Association between GGT to HDL-C ratio and NAFLD in the Japanese population: A cross-sectional study based on a public database

Abstract Background The connection between γ-glutamyl transpeptidase to high-density lipoprotein cholesterol (GGT/HDL-C) ratio and nonalcoholic fatty liver disease (NAFLD) has been reported in some research. Few studies have discussed their possible nonlinear relationship in the Japanese population. We sought to learn the connection between the GGT/HDL-C and NAFLD in a Japanese population through a cross-sectional study. Methods Participants were from the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) medical examination program's database. This program aimed to investigate chronic disease risk factors and advance public health. Participants received exams per year. A cross-section study was employed. A total of 14242 subjects (7402 males and 6840 females) were enrolled after screening according to strict exclusion criteria. Fatty liver disease was confirmed by abdominal ultrasonography. The data was stated to have been posted to the DATADRYAD website. Results After adjusting for a series of confounding factors (age, sex, BMI, SBP, DBP, AST, ALT, FPG, HBA1C, TC, TG, smoking status, ethanol consumption, exercise status), GGT/HDL-C ratio quartile was positively related to NAFLD (P for trend < 0.0001). GGT/HDL-C was nonlinearly associated with NAFLD, with an inflexion point of 17.36. The effect sizes and the confidence intervals on the left and right sides of the inflexion point were 1.10 (1.07, 1.12) and 0.99 (0.99, 0.99), respectively. In different groups of ALT, the effect sizes of GGT/HDL-C on NAFLD showed significant differences (P for interaction was < 0.0001). The subsequent subgroup and interaction analysis found no statistical significance for the subgroup of age, sex, BMI, SBP, DBP, smoking and drinking status, and amount of exercise. Conclusion The GGT/HDL-C ratio is nonlinearly connected to NAFLD. Their positive connection can be established when GGT/HDL-C is less than or equal to 17.36.