Research Looks at Underlying Causes for Cognitive Decline in Type 2 Diabetes

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By : Suvarna Sheth

Type 2 diabetes has been linked with an increased risk of cognitive dysfunction and dementia, but the underlying mechanisms are uncertain.

A new study published by researchers in Ukraine and The Netherlands sought to look into the underlying reasons for this connection.

“People with Type 2 diabetes have an increased risk of cognitive dysfunction and dementia and an impairment of cognitive functioning can severely affect their quality of life and negatively influence the control of diabetes,” Dr. Boris Mankovsky one of the study author’s told dLife.

“We have revealed some structural correlates in the brain which can underlie those cognitive changes,” he adds.

How was the Study Conducted?

Ninety‐three people with Type 2 diabetes between the ages of about 62 to 67, with diabetes for about 9 ± 6.7 years and HbA1c 65 ± 10 mmol/mol, 8.1 ± 1.3% were included in the study.

Cognitive functioning of these patients was assessed by a battery of tests covering memory, processing speed, and executive functioning.

Brain tissue volumes and white matter hyperintensity volumes were determined based on MRI results. Linear regression analyses were performed adjusted for age, sex and education.

What did the Results Show?

Imaging tests revealed that changes in white matter regions of the brain that are indicative of small vessel disease are associated with decreased processing speed (the time it takes a person to do a mental task) in people with Type 2 diabetes.

Also, higher blood pressure and worse kidney function were related to worse cognition.

The findings suggest that blood vessels in the brain may be involved in the mechanisms that lead to cognitive decline in individuals with Type 2 diabetes.

“For now, there are no specific measures to prevent cognitive decline in patients with diabetes proven in the clinical trials but we believe that maintenance of good metabolic control, avoidance of severe hypoglycemia and correction of cardiovascular risk factors can be beneficial in this regard,” Mankovsky says.

The authors conclude, in people with long‐standing, less strictly controlled Type 2 diabetes, white matter hyperintensities volumes were associated with decreased processing speed.

They say this suggests that cerebral small vessel disease is an underlying disease mechanism of cognitive dysfunction in these individuals.

Mankovsky indicates the next step in his team’s research will be to assess the association between cerebral blood flow, cerebral perfusion and cognitive functioning in people with Type 2 diabetes.

The study has been published in the Journal, Diabetic Medicine.