Hypoadiponectinemia: Association with risk of varying degrees of gestational hyperglycemia and with maternal ethnicity

Objective: The aims of this study were to examine the influence of maternal hypoadiponectinemia on the risk of varying degrees of gestational hyperglycemia as well as on ethnic differences in circulating levels of adiponectin. Methods: A case-control study nested within a prospective cohort of healthy pregnant women compared those who developed gestational diabetes mellitus (GDM, N = 80), or had an impaired glucose challenge test (GCT) non-GDM (defined as 1hr plasma glucose >140 mg/dl after a 50-g oral glucose load when screening for GDM but did not meet the diagnostic criteria for GDM by a diagnostic oral glucose tolerance test, N = 128) to normal controls (N = 557). Concentrations of serum adiponectin were determined at entry (~17 weeks) and during the 3rd trimester. Results: With multivariable adjustment, entry hypoadiponectinemia (the lowest tertile vs. other tertiles pooled) was strongly associated with an increased risk of GDM (AOR 2.68, 95% CI 1.62 - 4.41) and with impaired GCT non-GDM (AOR 1.58, 95% CI 1.05 - 2.38). This association persisted after adjustment for pregravid BMI despite the fact that the risk in obese women with low adiponectin was higher. Similar data were obtained during the 3rd trimester. The concentration of adiponectin during the 3rd trimester was significantly lower in African Americans compared to Hispanics or Caucasians and this difference was detectable in both cases and controls (p < 0.05 or p < 0.01 for each). Conclusions: The present results identified a unique graded association between hypoadiponectinemia during early pregnancy with risk of GDM and less severe hyperglycemia non-GDM independent of maternal BMI. The relationship persisted to the 3rd trimester. African American women have lower adiponectin level than Caucasian or Hispanic women. Hypoadiponectinemia may play a significant pathophysiological role in the development of GDM and of less severe gestational hyperglycemia.