IJMEG Copyright © 2010-present. All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711
Int J Mol Epidemiol Genet 2011;2(3):292-299

Original Article
Maternal plasma protein profiles in response to oral 50-gram glucose load in
mid-pregnancy: a pilot study

Daniel A. Enquobahrie, Chun-fang Qiu, Karin Hevner, Dejene Abetew, Michelle A. Williams

Center for Perinatal Studies, Swedish Medical Center, Seattle, WA, USA; Department of Epidemiology, University of
Washington, Seattle, WA, USA.

Received July 16, 2011, 2011; accepted August 12, 2011; Epub August 15, 2011; published August 30, 2011

Abstract: Accumulating evidence documents the initiation of diverse physiologic and biochemical response subsequent to an
oral glucose load. However, significant gaps in knowledge exist in the understanding of consequences of glucose load during
pregnancy, a state of insulin resistance. Using high dimensional protein arrays, we conducted a pilot proof-of-concept and
feasibility study to investigate profiles of 120 plasma proteins in pre- and post- 50-gram oral glucose challenge samples.
Participants (N=10) were selected from among women enrolled in a pregnancy cohort. Differences in plasma protein
concentrations between pre- and post-glucose load challenge samples were evaluated using Student’s T-test (paired) and
mean fold change comparisons.  Multiple testing adjusted p-values (i.e., false discovery rate q values) were computed using
Benjamini-Hochberg (BH) corrections. Plasma haptoglobulin, epidermal growth factor, hemoglobin, thrombospondin-1, and
S100 protein concentrations were two to five fold higher in post-glucose load compared with pre-glucose load samples (all q-
values <0.05). Among women aged >31 years (above median), post-load S100 protein was elevated 9.92-fold above pre-load  
concentrations, while it was elevated 4.10-fold among women aged <31 years (below median). Similarly, among women with
post-load glucose concentrations <101mg/dl (below median), S100 was elevated 8.26-fold while it was elevated 3.28 fold
among women with post-load glucose concentrations >101mg/dl (above median). Our study findings suggest that post-
glucose load changes in plasma biomarkers represent a diverse set of cellular responses including receptor for advanced
glycation end products (RAGE) , inflammation, oxidative stress and adipogenesis, during mid-pregnancy. Future studies of
larger populations and longer periods of follow-up are warranted. (IJMEG1107001).

Key words: Plasma protein, oral glucose load, mid-pregnancy

Full Text  PDF

Address all correspondence to:
Daniel A. Enquobahrie, MD, PhD
Center for Perinatal Studies
Swedish Medical Center
1124 Columbia Street, Suite 750
Seattle, WA 98104, USA.
Tel: 206 215 2595;   Fax: 206 215 6995
E-mail: danenq@u.washington.edu