Low plasma renin activity is an independent predictor of near-term incidence of hypertension in Asian populations

Background: Plasma renin activity is involved in the regulation of body salt content and blood pressure. However, there is a paucity of data regarding the association between low or high plasma renin activity and the development of hypertension. Method: We investigated the relation of baseline plasma renin activity to increases in blood pressure and the incidence of hypertension after four years in 2,146 non-hypertensive individuals from a community-based Korean population (mean age, 50 years), 58% of whom were women. We defined an “increase in blood pressure” as an increment of systolic blood-pressure ≥ 10 mmHg or initiation of antihypertensive drugs and defined “hypertension” as a systolic blood pressure of 140 mm Hg or higher, a diastolic blood pressure of 90 mm Hg or higher, or the use of antihypertensive medications. Results: After 4 years, the increase in blood pressure had increased in 27.9% of the participants, and hypertension had developed in 17.9%. After adjustment, the lowest sex-specific tertile of plasma renin activity was an independent risk factor of an elevation in blood pressure (Adjusted Odds Ratio 1.37, 95% confidence interval 1.07–1.74, p = 0.011) and hypertension (Adjusted Odds Ratio 1.84, 95% confidence interval 1.36–2.50, p < 0.001) compared to the highest sex-specific tertile. The associations between the plasma renin activity and blood-pressure outcomes were evident in adults with especially high urine sodium excretion. Conclusion: Low plasma renin activity was associated with the development of hypertension in the middle-aged Asian population, especially in peoples with high sodium intake.