Autonomic function assessment using analysis of heart rate variability

Background Systemic lupus erythematosus is a progressive autoimmune disease. There are reports suggesting that patients even without overt signs of cardiovascular complications have impaired autonomic function. The aim of this study was to assess autonomic function using heart rate turbulence and heart rate variability parameters indicated in 24-hour ECG Holter monitoring. Methods Twenty-six women with systemic lupus erythematosus and 30 healthy women were included. Twenty-four hour ambulatory ECG-Holter was performed in home conditions. The basic parameters of heart rate turbulence and heart rate variability were calculated. The analyses were performed for the entire day and separately for daytime activity and night time rest. Results There were no statistically significant differences in the basic anthropometric parameters. The mean duration of disease was 11.52 ± 7.42. There was a statistically significant higher turbulence onset (To) value in patients with systemic lupus erythematosus, median To = –0.17% (minimum –1.47, maximum 3.0) versus To = –1.36% (minimum –4.53, maximum –0.41), P < 0.001. There were no such differences for turbulence slope (Ts). In the 24-hour analysis almost all heart rate variability parameters were significantly lower in the systemic lupus erythematosus group than in the healthy controls, including SDANN and r-MSSD and p50NN. Concerning the morning activity and night resting periods, the results were similar as for the whole day. In the control group, higher values in morning activity were noted for parameters that characterise sympathetic activity, especially SDANN, and were significantly lower for parasympathetic parameters, including r-MSSD and p50NN, which prevailed at night. There were no statistically significant changes for systemic lupus erythematosus patients for p50NN and low and very low frequency. There was a positive correlation between disease duration and SDNN, R = 0.417; P < 0.05 and SDANN, R = 0.464; P < 0.05, a negative correlation between low/high frequency ratio and r-MSSD, R = –0.454; P < 0.05; p50NN, R = –0.435; P < 0.05 and high frequency, R = –0.478; P < 0.05. In contrast, there was no statistically significant correlation between heart rate turbulence and other variables evaluated, including disease duration and the type of autoantibodies. Conclusion: Our study confirms the presence of autonomic disorders with respect to both heart rate variability and heart rate turbulence parameters and the presence of diurnal disturbances of sympathetic–parasympathetic balance. Further studies are required.

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Effects of Metformin Added to Insulin in Adolescents with Type 1 Diabetes: An Exploratory Crossover Randomized Trial

Journal of Diabetes Research ◽

10.1155/2020/7419345 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Daizhi Yang ◽

Jinhua Yan ◽

Hongrong Deng ◽

Xubin Yang ◽

Sihui Luo ◽

...

Keyword(s):

Body Mass Index ◽

Heart Rate ◽

Heart Rate Variability ◽

Type 1 Diabetes ◽

Insulin Sensitivity ◽

Body Mass ◽

Autonomic Function ◽

Insulin Dose ◽

Glucose Variability

Background. To comprehensively assess the effects of metformin added to insulin on metabolic control, insulin sensitivity, and cardiovascular autonomic function in adolescents with type 1 diabetes. Materials and Methods. This was an exploratory, crossover, randomized trial conducted in adolescents with type 1 diabetes aged 12-18 years old. Participants were randomly received metformin (≤1000 mg/d) added to insulin for 24 weeks followed by insulin monotherapy for a subsequent 24 weeks or vice versa. Blood pressure, body mass index, insulin dose, estimated insulin sensitivity, glycated hemoglobin A1c (HbA1c), and lipid profiles were measured, with a 72-hour continuous glucose monitoring and 24-hour Holter monitoring performed at baseline, 24, and 50 weeks for the assessments of glucose variability and heart rate variability. Results. Seventeen patients with mean ± SD age 14.4 ± 2.3 years , body mass index 18.17 ± 1.81 kg / m 2 , median (IQR) diabetes duration 4.50 (3.58, 6.92) years, and HbA1c 9.0% (8.5%, 9.4%) were enrolled. The between-group difference in HbA1c of 0.28% (95% CI -0.39 to 0.95%) was not significant ( P = 0.40 ). Changes in body mass index, insulin dose, blood pressure, lipid profiles, and estimated insulin sensitivity were similar for metformin add-on vs. insulin monotherapy. Glucose variability also did not differ. Compared with insulin monotherapy, metformin add-on significantly increased multiple heart rate variability parameters. Conclusions. Metformin added to insulin did not improve metabolic control or glucose variability in lean/normal-weight adolescents with type 1 diabetes. However, metformin added to insulin significantly increased heart rate variability, suggesting that metformin might improve cardiovascular autonomic function in this population.

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