Elevated concentrations of retinol-binding protein-4 (RBP-4) in gestational diabetes mellitus: negative correlation with soluble vascular cell adhesion molecule-1 (sVCAM-1).
BACKGROUND
Retinol-binding protein-4 (RBP-4) may increase insulin resistance (IR) in animals, with elevated levels reported in humans with obesity and type 2 diabetes. There are, however, few data on concentrations of RBP-4 in gestational diabetes mellitus (GDM).


METHODS
We measured fasting serum levels of RBP-4, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in 50 women at 28 weeks of gestation, divided according to the results of a 50 g glucose challenge test (GCT) and a 75 g oral glucose tolerance test (OGTT): (1) controls (n = 20), normal responses to both GCT and OGTT; (2) intermediate group (IG) (n = 15): false positive GCT, but normal OGTT; and (3) GDM group (n = 15), both GCT and OGTT abnormal. IR was assessed by homeostasis model assessment (HOMA-IR) and by insulin resistance index (IRI) based on glycemia and insulinemia during OGTT.


RESULTS
All groups were matched for age and body mass index (BMI). RBP-4 levels (microg/ml, mean+/-standard deviation) were higher in women with GDM vs. controls (53.9 +/- 17.9 vs. 29.7 +/- 13.9, p < or = 0.001), with a trend towards higher RBP-4 in GDM compared with IG (38.0 +/- 19.3, p = 0.07). There was no significant correlation between RBP-4 and age, BMI, insulin, IRI or HOMA-IR, but there was a moderate, significant negative correlation between RBP-4 and sVCAM-1 (r(2) = 0.20, p = 0.001).


CONCLUSIONS
RBP-4 levels are elevated in women with GDM, but do not correlate with IR indices and correlate negatively with sVCAM-1. The physiological significance of RBP-4 rise in women with GDM remains to be elucidated.
Lewandowski
Krzysztof C
KC
Warwick Medical School, The University of Warwick, UK.
Stojanovic
Nemanja
N
Bienkiewicz
Malgorzata
M
Tan
Bee K
BK
Prelevic
Gordana M
GM
Press
Martin
M
Tuck
Susan
S
O'Hare
Paul J
PJ
Randeva
Harpal S
HS
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D016640:Diabetes, Gestational / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D011247:Pregnancy; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism*; D018709:Statistics, Nonparametric; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood*
D001786:Blood Glucose; D007328:Insulin; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1