Greater need for education regarding blood borne viruses

Dec 10 2007

A new cohort study could facilitate targeted interventions for adolescent offenders who are at a high risk of hepatitis C (HCV) infection and obesity related liver disease.

Researchers Dr David van der Poorten, Professor Dianna Kenny and Professor Jacob George sought to create a new definition for the normal upper limit of liver biochemistry to define the associations and implications of raised alanine aminotransferase (ALT).

ALT is measured to see if the liver is damaged or diseased. Low levels of ALT are normally found in the blood. However, when the liver is damaged or diseased, it releases ALT into the bloodstream, which makes ALT levels go up. Most increases in ALT levels are caused by liver damage.

The study, which is published in the December issue of Hepatology, examined the liver health of at risk adolescents examining data from a large cohort of young male offenders under supervision by the New South Wales Department of Juvenile Justice.

They examined the results of liver tests and lipid studies from blood samples of 439 young male offenders who agreed to participate in the health survey between October 2003 and December 2007. They also considered clinical, demographic, and lifestyle data and performed statistical analysis to determine relevant associations.

They determined that upper limit of normal for liver enzymes using the liver test of participants at low risk of liver disease (young men with normal BMI, cholesterol, triglycerides, and blood pressure; and no hepatitis B or C or high alcohol consumption). Those upper limits of normal were determined as being significantly lower than current upper limits for these tests.

Applying these cut offs to all participants, they found that 17 per cent had raised ALT, and compared to those with normal ALT, "there was a strong association for overweight and obesity," said Professor Kenny. "To prevent further hepatic damage and to minimise cardiovascular and diabetes risk, targeted interventions in adolescents at the earliest stages of metabolic dysfunction are a particularly high priority"

The new upper limit also detected 80 per cent of the HCV infected patients, who were significantly more likely to have injected drugs in the last 12 months.

"The study has provided a wealth of clinical and health related data relevant to adolescents," said Professor Kenny. "The new definition of normal adolescent ALT allows greater sensitivity in diagnosing early liver disease. By identifying those with hepatitis B, C and obesity related liver disease; targeted intervention can and should be implemented to minimise future health-related morbidity," she said.