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Updated: Jan 20, 2026
Sample Proportion and Population Proportion
A significant proportion of patients with choledocholithiasis have markedly elevated alanine aminotransferase
Helgi K Björnsson1,2, Einar S Björnsson1,2
1Division of Gastroenterology and Hepatology, Department of Internal Medicine, The National University Hospital of Iceland , Reykjavik , Iceland.
Abstract:
Objective: To determine the frequency and nature of liver enzyme elevations among patients presenting with choledocholithiasis (CDL). Methods: A prospective study identified all patients with serum level of alanine aminotransferase (ALT) ≥500 U/L (normal levels: <70 U/L in men, <45 U/L in women) over 1 year. Additionally, other patients with CDL were identified during the same period retrospectively by diagnostic codes and ERCP procedures, providing data on all CDL patients. Symptoms, liver tests, history of cholecystectomy, and radiological imaging were analyzed. Patients with radiologically confirmed CDL or a clinical diagnosis of CDL were included. Results: During the study period, 110 patients had CDL, 60% women, mean age 65 years. Overall 86/110 (78%) had confirmed CDL on imaging and 24/110 (22%) clinically diagnosed. Overall 26% had undergone cholecystectomy, median bile duct diameter 10.0 mm, median maximal liver tests: ALT 436, ALP 226, bilirubin 60 μmol/L (<25). Overall 9/110 (8%) had ALT ≥1000, 43/110 (39%) ALT levels between 500 and 1000 IU/L and 58/110 (53%) had ALT <500 IU/L. Patients with ALT ≥1000 had smaller bile duct diameter of 7 versus 10 mm (p < .001) but similar proportions of cholecystectomies. In the multivariate analysis age, maximal AST and maximal bilirubin were independent predictors of ALT >500. Maximal AST and bile duct diameter were independent predictors of ALT >1000. Conclusions: Approximately 8% of patients with CDL had markedly elevated ALT. These patients had smaller bile duct diameter. Pronounced ALT elevation is a part of the clinical spectrum of CDL.
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