Age, body mass index, and menstrual cycle influence young women's heart rate variability --a multivariable analysis

Heart rate variability (HRV) in women has been related independently to endogenous sex hormones, hormone replacement therapy, menopause, menstrual cycle, body mass index (BMI), and physical conditioning. However, the joint influence of all these factors has not been reported. The present study describes the relation between circadian variation HRV and assesses its association with BMI, age, and menstrual cycle in healthy young women. A multivariable analysis was performed to estimate the predictive variables involved in SDNN, pNN50, and rMSSD profile, using the classification and regression tree (CART) and the logistic regression models. It was found that the first predictive variable was age, which divided women in two groups: >29.5 years old and