title: Elevated serum gamma-glutamyltransferase levels are independently associated with insulin resistance in non-diabetic subjects.
abstract: We investigated the associations of gamma-glutamyltransferase (GGT) with visceral obesity, adiponectin and retinol binding protein 4 (RBP4), and insulin resistance (IR) and compared these associations with other liver enzymes in non-diabetes. We enrolled 94 healthy subjects 30-69 years old. Clinical and biochemical metabolic parameters were measured. Adiponectin and RBP4 were determined by ELISA. IR was examined by HOMA-IR. Visceral fat was determined by computed tomography scan. GGT and alanine aminotransferase (ALT) were positively correlated with waist circumference (WC), waist-to-hip ratio (WHR), visceral fat area (VFA), visceral-to-subcutaneous fat area ratio (VSR), HOMA-IR, and RBP4, but was negatively correlated with adiponectin (p<0.05). In multivariate regression, GGT was associated with male sex, HOMA-IR, and RBP4 (R(2)=0.48, p<0.05) and ALT was associated with HOMA-IR (R(2)=0.22, p<0.05). By logistic regression after adjusted for age and sex, the odds ratio (OR) for IR in the highest tertile of sex-specific GGT and ALT were significantly increased compared to those in the lowest [OR (95% CI); 6.90 (2.08-22.82), 3.38 (1.08-10.57), respectively]. However, these relationships after further adjustments for RBP4, adiponectin, VFA, VSR, WHR, WC, TG, and HDL remained significant in only GGT. In conclusions, GGT may be a useful marker of IR in non-diabetes.
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
authors.forename: Jang Yel
authors.initials: JY
authors.lastname: Shin
authors.forename: Sei Jin
authors.initials: SJ
authors.lastname: Chang
authors.forename: Young Goo
authors.initials: YG
authors.lastname: Shin
authors.forename: Kwang-Seok
authors.initials: KS
authors.lastname: Seo
authors.forename: Choon Hee
authors.initials: CH
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000201:enzymology; D012372:ROC Curve; D012016:Reference Values; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D015415:Biomarkers; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma; D005723:gamma-Glutamyltransferase; D000410:Alanine Transaminase