High Prevalence of Liddle Syndrome Phenotype Among Hypertensive US Veterans in Northwest Louisiana

Abstract

Liddle syndrome (LS) is an autosomal dominant disorder due to a gain-of-function mutation in the epithelial Na(+) channel and is perceived to be a rare condition. A cross-sectional study of 149 hypertensive patients with hypokalemia (<4 mmol/dL) or elevated serum bicarbonate (>25 mmol/dL) was conducted at a Veterans' Administration Medical Center Hypertension Clinic in Shreveport, LA. Data on demographics, blood pressure, and select blood tests were collected and expressed as percentages for categoric variables and as mean ± standard deviation (SD) for continuous variables. Patients were diagnosed with likely LS when the plasma renin activity (PRA) was <0.35 μU/mL/h and the aldosterone was <15 ng/dL and likely primary hyperaldosteronism (PHA) with PRA <0.35 μU/mL/h and aldosterone level >15 ng/dL. The cohort included predominantly elderly (67.1±13.4 years), male (96%), and Caucasian (57%) patients. The average blood pressure was 143.8/79.8 mm Hg±27.11/15.20 with 3.03±1.63 antihypertensive drugs. Based on the above criteria, 9 patients (6%) satisfied the criteria for likely LS and 10 patients (6.7%) were diagnosed with likely PHA. In this hypothesis-generating study, the authors detected an unusually high prevalence of biochemical abnormalities compatible with likely LS syndrome from Northwestern Louisiana, approaching that of likely PHA.