The following is an edited transcript of a conversation between 2 diabetes experts at the recent annual meeting of the European Association for the Study of Diabetes (EASD).
Leszek Czupryniak, MD, PhD: Hello. My name is Leszek Czupryniak and I'm here in Berlin at the 48th annual meeting of the EASD. I'm speaking with Dr. Boris Mankovsky, Professor of Endocrinology at Kiev University in the Ukraine. Hello, Boris.
Boris Mankovsky, MD: Hello. Nice to be here.
Dr. Czupryniak: Boris, you're an expert in diabetic neuropathy, and basically all of your research focuses on how diabetes affects the neurologic system. Just before this meeting, you attended another meeting, the EASD Diabetic Neuropathy Study Group. Combining all that you've heard and seen at both meetings, what can you tell us about the latest research on diabetic neuropathy?
Dr. Mankovsky: There have been some very interesting discussions. One of them, unfortunately, focused on the failures in recent clinical trials; we had many promising new drugs to treat patients with diabetic neuropathy, but unfortunately, most of those clinical trials failed. So, we spent some time talking about why that happened, and we concluded that we probably had selected the wrong endpoints to assess the real efficacy of the medications.
In treating diabetic neuropathy, we usually have to distinguish between disease-modifying medications, which would affect the pathogenesis of diabetic neuropathy, and symptom-modifying medications. Of course, it would be great to have medications that could relieve patients' pain and also modify the natural course of diabetic neuropathy. But unfortunately, so far we don't have such a medication that can act in both directions.
As for new clinical trials, I would like to call your attention to the COMBO-DN trial, which was a large, multinational trial that compared the efficacy of 2 pain-relieving medications, duloxetine and pregabalin, in patients with painful diabetic neuropathy. First, it was shown that duloxetine was superior to pregabalin in relieving patients of their pain. Then, patients who did not respond were given combination therapy with both drugs. However, there was no statistically significant difference between combination treatment and monotherapy.
Unfortunately, only one third of patients with painful diabetic neuropathy achieved a reduction of pain of more than 50%. In other words, in many cases, painful diabetic neuropathy is very difficult to treat.
Dr. Czupryniak: So, neuropathy is still one of the most difficult diabetes complications to treat, and it's also difficult to examine and study. But it's good to know that we probably do not need to combine these agents, which would only increase the pharmacologic burden on patients.
Any other interesting research you can share from this meeting?
Dr. Mankovsky: Yes. In fact, this was probably the first time in the long history of EASD that we had a special session devoted to hyperglycemia and the brain. It's really very exciting -- at least for me -- because for many years, we believed that the brain was not affected by diabetes. Now, the brain is probably considered another target for diabetic complications.
Brain damage can occur in 3 different ways. It can be affected by cerebrovascular disorders; it's well known that diabetes is an independent risk factor for stroke. Also, diabetes could lead to cognitive impairments and even dementia; many trials have confirmed that diabetes is associated with a 2- to 3-times higher risk for Alzheimer disease. Finally, diabetes is also associated with a higher risk for depression. So, unfortunately, there are 3 ways that diabetes can lead to brain damage.
At the session here, there was a very interesting presentation from researchers in Poland. That study covered a 10-year follow-up of patients with diabetes, identifying risk factors for stroke: age, fasting glycemia levels, daily albuminuria, atrial fibrillation, and smoking.
Another interesting dimension of this session involved the investigation of cognitive disturbances in patients with diabetes. It was noted once again that diabetes is associated with memory impairments and executive function impairments, so we should keep this in mind when treating our patients with diabetes.
Dr. Czupryniak: Yes. And my feeling is that brain problems in diabetes are somehow not appreciated enough; they are underrecognized by the general medical community. We remember to think about the kidneys, heart, eyes, and feet, but the brain often is omitted in this long list of potential diabetes complications.
Dr. Mankovsky: Absolutely. In fact, we used to say that diabetic neuropathy was a forgotten complication of diabetes, and brain disease is probably even more forgotten.
Dr. Czupryniak: Thank you, Boris, for coming to us and sharing the latest news and views on diabetic neuropathy.
Dr. Mankovsky: Thank you.
Medscape Diabetes © 2012 WebMD, LLC
Cite this: How Does Diabetes Affect the Brain? - Medscape - Nov 02, 2012.