LEPTIN RESISTANCE AND ITS CLINICAL AND PROGNOSTIC SIGNIFICANCE IN RELATION WITH METABOLIC DISORDERS IN THE HOSPITAL PERIOD OF MYOCARDIAL INFART
Authors:   Research Institute of Complex Problems of Cardiovascular Diseases, Kemerovo Russian Federation, Gorbatovskaya Evgeniya Evgenievna 
Published: October 2023

Introduction. Leptin resistance (LR) is characterized by a weakening of the positive metabolic effect of leptin, despite its elevated level, while maintaining some of the pleiotropic effects, including those on the cardiovascular system. However, since most of the data have been obtained in cellular and animal models, the role of LR in cardiovascular diseases remains unclear. The lack of precise diagnostic criteria for assessing LR limits the study of this phenomenon. As a result, data on the incidence and contribution of LR in MI are critically scarce today, in addition, they are extremely contradictory. Purpose: to evaluate the prevalence of LR and its clinical and prognostic significance in conjunction with metabolic disorders in the hospital period of myocardial infarction (MI). Materials and methods. The study included 114 men with an established diagnosis of ST elevation MI. Patients on the 1st and 12th day of MI measured the concentration of leptin, the leptin receptor. The free leptin index (FLI) was calculated as the ratio of leptin concentration (ng/mL) to the concentration of soluble leptin receptor (ng/mL) multiplied by 100. LR was recorded at leptin > 6.45 ng/mL and LL >25. Assessment of glucose, lipid spectrum (total cholesterol, TAG, LDL-C, VLDL-C, HDL-C, FFA) in blood serum was performed using standard test systems from Thermo Fisher Sientific on an automatic biochemical analyzer Konelab 30i (Finland) , the content of C-peptide and insulin were determined using enzyme immunoassay (Monobind, USA) according to the protocol established by the manufacturer. To determine insulin resistance (IR), the QUICKI index was calculated, the severity of IR was assessed according to A. Katz et al. A comparative analysis of clinical and anamnestic characteristics and cardiovascular prognosis between patients with and without PR was carried out. Data analyzed using Statistica 10.0. Results. In patients with MI in the whole group in the hospital period, there was an increased content of leptin relative to the reference interval of 2.0-5.6 ng/ml. On the 1st and 12th days of the disease, the leptin concentration in patients with MI was 11.6 [6.6;20.5] ng/ml and 11.5 [5.4;13.9] ng/ml, respectively. . The content of the leptin receptor did not go beyond the established reference interval. LSI on the 1st day of the disease was 32.7 [14.3; 70.5], on the 12th day - 31.9 [16.2; 64.5]. The prevalence of LR in the hospital period for MI was 64%. LR was associated with CVD risk factors - hereditary burden for cardiovascular pathology (p=0.02), arterial hypertension (p=0.01), dyslipidemia (p=0.001), obesity (p=0.001). When assessing the metabolic profile, a statistically significant increase in the content of glucose (p=0.02), insulin (p=0.02) and C-peptide (p=0.03) on the 1st day of MI, insulin (p=0 .01) and C-peptide (p=0.03) on the 12th day of the disease, a decrease in the QUICKI index (p=0.03) throughout the hospital period in patients with PR compared with patients without PR. In the group of patients with PR, 45 people (61.8%) had a moderate and severe degree of IR, in patients without PR - in 12 patients (29.2%). When conducting a correlation analysis, a significantly significant direct relationship was found between the level of insulin on the 12th day of MI and LSI (r=0.509, p=0.02), as well as an inverse correlation between the QUICKI index on the 12th day and LSI (r= -0.367, p=0.01). Among the studied parameters of lipid metabolism, only the content of FFA on the 1st day of the disease in the group of patients with LR was higher than in the group without LR (p=0.03). Patients with LR were more often prone to early postinfarction angina (p=0.03), recurrent MI (p=0.001), rhythm and conduction disturbances (p=0.03) during the hospital period of MI. Prognostic significance in relation to the risk of adverse cardiovascular events in the hospital period of MI, according to logistic regression analysis, had LSI both on the 1st and 12th days of the disease, as well as FFA levels on the 1st day of the disease. Conclusion. Patients with MI are characterized by a high prevalence of LR in the hospital period. LR is associated with CVD risk factors, metabolic disorders, and IR formation. The identified features in the presence of LR can probably contribute to the development of adverse cardiovascular events in the hospital period of MI.