CHICAGO – Patients with type 1 diabetes and microangiopathy had a greater loss of executive function and brain volume over the course of 4 years compared with healthy controls, a small study showed.
Also, poorer glycemic control and higher systolic blood pressure at the beginning of the study were predictors of alterations in cognition and the brain over time, said Dr. Eelco van Duinkerken of VU University Medical Center, Amsterdam, who presented his abstract at the annual meeting of the American Diabetes Association. He added that the decline was not comparable with mild cognitive impairment.
Dr. van Duinkerken said that studies have shown that cognitive and structural changes in the brain are frequently found in patients with type 1 diabetes, particularly those with peripheral microangiopathy. But scientists don’t know yet how the brain’s structure and function change over time in adult patients with type 1 diabetes.
Naseem S. Miller/IMNG Medical Media
Dr. Eelco van Duinkerkern
Dr. van Duinkerken and his colleagues studied 25 patients with type 1 diabetes who had microangiopathy. They were, on average, 46 years old at baseline; 40% were male, with an average IQ of 112 and a hemoglobin A1c level of 7.9. They had diabetes for at least 10 years. They had no disease affecting their brain, no psychiatric comorbidity, and no MRI contraindications.
The patients were compared with 25 closely matched controls (baseline age, 44 years; males, 52%; average IQ, 109; HbA1c, 5.4).
Researchers analyzed the patients’ general cognitive ability, memory, information-processing speed, executive function, attention, and motor and psychomotor speed at baseline and at follow-up, which was 4 years later.
They used a 3D-T1 structural MRI scan at baseline and follow-up to determine whole-brain volume loss.
After 4 years, the results showed that the study group had a significantly greater decline in executive function, compared with the control group (P = .030). Also, the study group showed a larger percentage of whole-brain volume loss (–1.34% vs. –0.68% in controls; P = .036), markedly in the right frontal and central areas.
A larger loss of frontal and central brain volume was related to an accelerated decline in executive function in both groups (P = .025). But a higher baseline HbA1c level was associated with a larger decline in executive performance (P = .003), and a higher baseline systolic blood pressure was correlated with frontal brain volume loss at the time of follow-up (P = .003).
"We need more long-term data on this," said Marjorie Cypress, Ph.D., who is the 2013 president-elect of the ADA’s health care and education committee and serves on the board of directors. "It’s concerning, obviously. And what else do we need to look at that may contribute to it. We need more studies," said Dr. Cypress, who was not involved in the study.
Dr. van Duinkerken has received research support from Novo Nordisk A/S. The study was supported by VU University Medical Center. Dr. Cypress reported having no financial disclosures relevant to the study.
*Correction, 8/23/2013: An earlier version of this story incorrectly reported the percentage of whole-brain volume loss in the Vitals.
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