Background: Higher fetuin-A levels have been linked to fatty liver disease (FLD), the most common cause of elevated alanine aminotransferase (ALT) levels, but associations between ALT and fetuin-A level have been inconsistent. The presence of the metabolic syndrome in individuals with elevated ALT levels has been shown to characterize more severe FLD. Thus, aim of the study was to investigate the association between fetuin-A level and the coexistence of elevated ALT levels and metabolic syndrome (ALT-MetS).
Methods: A population-based cross-sectional study including 728 individuals (age 50-77 years) was conducted. We used multivariable logistic regression analysis to assess the association between serum fetuin-A level and the dichotomous outcome ALT-MetS, defined as coexistence of elevated ALT level (>75th percentile) and metabolic syndrome (any three of the components: abdominal obesity, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure, abnormal glucose metabolism).
Results: Individuals with a high fetuin-A level had an odds ratio (OR) for ALT-MetS of 2.22 [95% confidence interval (CI) 1.36-3.63; Ptrend=<0.001] comparing extreme tertiles. After excluding individuals with cancer, stroke, or myocardial infarction, individuals with high fetuin-A levels had an OR for ALT-MetS of 2.48 (95% CI 1.38-4.47) comparing extreme tertiles, and we observed statistical interaction between fetuin-A level and age (P=0.048). Fetuin-A level was associated with ALT-MetS in young individuals, defined as <64 years of age (OR 3.30, 95% CI 1.45-7.55; Ptrend=0.004), and not statistically significant in older individuals (OR 1.79, 95% CI 0.74-4.31; Ptrend=0.197).
Conclusions: Fetuin-A level was positively associated with ALT-MetS, particularly in younger individuals. Prospective studies in larger populations are warranted.