Abstract: FR-PO0897
Late-Onset Suspected Liddle Syndrome Presenting with Refractory Hypokalemia and Resistant Hypertension
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Case Reports - 1
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Anwar, Amna, Jefferson Einstein Philadelphia Hospital, Philadelphia, Pennsylvania, United States
- Elrefy, Omar A., Jefferson Einstein Philadelphia Hospital, Philadelphia, Pennsylvania, United States
- Chewaproug, Daranee, Jefferson Einstein Philadelphia Hospital, Philadelphia, Pennsylvania, United States
- Mubin, Fareeha, Jefferson Einstein Philadelphia Hospital, Philadelphia, Pennsylvania, United States
- Ahmed, Zahoor, Jefferson Einstein Philadelphia Hospital, Philadelphia, Pennsylvania, United States
Introduction
Liddle syndrome is a rare gain-of-function disorder of the epithelial sodium channel (ENaC) characterized by hypertension, hypokalemia, metabolic alkalosis, and suppressed renin–aldosterone levels. Although it usually presents earlier in life, delayed presentations may occur and remain underrecognized. We describe an elderly patient with suspected late-onset Liddle syndrome.
Case Description
A 78-year-old woman with hypertension, prior cerebrovascular accidents with residual left hemiplegia, peripheral arterial disease, and deep vein thrombosis on anticoagulation presented with syncope. Blood pressure remained elevated at 150–160 mmHg despite angiotensin receptor blocker therapy.
Laboratory evaluation revealed severe anemia (hemoglobin 4.6 g/dL) from a bleeding duodenal arteriovenous malformation treated endoscopically. Hypokalemia to 2.7 mmol/L persisted despite potassium supplementation exceeding 120 mEq/day.
Further workup showed metabolic alkalosis and renal potassium wasting with a urine potassium-to-creatinine ratio of 26 mEq/g. Aldosterone and ACTH levels were suppressed. The patient denied diuretic use, licorice ingestion, vomiting, or diarrhea. Adrenal imaging was unremarkable.
Spironolactone failed to improve hypokalemia. Triamterene 50 mg twice daily was initiated for suspected ENaC-mediated potassium wasting, resulting in rapid potassium normalization and improved blood pressure control. Outpatient genetic testing for ENaC mutations is planned.
Discussion
This case illustrates suspected late-onset Liddle syndrome in an elderly patient with resistant hypertension and refractory hypokalemia. Metabolic alkalosis, renal potassium wasting, suppressed aldosterone, and lack of response to spironolactone strongly suggested ENaC-mediated sodium retention.
Although Liddle syndrome usually presents earlier in life, delayed diagnosis in older adults has been reported. The absence of longstanding hypokalemia does not exclude the diagnosis, as hypokalemia may exhibit incomplete penetrance. Rapid response to triamterene further supported ENaC hyperactivity.
Primary hyperaldosteronism was less likely given suppressed aldosterone and poor response to spironolactone. Early recognition is important, as ENaC inhibition can rapidly correct electrolyte abnormalities and improve blood pressure control even before genetic confirmation is obtained.