Endocrine Abstracts

Actuality: Currently, there is no doubt about the negative effect of diabetes mellitus (DM) on the state of the central nervous system. One of the pathological manifestations are anatomical changes in the brain, which in turn can lead to the development of functional disorders and cognitive decline. Conducting imaging research methods allows us to assess the presence or absence of brain atrophy at an early stage.

The aim: To identify the relationship between blood glucose indicators (including variability) and magnetic resonance imaging (MRI) of the brain in patients with DM type 1.

Materials and methods: 58 patients with DM type 1 at the age of 29[25;32] and 20 people without diabetes (matched by sex and age) were examined. Using the EasyGV calculator was calculated the glycemia variability coefficients (standard deviation (SD), prolonged glycemic index (CONGA), glycemic lability index (LI), hypoglycemia risk index (LBGI), index risk of hyperglycemia (HBGI), mean daily differences (MODD),). Also MRI of the brain was performed to determine the volume of the gray matter of the cerebral cortex, white matter and hippocampus. Statistical processing - IBM SPSS Statistics 20.0.0 (significant differences - P<0.05).

Results: The average level of HbA1c in patients with type 1 diabetes was 8.4[7.5;8.9]%. Indicators of glycemia variability were: SD 6.25[3.1;7.7]mmol/l, CONGA 4.65[3.3;7.3]mmol/l, LI 4.25[3.3,5.1](mmol/l)²/hour, LBGI 3.85[2.6,5.2], HBGI 7.75[5.6;12.5], MODD, 3.85[2.9;5.6]mmol/l. According to the results of MRI, the volumes of the brain structures of interest (patients with DM type 1/control group) were determined: the volume of the gray matter of the cerebral cortex, cm³ – 516.95[504.71;542.1]/543.19[523.24;554.17] (P=0.004); white matter volume of the brain cm³ – 675.37[661.33;687.68]/630.66[625.03;641.59] (P=0.001); the volume of the hippocampus on the left, cm³ – 3.08[2.93;3.2]/3.09[3;3.24] (P=0.325); the volume of the hippocampus on the right, cm³ – 3.09[2.92;3.23]/3.01[2.9;3.21] (P=0.537). Subsequently, the analysis of the relationship of the MRI results with the coefficients of glycemia variability was carried out. A positive correlation was found between the volume of gray matter of the cerebral cortex and HbA1c (r=0.295, P=0.025), as well as a negative correlation between the CONGA index and the left hippocampus (r=–0.265, r=0.044).

Conclusions: The study revealed the negative impact of chronic hyperglycemia on the state of the cerebral cortex. Atrophy of the cortex can be the cause of cognitive impairment, which is often found in patients with diabetes.