Red Blood Cell Potassium as a Measure of Body Potassium in Thiazide-Treated Patients with Essential Hypertension

Abstract

In 34 patients with essential hypertension, 25 males and 9 females, red blood cell potassium (K_RBC), exchangeable potassium (K_E), and serum potassium (K_s) were determined after 4 weeks of treatment with 75 mg of hydrochlorothiazide daily, without additional KC1 or potassium-sparing diuretics, and again after another 5 weeks’ treatment, during which period supplements of either 60 mmol KC1 or 100 mg spironolactone were given daily. After thiazide treatment, K_RBC and K_E values were lower than in normal individuals. In the women, K_RBC and K_E were significantly correlated. After addition of KC1 or spironolactone, significant increases in K_RBC and K_E were found, but no significant correlation between these changes. It is concluded that the changes in exchangeable potassium are accompanied by changes in red blood cell potassium, but that correlation between these parameters is not pronounced.

Key Words:

• Diuretics
• erythrocyte potassium
• exchangeable potassium
• hypertension
• thiazide
• spironolactone