title: Gender differences of oligomers and total adiponectin during puberty: a cross-sectional study of 859 Danish school children.
abstract: BACKGROUND
  Pubertal stages have been shown to influence total adiponectin (ADPN) levels. Furthermore, testosterone has been shown to alter the isomer distribution of ADPN.
  
  
  OBJECTIVE
  The goal of this study was to investigate whether pubertal stages and testosterone levels influenced total serum ADPN levels and the distribution of ADPN isomers.
  
  
  METHODS
  This is a cross-sectional study.
  
  
  METHODS
  The study included 859 children and adolescents (396 males) aged 6-20 yr.
  
  
  METHODS
  Total ADPN and ADPN isomers were measured using a validated in-house immunofluorometric assay. Fractioning of the ADPN into the three major molecular fractions was performed in representative subgroups of pre- and postpubertal males and females (n = 40, 10 in each group) using a validated fast protein liquid chromatography method.
  
  
  RESULTS
  Total ADPN levels before puberty were 13.4 (11.1-15.9) mg/liter (median and interquartile range) and 14.7 (12.3-18.1) mg/liter (P = not significant), in males and females, respectively. After puberty, ADPN levels were significantly reduced in males, 9.7 (8.2-12.0) mg/liter but remained unchanged in females, 12.1 (9.7-15.3) mg/liter (P < 0.0001). Concomitantly, a reduction was seen in the ratio of high-molecular-weight (HMW) isomers to total ADPN (HMW ratio) when comparing prepubertal and postpubertal males. Also, postpubertal males had lower HMW ratios than corresponding females (P = 0.038). Finally, a negative correlation was seen between HMW ratio and testosterone (r = -0.430, P = 0.007).
  
  
  CONCLUSIONS
  Serum total ADPN levels decrease through puberty in males. Also, a reduced HMW ratio is seen in males at the onset of puberty. We speculate that the suppression of HMW ADPN may be caused by testosterone.
authors.affiliation: The Medical Research Laboratories, Clinical Institute, Medical Department M (Diabetes and Endocrinology), Aarhus University Hospital, DK-8000 Aarhus C, Denmark.
authors.forename: Kristian Kjaer
authors.initials: KK
authors.lastname: Andersen
authors.forename: Jan
authors.initials: J
authors.lastname: Frystyk
authors.forename: Ole D
authors.initials: OD
authors.lastname: Wolthers
authors.forename: Carsten
authors.initials: C
authors.lastname: Heuck
authors.forename: Allan
authors.initials: A
authors.lastname: Flyvbjerg
mesh_terms: D052242:Adiponectin / Q000737:chemistry / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002648:Child; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D015200:Fluoroimmunoassay; D006801:Humans; D007118:Immunoassay; D007536:Isomerism; D008297:Male; D011627:Puberty / Q000502:physiology*; D012727:Sex Characteristics; D013739:Testosterone / Q000097:blood
chemical_list: D052242:Adiponectin; D013739:Testosterone