To the Editor, I read the paper by Silva et al. entitled ‘‘Sensitivity, Specificity and Predictive Value of Heart Rate Variability Indices in Type 1 Diabetes Mellitus’’ published in Arquivos Brasileiros de Cardiologia in March 2017. They aimed to compare Heart Rate Variability (HRV) indices and evaluate their sensitivity, specificity, and predictive value in young type 1 diabetic patients and healthy volunteers. It was showed a decrease in sympathetic and parasympathetic activities, as well as overall variability of autonomic nervous […]