Prevalence and Etiology of Elevated Aminotransferases in a Cohort of Patients referred to a German University Hospital

Elevated liver enzyme values are associated with an increased risk of liver-specific mortality but are also a risk factor for non-hepatic diseases including diabetes mellitus type 2, metabolic syndrome, cardiovascular diseases and malignancies. Many liver diseases identified by an ALT screening can be treated successfully including prevention of development of clinical endpoints. Our aim was to study the prevalence and etiology of elevated liver enzymes in patients referred to a German University Hospital. Methods: 4,786 patients referred to the Department of Internal Medicine (General Internal Medicine, Gastroenterology, Cardiology, Nephrology), University of Kiel, were screened routinely for liver enzymes (ALT, AST, GGT, alkaline phosphatase, bilirubin) in a 6-month period. Patients with elevated aminotransferases but no evidence for viral associated hepatitis (Hepatitis A, B, C, D, E; CMV, EBV) were further analyzed in a retrospective cohort study. Results: Of the 4,786 patients 408 cases (8.5%) showed elevated AST/ALT values with no evidence for viral hepatitis. GGT values were elevated in 1,229 cases (25.6%) and alkaline phosphatase/bilirubin values in 175 cases (3.6%). By studying the individual health records 206 patients (50.5%) of the 408 cases with elevated ALT/AST values were analyzed for liver associated diseases. Non-alcoholic fatty liver disease (NAFLD) was diagnosed in 68 cases (33%) (NASH 47 cases, NASH associated cirrhosis 21 cases). Presumed alcoholic liver disease was found in 35 cases (16.9%) (alcoholic cirrhosis 16 cases). In 24 cases (11.6%) drug-induced liver toxicity and in 17 cases (8.2%) acute liver failure was recorded. Malignant liver tumors were found in 27 cases (13.1%) (Hepatocellular carcinoma 14 cases, metastases 13 cases). Conclusion: In our retrospective study patients referred to a tertiary hospital and screened for elevated AST/ALT values in half of the patients a liver-associated disease was diagnosed, most frequently caused by NAFLD, alcoholic liver disease or drug-induced liver toxicity. Thus abnormal liver enzymes should lead to focused investigation for underlying liver disease.

Corresponding author: Günther, Rainer

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