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 DundeeStep 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 respect-