Predictors of the Development of Hyperkalemia in Patients Using Angiotensin-Converting Enzyme Inhibitors

Abstract

Angiotensin-converting enzyme inhibitors (ACEI) are the antihypertensives of choice in patients with chronic renal failure (CRF). ACEI by decreasing the synthesis of aldosterone, the main regulator of serum potassium, predispose to the development of hyperkalemia. Although hyperkalemia with administration of ACEI is uncommon in patients with a normal renal function, a preexisting abnormality in potassium hemostasis, as seen in patients with chronic renal failure, may increase the risk of hyperkalemia. To determine the predictors of development of hyperkalemia (K >5.1 mEq/l) in patients on ACEI, we retrospectively reviewed medical records of 119 patients followed in our renal clinic. The mean age of the patients was 56 +/- (SD) 13 (range 20-84) years. Sixty-three percent were males, and 37% were females. Sixty-seven percent had a history of diabetes. Eighty five percent of the patients had CRF [creatinine clearance (CrCl) <80 ml/min]. The baseline serum Cr was 2.3 +/- 1.2 (range 0.6-6.9) mg/dl, and the CrCl was 50 +/- 27.5 ml/min. Of the 119 patients 46 (38.6%) developed hyperkalemia (mean K 5.68 +/- 0.3, range 5.2-6.7 mEq/l). Ninety-six percent of the patients who developed hyperkalemia had CRF, and 84% were diabetics. Pearson product-moment correlation revealed a significant positive correlation of hyperkalemia with Cr and a negative correlation of hyperkalemia with CrCl and HCO(3) (Cr: r = 0.42, p < 0.0001; CrCl: r = -0.34, p < 0.0001; HCO(3): r = -0.41, p < 0.0001). Multivariate logistic regression analysis revealed diabetes and serum creatinine to be the main predictors of hyperkalemia. In 31 patients hyperkalemia resolved either with a low-potassium (2 g/day) diet or with diet and a decrease in the dose of ACEI. In 15 patients ACEI had to be discontinued due to persistent hyperkalemia. We conclude that hyperkalemia is common in patients with CRF on ACEI. The majority of the patients who develop hyperkalemia on ACEI have CRF and diabetes. A large number of patients with CRF require discontinuation of ACEI due to hyperkalemia and are deprived of their renoprotective effects.