Different LF and HF HRV responses to cold pressor test in normotensive and prehypertensive men

Hypertension is a global health problem and a risk factor of cardiovascular disease, cerebrovascular and kidney disease. The cold pressor test (CPT) is commonly used as a sympathoexcitatory manoeuvre. Heart rate variability (HRV) is a useful tool for assessment of autonomic nervous system activity. The aim of this study was to evaluate cardiovascular and HRV responsiveness to CPT in 46 normotensive and 25 prehypertensive (PHT) young man. In ECG was recorded at rest and CPT for 5 min each to evaluate heart rate (HR), total power (TP), low frequency (LF) and high frequency (HF) power. General linear model was used to test for effect of prehypertension and CPT on HR, systolic blood pressure (SBP), diastolic blood pressure (DBP) and HRV variables and their responses to cold. The stepwise multiple linear regression analysis was used to reveal predictors of ∆HR, ∆SBP and ∆DBP. All analyses were conducted using SPSS 22. Blood pressure responsiveness to CPT was not associated with PHT; instead, it was associated with BMI. The ∆HR, ∆SBP, and ∆DBP were not significantly different between normotensive and prehypertensive subjects. However, ∆LnTP, ∆LnLF, and ∆LnHF were significantly higher in normotensives than in prehypertensives: LnTP, LnLF, and LnHF increased in normotensive subjects while these indices decreased in prehypertensives.