Soluble Leptin Receptor and Risk of Gestational Diabetes in a Multiethnic Population: A Prospective Cohort Study

Context: Soluble leptin receptor (sob-R), a potential marker of leptin resistance, is inversely associated with risk of type 2 diabetes, independently of leptin concentrations. We have previously shown that ethnic difference in leptin concentration may partly explain the increased risk of gestational diabetes (GDM) in South Asians. Objective: Our objective was to investigate whether sOb-R concentrations are associated with risk of GDM, whether concentrations of sOb-R differ across ethnic groups, and whether ethnic differences in sOb-R explain the ethnic differences in GDM risk. Design and Setting: The STORK Groruddalen study; a prospective cohort study of pregnant women living in Oslo, Norway, between May 2008 and May 2010. Participants: Of the total sample (n = 823), 680 (47.1% Europeans) had sOb-R measured in pregnancy week 15 and an oral glucose tolerance test performed in week 28. Main outcome measure: GDM was diagnosed according to World Health Organization 2013 criteria. Results: sOb-R was inversely associated with GDM (odds ratio, 0.76 - 95% confidence interval, 0.69-0.83] per ng/ml increase in sOb-R, P <.001) in crude analysis. The association was attenuated after adjustments for covariates and leptin (0.85 [0.77-0.95], P =.004). Compared to women with sOb-R higher than 5 ng/ml, the odds ratio of GDM was 0.29(0.11-0.78; P=.014) among women with sOb-R greater than 10 ng/ml and 0.59 (0.37-0.94; P =.026) among women with sOb-R 5-10 ng/ml, in adjusted analysis. sOb-R levels did not differ across ethnic groups, and sOb-R did not explain ethnic differences in GDM risk. Conclusions: There was an independent, inverse association between sOb-R and GDM, with the lowest risk of GDM observed among higher sOb-R concentrations.