RBP4 and metabolic dysfunction-associated steatotic liver disease: The positive correlations between serum RBP4 and GGT levels were even more prominent in subjects with NAFLD than in controls after adjusting for age, gender, body mass index and HOMA (NAFLD subjects: r = 0·3478, P = 0·0049 vs. controls: r = 0·2048, P = 0·0821).