Adipokines in the prediction of gestational diabetes.

Gestational diabetes (GD) is associated with significant maternal and foetal
morbidity. Currently, GD is diagnosed during the late second or early third
trimester, leaving a small window for treatment to reduce the risk of
complications. There is need to predict GD earlier in order to minimize foetal
exposure to hyperglycaemia and allow for preventative strategies and timely
intervention. Adipokines are secreted by adipose tissue and play a regulatory
role in many physiological pathways, glucose metabolism. Prospective studies
have shown a relation between first trimester adipokines (adiponectin, leptin)
and subsequent GD risk. Studies of adipokines and GD risk among non-Caucasian
populations are sparse. We hypothesize that adiponectin concentrations will be
lower and leptin concentrations higher in women with GD versus non-GD.
Furthermore, we predict that concentrations of adiponectin will be higher and
concentrations of leptin lower among Caucasian women compared to non-Caucasian
women.

Primary objective: To determine the association between serum adiponectin and
the risk of developing gestational diabetes.
Secondary objective: To determine the association between serum leptin in
pregnancy and the risk of developing gestational diabetes.
Other objective: To determine adipokine variability among Caucasian and
non-Caucasian women.

Design: prospective cohort study. (minimal of N=42 with GD and N=42 without GD)
N=24 (N=15 GD; N= 9 non-GD) blood samples will be used from the control group
of the Medico-GDM trial. Therefore, an additional N=27 subjects need to be
included in the GD group and N=33 in the non-GD group. Inclusion in the non-GD
group will be reached earlier (GD prevalence 20-25% in high risk). Recruitment
will continue until at least these numbers are reached. Duration: one year.

Blood samples from Medico-GDM trial (NL48005.101.14):
N=24 (N=15 GD; N= 9 non-GD) blood samples from women who participated in the
Medico-GDM trial at the Maasstad Hospital between October 2014 until present,
will be utilized for this study. The Medico-GDM trial is an open label,
randomized controlled trial studying the effect of metformin in pregnant women
with a high risk for gestational diabetes. In this study women gave informed
consent for storage of first trimester blood samples for other future study
purposes and gave permission to be re-contacted. Therefore, all women will
receive information and they will be re-contacted to ask for permission to use
the blood samples for this study. The blood samples from the Medico-GDM trial
can be used because it involves the same study population (pregnant women with
a high risk of gestational diabetes). Pre-existing type 1 or 2 diabetes
mellitus was also an exclusion criterion for this study. Only samples from the
control group (no metformin) will be used due to the theoretical effect of
Metformin on the development of GD.

The burden of participating in this study is minimal and there are no risks
involved. One extra blood sample 8.5 ml will be collected. Women participating
have no direct benefit. However, this research question might allow for better
GD prediction models in the future.