C-peptide, IGF-I, sex-steroid hormones and adiposity: a cross-sectional study in healthy women within the European Prospective Investigation into Cancer and Nutrition (EPIC).
OBJECTIVE
The risk of some cancers is positively associated with body weight, which may influence circulating levels of sex-steroid hormones, insulin and IGF-I. Interrelationships between these hormones and the associations with adiposity were evaluated in healthy women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).


METHODS
A cross-sectional analysis was performed on anthropometric and hormonal data from 743 pre- and 1217 postmenopausal women. Body mass index (BMI) and waist circumference were used as indicators of adiposity. C-peptide, Insulin Growth Factor (IGF)-I, Insulin Growth Factor binding protein (IGFBP)-3, androgens, estrogens and sex hormone binding globulin (SHBG) were measured by immunoassays; free sex steroid concentrations were calculated.


RESULTS
BMI and waist circumference were positively correlated with estrogens in postmenopausal women and with C-peptide, free testosterone and inversely with SHBG in all women. C-peptide and IGF-I were inversely correlated with SHBG, and positively with free sex steroids in postmenopausal women. IGF-I was positively associated with postmenopausal estrogens and androgen concentrations in all women.


CONCLUSIONS
Sex-steroid concentrations appear to be regulated along several axes. Adiposity correlated directly with estrogens in postmenopausal women and with insulin, resulting in lower SHBG and increased levels of free sex steroids. Independent of adiposity and insulin, IGF-I was associated with decreased SHBG levels, and increased concentrations of androgens and postmenopausal estrogens.
International Agency for Research on Cancer, 150 Cours Albert Thomas, 69372, Lyon CEDEX 08, France.
Irene D
ID
Bezemer
Sabina
S
Rinaldi
Laure
L
Dossus
Carla H van
CH
Gils
Petra H M
PH
Peeters
Paulus A H van
PA
Noord
H Bas
HB
Bueno-de-Mesquita
Soren Paaske
SP
Johnsen
Kim
K
Overvad
Anja
A
Olsen
Anne
A
Tjønneland
Heiner
H
Boeing
Petra H
PH
Lahmann
Jakob
J
Linseisen
Gabriele
G
Nagel
Naomi
N
Allen
Andrew
A
Roddam
Sheila
S
Bingham
Kay-Tee
KT
Khaw
Emmanuelle
E
Kesse
Bertrand
B
Téhard
Françoise
F
Clavel-Chapelon
Antonio
A
Agudo
Eva
E
Ardanaz
J R
JR
Quiros
Pilar
P
Amiano
C
C
Martínez-Garcia
M J
MJ
Tormo
Valeria
V
Pala
Salvatore
S
Panico
Paolo
P
Vineis
Domenico
D
Palli
Rosario
R
Tumino
Antonia
A
Trichopoulou
N
N
Baibas
D
D
Zilis
Bertrand
B
Hémon
Teresa
T
Norat
Elio
E
Riboli
Rudolf
R
Kaaks
D000728:Androgens / Q000097:blood; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood*; D003430:Cross-Sectional Studies; D004967:Estrogens / Q000097:blood; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D049629:Waist-Hip Ratio
D000728:Androgens; D002096:C-Peptide; D004967:Estrogens; D018972:Insulin-Like Growth Factor Binding Protein 3; D012738:Sex Hormone-Binding Globulin; D007334:Insulin-Like Growth Factor I