Liver tests are common, but the occurrence and consequences of abnormal results have been unclear. Now, a research team has determined that one in six people aged 75 years and older is likely to have at least one abnormal liver test, and those who have two or more are twice as likely to die from cancer and 17 times more likely to die from liver disease.
Using a random sampling of 13,276 patients registered with 53 general practices, the investigators compared patients who had abnormal liver tests with patients in the same age group who had normal results during an average follow-up period of just over seven years. The liver tests included those for abnormal levels of aspartate transaminase (AST), alkaline phosphatase (ALP), and bilirubin.
A total of 2,175 subjects (16.1%) had at least one abnormal test. In addition, 1.5% of patients had two abnormal tests, and 0.07% had three abnormal tests. The prevalence of a single abnormal liver test was 3.3% for AST, 9.2% for ALP, and 5.4% for bilirubin.
Abnormal AST was also associated with a sevenfold increased risk of death from liver disease. However, only 1.8% of patients with an abnormal AST died from liver disease during follow-up. Abnormal ALP carried a nearly sixfold increased risk of death from liver disease, and raised the risk of death from heart disease by 34%, cancer by 61%, and respiratory disease by 58%. Only 1% of patients with an abnormal ALP died from liver disease during follow-up (Aliment Pharmacol Ther. 2011;34:324-334).