Influence of the course of type 1 diabetes on the left ventricular myocardial geometry and intracardiac hemodynamic

The aim of the study was to examine changes in left ventricle (LV) geometry and to evaluate the systolic and diastolic function of LV in patients with type 1 diabetes mellitus (T1DM) depending on the course of the disease. Materials and methods. 63 patients with T1DM were examined. The mean age was 31.5 (24.0, 39.0) years, the duration of the disease was 11.0 (5.0, 18.0) years. Laboratory tests: C-peptide, HbA1c, blood creatinine, first morning urinary albumin excretion (UAE), glomerular filtration rate (GFR) according to the formula CKD-EPI were made. Long-term monitoring of blood glucose levels during 6 days was conducted by using the CGMS system. Transthoracic echocardiography and tissue Doppler imaging were used. Patients were divided into groups: Group 1 – HbA1c≤7.0% (n = 21), Group 2 – HbA1c> 7.0% (n = 42). 10 sex- and age-matched healthy controls were included. Results. Patients with DM 1 had significantly higher indices of the LV mass index (LVMI), LV posterior wall thickness, interventricular septal excursion and left ventricular posterior wall excursion (p <0.05). Hypoglycemic episodes lead to thickening of the interventricular septum and LV posterior wall thickness, increase of LV end-systolic volume, decrease of ejection fraction, and prolongation of isovolumteric relaxation time (p <0.05). Diastolic dysfunction with impaired relaxation (grade I) was 18 in patients with DM 1 (28.57%) without significant differences between the 1-st and 2-nd groups. Concentric remodeling of LV occurs in 16 (76.2%) patients of group 1 and in 27 (64.29%) of group 2. Eccentric hypertrophy of LV is determined in 1 (4.76%) patient of group 1 and in 5 (11.9%) of group 2, respectively, and only in 9.52% patients with T1DM. Conclusions. Patients with DM 1 have signs of structural and geometric reconstruction and diastolic dysfunction. Hypoglycemia is a significant factor leading to the formation of LV hypertrophy, as well as to decrease both of diastolic and systolic function of the myocardium.