Patients With Diabetic Foot Show Cognitive Deterioration

The lesions are indicative that the diabetes is causing systemic deterioration, which also affects the brain, explains lead researcher Dr. Rachel Natovich of Ben-Gurion University

Diabetics with diabetic foot turn out to have impaired cognition compared with diabetics without diabetic foot. The picture shows a man surrounded by candy.
Ayala Tal

Diabetics with diabetic foot turn out to have substantially impaired cognitive function compared with diabetes patients without diabetic foot, a study at the Ben-Gurion University of the Negev has found.

"Diabetic foot" is a complication of diabetes that starts with ulcers on the foot that refuse to heal, followed by necrosis. But why should infected feet impair brain function?

They don't. They are the symptom. "Generally speaking, there is a clear correlation between diabetes and cognitive deterioration," explains Dr. Rachel Natovich, who led the study the first to compare cognitive performance in patients with and without diabetic foot. "Diabetes is a multi-system condition and among other things, it affects the brain. The risk of a diabetic developing dementia is twice that of a 'normal' person. Diabetic foot is simply a symptom that the diabetes is causing deterioration of the entire cardio-vascular system," she says.

The cognitive profiling done by the Be'er Sheva researchers found significant differences between diabetics with affected foot / no affected foot. Crucially, the cognitive abilities of the two groups was about the same before they developed the condition (the pre-morbid state); but the current cognitive status of patients with diabetic foot was significantly impaired in all indices, say the researchers.

Specifically: Diabetics with diabetic foot remember less. Their concentration is impaired. They evince difficulty with learning, their cognitive and psycho-motor responses are slower  and their verbal fluency is decreased, though they might have what to say, since their inhibition is also decreased.

It had already been clear that patients with diabetic foot perceive their quality of life and health as suffering, but they were also found to be at greater risk of developing serious depression.

Unfortunately, although diabetes is generally a manageable disease – "You can live to 120 with it, managed properly, Natovich quips - adhering to a medical schedule requires cognitive ability. One practical implication of Natovich's study is that doctors should add routine cognitive monitoring to the functionality tests patients presenting with diabetic foot undergo.

On the upside, say the researchers, diabetic foot is easily preventable by wearing the right shoes, daily foot care and screening, and medical monitoring. And if that is not done, treatment could involve hospitalizations to treat the lesions, and ultimately amputation of the necrotic foot. The lifetime risk of a person with diabetes developing a foot ulcer could be as high as 25%.

Earlier this week, a study done at Emory University, Atlanta found that diabetics blinded by the disease (suffering from proliferative diabetic retinopathy) can be helped by a three-month course of ranibizumab injections, which has lesser side effects than the standard treatment of laser surgery for the condition. Diabetic blindness is caused by high sugar levels in the blood damaging eye cells.

According to the Israel Diabetes Association, Israel had 309,100 known cases of diabetes in 2014, out of 387 million worldwide. Last year 2,300 Israelis died of the disease, says the association. Like in the rest of the world, diabetes has been on the rise, both type 1 and type 2.

In short, more and more people are developing the condition and as many as a quarter of them could wind up with diabetic foot and, apparently, cognitive malfunction as well. Which leads the Be'er Sheva team to warmly recommend: since patients with diabetic foot may not be thinking clearly, the family and doctor, otherwise known as the kupat holim, need to take a more active role.