ARCELONA, Spain — A new analysis has found that some men with type 1 diabetes fluctuate in and out of a state of impotence over the course of their disease. The findings, from the landmark Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications(DCCT/EDIC) study, also show that the longer such men remain affected by erectile dysfunction, the greater the likelihood that it might become permanent.
"We have shown there is a subset of men [with type 1 diabetes] who have erectile dysfunction, and it may resolve but in many cases it comes back, and that's never really been established before," urologist Hunter Wessells, MD, FRCP, from the University of Washington, Seattle, told Medscape Medical News.
"We think those are important patients, because it may be that factors can be modified that would prevent the return of erectile dysfunction," added Dr. Wessells, who presented the findings at the European Association for the Study of Diabetes (EASD) 2013 Meeting last week.
However, he admitted, "What we don't have is strong evidence-based data to support what you should do when you find a patient like this. All physicians tend to think of erectile dysfunction as irreversible, when probably there is always a point at which it is reversible, but identifying when that is and intervening early enough [to make a difference] is what we don't have a good guide on."
What is also unclear, he says, "is whether these men who fluctuate in and out of a state of erectile dysfunction should be treated differently from those who remain in a permanent state of erectile dysfunction."
Glycemic Control Is Likely Key to Potency
Dr. Wessells explained that men with diabetes have a 3-fold higher risk for erectile dysfunction compared with the general population, with around 50% of such patients being affected by impotence at some point in their lives.
He and his colleagues set out to describe the course of erectile dysfunction over time and look at factors associated with it, in a longitudinal cohort of men from EDIC, which began in 1994 as the follow-on study to DCCT. In it, 680 men were followed, with 636 assessed by year 16.
The men were asked yearly whether they had ever suffered from impotence, with a simple "yes" or "no" as the answer, which Dr. Wessells acknowledged was "a somewhat blunt" measurement of erectile dysfunction.
Following a first instance of erectile dysfunction, subjects were classified as regaining potency if they indicated not being impotent at any point during the 5 years following their index event.
The incidence of erectile dysfunction increased from 5.5% (n=42) at EDIC year 1 (1994) to 33.6% (n=219) by EDIC year 16 (2009). The majority of men reported erectile dysfunction at least once during the 16 years of follow-up (53.5%).
Of those who did report the condition, there was a subset who moved in and out of the state of erectile dysfunction, "and this is something we don't normally capture in cross-sectional studies," Dr. Wessells noted. Equally, there were men who reported erectile dysfunction and never regained potency over the course of the study, as well as men who remained potent throughout the study.
Dr. Wessells and colleagues pinpointed HbA1c levels and age as being significantly associated with a return to potency, albeit only in subjects with 4 or fewer consecutive years of erectile dysfunction. Therefore "glucose control" is likely key, he said. Other factors that were significantly associated with erectile dysfunction included blood pressure, smoking status, body mass index (BMI), and education.
Erectile Dysfunction for Many Years = Point of No Return?
The researchers found that the likelihood of regaining potency within 5 years decreased with every additional year of prior reported erectile dysfunction.
For example, in those with a single report of erectile dysfunction, (n=198), 67.7% regained potency within 5 years, while for those with 4 consecutive years of erectile dysfunction (n=70), only 32.9% did. And in the 44 men with 5 or more consecutive years of erectile dysfunction, there was a less than 20% subsequent chance of regaining potency.
Dr. Wessells said that what remains unclear is whether, among the men who fluctuate in and out of erectile dysfunction, there is "a point of no return," at which time they are unlikely to ever regain potency. Although such a "point" has been observed in animal models, it is not known whether such a phenomenon exists in humans, he noted.
One of the reasons that it is difficult to drill down into this further is that the mechanism of erectile dysfunction in type 1 diabetes is "likely multifactorial," he explained. The target organ, the penis, "has vascular, neurogenic, and hormonal input, so we are talking about metabolic issues, nerves, and a microvascular component in this condition."
Also unknown is "the relationship between the onset of erectile dysfunction and other diabetic complications," he said, ie, "whether erectile dysfunction is a harbinger of anything else."
Further research will be needed to explore biomarkers, behavior modification, and clinical management that predicts and reduces the risk of remaining impotent, he concluded.
Dr. Wessells has reported no relevant financial relationships.