Sex hormone-binding globulin SHBG is a circulating glycoprotein that transports testosterone and other steroids in the blood. Interest in SHBG has escalated in recent years because of its inverse association with obesity and insulin resistance, and because many studies have linked lower circulating levels of SHBG to metabolic syndrome, type 2 diabetes, nonalcoholic fatty liver disease, polycystic ovary syndrome, and early puberty. The purpose of this review is to summarize molecular, clinical, endocrine, and epidemiological findings to illustrate how measurement of plasma SHBG may be useful in clinical medicine in children.
Sex hormone-binding globulin SHBG is a glycoprotein produced in the liver that transports certain sex steroids in the circulation and regulates their access to target cells. Many studies have linked lower circulating levels of SHBG to obesity, type 2 diabetes, metabolic syndrome, non-alcoholic fatty liver disease, polycystic ovary syndrome, and early puberty. Our review was written to summarize the molecular, clinical, endocrine, and epidemiological findings which illustrate how measurement of plasma SHBG levels may be useful in clinical medicine in children.
We believe that this review is novel and will be useful for the physicians who manage pediatric obesity and related comorbidities and for scientists who conduct translational research in this area. Sex hormone-binding globulin SHBG is a KDa homodimeric glycoprotein that is encoded by a single gene on the short arm of chromosome Variable glycosylation explains the variation in molecular weight and is known to be increased by estrogens, but its significance is unknown.
Circulating SHBG is produced primarily by hepatocytes, however, the gene is also expressed in the brain, uterus, prostate, breast, ovary, and testis 1 , as well as in certain ovarian and prostate cancers. SHBG is found in the circulation of numerous mammals but is seemingly absent in the plasma of adult rats and mice, guinea pigs, and pigs.
SHBG transports testosterone and other steroids in the blood plasma, reduces their metabolic clearance rate, and regulates their access to target tissues 2. Homozygous missense mutation resulting in a complete deficiency of plasma SHBG has been reported in a few cases. An affected adult male complained of low libido, decreased spontaneous morning erections, fatigue, muscular weakness, decreased shaving frequency, and had small testes and a low bone mass.
