High serum levels of reactive nitrogen species and low total antioxidant capacity in patients with resistant hypertension compared to those in age- gender matched healthy controls, controlled hypertension and follow up with propranolol treatment in the extended APPROPRIATE trial.

OBJECTIVES

To perform a comparative analysis of the extended APPROPRIATE trial of measures of reactive nitrogen species and antioxidant capacity in patients having resistant hypertension with controlled hypertension and healthy controls.

RESULTS

Mean serum NO- and NOx levels were significantly lower and mean AOC was significantly higher in patients with controlled hypertension (n = 38) and healthy controls (n = 38) compared to resistant hypertension (RHTN) patients (n = 40) at the pre-intervention stage (p < 0.001). The serum NO-, NOx and AOC levels of both controlled hypertension and healthy controls were comparable to those of the RHTN patients following treatment with propranolol (n = 18). Considering all samples (n = 114) we noted that there were significant weak and moderate positive correlations between NO levels with systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r = 0.396, p < 0.001 and r = 0.292, p = 0.004) as well as total NOx levels with SBP and DBP (r = 0.636 and r = 0.480 respectively, p < 0.001). Conversely, there was a significant negative correlation between AOC levels with SBP and DBP (r= -0.846 and r = -0.626 respectively, p < 0.001).