Aldosterone to renin ratio as a determinant of exercise blood pressure response in hypertensive patients

Abstract

Aldosterone to renin ratio (ARR) is a marker of inappropriate aldosterone activity in hypertension. Since aldosterone may adversely affect vascular compliance, we hypothesised that the ARR would relate to exercise blood pressure (BP) responses in hypertension. Blood sampling was done in untreated hypertensives for plasma renin activity (PRA, ng/mL/hr) and plasma aldosterone (PA, pmol/L). ARR was derived by dividing the PA value by the PRA value, and this index was normalised by natural logarithm (lnARR) for further analyses. Each patient underwent 24-h ambulatory BP (ABP), and a 3-min submaximal exercise test using the Dundee Step Test. The Spearman rank correlation coefficients between lnARR and office BP (OBP), ABP and exercise BPs and BP changes estimated during exercise were assessed. A total of 119 (66 males) hypertensive subjects aged 48 (s.d. 12) years were studied. The respective OBP, ABP, exercise BP and the change in exercise BP were 167(23)/105(11), 140(15)/87(10), 189(26)/107(12) and 25(15)/2(9) mmHg. lnARR was significantly correlated with exercise systolic BP (r = 0.24, P < 0.001), exercise diastolic bp (r = 0.23, P < 0.05), systolic abp (r = 0.22, P < 0.05) and systolic obp (r = 0.19, P < 0.05). in a multiple regressional analysis controlling for age and sex and all other bp measurements to assess the relative strengths of correlation between all the bp indices with lnarr, only exercise systolic bp (P = 0.012) and the change in systolic BP during exercise (negatively, P = 0.013) emerged as significant independent predictors of lnARR. In conclusion, there was an independent and significant correlation between ARR and exercise systolic BP.