Abstract 11900: Potassium Magnesium Citrate is Superior to Potassium Chloride in Reversing Metabolic Side Effects of Chlorthalidone

Abstract

Thiazide-type diuretics (TD) are the first-line treatment of hypertension in many guidelines because of its consistent benefit in lowering BP and cardiovascular risk. TD is also known to cause excess risk of diabetes mellitus (DM), which may limit its long-term use. Although hypokalemia was thought to be the main mechanism of TD-induced dysglycemia, potassium (K) supplementation alone does not consistently prevent TD-induced elevation in fasting plasma glucose (FPG). In addition to reducing serum K, TD triggers magnesium (Mg) depletion. However, it is unknown if Mg supplementation attenuates metabolic side effects of TD. Accordingly, we conducted a randomized double-blinded clinical trial in 60 hypertensive patients without DM to compare effects of KCl (40 meq daily) vs. KMgCitrate (Cit) powder containing identical amount of K, 20 meq of Mg, and 74 meq of Cit daily during chlorthalidone (CTD) treatment. Each patient received CTD alone (25 mg/day) for 3 weeks prior to randomization. The primary endpoint was the change in FPG after 4-month of treatment from baseline (CTD alone) after adjusting for baseline FPG as a covariate. The mean age of subjects was 59±11 years (45% Female, 30% Black participants). We found that CTD induced a significant rise in FPG, insulin, and a significant fall in serum K and 24-h urinary citrate excretion (all p < 0.05). We found that KMgCit significantly increased serum K, 24-hour urinary Mg, and 24-hour urinary Cit excretion; and attenuated the rise in FPG which was not observed with KCl (Figure 1 A-C). There were no significant differences in liver fat by MRI or fasting plasma insulin between the 2 groups. In conclusion, our study showed beneficial effects of magnesium supplementation in maintaining serum K and reversing effects CTD on plasma glucose, which may improve safety profile and optimize long-term cardiovascular outcomes in hypertensive patients.