Gray Matter Volume Reductions Linked to Diabetes

Patients with vs without diabetes present with volumetric and structural gray matter reductions, according to study findings published in Diabetes/Metabolism Research and Reviews.

Although previous research findings suggest an association between diabetes and microvascular complications that can lead to structural alterations in the central nervous system, no community-based cohort studies have been conducted.

To identify differences in gray and white matter between individuals with and without diabetes, researchers conducted a prospective, population-based case-control biobank study. Data was collected from 22 United Kingdom assessment centers between 2006 and 2010.

The researchers collected data regarding cognition, pain measures, and whole brain and regional magnetic resonance imaging (MRI). Participants with diabetes were matched by age and sex to control participants without diabetes.

The study included 601 participants with diabetes and 1803 participants without diabetes. Among patients with diabetes, the average duration of diabetes was 11 years (SD, 14) at baseline. Compared with the control group, the diabetes group had fewer White individuals and higher proportions of Asian, Black, and ethnically mixed individuals. 

Regarding cognitive measures, the researchers observed that participants with vs without diabetes completed number and alphanumeric trial exercises in longer time but made similar number of errors. Participants with diabetes scored lower than control participants in symbol digit, numeric memory, and fluid intelligence tests. 

Pain measurements were greater among participants with diabetes compared with those without diabetes, particularly for general pain within the previous 3 months and pain experienced in the past month. No significant differences were observed for cognition or pain measures between patients with type 1 or type 2 diabetes.

According to the univariate analysis, gray matter volume was significantly lower among participants with diabetes vs those without diabetes, with a mean percentage difference ranging from 2.2% to 7% (all P <.0002). 

Among participants with vs without diabetes, the researchers observed reductions in the whole brain, subcortical gray matter, and total gray matter volume (all P <.0002). The subcortical segmentation analysis showed an increased volume in the third, fourth, and lateral ventricles bilaterally (all P <.0002), whereas the bilateral basal ganglia, thalami, cerebellum, and central and mid-anterior corpus callosum showed reduced volume among participants with vs without diabetes (all P <.0002).

The researchers observed decreased volume in the visual, sensorimotor, and default mode networks among participants with diabetes compared with those without diabetes (all P <.0002). Fractional anisotropy was also significantly reduced along the thalamocortical radiations, thalamostriatal projections, and commissural fibers of the corpus callosum (all P <.001).

Study limitations include the lack of consideration for the interconnectedness of adjacent brain regions in the univariate analyses. 

“Structural alterations and neural remodeling of the central nervous system are likely to be involved early in the development and maintenance of incipient diabetes‐related microvascular complications,” the researchers wrote.

This article originally appeared on Endocrinology Advisor