Association of negative affect with resting heart rate variability in medical students.

Resting heart rate variability (HRV) reflects rhythmic changes in heart rate over time associated with autonomic nervous system (ANS) activity. It has served as a predictor of health and the development of various diseases. Therefore, it is important to determine factors that could potentially influence HRV. The aim of our study was to investigate whether negative affect is associated with resting HRV, heart rate and blood pressure (BP). The research sample consisted of 425 medical students (294 women) (mean age 20.8 ± 1.5 years). Exclusion criteria included the presence of any significant medical condition and/or the use of any related medications. HRV was measured for 5 min in the supine position. Predictor variables included neuroticism (NEO-FFI), perceived stress over the past month (PSS-10), state anxiety (STAI-X1). Covariates included sex, age, BMI, allergy, physical activity, sleep quality, respiration rate. Dependent variables included logarithmically transformed (ln) HRV parameters (RMSSD, HF, SDNN, LF), heart rate, ln systolic and ln diastolic BP. Hierarchical linear regression was used for statistical analysis, and a Bonferroni correction was applied to the p-value of the change in the coefficient of determination. Resting HRV, heart rate, and BP were not statistically significantly associated with neuroticism, perceived stress, or state anxiety. Our results demonstrated a lack of association between negative affect and resting cardiac ANS activity in the sample of non-clinical young adults.