THE IMPACT OF TYPE 2 DIABETES ON CARDIAC ARRHYTHMIAS IN ELDERLY PATIENTS DURING THE SUBACUTE PHASE OF MYOCARDIAL INFARCTION: A CLINICAL AND METABOLIC CORRELATION STUDY

Аннотация

Type 2 diabetes mellitus (T2DM) is a growing medical-social problem, characterized by widespread prevalence, increasing incidence, and serious complications. The combination of micro- and macrovascular complications in T2DM leads to early disability and death. The disease is often accompanied by atherosclerosis, resulting in lipid and carbohydrate metabolism disturbances, hypercholesterolemia, hypertriglyceridemia, and low levels of high-density lipoproteins. T2DM promotes the development of cardiovascular issues, including arrhythmias, particularly during the acute period of myocardial infarction (MI). The research aims to explore the prevalence and correlation of arrhythmias in elderly patients with MI and diabetes, highlighting the role of metabolic factors such as glycemic control and kidney function in arrhythmia development. The study found that the incidence of arrhythmias was higher in patients with T2DM, with significant correlations to age, diabetes duration, glycemic control, and the presence of diabetic nephropathy. Moreover, the study revealed a U-shaped relationship between the frequency of arrhythmias and HbA1c levels. These findings suggest that optimal management ofdiabetes and early detection ofarrhythmias canimprove outcomes inelderly patients with MI. Keywords: Type 2 Diabetes Mellitus, Myocardial Infarction, Arrhythmias, Glycemic Control, Diabetic Nephropathy, Elderly Patients, Hyperglycemia, HbA1c, Metabolic Factors, CardiovascularDisease. Type 2 diabetes mellitus (T2DM) remains a pressing medical and social challenge due to its increasing prevalence, rising incidence, and severe clinical outcomes. The combination of microvascular and macrovascular complications significantly contributes to early disability and increased mortalityamongaffected individuals. T2DM and atherosclerosis are integrally linked through shared metabolic disturbances, including hyperglycemia, hypercholesterolemia, hypertriglyceridemia, and decreased high-density lipoprotein (HDL) levels. These imbalances foster a cluster of cardiovascular risk factors such as hyperlipoproteinemia, arterial hypertension, insulin resistance, and hypercoagulability, thereby exacerbatingthe progression of cardiovascular diseases. Myocardial infarction in diabetic patients is of particular clinical concern and is increasingly drawing attention from researchers. Although T2DM is now more frequently diagnosed in younger individuals, it predominantly affects middle-aged and elderly populations, where comorbidities aggravate the course and prognosis of myocardial infarction and complicate its management. Cardiac arrhythmias are common and potentially life-threatening cardiac complications in patients with T2DM. Sudden cardiac death in diabetic individuals has been linked to acute arrhythmias, 183 INTERNATIONAL MULTIDISCIPLINARY JOURNAL FOR RESEARCH & DEVELOPMENT SJIF2019:5.2222020:5.5522021:5.6372022:5.4792023:6.5632024:7,805 eISSN:2394-6334 https://www.ijmrd.in/index.php/imjrd Volume12,issue06(2025) often associated with autonomic nervous system dysfunction and QT interval prolongation. Notably, elevated glycated hemoglobin levels (>8%) have been correlated with a higher incidence of ventricular tachycardia, regardless of QT duration. Atrial fibrillation and other tachyarrhythmias are particularly concerning in diabetic patients with concomitant arterial hypertension and insulinresistance. Arrhythmias frequently complicate the clinical course of myocardial infarction. This study aimed to compare the incidence of arrhythmias in elderly patients during the subacute phase of myocardial infarction with and without type 2 diabetes mellitus, and to identify potential arrhythmogenic factors contributing to theirdevelopment. Materials andMethods A total of 194 patients diagnosed with myocardial infarction were enrolled in this study. The primary group (Group I) consisted of 99 patients with concomitant type 2 diabetes mellitus, while the control group (Group II) included 95 patients without diabetes. The diagnosis of diabetes was established according tothecriteria set bytheWHOExpert Committee (1999). All participants underwent comprehensive clinical, laboratory, and instrumental evaluations. These included resting electrocardiography (ECG), echocardiography in both M- and B-modes, and biochemical tests measuring blood glucose, glycated hemoglobin (HbA1c), glucosuria, microalbuminuria, proteinuria, and full lipid profiles. Sympathetic nervous system activity was assessed through β-adrenoreceptor binding on erythrocyte membranes (β-ARM) as a functional biomarker. In a subgroup of 43 patients from the primary group, serum levels of immunoreactive insulin and C-peptide were additionally quantified using standard radioimmunoassay kits provided by Immunotech (Czechia). The severity of myocardial infarction in all patients was stratified into four subgroups according to the classification developed by E.S. Niposayeva and D.M. Aronov (1998), which is u