Objectives: Elevated liver enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) may be associated with metabolic syndrome (MetS) and cardiovascular disease. We investigated the association of cardiometabolic risk factors and liver enzymes in a nationally representative sample of Iranian children and adolescents.
Methods: The national study was conducted in the framework of the third survey of Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable Disease study. Subjects were 3948 students (1942 girls, 67.55% urban, mean age 14.7 ± 2.4 years) who were recruited by multistage random cluster sampling from 27 provincial counties in Iran. Physical examination and laboratory tests were conducted under standard protocols.
Results: Participants with elevated serum ALT had higher levels of almost all cardiometabolic risk factors than other participants; this difference was not significant for fasting blood glucose, total cholesterol, and diastolic blood pressure in both sexes, as well as low-density lipoprotein cholesterol in girls. Participants with generalized and abdominal obesity, MetS, elevated blood pressure, triglycerides, and total cholesterol had increased risk for elevated ALT; this risk remained significant after adjusting for sex and age. Low high-density lipoprotein cholesterol was found as a predictor for both elevated ALT (odds ratio 2.182, 95% confidence interval 1.533–3.105) and AST (odds ratio 2.022, 95% confidence interval 1.438–2.844) even after adjusting for all potential confounders. General (B 0.158, SE 0.030) and abdominal obesity (B 0.058, SE 0.029), MetS (B 0.231, SE 0.048), and triglycerides (B 0.094, SE 0.030) were associated with ALT:AST ratio after adjusting for all potential confounders (P < 0.001).
Conclusions: We documented strong relations of elevated ALT, AST levels, and ALT:AST ratio with most cardiometabolic risk factors. This relation was independent of anthropometric indexes. Liver enzymes can be considered as a cardiometabolic risk factor from childhood, and as an additional component of the MetS.