To investigate the association between serum potassium/hypokalemia and electrocardiographic left ventricular hypertrophy (ECG-LVH) in patients with hypertension or primary aldosteronism (PA).

A retrospective analysis was performed in 1 107 patients with hypertension admitted to the Hypertension Center of Xinjiang Uygur Autonomous Region People′s Hospital between January 2010 and January 2014, who underwent standardized PA screening and simultaneously measured blood potassium and electrocardiogram, and 177 patients were diagnosed with PA. Logistic regression analysis was used to evaluate the association between serum potassium/hypokalemia and ECG-LVH in patients with hypertension or PA. Area under the operating characteristic curve (AUC) was used to assess the accuracy of serum potassium/hypokalemia to predict the ECG-LVH risk.

Serum potassium (OR=0.482, P=0.033) and hypokalemia (OR=1.819, P=0.033) were respectively associated with ECG-LVH, independent of blood pressure, renin activity, and aldosterone-to-renin. And in PA patients, these associations were significantly independent of systolic blood pressure [(OR=0.070, P=0.004) and (OR=6.472, P=0.007)], respectively. Moreover, serum potassium can screen for ECG-LVH risk with AUCs of 0.607 and 0.784 in patients with hypertension or PA. When serum potassium <3.28 mmol/L in patients with PA, the predict value of ECG-LVH risk were high, with sensitivity and specificity of 71.4% and 89.6%, respectively.

Both serum potassium and hypokalemia are independently associated with ECG-LVH, regardless in patients with hypertension or PA. Especially in patients with PA, hypokalemia is associated with cardiac hypertrophy.