Compared to the commonly acceptable reference for the increased ALT levels defined as ≥30 U/L in men and ≥20 U/L in women [44] from the general population, we observed that the ALT threshold for a greater risk of new-onset MetS (≥19 U/L in men and ≥13 U/L in women) was lower among young adults. This evidence concerns the gene GPT and metabolic syndrome.