Relationship between circulating insulin-like growth factor components and sex hormones in a population-based sample of 50- to 80-year-old men and women.
There is a large body of evidence that points to a systemic link between the somatotropic axis and sex hormones, but epidemiologic data on the interactions between the two hormonal systems are still missing. We examined here the associations between the plasma levels of insulin-like growth factor (IGF) I, IGF-II, IGF-binding protein 3 (IGFBP-3), and sex hormones in a population-based sample of 486 men and women, aged 50-80 yr. The strongest association was an age-independent inverse correlation between all three circulating IGF components and sex hormone-binding globulin (SHBG), the major testosterone-binding protein in plasma. Consistent with this, bio-available (non-SHBG-bound) but not total testosterone levels were positively associated with the IGF system in men, and 3 alpha-androstanediol glucuronide was positively correlated with circulating IGFs in women. Moreover, part of the correlation between the circulating IGF system and bone mineral density at the femur and the calcaneus could be accounted for by SHBG. Our data suggest that sex hormones and the GH/IGF system are significantly interrelated in the elderly population. These hormonal interactions may play an important role in human aging and the pathogenesis of age-related diseases.
Pfeilschifter
J
J
Department of Internal Medicine, University of Heidelberg, Germany.
Scheidt-Nave
C
C
Leidig-Bruckner
G
G
Woitge
H W
HW
Blum
W F
WF
Wüster
C
C
Haack
D
D
Ziegler
R
R
D000368:Aged; D000369:Aged, 80 and over; D015113:Androstane-3,17-diol / Q000031:analogs & derivatives / Q000097:blood; D015519:Bone Density; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood
D012739:Gonadal Steroid Hormones; D018972:Insulin-Like Growth Factor Binding Protein 3; D012738:Sex Hormone-Binding Globulin; D015113:Androstane-3,17-diol; C028895:androstane-3,17-diol glucuronide; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II