USA: A recent study published in Hypertension has shown potassium magnesium citrate (KMgCit) to be superior to potassium chloride (KCl) in preventing thiazide diuretic (TD)-induced hyperglycemia in patients with hypertension without diabetes. Potassium chloride is the common form of potassium supplement used in clinical practice.
Thiazide diuretics are the first-line hypertension treatment because of their consistent benefit in lowering blood pressure (BP) and cardiovascular (CV) risk. TD is also known to cause an excess diabetes risk, which may limit long-term use. Potassium depletion is suggested to be the main mechanism of TD-induced hyperglycemia, TD also triggers, but also triggers magnesium (Mg) depletion.

There has been no investigation of the role of Mg supplementation in modulating metabolic side effects of TD. Considering this, Wanpen Vongpatanasin, University of Texas Southwestern Medical Center, Dallas, TX, and colleagues aimed to determine the effect of KMgCit on fasting plasma glucose and liver fat by magnetic resonance imaging during thiazide diuretic therapy.
For this purpose, they conducted a double-blind RCT comprising 60 nondiabetic hypertension patients to compare the effects of KCl versus KMgCit during chlorthalidone treatment. Each patient received chlorthalidone alone for three weeks before randomization. The primary endpoint was the change in fasting plasma glucose following 16 weeks of KMgCit or KCl supplementation from chlorthalidone alone. The mean age of subjects was 59±11 years.
The study revealed the following findings:
Chlorthalidone alone induced a significant rise in fasting plasma glucose, and a significant fall in serum K, serum Mg, and 24-hour urinary citrate excretion.
KMgCit attenuated the rise in fasting plasma glucose by 7.9 mg/dL versus KCl, which was not observed with KCl.
There were no significant differences in liver fat between the 2 groups.
"These findings suggest that potassium magnesium citrate may offer a superior alternative to potassium chloride, typically used in clinical practice, in maintaining serum potassium during thiazide-diuretic treatment while avoiding thiazide-induced hyperglycemia," the researchers wrote.
'This action may improve cardiovascular safety and tolerability in patients with hypertension treated with this drug class," they concluded.
Reference:
Vongpatanasin W, Giacona JM, Pittman D, Murillo A, Khan G, Wang J, Johnson T, Ren J, Moe OW, Pak CCY. Potassium Magnesium Citrate Is Superior to Potassium Chloride in Reversing Metabolic Side Effects of Chlorthalidone. Hypertension. 2023 Dec;80(12):2611-2620. doi: 10.1161/HYPERTENSIONAHA.123.21932. Epub 2023 Oct 17. PMID: 37846572.