title: Serum retinol binding protein 4 is associated with visceral fat in human with nonalcoholic fatty liver disease without known diabetes: a cross-sectional study.
abstract: BACKGROUND
  High serum Retinol Binding Protein 4 (RBP4) levels were associated with insulin-resistant states in humans. To determine which fat compartments are associated with elevated RBP4 levels in humans, we measured serum RBP4 and hepatic fat content (HFC), visceral (VFA) and subcutaneous abdominal fat area (SFA) in 106 subjects with non-alcoholic fatty liver disease (NAFLD) without known diabetes.
  
  
  METHODS
  106 patients with NAFLD (M/F: 61/45, aged 47.44±14.16 years) were enrolled. Subjects with known diabetes, chronic virus hepatitis, and those with alcohol consumption≥30 g/d in man and ≥20 g/d in woman were excluded. Anthropometrics and laboratory tests, including lipid profile, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyltransferase (γ-GT) were conducted. HFC, VFA and SFA were determined by CT scan. Serum RBP4 was detected by an enzyme immunoassay kit and validated by quantitative Western blotting.
  
  
  RESULTS
  Circulating RBP4 was negatively associated with high-density lipoprotein cholesterol (HDL-c) (r=-0.392, p<0.001), but positively with waist-to-hip ratio (WHR) (r=0.343, p=0.001), triglyceride (r=0.330, p=0.002), VFA (r=0.298, p=0.027), systolic blood pressure (r=0.247, p=0.020), diastolic blood pressure (r=0.241, p=0.023), γ-GT (r=0.239, p=0.034), waist circumference (r=0.218, p=0.040). Differently, serum RBP4 levels were not associated with HFC (r=0.199, p=0.071), SFA, age, BMI, total cholesterol, low-density lipoprotein cholesterol (LDL-c), ALT or AST (all p>0.05). Multiple linear regression analysis revealed that RBP4 correlated independently with VFA (Standard β=0.357, p=0.019) and HDL-c (Standard β=-0.345, p=0.023) in all subjects, HDL-c (Standard β=-0.315, p=0.040) in men, VFA/SFA in women (Standard β=0.471, p=0.049), not with HFC. However, serum RBP4 was positively correlated with HFC when HFC below 6.34% (r=0.574, p=0.001).
  
  
  CONCLUSIONS
  RBP4 could be a marker of abdominal obesity, however, the role of RBP4 in the pathogenesis of NAFLD is not sufficiently elucidated.
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. changxinxiawei@163.com.
authors.forename: Xinxia
authors.initials: X
authors.lastname: Chang
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. yanhmpw@126.com.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Yan
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. bianhuaer@163.com.
authors.forename: Hua
authors.initials: H
authors.lastname: Bian
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. dr_xiamingfeng@163.com.
authors.forename: Mingfeng
authors.initials: M
authors.lastname: Xia
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. zhanglinshan111@163.com.
authors.forename: Linshan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of clinical nutrition, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. gao.jian@zs-hospital.sh.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, 200032, China. gao.xin@zs-hospital.sh.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000473:pathology*; D008099:Liver / Q000473:pathology; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000097:blood* / Q000473:pathology; D054839:Retinol-Binding Proteins, Plasma / Q000032:analysis*; D050507:Subcutaneous Fat, Abdominal / Q000473:pathology
chemical_list: D015415:Biomarkers; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma