SAN DIEGO — Treatment options for sexual dysfunction in diabetic patients are surprisingly limited, and new therapeutic targets are needed for both sexes, according to new data presented here at the American Diabetes Association (ADA) 2017 Scientific Sessions.
To enable this, more information on who with diabetes is at highest risk of developing sexual dysfunction and the specific mechanisms underlying the dysfunction is needed, said Hunter Wessells, MD, of the department of urology, University of Washington School of Medicine, Seattle, during a symposium on urologic complications and sexual dysfunction in diabetes.
Clinicians should start asking about sexual function when diabetes patients are still in their 40s and intervene as soon as the first symptoms occur, said Dr Wessells.
This is because research indicates that sexual dysfunction can occur in those with diabetes years earlier than it affects those in the general population, he stressed.
Asked for comment, Aruna V Sarma, PhD, research assistant professor of urology, University of Michigan School of Public Health, Ann Arbor, said sexual dysfunction may not be as lethal as neuropathy or nephropathy, but "these are conditions that matter to the participants, they are bothersome, and they impact quality of life.
"We have an opportunity to motivate individuals to improve their diabetes care, because an 18-year-old or 30-year-old type 1 diabetic may be more motivated to try to prevent erectile dysfunction that may occur in their 40s, rather than perhaps a more abstract notion of what may occur with neuropathy later in life. So there may be an opportunity here to try to improve sequelae that may occur in the future."
Accelerated Aging: Sexual Dysfunction Manifests Early in Diabetes
For example, erectile dysfunction will affect 50% of men with diabetes by the time they are 50 years of age, with a mean age of onset of 45 years, Dr Wessells said.
"Is that abnormal? Absolutely." Among men in the general population, the rate of erectile dysfunction does not reach 50% until they are in their 70s, so "this represents a 20-year acceleration of the aging process" for diabetic men, he explained.
For women, data from the Diabetes Control and Complications Trial(DCCT) in type 1 diabetes suggest that two of the biggest risk factors for sexual dysfunction are being married and a history of depression or treatment with antidepressants.
"We think of diabetes as impacting blood vessels and nerves, but there are all these other aspects that need exploration so we can understand how we can better intervene to help these patients," Dr Wessells explained.
Adding to the urgency of the problem is that as they live longer, men and women alike are seeking to prolong their sexual function as much as possible.
There is evidence that, for people with diabetes, the impact of sexual dysfunction on quality of life equals or exceeds that of neuropathy, nephropathy, or retinopathy.
A Multifactorial Problem
Treatments have been difficult to develop in part because of the multifactorial nature of sexual function, Dr Wessells said.
For men, most of the emphasis has been placed on erectile dysfunction, but problems may also take the form of diminished libido or ejaculatory or orgasmic dysfunction. Women similarly may experience low desire, impaired arousal, or difficulty with orgasm.
"We know almost nothing about how diabetes affects central nervous system control of sexual behavior or about its impact on other components of sexual tissue such as endothelial cells, smooth-muscle cells, and the autonomic nerves involved in arousal in both sexes," he pointed out.
First-line treatment options for men include phosphodiesterase 5 inhibitors such as sildenafil (Viagra, Pfizer) and tadalafil (Cialis, Lilly).
These are effective "but they are still not good enough, because these patients have more severe erectile dysfunction, so will they improve enough to be normal? That is the question."
Second-line therapies include vacuum erection devices, injection of vasoactive substances into the penis, and penile implants.
For premenopausal women, flibanserin (Addyi, Sprout Pharmaceuticals), approved in the US in 2015, may restore some sexual desire, but its exact mechanism of action is unknown, and it is associated with side effects including hypotension and syncope, Dr Wessells warned.
An effective approach to the sexual complications of diabetes should start with risk stratification, because "better knowledge of the risks may lead to earlier intervention," Dr Wessells explained.
There is some evidence that better glycemic control in men is associated with a lower risk of developing erectile dysfunction, for example.
But the picture is more complicated than that, he added. Data from the DCCT for example, have shown that, while some men develop permanent erectile dysfunction, others may have it for a while, then go into remission, and continue this back-and-forth pattern until age catches up with them.
In addition, some men may smoke or have terrible glycemic control yet never develop erectile dysfunction, while a few who follow doctor's orders to the letter nevertheless become impotent while still in their 40s.
"We have to learn what is protective in some men and see whether we can use that to help others."
There is also evidence that intensive lifestyle interventions may improve sexual function in people with type 2 diabetes, Dr Wessells said.
Weight loss has been associated with an improvement of erectile dysfunction in men and a slight decrease in sexual dysfunction in women.
Neither Dr Wessells nor Dr Sarma disclosed any relevant financial relationships.
American Diabetes Association 2017 Scientific Sessions. June 9, 2017; San Diego, California. Presentation 1-AC-SY06
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