Relationship of Early Pregnancy Waist-to-Hip Ratio versus Body Mass Index with Gestational Diabetes Mellitus and Insulin Resistance.

OBJECTIVE: To determine the risk of gestational diabetes mellitus (GDM) and insulin resistance (IR) in obesity defined by body mass index (BMI), waist-to-hip ratio (WHR), or both combined. METHODS: Secondary analysis of a randomized multicenter trial of antioxidant supplementation versus placebo in nulliparous low-risk women to prevent pregnancy associated hypertension. Women between 9 and 16 weeks with data for WHR and BMI were analyzed for GDM (n = 2,300). Those with fasting glucose and insulin between 22 and 26 weeks (n = 717) were analyzed for IR by homeostatic model assessment of IR (normal, ≤ 75th percentile). WHR and BMI were categorized as normal (WHR, < 0.80; BMI, < 25 kg/m(2)); overweight (WHR, 0.8-0.84; BMI, 25-29.9 kg/m(2)); and obese (WHR, ≥ 0.85; BMI ≥ 30 kg/m(2)). Receiver operating characteristic curves and logistic regression models were used. RESULTS: Compared with normal, the risks of GDM or IR were higher in obese by BMI or WHR. The subgroup with obesity by WHR but not by BMI had no increased risk of GDM. BMI was a better predictor of IR (area under the curve [AUC]: 0.71 [BMI], 0.65 [WHR], p = 0.03) but similar to WHR for GDM (AUC: 0.68 [BMI], 0.63 [WHR], p = 0.18). CONCLUSION: Increased WHR and BMI in early pregnancy are associated with IR and GDM. BMI is a better predictor of IR compared with WHR. Adding WHR to BMI does not improve its ability to detect GDM or IR.

The Effect of Simvastatin on Infection-Induced Inflammatory Response of Human Fetal Membranes.

PROBLEM: Inflammatory cytokines and matrix metalloproteinases (MMPs) contribute to preterm labor pathophysiology. The objective of this study was to test anti-inflammatory properties of simvastatin in human fetal membranes exposed to lipopolysaccharide (LPS). METHOD OF STUDY: Normal term human fetal membrane explants (n = 11) were allocated to one of the six study groups: control, LPS only (100 ng/mL), simvastatin only (125 ng/mL), simvastatin given 6 hrs prior to LPS (S-L), simvastatin given 6 hrs post-LPS (L-S), and simvastatin and LPS given simultaneously (L+S). Explants were incubated for 24 hrs. Multiplex ELISA for cytokines: IL-1ß, IL-6, IL-10, and TNF-α; soluble cytokine receptors: sIL-1R2, sIL-6R, sTNFR1, and R2; MMPs (1, 2, 7, 9, and 10); and tissue inhibitor of metalloproteinase-2 (TIMP-2) was performed on tissue culture supernatants. Pairwise comparison between different groups was conducted by least square mean estimates. RESULTS: Compared with controls, LPS stimulation increased cytokine production and their tissue bioavailability (measured as the molar ratio of cytokine to its soluble receptor), thus confirming membrane immune reactivity (P < 0.01). Pre-treatment with simvastatin (S-L) reduced IL-6 (P = 0.02), TNF-α (P = 0.02), and MMP-9 (P = 0.01); post-treatment (L-S) reduced IL-1ß (P = 0.02) and TNF-α (P = 0.04), while simultaneous treatment (L+S) did not reduce any of the cytokines tested. Simvastatin reduced the molar ratio of TNF-α/sTNFR1 or R2 and IL-1ß/sIL-1R2 (P = 0.01 and 0.04 in S-L group; P = 0.01 and 0.004 in L-S group, respectively). S-L additionally reduced MMP-9/TIMP-2 molar ratio (P = 0.0007). CONCLUSIONS: Simvastatin downregulates LPS-induced inflammatory response and restores homeostasis between pro- and anti-inflammatory processes. Simvastatin may reduce fetal inflammatory response associated with infection-induced preterm birth.

Can statins reduce the inflammatory response associated with preterm birth in an animal model?

OBJECTIVE: The objective of the study was to determine the effect of statins on lipopolysaccharide (LPS)-induced inflammatory response in a mouse model of preterm birth (PTB). STUDY DESIGN: Day 15 CD1 mice were randomly allocated to intraperitoneal LPS injection (100 µg) or control. Mice in the LPS group were pretreated, 16 and 2 hours prior, with pravastatin (10 µg/g), simvastatin (10 µg/g), or vehicle control. Animals were sacrificed 6 hours after LPS. Cytokine messenger ribonucleic acid (mRNA) expression in the uterus and cervix, and concentrations in the maternal serum and amniotic fluid (AF) were determined. RESULTS: Pravastatin reduced interleukin (IL)-1ß and IL-6 mRNA expression in the uterus and cervix, respectively, and serum IL-1ß and granulocyte-macrophage colony-stimulating factor (GM-CSF) concentrations. Simvastatin reduced IL-1ß and IL-6 mRNA expressions in the uterus, IL-6 and tumor necrosis factor alpha (TNF-α) in the cervix, and IL-1ß, IL-2, IL-12p70, IL-13, TNF-α, GM-CSF, and interferon-γ concentrations in the serum and IL-6 in AF. CONCLUSION: Statins reduce the LPS-induced inflammatory responses in a mouse model of PTB.