Associations between different heart rate variability ratios and cardiometabolic risk factors in young adults

Aims To study the association of two different heart rate variability (HRV) ratios with cardiovascular disease (CVD) risk factors in young adults. Method A total of 132 participants (89 women) were included in this cross-sectional study. We assessed their HRV and computed the low frequency-to-high frequency ratio (LF/HF) and, from the Poincare plot, the ratio of the inverse of the longitudinal (SD2) to the transversal (SD1) axes ([1000/SD2]/SD1; sympathetic: parasympathetic [S:PS] ratio). From blood samples, we determined total cholesterol, high-density (HDL-C) and low-density lipoprotein-cholesterol, triglycerides, glucose, insulin, and the homeostatic model assessment of insulin resistance (HOMA) index. Multiple linear regression models were adjusted for age. Results Both, the LF/HF and the S:PS ratios, were positively associated with glucose metabolism markers (glucose, insulin, HOMA index), and negatively associated with HDL-C in women but not in men. Conclusion We showed that the LF/HF and the S:PS are associated similarly with CVD risk factors in young women.