Nelson Vergel
Founder, ExcelMale.com
A Longitudinal Study of Growth, Sex Steroids and Insulin-like Growth Factor I in boys with Physiological Gynecomastia
Physiological gynecomastia is common in pubertal boys and appears to be associated with increased levels of insulin like growth factor-1 (IGF-1) and pubertal growth, but not with a shift in the balance between estrogen and testosterone, a new study suggests.
The findings were published online August 19 in the Journal of Clinical Endocrinology and Metabolism by Mikkel G Mieritz, MD, a PhD student working in the department of growth and reproduction, Rigshospitalet, University of Copenhagen, Denmark, and colleagues.
In their discussion, Mieritz and colleagues note that IGF-1 together with estrogen is essential for the growth of breast tissue, and it appears that the effect of growth hormone on breast growth is mediated through IGF-1. "The stimulatory effect of IGF-1 on breast formation was synergized by [estradiol], which was also elevated in boys with gynecomastia in our study. However, serum testosterone was similarly elevated, leaving the estradiol/testosterone ratio unaltered."
http://press.endocrine.org/doi/10.1210/jc.2015-2836
Physiological gynecomastia is common in pubertal boys and appears to be associated with increased levels of insulin like growth factor-1 (IGF-1) and pubertal growth, but not with a shift in the balance between estrogen and testosterone, a new study suggests.
The findings were published online August 19 in the Journal of Clinical Endocrinology and Metabolism by Mikkel G Mieritz, MD, a PhD student working in the department of growth and reproduction, Rigshospitalet, University of Copenhagen, Denmark, and colleagues.
In their discussion, Mieritz and colleagues note that IGF-1 together with estrogen is essential for the growth of breast tissue, and it appears that the effect of growth hormone on breast growth is mediated through IGF-1. "The stimulatory effect of IGF-1 on breast formation was synergized by [estradiol], which was also elevated in boys with gynecomastia in our study. However, serum testosterone was similarly elevated, leaving the estradiol/testosterone ratio unaltered."
http://press.endocrine.org/doi/10.1210/jc.2015-2836
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