The impact of propranolol on nitric oxide and total antioxidant capacity in patients with resistant hypertension—evidence from the APPROPRIATE trial

Abstract

Abstract Objectives The objective was to assess the effect of propranolol on oxidative stress and anti-oxidant potential in patients with resistant hypertension as a secondary analysis of the APPROPRIATE trial. This randomized double blinded clinical trial recruited patients with resistant hypertension and allocated forty patients to propranolol and placebo in 1:1 ratio. The pro-oxidant state (nitrate and nitrite) was assessed using modified Griess assay. The total anti-oxidant capacity was measured using ABTS assay. Results Analysis was performed for 18 patients from the propranolol group and 15 from the placebo group. A decline in end point ambulatory blood pressure (p = 0.031) and greater mean reduction in office SBP (29.7 ± 13.0 mmHg, p = 0.021) was noted in the propranolol arm. Nitrate and nitrite levels were lower at the end of a 90 day follow up period in both arms, with a greater mean reduction with propranolol. A significant increase in the AOC was noted in both arms with higher incremental value with Propranolol. The findings of this study do not demonstrate a statistically significant effect of propranolol on the oxidative stress/antioxidant balance in patients with resistant hypertension. The observed trends merit further evaluation.