys above.

In the Massachusetts Male Aging Study, which followed 847 men aged 40 to 69 who started without ED, the age-adjusted risk of developing ED was higher in men with diabetes, as well as in men with heart disease and hypertension.⁷ Diabetes is rarely the only factor.

Why does diabetes cause ED?

Erections depend on two systems working together: nerves that send the signal and blood vessels that widen and fill the penis. High blood glucose over time can damage both. The NIH describes damage to blood vessels and nerves from high blood glucose as the route to sexual problems in diabetes.²

• Nerve damage (neuropathy). Diabetic neuropathy can affect the nerves involved in erection and ejaculation.²
• Blood vessel disease. Narrowed or stiffened arteries reduce blood inflow. This is the same vascular disease that affects the heart, which is why ED can be an early warning of heart disease.⁸
• Related conditions. The NIH lists poorly controlled blood sugar, nerve damage, untreated high blood pressure, untreated high cholesterol, excess weight, inactivity, certain medicines, heavy alcohol use and smoking as factors that make sexual problems more likely in men with diabetes.²
• Low testosterone. The NIH notes that men with diabetes, especially those who are older and overweight, are more likely to have low testosterone, which can contribute to ED.²
• Medicines and mood. Some blood pressure drugs and antidepressants are listed as possible contributors, and depression and anxiety are common with chronic illness. See our review of blood pressure medicines and ED for what the trials found.⁸

Can ED be the first sign of diabetes?

Sometimes. The NIH states that changes in sexual function may be a sign that a person has diabetes, and advises talking with a health care professional about any symptoms of diabetes, including sexual problems.² A clinician evaluating ED will often check blood glucose or hemoglobin A1c along with blood pressure, lipids and testosterone. That is a standard part of a work-up, not a diagnosis in itself.

ED in a man with diabetes also carries information about the heart. In a prospective study of 291 men with type 2 diabetes and silent coronary artery disease confirmed on angiography, followed for an average of about four years, ED predicted major cardiac events (hazard ratio 2.1; 95% CI 1.6 to 2.6).⁶ The study was observational, so it shows an association and not that ED causes heart events. It is one reason clinicians treat new ED in a man with diabetes as a prompt to review cardiovascular risk.

Is ED from diabetes permanent?

There is no single answer, and no trial shows that ED from diabetes always reverses or always persists. What the evidence does say:

• The NIH says good diabetes management may help prevent and treat ED caused by nerve damage and circulation problems.²
• In Look AHEAD, a randomized trial of overweight or obese men with type 2 diabetes, an intensive lifestyle program produced an average weight loss of 9.9% at one year versus 0.6% in the education-only group. Erectile function scores held steady or improved slightly in the lifestyle group (17.3 at baseline, 18.6 at one year) and were flat in the control group (18.3 and 18.4). Among those with ED, 8% of the lifestyle group worsened by one severity category versus 20% of controls. The authors called the benefit mild, and the difference in score change was borderline once baseline differences were adjusted for (P = 0.06).⁹
• Risk of ED in type 2 diabetes grows with years since diagnosis, so nerve and vessel damage that has built up over decades is less likely to reverse than early changes.³

In practice, ED that is mostly vascular or neurological tends to be more persistent than ED driven by anxiety, a medicine or a short-term blood sugar problem, but a clinician can only sort out which applies in an individual man.

Do ED medicines help men with diabetes?

PDE5 inhibitors have been tested specifically in men with diabetes. Response is often smaller than in men without diabetes, but trials showed meaningful improvement versus placebo:

The same safety limits apply as for any man: PDE5 inhibitors must not be combined with nitrates, and the labels list cautions for alpha-blockers and for cardiovascular conditions.^10,11 Men with diabetes often have heart disease or take several medicines, so the full medication list matters. Our guide to ED medication interactions covers the main combinations. Both trials were sponsor-funded and short, and they do not show what happens over years of use.

What should a man with diabetes and ED do first?

1. Tell the clinician managing the diabetes. The NIH advises seeing a health care professional about sexual problems because they may mean diabetes care needs adjusting.²
2. Review the whole risk picture. Blood pressure, cholesterol, kidney function, testosterone, sleep, mood and current medicines all feed into ED.⁸
3. Look at the modifiable factors. Glucose control, weight, physical activity, alcohol and smoking are the ones the NIH names.²
4. Ask about treatment options. Oral PDE5 inhibitors were effective in the trials above, and a clinician can advise whether they are safe given heart health and other medicines.^4,5

Limits of the evidence

Prevalence studies in diabetes use different questionnaires, ages and definitions, and the 2017 review itself found substantial heterogeneity (I-squared of 67% for the control comparison). Cohort data are observational and cannot separate diabetes from the conditions that travel with it. The treatment trials lasted 12 weeks and were funded by the manufacturers. The Look AHEAD analysis covered one year and found a mild effect. Individual outcomes can differ from any average.

Questions readers ask

Is ED related to diabetes?

Yes. A 2017 meta-analysis of 145 studies found ED in about 52.5% of men with diabetes, with roughly 3.6 times the odds of ED compared with healthy controls. High blood glucose can damage the nerves and blood vessels involved in erections.

Is ED from diabetes permanent?

Not always, and not predictably. The NIH says good diabetes management may help prevent and treat ED caused by nerve damage and circulation problems. Risk rises with years since diagnosis, so long-standing damage is less likely to reverse than early changes. A clinician can assess the individual picture.

How soon can diabetes cause ED?

The NIH says men with diabetes may develop ED 10 to 15 years earlier than men without diabetes. In some men ED appears before diabetes is diagnosed, which is why blood glucose is often checked during an ED evaluation.

Are Viagra and Cialis effective in men with diabetes?

In placebo-controlled 12-week trials, sildenafil and tadalafil both improved erectile function in men with diabetes, including men with poor glycemic control. They must never be combined with nitrates, and a clinician needs to check heart health and other medicines first.

Does type 1 or type 2 diabetes cause more ED?

Estimates differ by study. The 2017 meta-analysis found higher pooled prevalence in type 2 (66.3%) than type 1 (37.5%), while a large US cohort found a higher adjusted relative risk in type 1 (3.0) than type 2 (1.3). Age and duration of disease differ between the groups, which complicates comparison.

Further reading

Part of our guide: ED and Your Health: The Heart, Blood Pressure, Diabetes and Age

• What Causes Erectile Dysfunction in Young Men?
• ED and Blood Pressure Meds: Which Ones, If Any, Affect Erections?
• ED and Heart Health: Why Erectile Dysfunction Can Be an Early Warning
• Sildenafil Headache: How Common Is It?