Background: Although higher plasma renin activity (PRA) is associated with poor clinical outcomes including higher death and cardiovascular events, its association with prevalence of chronic kidney disease (CKD) is not clear. We hypothesized that higher levels of PRA and lower levels of aldosterone-to-PRA ratios (ARRs) are associated with greater CKD prevalence in a large and ethnically diverse population of southern California who underwent uniform healthcare.
Methods: During the period 1 January 1998 to 31 October 2009, the adult population who was under the care of Kaiser Permanente Southern California with documented outpatient values of PRA and minimum of 6 months continuous enrollment were examined. CKD defined by an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m2. PRA levels and ARR were categorized into quartiles. Multivariate logistic regressions were used to calculate odds ratios for CKD based on PRA controlling for age, sex, black race, diabetes status, hypertension, and type of medication use.
Results: We identified 9495 individuals including 7887 with hypertension. Study population included 60% women, 35% whites, 20% blacks, 20% Hispanics, and 26% diabetic patients. Adjusted odds ratios (95% confidence interval) for CKD across second, third, and fourth quartiles of PRA quartile (reference: first quartile) were 1.5 (1.2-1.7), 1.5 (1.3-1.8), and 2.2 (1.9-2.6), respectively. Each 10-unit increase in PRA was associated with odds ratio for CKD of 1.3 (1.2-1.4). ARR showed a similar but inverse trend with CKD.
Conclusion: Higher levels of PRA are associated with greater rates of CKD in our large ethnically diverse population of primarily hypertensive patients. Whether modulation of PRA can mitigate prevalence of CKD needs to be studied in interventional trials.