Serum alanine aminotransferase, metabolic syndrome, and cardiovascular disease in an Australian population.

OBJECTIVES: Elevations of serum alanine aminotransferase (ALT) are common and have been associated with metabolic syndrome (Met S) and cardiovascular risk. The aim of this study was to determine whether elevated ALT concentrations are predictive of Met S or cardiovascular events.

METHODS: In 1994/95, surviving participants of the previously conducted Busselton health population surveys completed a series of clinical and biochemical assessments. Using the Western Australian Health Department data linkage system, admissions for cardiovascular disease (CVD) were determined for 15 years before the survey (from 1980 to 1994). Incident CVD events during the 10-year follow-up period to the end of 2004 were also ascertained. Met S was defined using NCEP ATP III (2005) criteria.

RESULTS: 3,719 Subjects (1,544 men and 2,175 women), aged 25-84 years who did not have serologically diagnosable chronic liver diseases or excessive consumption of alcohol, had their levels of ALT measured. The prevalence of Met S was 17% in men and 15% in women. In age-adjusted analyses, ALT was significantly associated with Met S and each of its five components and the association with Met S remained significant after adjustment for insulin resistance. There was no positive association between ALT and incident CVD events over the 10-year follow-up period in age-adjusted or multivariate-adjusted analyses.

CONCLUSIONS: The findings from this Australian population-based cohort study support a strong association between ALT concentration and Met S independent of insulin resistance. Serum ALT level does not appear to contribute significantly to cardiovascular risk assessment.