Diabetes mellitus (DM) is one of the main causes of premature death due to the increased risk of cardiovascular disease (CVD). One of the factors affecting the high incidence of CVD in diabetes is cardiac autonomic neuropathy (CAN), but the question of the association of CAN and myocardial remodeling remains open. Aim — to study morphological and functional parameters of the geometry of the left ventricle (LV) and to assess the association between LV remodeling and the severity of dysregulation of the sinus node of the heart in patients with diabetes and concomitant diseases of the circulatory system and kidneys. Materials and methods. We examined 310 patients (142 men and 168 women) with diabetes at the age of 18—70 years: 147 patients with type 1 diabetes, 163 patients with type 2 diabetes. The duration of diabetes was 10.0 [4; 16] years, the onset of diabetes — 46.0 [34; 52] years. All patients had concomitant diseases: Charlson comorbidity index — from 1 to 6 points. 4 groups were formed depending on comorbidity pattern: Group 1 — 130 patients with risk factors for non-infectious and concomitant diseases, with the exception of kidney disease and coronary heart disease (CHD); Group 2 — 102 patients with chronic kidney disease (CKD) up to and including C3a associated with diabetic nephropathy and/or chronic pyelonephritis in the latent phase; 3rd group — 47 patients with coronary artery disease, stable angina pectoris class I—III; 4th group — 31 patients with a combination of CHD + CKD. In addition, according to echocardiography, all patients were divided into 2 groups: 146 patients with normal left ventricular geometry (NG LV) and 164 patients with LV myocardial remodeling (MR LV). Examination of heart rate variability (HRV) was carried out using the high-resolution RKG method on the KAP-RK-01-Mikor apparatus; as a result, 94 patients with CAN and 216 without CAN were identified. Echocardiography was performed according to a standard technique with the assessment of indices and types of remodeling according to the recommendations of Russian Society of Cardiology, 2012. Results. In the MR LV group, there were 8 [6; 10] concomitant pathologies vs. 4 [3; 7] in the group of NG LV (p<0.001). An analysis of the concomitant diseases demonstrated that the vast majority of patients (90.3%) with a combination of the 3 most socially significant pathologies (DM + CHD + CKD) were in the MR LV group (p<0.05). Comparative analysis of HRV in patients with NG LV and MR LV, respectively: total heart rate variability (s) — 0.023 0.016; 0.032 vs 0.017 0.012; 0.024 (p<0.001); standard deviations (s) of humoral-metabolic (0.015 0.011; 0.021 versus 0.012 0.008; 0.017, p<0.001), sympathetic (0.09 0.006; 0.015 vs. 0.006 0.004; 0.010, p<0.001) and parasympathetic waves (0.011 0.007; 0.019 vs. 0.008 0.005; 0.012, p<0.001) and their percentage ratios (VLF% — 50.3 [38.0; 64.1] vs. 53.7 [40.0; 69.2], p>0.05; LF% — 17.6 [10.5; 27; 0] vs. 13.6 [8.5; 21.1], p<0.05; HF% — 24.6 [15.7; 42.6] vs. 24.1 [15.2; 41.7], p>0.05). Conclusion. We found a greater number of concomitant pathologies and lower rates of sympatho-parasympathetic control with an increase in the share of humoral-metabolic effects in patients with MR LV.