Effect of Adrenomedullin on Cardiovascular Response to Sympathetic Autonomic Stress in Normotensive and Hypertensive Nigerians

Abstract

Adrenomedullin is a potent vasodilator with established cardio-protective potentials when the body is exposed to stress. Sympathetic autonomic stress can lead to systolic (SBP) and diastolic blood pressure (DBP) reactivity which is a predictor of stroke. This study was to determine the effect of Adrenomedullin on cardiovascular response to sympathetic autonomic stress using the Cold Pressor Test in normotensive (NT) and hypertensive (HT) adults. Cardiovascular response to the CPT was measured among 30 NT and 30 HT participants, via blood pressure and heart rate before and after exposure to the cold pressor test (CPT). Plasma Adrenomedullin (ADM) was also determined by means of ELISA. Data were expressed as mean±S.E.M and statistical significance was accepted at 95% confidence interval. Exposure to CPT led to significant increases in SBP and DBP in both NT and HT participants with greater effect in HT (p<0.0001). Plasma Adrenomedullin was significantly higher among the NT but the difference on effect of response to CPT in both groups of participants was not significant. There was a negative and insignificant correlation between the ADM level and change in SBP and DBP among the NT participants but a positive and insignificant correlation with both SBP and DBP among the HT participants. We conclude that plasma Adrenomedullin may prevent the development of hypertension in black individuals.