Adiponectin and insulin resistance in early- and late-onset pre-eclampsia

Objective  To evaluate the importance of adiponectin and insulin resistance in early- and late-onset pre-eclampsia. Design  A nested case–control study in 72 pregnant women who participated in the first-trimester Down-syndrome-screening programme and who delivered at our hospital. Setting  University Hospital, Department of Obstetrics and Gynecology. Population  Pregnant women: 36 women with pre-eclampsia of which 20 late onset and 16 early onset were compared with 36 uncomplicated pregnancies who delivered at term. Methods  In all the women, insulin resistance was calculated by the homeostasis model assessment ratio (HOMA-IR) and plasma adiponectin was determined using an enzyme-linked immunosorbent assay. Main outcome measures  Insulin resistance and adiponectin concentration. Results  First-trimester plasma adiponectin mean levels in the whole pre-eclampsia group were significantly lower than that in the control group (8.4 ± 3.3 versus 14.8 ± 4.6 microgram/ml; P < 0.001), whereas first-trimester mean HOMA-IR values were significantly higher in the pre-eclampsia group than that in the control group (2.0 ± 1.1 versus 1.0 ± 0.4; P= 0.01). Plasma adiponectin concentrations at delivery in the pre-eclampsia group were significantly higher than that in the control group (9.2 ± 3.7 versus 7.8 ± 2.6 microgram/ml; P= 0.04). First-trimester plasma adiponectin mean concentrations in the late-onset subgroup were significantly lower compared with the concentrations in early-onset subgroup (6.2 ± 1.4 microgram/ml versus 11.1 ± 3.2 microgram/ml; P < 0.001), and there was a significant difference in adiponectin plasma values only between women in the late-onset pre-eclampsia group versus those in the control group (P < 0.001). First-trimester mean HOMA-IR values were significantly higher in the late-onset subgroup compared with that of the early-onset subgroup (2.5 ± 1.3 versus 1.3 ± 0.3; P= 0.02), and there was a significant difference only between the control group versus the late-onset subgroup (P= 0.001). Conclusions  First-trimester adiponectin and HOMA-IR values seem to select two completely different populations: early- and late-onset pre-eclampsia, which might suggest a different pathogenesis.