Increment in Systolic Blood Pressure During Cold Pressure Test Is Associated with Baseline LF Power in Young Prehypertensive Men
Authors: Shekh Vera Evgenievna 
Published: June 2021

The cold pressor test (CPT) is commonly used as a sympathoexcitatory maneuver to provoke an increment in arterial pressure and heart rate and to measure cardiovascular reactivity to stress. However, use of the CPT as a predictor test of future hypertension is still debatable. We investigated whether exaggerated blood pressure responsiveness to CPT is observed in young prehypertensive men and determined baseline HRV indices and autonomic nervous system contribution into the elevation of blood pressure.

CPT was performed in 81 normotensive and 72 prehypertensive men enrolled from V.N. Karazin Kharkiv National University student population. All participants gave written informed consent. After 5 min resting stage subjects placed their right hand into ice‐cold water for 1 minute. ECG was continuously recorded and resting HRV indices were interpreted (CardioLab 2010). Blood pressure was measured at the end of each stage (Nissei WS‐1011). GLM one‐way MANOVA and MANCOVA with height and BMI were used to test for possible effects of prehypertension on heart rate (ΔHR) and blood pressure (ΔSBP and ΔDBP) responses. The stepwise multiple linear regression analysis was carried out to assess the relative importance of baseline LnLF (LnLFrest) and LnHF (LnHFrest) power in HR, SBP, and DBP increments, adjusted also for the presence of prehypertension, BMI, height, and two‐way interactions.

In the current study, prehypertensive subjects did not demonstrate higher cardiovascular reactivity to CPT (Table 1). Moreover, normotensives had higher SBP response to CPT (Table 1). When height and BMI were taken into account this difference was even more significant (not shown). Previous studies have yielded inconsistent results with some showing higher and some showing the same and even lower blood pressure reactivity to CPT in prehypertensive subjects or in persons with family history of hypertension.

The stepwise multiple regression analysis revealed that ΔSBP in prehypertensives and ΔDBP in all subjects were negatively associated with LnLFrest possibly indicating, according to our hypothesis, activity of the inhibitory interneurons projected to the presympathetic neurons in the rostral ventrolateral medulla. The central inhibition of sympathetic activity reduced the increment of SBP in subjects developing hypertension and controlled increment of DBP in all subjects (Table 2).

It was shown that increments in both SBP and DBP were associated with ΔHR only in the prehypertensive subjects and in persons with increased BMI (Table 2). These findings may be partially explained by blunting of baroreceptor reflex sensitivity and/or resetting of the baroreceptor reflex to a higher control point.in prehypertensives and in subjects with increased BMI. The increments in SBP and DBP associated also with ΔHR in subjects with a high level of baseline parasympathetic activity as shown by the positive association between LnHFrest by ΔHR interaction and ΔSBP or ΔDBP (Table 2) possibly because high LnHFrest reduces HR and increases atrioventricular delay which may contribute to a ventricular filling.

In conclusion, young prehypertensive subjects demonstrated lower SBP response to CPT than normotensives possibly due to their increment in SBP was associated with resting LnLF power, indicating according to our hypothesis, inhibition of the presympathetic medullary neurons; ΔSBP and ΔDBP were associated with ΔHR only in prehypertensives and in persons with high baseline parasympathetic activity.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.