Adherence to the Mediterranean diet moderates the association of aminotransferases with the prevalence of the metabolic syndrome; the ATTICA study

BACKGROUND: Elevated liver enzymes are markers of liver steatosis and metabolic syndrome. We aimed to investigate the association of Mediterranean diet on the relationship between aminotransferases (i.e., AST, ALT, gGT) and the metabolic syndrome. METHODS: The ATTICA study has randomly enrolled 1514 adult males (18–87 yrs) and 1528 females (18–89 yrs) from the greater area of Athens. Adherence to Mediterranean diet was assessed through the MedDietScore. According to NCEP III criteria, participants were classified into those with or without the metabolic syndrome. RESULTS: Women with metabolic syndrome had higher γGT (p = 0.02) and lower AST/ALT levels (p = 0.018) than those without, and men with metabolic had a lower AST/ALT ratio (p = 0.01) compared to those without metabolic syndrome. The AST/ALT ratio was also positively correlated with MedDietScore (rho = 0.17, p < 0.001), while higher MedDietScore was associated with lower likelihood of having the metabolic syndrome in a multi-adjusted analysis (OR = 0.34, 95% CI: 0.16–0.73). Stratified analysis by the level of adherence to the Mediterranean diet, revealed that only in subjects away or with moderate adherence to the Mediterranean diet, an increase in the AST/ALT ratio was associated with lower likelihood of having the metabolic syndrome (OR = 0.33, p < 0.05 and OR = 0.34, p < 0.09, respectively); however, when we focused in those with greater adherence to the Mediterranean diet, AST/ALT ratio was not associated with the presence of the syndrome (OR = 0.51, p = 0.55). These findings remained similar in both genders, and even when the quantity of alcohol drinking was taken into account. CONCLUSION: Aminotransferases ratio constitutes a marker of the metabolic syndrome among healthy adults; however, this relationship is moderated when individuals are close to the Mediterranean dietary pattern.