Superimposed preeclampsia in women with chronic kidney disease

AIM

To evaluate whether pregnant women with chronic kidney disease (CKD) adapt poorly to increases in renal blood flow. This can exacerbate renal function and impair perinatal outcome, as there is a major interplay between CKD and preeclampsia (PE).

METHODS

We analyzed the outcomes of 90 pregnant women with preexisting CKD. The estimated glomerular filtration rate (eGFR) was measured along with the levels of angiogenic factors, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor, which might act in the pathophysiology of PE.

RESULTS

In pregnancies with CKD, PE and preterm delivery were increased and the increased blood pressure worsened the perinatal outcomes much more than the increased proteinuria. All pregnancies with severe renal insufficiency were delivered preterm because of impaired renal function. The eGFR was correlated significantly with 24-hour creatinine clearance (r = 0.830). Significant differences in sFlt-1 and placental growth factor levels were found between severe PE without any complications and severe superimposed PE (p < 0.05), and between women with and without declining renal function in superimposed PE (p < 0.01).

CONCLUSION

Pregnancies with CKD have a high risk of obstetrical complications. The eGFR might serve for evaluating renal function during pregnancy. Angiogenic factors might be potential markers for a differential diagnosis between PE and worsening renal function.

Potential interaction of brain natriuretic peptide with hyperadiponectinemia in preeclampsia

Adiponectin was reported recently to have roles in the pathophysiology of preeclampsia. Moreover, elevation of adiponectin and brain natriuretic peptide (BNP) has been observed in preeclampsia. We examined the possible links between adiponectin and BNP in the pathophysiology of preeclampsia. We performed a cross-sectional study in 56 preeclampsia patients and 56 controls matched for gestational age and body mass index. The BNP, leptin, and adiponectin levels were measured by ELISA, and their mRNA expressions were evaluated in omental adipose tissue by real-time PCR. The effects of BNP on adiponectin and leptin mRNA expression and secretion were investigated in primary cultures of adipocytes from obese and normal-weight women. The BNP, adiponectin, and leptin levels were significantly higher in preeclampsia patients compared with controls. The adiponectin level was increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients. Adiponectin mRNA expression was increased significantly in adipose tissues of preeclampsia patients compared with controls and was also increased significantly in normal-weight preeclampsia patients compared with overweight preeclampsia patients, whereas leptin was not. BNP and adiponectin showed significant positive correlations in both normal-weight and overweight preeclampsia patients. BNP had a significantly weaker effect on adiponectin in overweight compared with normal-weight preeclampsia patients. Moreover, BNP had a weaker effect on adiponectin production in adipocytes from overweight women compared with adipocytes from normal-weight women using primary culture of human adipocytes. These data suggested that BNP may play a role in hyperadiponectinemia of preeclampsia patients. The weaker effect of BNP on adiponectin production may participate in the pathophysiology of overweight preeclampsia patients.

Retinol-binding protein 4 and insulin resistance in preeclampsia

Preeclampsia is characterized by the onset of high blood pressure and proteinuria during pregnancy, which results in substantial maternal and neonatal morbidity and mortality. Insulin resistance has been observed before the onset of preeclampsia, and is implicated in its pathophysiology. Recently, retinol-binding protein 4 (RBP4), which carries retinol in circulation, has been shown to be a potential regulator of insulin resistance originating from adipose tissue. Here we measured insulin resistance and RBP-4 levels in patients with preeclampsia and in women with normal pregnancies matched for gestational age and body mass index at Okayama University Hospital. Our aim was to examine the potential role of RBP4 in the pathophysiology of this disorder. There were no significant differences in RBP4 levels between all patients with preeclampsia and controls. However, the RBP4 level and homeostasis model assessment as an index of insulin resistance (HOMA-IR) in overweight patients with late-onset preeclampsia were significantly higher than in overweight controls carrying normal pregnancies and in normal weight women with late-onset preeclampsia. In contrast, there were no significant differences between the overweight and normal weight groups among patients with early-onset preeclampsia and in healthy pregnant women. These data suggest that RBP4 might act in the pathophysiology of late-onset preeclampsia via increased insulin resistance in obese women.