title: Elevated serum IGF-I, but unaltered sex steroid levels, in healthy boys with pubertal gynaecomastia.
abstract: OBJECTIVE
  Pubertal gynaecomastia is a very common condition. Although the underlying aetiology is poorly understood, it is generally accepted that excess of oestrogens and deficit of androgens are involved in the pathogenesis. Furthermore, adiposity as well as the GH/IGF-I axis may play a role. In this study, we elucidate the association of adiposity and levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), testosterone, oestrogen, IGF-I and IGFBP-3 with the presence of pubertal gynaecomastia in a large cohort of healthy boys.
  
  
  METHODS
  A total of 501 healthy Danish school boys (aged 6·1-19·8 year) from the COPENHAGEN Puberty Study.
  
  
  METHODS
  Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Body fat percentage was calculated by means of four skin folds and impedance. Nonfasting blood samples were analysed for FSH, LH, testosterone, SHBG, oestradiol, IGF-I, IGFBP-3 and prolactin.
  
  
  RESULTS
  We found that 23% (31/133) of all pubertal boys had gynaecomastia. More specifically, 63% (10/16) of boys in genital stage 4 had gynaecomastia. Boys with gynaecomastia had significantly higher IGF-I levels compared with controls (IGF-I SD-score 0·72 vs -0·037, P < 0·001). This difference was maintained after adjusting for confounders (age and pubertal stage). Sex steroid levels, oestradiol/testosterone ratio or free testosterone were not associated with the presence of gynaecomastia with or without adjustment for confounders.
  
  
  CONCLUSIONS
  IGF-I levels were elevated in healthy boys with pubertal gynaecomastia compared with boys without gynaecomastia, whereas sex steroid levels did not differ. We speculate that the GH-IGF-I axis may be involved in the pathogenesis of pubertal gynaecomastia.
authors.affiliation: Department of Growth and Reproduction, Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Mikkel G
authors.initials: MG
authors.lastname: Mieritz
authors.forename: Kaspar
authors.initials: K
authors.lastname: Sorensen
authors.forename: Lise
authors.initials: L
authors.lastname: Aksglaede
authors.forename: Annette
authors.initials: A
authors.lastname: Mouritsen
authors.forename: Casper P
authors.initials: CP
authors.lastname: Hagen
authors.forename: Linda
authors.initials: L
authors.lastname: Hilsted
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Andersson
authors.forename: Anders
authors.initials: A
authors.lastname: Juul
mesh_terms: D000273:Adipose Tissue; D050154:Adiposity; D000293:Adolescent; D000728:Androgens / Q000097:blood; D000886:Anthropometry; D002648:Child; D015331:Cohort Studies; D003718:Denmark; D004958:Estradiol / Q000097:blood; D005640:Follicle Stimulating Hormone / Q000097:blood; D006177:Gynecomastia / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D015995:Prevalence; D013256:Steroids / Q000097:blood*; D013739:Testosterone / Q000097:blood; D055815:Young Adult
chemical_list: D000728:Androgens; D013256:Steroids; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone