Frontiers in Endocrinology (Nov 2021)

High Fasting Glycemia Predicts Impairment of Cardiac Autonomic Control in Adults With Type 2 Diabetes: A Case-Control Study

  • Lucas Raphael Bento Silva,
  • Lucas Raphael Bento Silva,
  • Paulo Gentil,
  • Paulo Gentil,
  • Paulo Gentil,
  • Camila Simões Seguro,
  • Gabriela Teles de Oliveira,
  • Maria Sebastiana Silva,
  • Maria Sebastiana Silva,
  • Antônio Roberto Zamunér,
  • Thomas Beltrame,
  • Thomas Beltrame,
  • Ana Cristina Silva Rebelo,
  • Ana Cristina Silva Rebelo,
  • Ana Cristina Silva Rebelo

DOI
https://doi.org/10.3389/fendo.2021.760292
Journal volume & issue
Vol. 12

Abstract

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IntroductionType 2 diabetes (T2D) is characterized by a metabolic disorder that elevates blood glucose concentration. Chronic hyperglycemia has been associated with several complications in patients with T2D, one of which is cardiac autonomic dysfunction that can be assessed from heart rate variability (HRV) and heart rate recovery (HRR) response, both associated with many aspects of health and fitness, including severe cardiovascular outcomes.ObjectiveTo evaluate the effects of T2D on cardiac autonomic modulation by means of HRV and HRR measurements.Materials and MethodsThis study has an observational with case-control characteristic and involved ninety-three middle-aged adults stratified into two groups (control group - CG, n = 34; diabetes group - DG, n = 59). After signing the free and informed consent form, the patients were submitted to the evaluation protocols, performed biochemical tests to confirm the diagnosis of T2D, collection of R-R intervals for HRV analysis and cardiopulmonary effort test to quantify HRR.ResultsAt rest, the DG showed a reduction in global HRV (SDNN= 19.31 ± 11.72 vs CG 43.09 ± 12.74, p < 0.0001), lower parasympathetic modulation (RMSSD= 20.49 ± 14.68 vs 52.41 ± 19.50, PNN50 = 4.76 ± 10.53 vs 31.24 ± 19.24, 2VD%= 19.97 ± 10.30 vs 28.81 ± 9.77, p < 0.0001 for both indices) and higher HRrest when compared to CG. After interruption of physical exercise, a slowed heart rate response was observed in the DG when compared to the CG. Finally, a simple linear regression showed that fasting glycemia was able to predict cardiac autonomic involvement in volunteers with T2D.ConclusionPatients with T2D presented lower parasympathetic modulation at rest and slowed HRR after physical exercise, which may be associated with higher cardiovascular risks. The findings show the glycemic profile as an important predictor of impaired cardiac autonomic modulation.

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