Evaluation on heart rate variability parameters in elderly with type 2 diabetes mellitus using principal component analysis

BACKGROUND: Cardiac autonomic neuropathy in type 2 diabetes mellitus (T2DM) patients is frequent and associated with high cardiovascular mortality. Our aim was to evaluate the impact of T2DM on HRV parameters among elderly women using principal’s components analysis (PCs).METHODS: This study was designed as a cross-sectional study of consisted of 20 elderly subjects 60 to 70 years of old. All subjects were diagnosed with T2DM, selected at random from the Project of the Health Promotion Program in Macapá (AP). All subjects were instructed to lie in the supine position for 5 min at rest while breathing normally with a heart rate monitor Polar V800 working at a sampling rate of 1000 Hz was used to record RR intervals (RRi). The HRV analysis in the time domain was performed by the SinusCor Matlab package software to obtain the classical parameters pNN50, SDNN, RMSSD and MeanRRi and, subsequently, re-sampling procedure to bootstrapping based on 1000 samples. The PCs involve the calculation of the eigenvalue decomposition of the HRV parameters covariance matrix and use of the biplot graph, in order to understand the importance of each variable.RESULTS: T2DM was associated with RMSSD (PC1: 0.81 and PC2: -0.03) and SDNN (PC1: 0.57 and PC2: -0.04) HRV parameters showed greater contributions to PC1 and the MeanRRi HRV parameter (PC1: 0.06 and PC2: 0.98) showed bigger contributions to PC2.CONCLUSIONS: The benefits of HRV evaluation in assessing and monitoring the severity of T2DM should be potential as a non-invasive, reliable and pain-free measurement.