The majority of studies entered in this systematic review, reported that the NAFLD was significantly more common among men (7 of 8 papers), obese people (15 of 15 papers), older ages (10 of 10 papers), patients with systolic hypertension (5 of 8 papers), patients with diastolic hypertension (7 of 9 papers), those with hypertriglyceridemia (14 of 16 papers), high serum HOMA level (4 of 4 papers), patients with metabolic syndrome (4 of 4 papers), and high serum ALT level (8 of 12 papers). This evidence concerns the gene GPT and hypertriglyceridemia.