A Longitudinal Study of Growth, Sex Steroids, and IGF-1 in Boys With Physiological Gynecomastia.
BACKGROUND
Physiological gynecomastia is common and affects a large proportion of otherwise healthy adolescent boys. It is thought to be caused by an imbalance between estrogen and testosterone, although this is rarely evident in analyses of serum.


OBJECTIVE
This study aimed to describe the frequency of physiological gynecomastia and to determine possible etiological factors (eg, auxology and serum hormone levels) in a longitudinal setup.


METHODS
A prospective cohort study of 106 healthy Danish boys (5.8-16.4 years) participated in the longitudinal part of the COPENHAGEN Puberty Study. The boys were examined every 6 months during an 8-year follow-up. Median number of examinations was 10 (2-15).


METHODS
Blood samples were analyzed for FSH, LH, testosterone, estradiol, SHBG, inhibin B, anti-Müllerian hormone, IGF-1, and IGF binding protein-3 by immunoassays. Auxological parameters, pubertal development, and the presence of gynecomastia were evaluated at each visit.


RESULTS
Fifty-two of 106 boys (49%) developed gynecomastia, of which 10 (19%) presented with intermittent gynecomastia. Boys with physiological gynecomastia reached peak height velocity at a significantly younger age than boys who did not develop gynecomastia (13.5 versus 13.9 years, P = .027), and they had significantly higher serum levels of IGF-1 (P = .000), estradiol (P = .013), free testosterone (P < .001), and FSH (P = .030) during pubertal transition. However, no differences in serum LH or in the estradiol to testosterone ratio were found.


CONCLUSIONS
Gynecomastia is frequent in pubertal boys. Increased IGF-1 levels and pubertal growth appear to be associated, whereas changes in estrogen to testosterone ratio seem negligible.
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Mikkel G
MG
Mieritz
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Lars L
LL
Rakêt
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Casper P
CP
Hagen
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
John E
JE
Nielsen
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Maj-Lis M
ML
Talman
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Jørgen H
JH
Petersen
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Stefan H
SH
Sommer
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Katharina M
KM
Main
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Niels
N
Jørgensen
Department of Growth and Reproduction (M.M., C.P.H., J.E.N., K.M.M., N.J., A.J.), Rigshospitalet, University of Copenhagen, Denmark; Department of Mathematical Sciences (L.L.R.), University of Copenhagen, Denmark; Department of Pathology (M.-L.M.T.), Rigshospitalet, University of Copenhagen, Denmark; Department of Biostatistics (J.H.P.), University of Copenhagen, Denmark; and Department of Computer Science (S.H.S.), University of Copenhagen, Denmark.
Anders
A
Juul
D000293:Adolescent; D054304:Anti-Mullerian Hormone / Q000097:blood; D001827:Body Height / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004958:Estradiol / Q000097:blood*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006177:Gynecomastia / Q000097:blood / Q000503:physiopathology*; D006801:Humans; D007265:Inhibins / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D011446:Prospective Studies; D011627:Puberty / Q000097:blood / Q000502:physiology; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood*
C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D012738:Sex Hormone-Binding Globulin; C422364:inhibin B; D013739:Testosterone; D004958:Estradiol; D007265:Inhibins; D007334:Insulin-Like Growth Factor I; D054304:Anti-Mullerian Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone