Physical inactivity is associated with reduced heart rate variability in exercising eutrophic, type 1 diabetic and obese children

Abstract

Problem Statement: Although there is progress in understanding the impact of obesity and Type 1 diabetes in children, are not fully understood whether these conditions are associated with cardiac autonomic modulation. Purpose: To evaluate the effects of the sedentary lifestyle in the HRV of children with DM 1 or obese. Approach: After performing the ethical procedures, we applied the International Questionnaire of Physical Activity (IPAQ - C), short version, adapted for children and adolescents. We selected male children aged 6 to 12 years, classified as eutrophic (n = 8), diabetic (n = 8) and / or obese (n = 8). They were then submitted to anthropometric and cardiometabolic evaluations and an aerobic capacity test (Shuttle Run Test). Subsequently, the children were submitted to the 6-minute walk test (6-MWT) to record HRV in response to exercise. Results: The parameters of heart rate variability were reduced in DM 1 and obese when compared with eutrophic children (p <0.001). Analysis of heart rate variability in the time domain in the exercise of eutrophic, obese and DM1 children through the cardiac interval, standard deviation, variance and RMSSD were reduced in DM 1 and obese when compared to eutrophic children (p <0.001). The components of low and high frequency by the frequency domain at exercise were reduced in DM1 and obese when compared with eutrophic children (p <0.001). We found positive and significant moderate to very strong correlations between IPAQ and HRV parameters. We also observed moderate to strong correlation between obesity evaluated by Z-score and HRV. There was not correlations between glycemic control infer by Hb1Ac and HRV data. In addition, a very strong association was found between the IPAQ parameters and the cardiac vagal tone assessed by the RMSSD (p <0.0001). Conclusion: The level of physical activity showed a strong association with HRV, with lower levels in the obese and DM 1 group.