Endocrine Abstracts

Actuality: At present, the role of chronic hyperglycemia in type 1 diabetes mellitus (DM1) in the onset of diabetic encephalopathy has been proven. At the same time, violations in the metabolic composition of brain cells were detected in persons with DM1, estimated with the proton magnetic resonance spectroscopy (¹H-MRS). However, the relationship between the results of these studies has not yet been studied.

The aim: To reveal the relationship between the measures of glycemic variability and the results of ¹H-MRS of patients with DM1.

Materials and methods: Fifty-eight patients with DM1 at the age of 29 (25–32) years. A complete clinical and laboratory examination was carried out. Using the EasyGV^© software, the measures of glycemic variability was calculated (standard deviation (SD), continuous overlapping net glycemic action (CONGA), lability index (LI), low blood glucose index (LBGI), high blood glucose index (HBGI), mean of daily differences (MODD), mean amplitude of glycemic excursions (MAGE)). The ¹H-MRS of the brain was performed to determine the main spectra of choline (Cho), creatine/creatine phosphate (Cr, PCr), N-acetylaspartate (NAA).

Results: The fasting glycemia in patients with DM1 was 8.6 (7.3–9.6) mmol/l, the average level of HbA1c was 8.4 (7.5-8.9)%. The measures of glycemic variability were calculated: S.D. 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, MAGE 7.6(4.6–8.9) mmol/l. Based on the results of the ¹H-MRS, an analysis of the relationship with the measures of glycemic variability was carried out. A positive correlation with the parameters of Cr (P=0.003) and PCr (P<0.001) in the right hippocampus, PCr in the gray matter on the right (P=0.036), NAA in the gray matter on the left (P=0.024) was found on the CONGA. LI - negative correlation with Cho in the left hippocampus (P=0.044) and PCr in the right hippocampus (P=0.023). LBGI – positive correlation with NAA in the left hippocampus (P=0.012) and in white matter (P=0.026). MODD – positive correlation with NAA in gray matter on the left (P=0.001). No statistically significant correlations were found for the SD, HBGI and MAGE (P>0.05).

Conclusions: The study revealed a direct and inverse relationship between the measures of glycemic variability and metabolites that characterize the state of cell membranes, the neuronal integrity and metabolism of brain cells, which indicates the effect of glycemic variability on biochemical processes in the brain.