Cardiovascular and metabolic risk markers are related to parasympathetic indices in pre-pubertal adolescents

Objective To analyse the relationship between different heart rate variability indices, resting heart rate, and cardiovascular markers in adolescents. Methods A cross-sectional study was carried out with information from an ongoing cohort study. The sample was composed of 99 adolescents who complied with the following inclusion criteria: aged between 11 and 14 years; enrolled in a school unit of elementary education; absence of any known diseases; no drug consumption; and a formal consent signed by the parents or legal guardians. Weight, height, heart rate variability, lipid profile, inflammatory markers, blood pressure, resting heart rate, intima-media thickness, blood flow, and trunk fatness were measured. Partial correlation and linear regression (expressed by and 95% confidence intervals [95%CI]) analyses were used to analyse the relationships between the variables. Results In the linear regression analysis, even after adjustments for sex, age, trunk fatness, and somatic maturation, parasympathetic activity presented significant correlations with maximum carotid artery blood flow (=-0.111 [95%CI=-0.216; -0.007]), systolic blood pressure (=-0.319 [95%CI=-0.638; -0.001]), and resting heat rate (=-0.005 [95%CI=-0.009; -0.002]). Conclusion Parasympathetic activity at rest is inversely related to maximum and minimum blood flow, triacylglycerol levels, and systolic blood pressure. These findings suggest that heart rate variability has the potential to discriminate pre-pubertal adolescents at increased risk.