The short version: ED is common, and it travels with heart risk
The Massachusetts Male Aging Study (MMAS) gave medicine its first solid, population-based picture of erectile dysfunction. In a random sample of men aged 40 to 70, about half had some degree of ED, and the odds rose steeply with age. Just as important, ED showed up most often in men with the same conditions that damage arteries: heart disease, high blood pressure and diabetes.
That second finding is the one that changed practice. It reframed ED from a private embarrassment into a sign worth investigating, and later research confirmed that ED often appears before a heart problem does.
How the study worked
Before the MMAS, most ED figures came from men who had already sought treatment, which skews the picture toward the worst cases. The MMAS took a different route. Researchers drew a random community sample of men aged 40 to 70 from cities and towns near Boston and interviewed them at home between 1987 and 1989.
Trained interviewers collected blood samples, physical measurements, health histories, medication lists, smoking and lifestyle details, and psychological scores. Each man also filled out a private sexual activity questionnaire, which the researchers used to grade erectile function as none, minimal, moderate or complete dysfunction. In all, 1,709 men completed that first round, and the group was followed up roughly nine years later. Because nobody was chosen for having a complaint, the results describe ordinary men in their communities rather than patients already sitting in a urology office.
What the first results showed
The headline numbers, published in the Journal of Urology in 1994, were striking for their time:
- 52% of men aged 40 to 70 had minimal, moderate or complete ED.
- Complete ED tripled with age, from 5% at 40 to 15% at 70.
- Age was the single factor most strongly tied to ED.
After adjusting for age, ED was more likely in men with heart disease, high blood pressure, diabetes and the medicines used for them, and in men with higher scores for anger and depression. It was less likely in men with higher HDL cholesterol and higher levels of the adrenal hormone DHEA. Smoking raised the chance of complete ED in men who already had heart disease or high blood pressure.
The authors concluded that ED had multiple causes, including several risk factors for vascular disease, and that some of it might be due to factors that can be changed.
How often new ED develops
The follow-up round let researchers measure incidence, meaning how many men without ED developed it over time. That 2000 analysis followed 847 men who were free of ED at the start for an average of 8.8 years.
| Age at start | New ED cases per 1,000 men per year |
|---|---|
| 40 to 49 | 12.4 |
| 50 to 59 | 29.8 |
| 60 to 69 | 46.4 |
| All ages | 25.9 |
Risk was higher in men with diabetes, heart disease, high blood pressure and less formal education. A related MMAS analysis of lifestyle changes looked at 593 healthy men over the same period. Men who stayed sedentary had the highest risk of developing ED, while men who stayed active or took up exercise in midlife had the lowest. Obesity at the start predicted higher risk even when men lost weight later, and changes in smoking or drinking did not shift risk within that window, which led the authors to argue that healthy habits pay off most when adopted early.
What later research added
The MMAS pointed to a link between ED and vascular disease. Later studies tested whether ED actually predicts heart events, and the answer has been yes.
- The Prostate Cancer Prevention Trial. Among 9,457 men aged 55 and older in the trial’s placebo group, new ED was tied to a 25% higher risk of a later cardiovascular event after adjusting for other risk factors. The authors said the size of that risk was in the range of current smoking or a family history of heart attack.
- A 2011 meta-analysis. Pooling 12 prospective studies with 36,744 men, researchers found that men with ED had a 48% higher risk of cardiovascular disease, a 46% higher risk of coronary heart disease, a 35% higher risk of stroke and a 19% higher risk of death from any cause.
- Guidelines. The AUA erectile dysfunction guideline now tells clinicians to counsel men that ED is a risk marker for cardiovascular disease, and notes that ED symptoms may come before a cardiovascular event by up to five years.
Our page on ED as an early sign of heart disease explains the shared biology: the small arteries of the penis tend to show narrowing and stiffness before larger arteries do.
What the study could not tell us
The MMAS has limits worth knowing. Its men came from one region of Massachusetts, and its national projections were made for white men only. Function was measured by questionnaire, not by physical testing. The first round also took place before modern ED pills existed, so it says nothing about how treatment changes the picture.
None of that undoes its central lesson. Later work in other populations has kept finding the same pattern, and the MMAS also spun off useful side questions, such as whether long hours on a bike matter. Our look at whether cycling causes erectile dysfunction picks up that thread.
What the MMAS means for your next visit
The practical takeaway is simple: new or worsening ED deserves an evaluation, not just a pill. At Ultimate Male in San Gabriel and Downey, an ED visit starts with a health history and on-site labs, often including blood sugar, cholesterol and morning testosterone, because those are the factors the MMAS and later studies kept flagging. Our guide to blood tests for erectile dysfunction lists what is usually checked and why.
From there, a PA-C or MD talks through erectile dysfunction treatment options that fit your health picture, and flags anything that should go to your primary care doctor or a cardiologist. Chest pain, shortness of breath with exertion or stroke symptoms are a different matter: call 911 or go to the nearest emergency room.
