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 NO2- 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 NO2-, 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 NO2- 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).