The activity of matrix metalloproteinases and the concentration of their tissue inhibitors in the blood serum of patients with type 2 diabetes mellitus, depending on the stage of compensation of the disease

The aim of the study was to test the hypothesis on the possible reason for the decrease in the activity of matrix metalloproteinases (MMPs) as a consequence of the high concentration of their tissue inhibitors (TIMPs) in the blood serum of patients with type 2 diabetes mellitus (T2DM). Material and methods. In the experimental part of the article, we used the blood serum of patients under observation in the clinic of the Federal Research Center of Fundamental and Translational Medicine. According to the content of glycated hemoglobin (HbA1С) in blood serum, the patients were divided into 3 groups: at the stage of compensation (6.0–6.5 % HbA1С), at the stage of subcompensation (6.6–7.0 % HbA 1С) and decompensation (> 7.0 % HbA1С). The activity of MMPs 2 and 7 in blood serum samples was measured by a fluorimetric method using a fluorescent substrate specific for these MMPs. The concentration of TIMP-1 (inhibitor of all non-membrane-bound MMPs) and TIMP-2 (active against MMP-2 and -7) in blood serum were determined by enzyme immunoassay. Results and discussion. In patients with T2DM, the MMP-2 and -7 activities decreased, more pronouncedly at the stage of decompensation. An increase in the concentration of TIMP-1 was observed in the serum of all patients, while no significant changes in the content of TIMP-2 were found. At the stage of decompensation, a decrease in MMP activity was accompanied by a decrease in the content of insulin, C-peptide and a corresponding increase in the level of proinsulin. An inverse correlation was found between the concentrations of TIMP-1 and insulin in patients at the stage of decompensation of T2DM. It is assumed that the activity of MMP-2 and -7, in comparison with their inhibitors, forms stronger correlations with the parameters of carbohydrate metabolism

PREVALENCE OF INSULIN RESISTANCE AND ITS ASSOCIATION WITH METABOLIC SYNDROME COMPONENTS IN ADOLESCENTS: POPULATION STUDY RESULTS

Aim. To study the blood levels of insulin and glucose, to assess the prevalence of insulin resistance (IR), and to investigate the association between IR and the components of metabolic syndrome (MS) in a population sample of adolescents aged 14–17 years. Material and methods. A representative sample of Novosibirsk City adolescents, aged 14–17 years, was examined (n=667). The examination included the standard questionnaire survey, blood pressure (BP) measurement, anthropometry, and the assessment of serum levels of lipids, insulin, and glucose. Hyperinsulinemia (HI) was diagnosed if basal insulin levels were ≥15 μIU/ml, while fasting hyperglycaemia (FHG) was registered if fasting glucose levels were ≥5,6 mmol/l. IR was diagnosed if HOMA index was >3,7. Results. In Novosibirsk adolescents, the prevalence of IR reached 11,8% (13,4% in boys and 10,5% in girls). FHG was registered in 2% of boys and 0,8% of girls; the prevalence of HI was 22,5% and 21%, respectively. The presence of IR was associated with higher values of waist circumference, BP, blood triglycerides, body mass index, and lower levels of high-density lipoprotein cholesterol. The 90% percentile of HOMA distribution in this adolescent population sample was 4,1 (4,7 in boys and 3,7 in girls). Conclusion. The study results justify the need for a regular monitoring of carbohydrate metabolism markers in adolescents