title: Differences in Adipokine and Hepatokine Levels among Non-diabetic Population Classified by Age and Sex.
abstract: BACKGROUND
  Leptin, angiopoietin-related growth factor (AGF), adiponectin (ADP), and retinol-binding protein 4 (RBP4) are cytokines associated with the development of metabolic disorders, such as type 2 diabetes and cardio vascular disease. However, the levels of these cytokines have not extensively studied in non-diabetic subjects. Therefore, we analyzed the differences in these cytokine levels according to sex and age in non-diabetic Korean population.
  
  
  METHODS
  Blood samples were collected from 59 non-diabetic Korean adults (male, 32; female, 27). The anthropometric and biochemical data were measured at the health examination center. Serum adipokines and hepatokines were measured by enzyme linked immunosorbent assay (ELISA). The data were analyzed according to sex and age-based quartiles.
  
  
  RESULTS
  Serum leptin values were higher in females (8.60 ± 3 μg/ml) compared with males (2.99 ± 2.9 μg/ml). However, RBP4 was higher in males (84.05 ± 47.04 μg/ml) than in females (61.25 ± 45.42 μg/ml). The AGF and ADP values were not significantly different between males and females. RBP4 level was inversely correlated with age quartile in males, while leptin was significantly associated with body mass index and insulin resistance.
  
  
  CONCLUSIONS
  RBP4 and AGF levels showed age-associated change, and leptin was consistently higher in females. Therefore, a large-scale analysis to determine the normal range of adipokines and hepatokines concentration in healthy Korean population is necessary. When interpreting adipokine and hepatokine levels, the difference in age and sex needs to be taken into account.
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Jin Sae
authors.initials: JS
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Dhananjay
authors.initials: D
authors.lastname: Yadav
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Yeon Sik
authors.initials: YS
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Hong Min
authors.initials: HM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea ; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Choon Hee
authors.initials: CH
authors.lastname: Chung
keywords: Adiponectin (ADP); Angiopoietin-related growth factor (AGF); Leptin; Non-diabetic subjects; Retinol-binding protein 4 (RBP4)