Background and Aims: To study the correlation of heart rate variability (HRV) in patients with type 1 diabetes mellitus (T1DM) depending on glucose control and hypoglycemia.

Materials and Methods: The study involved 87 patients with T1D, including 45 men (52%), women - 42 (48%). The average age of patients - 26,6±1,48 years, disease duration 11,6±1,42 years, BMI 23,2 ± 0,63 kg/m2. All patients used basic-bolus insulin therapy with daily dose of Units 45±2,26. All patients were conducted with Continuous Glucose Monitoring System (CGMS) and 24-Hour Holter Monitoring (HM) in same time. Echocardiography was used to exclude organic pathology of the heart. Patients were divided to groups according to HbA1c. Group 1 had HbA1c?7,5%; group 2 had HbA1c>7,5%, and subgroups: A-without hypoglycemia, B-with hypoglycemia.

Results. Groups did not differ in the frequency of hypoglycemia. Calculation of results depending on the duration T1DM showed an increase LF/HF (r=0,472; p<0,05). Groups differed significantly according to the following frequency characteristics of heart rate such as VLF, LF, HF (p<0,05). The groups did not differ in other factors. In Group 2B as compared to 2A identified decrease such time-domain indicators of HRV: RMSSD 22,8 ms (15,0; 36,0) vs. 32,6 ms (27,0; 43,0); pNN50 daily 3.50% (1.0; 10.0) vs. 8.50% (6,00-13,50) and daily frequency characteristics HRV: HF 380,0 ms2 (149,0; 715,0) to 719.0 ms2 (475.0, 1153.0) and increased LF/HF 4,35 (4,10; 6,50) vs. 3.30 (2.30; 4.30). All findings are significant (p<0,05). A similar pattern was observed in patients in 1st group.

Conclusions: HRV is lower in patients with bed glucose control (HbA1c>7,5%). The most reliable criteria for assessing changes in HRV are in patients with T1DM are RMSSD, LF, HF and LF/HF are. Hypoglycemia is the most significant factor that reduces the HRV.


K. Moshenets: None. N. Pertseva: None.

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