Dimensional analysis of heart rate variability parameters for metabolic dysfunctions diagnosis

Obesity, metabolic syndrome (MS) and insulin resistance (IR) are diseases related to lifestyle, they have become a social and public health problem. There are numerous diagnostic criteria of MS, the most used is the diagnostic criterion according to NCEP-ATP III and the NCEP-ATP III revised version. Otherwise, obesity and IR are diagnosed through HOMA-IR and body mass index (BMI), respectively. These methods have diagnostic limitations; in HOMA-IR case there can be false negatives in incipient stages of the disease. BMI may show false positives in subjects with a high percentage of muscle mass. In addition to the anthropometric and biochemical variables, other types of parameters have been studied for the diagnosis of obesity, MS and IR; studies reveal that heart rate variability (HRV) parameters can discriminate between diabetic, MS and control subjects. The aim of this research is to propose dimensionless indexes that can be used to diagnose subjects with MS, IR and obesity using HRV parameters (RR, RMSSD, SD, HF and LF). For this purpose, seven dimensionless indexes, designed from the π Vaschy-Buckingham theorem, were assessed using ROC curves and a database of 40 subjects. The index π₁, built with the variables: HF and RMSSD; obtained a better performance as classifier of MS, IR and obesity, presenting an area under the ROC curve greater than 0.70, a sensitivity and specificity greater than 0.70 in each pathology. The π1 dimensionless index designed in this study is a simple method that allows diagnosing three pathologies from a non-invasive test such as electrocardiogram.