DIAGNOSIS OF INSULIN RESISTANCE IN PATIENTS WITH ARTERIAL HYPERTENSION

Pathogenetic factors that affect the arising and progression of hypertension include dyslipidemia and abdominal obesity, also impaired glucose metabolism and development of insulin resistance, the compensatory hyperinsulinemia caused by it. One way to evaluate insulin resistance is to determine the level of the insulin in the blood plasma. However, indices that are calculated using the ratio of blood plasma insulin to glucose are more commonly used. The purpose of this research was to investigate the incretory function of the pancreas on the indicator of C-peptide depending on the level of endogenous insulin (EI) and homeostatic models of insulin resistance in pa-tients with AH with metabolic syndrome (MS). Materials and methods. The study examined 94 patients aged between 48 and 68 suffering from AH with MS. The patients underwent a general clinical exam-ination, 24-hour ambulatory blood pressure monitoring, oral glucose tolerance test (OGTT) with the measurement of blood glucose levels, EI levels, and C-peptide levels in the fasting state and 1-2 hours after the glucose load. Insulin sensitivity index (ISI), HOMA-IR index, β-cell function (HOMA-β) index were calculated using the standard formulas. Based on the EI levels, the patients were divided into three groups: group 1 – 29 patients with normal EI levels; group 2 – 38 patients with reactive hyperinsulinemia; group 3 – 27 patients with spontaneous hyperinsulinemia. The control group – 10 healthy individuals. Results of research. It was found, that in group 1, the levels of C-peptide in the fasting state and after OGTT were (0.97±0.016) and (1.02±0.10) ng/ml (p>0.05) respectively, the controls – (1.06±0.30) ng/ml; ISI index ranged within the controls – (1.13±0.29) (p>0,05). In group 2, the levels of C-peptide in the fasting state were similar to the controls, (p>0.05), and increased by almost 2.0 times (p<0.05) after OGTT; ISI index was 1.5 times (p<0.05) lower than the controls. In group 3, the C-peptide levels were 1.5 and 2.8 times (p<0.05) higher both in the fasting state and after OGTT, respectively; ISI index was 3.4 times (p<0.05) lower than the controls. HOMA-IR index in group 1, 2 and 3 was respectively 1.5, 2.6 and 6.7 times (p<0.05) higher than the controls – (1.08±0.29). The level of the C-peptide increases as insulin secretion increases and insulin resistance develops. In group 1 and 2, НОМА-β index ranged within the controls – (166.24±26.42) (p>0.05), in group 3 – was increased by 2.0 times (p<0.05). Conclusions. In patients with reactive hyperin-sulinemia, the intensity of increase in C-peptide in the blood was twice lower than the intensity of increase in ЕІ after the load with glucose. The patients with spontane-ous hyperinsulinemia were characterized by a decrease in the rate of increase in insulin secretion after glucose load-ing compared with patients that have reactive hyperinsu-linemia. This indicated the preserved secretion function of the pancreas on the one hand and on the other the formation of insulin resistance. Prerequisites for the de-velopment of insulin resistance are fasting hyperglycemia and postprandial hyperglycemia, hyperinsulinemia. De-termination of levels of ЕІ, C-peptide in ОGTT condi-tions, calculation of the HOMA-IR index, ISI are highly informative indicators for determining the presence and assessment of the degree of insulin resistance.