Adiponectin concentrations in maternal serum: elevated in preeclampsia but unrelated to insulin sensitivity

Adiponectin is an adipocyte-derived protein with profound insulin-sensitizing, anti-inflammatory, and antiatherogenic effects. Surprisingly, recent evidence suggests that adiponectin concentrations are increased during preeclampsia, which is characterized by insulin resistance. We studied whether serum adiponectin is related to insulin sensitivity in preeclamptic and normotensive pregnant women.

We measured serum adiponectin concentrations and insulin sensitivity (intravenous glucose tolerance test/minimal model) in 22 women with preeclampsia and 15 normotensive controls with similar pre-pregnancy body mass index (BMI) (range 18-29 kg/m(2)) between 29 and 39 weeks of gestation. Fourteen cases and 10 controls were also studied 6-22 weeks after delivery. No subject had gestational diabetes.

During pregnancy, the mean adiponectin concentration in preeclamptic women was 10.3 (SD 4.2) mug/mL as compared to 7.9 (SD 2.9) microg/mL in normotensive controls (95% confidence interval [CI] for difference 0.1-5.3 microg/mL; P = .04). Adiponectin concentrations were unrelated to insulin sensitivity both in preeclamptic and normotensive subjects; insulin sensitivity was decreased in preeclampsia (P = .01). After delivery, mean adiponectin concentration was lower than during pregnancy: 7.4 (SD 3.0) microg/mL in preeclamptic subjects (P = .001) and 7.1 (SD 1.6) microg/mL in normotensive controls (P = .06) and similar in cases and controls (95% CI for difference -1.7-2.3 microg/mL, P = .7).

Despite their reduced insulin sensitivity, preeclamptic women have higher adiponectin concentrations than normotensive pregnant women. These concentrations are unrelated to insulin sensitivity. After pregnancy, the difference in adiponectin concentrations is no longer present between the two groups. These findings are consistent with a role of adiponectin in the pathophysiology of preeclampsia.