PROGRAMMED AEROBIC EXERCISE DOES NOT AFFECT HEART RATE VARIABILITY IN DIABETIC PATIENTS
Authors: Filho Dario Sobral, Filho Marcos Antonio Oliveira, Denise Maria Vancea, Amanda Garrido, Maria de Fatima Monteiro, Naila Vera Lima, Fernanda Pantoja, Catarina Duarte, Vivianne Cruz, Viviane Gouveia
Background: Although the effects of diabetes type 2 on the autonomic regulation of heart rate are well established, it has still to be clarified whether the habit of regular physical exercise can produce long-term changes in this regulation.
Objective: To evaluate the effect of programmed aerobic exercise of moderate intensity on heart rate variability indices and metabolic control of type 2 diabetic patients.
Methods: Fourteen type 2 diabetic patients underwent 12 weeks of aerobic exercises three times a week. Their heart rate variability was evaluated by 24-hour holter, in addition to the treadmill stress test and assay of glycosylated hemoglobin (HbA1c) and blood fasting sugar levels at the start and end of the study. Glucose was also assayed before and after each session of exercises.
Results: The evaluation of heart rate variability revealed no statistically significant changes (SDNN =102.14±31.25 / 95.79±23.07 / = -6.35 / p=0.258) and pNN50=4.05±6.00 / 2.83±4.14 / = -1.22 / p=0.510). There were likewise no significant changes found in HbA1c (6.86±1.83 and 7.09±1.68 / p=0.975) or in blood fasting sugar levels (172.0±50.92 / 168.0±56.56 / = -4). Mean capillary glucose before and after each session of exercises showed a statistically significant decrease (225.50±74.66 and 186.93±65.07 / = -38.57).
Conclusions: Programmed physical exercises for a period of 12 weeks were not able to produce any modifications in heart rate variability in type 2 diabetic patients. As regards the glucose control parameters, they showed only a decrease in glucose before and after each session of exercises.