Epidemiology

ALT level a measure of overall health

Last Updated: 2006-10-31 13:21:05 -0400 (Reuters Health)

By Karla Gale

NEW YORK (Reuters Health) - Physicians, and the public at large, should pay more attention to serum levels of alanine aminotransferase (ALT), according to recommendations from the American Association for the Study of Liver Diseases (AASLD).

"There is growing evidence that ALT is a marker of general health," Dr. Adrian Di Bisceglie told Reuters Health. "ALT needs to be accorded some respect and attention." Dr. Di Bisceglie is chair of the public policy committee for AASLD and professor of internal medicine at St. Louis University.

The relative importance of ALT as a gauge of general health is illustrated by a presentation this week at the AASLD annual meeting in Boston.

Dr. W. Ray Kim and associates at the Mayo Clinic College of Medicine in Rochester, Minnesota studied residents of Rochester, 18,330 of whom had their aspartate aminotransferase (AST) level measured and 6792 who had their ALT measured at least once in 1995. Abnormally high AST levels were documented for 2339, and abnormally high ALT levels in 907.

Dr. Kim's group observed an increase standardized mortality ratio (SMR) for all causes of death among subjects with elevated levels of either enzyme. For subjects with AST levels greater than 2-times the upper limit of normal, the SMR was 1.79, and for ALT, it was 1.63 (p < 0.01 for both). For AST levels, any elevation above normal was significantly associated with increased risk of death.

In their meeting abstract, the investigators emphasize that the increased SMR included not only mortality from liver disease, but from all other causes as well.

Findings like these bolster the AASLD's campaign for adoption of ALT as one of the measurements in the Health Plan and Employer Date Information Set (HEDIS) used in accrediting health plans, Dr. Di Bisceglie said. "To be accredited, HEDIS requires that children be vaccinated and that women undergo routine screening for breast cancer, but there is no mention of testing for measures of liver disease."

Many deaths are caused by viral hepatitis, and many deaths are due to fatty liver disease, he continued, "and only a small part of these deaths are due to alcohol and drug abuse," as is often assumed by the public.

"So if ALT levels are increased, physicians should rule out important, treatable causes of liver disease, such as viral hepatitis," Dr. Di Bisceglie stressed. "After that, physicians can assume the elevated liver enzyme levels are due to fatty liver disease, and they should consider modifiable lifestyle issues, such as obesity and lack of physical exercise as the cause."