Fasting Serum Free Fatty Acids and Triglycerides are Increased Before 20 Weeks of Gestation in Women who Later Develop Preeclampsia

Metabolic profiling of pregnancies complicated by preeclampsia: A longitudinal study

INTRODUCTION

Preeclampsia is associated with maternal metabolic disturbances, but longitudinal studies with comprehensive metabolic profiling are lacking. We aimed to determine metabolic profiles across gestation in women who developed preeclampsia compared with women with healthy pregnancies. We also explored the respective effects of body mass index (BMI) and preeclampsia on various metabolic measures.

MATERIAL AND METHODS

We measured 91 metabolites by high-throughput nuclear magnetic resonance spectroscopy at four time points (visits) during pregnancy (weeks 14-16, 22-24, 30-32 and 36-38). Samples were taken from a Norwegian pregnancy cohort. We fitted a linear regression model for each metabolic measure to compare women who developed preeclampsia (n = 38) and healthy controls (n = 70).

RESULTS

Among women who developed preeclampsia, 92% gave birth after 34 weeks of gestation. Compared to women with healthy pregnancies, women who developed preeclampsia had higher levels of several lipid-related metabolites at visit 1, whereas fewer differences were observed at visit 2. At visit 3, the pattern from visit 1 reappeared. At visit 4 the differences were larger in most subgroups of very-low-density lipoprotein particles, the smallest high-density lipoprotein, total lipids and triglycerides. Total fatty acids were also increased, of which monounsaturated fatty acids and saturated fatty acids showed more pronounced differences. Concentration of glycine tended to be lower in pregnancies with preeclampsia until visit 3, although this was not significant after correction for multiple testing. After adjustment for age, BMI, parity and gestational weight gain, all significant differences were attenuated at visits 1 and 2. The estimates were less affected by adjustment at visits 3 and 4.

CONCLUSIONS

In early pregnancy, the metabolic differences between preeclamptic and healthy pregnancies were primarily driven by maternal BMI, probably representing the women's pre-pregnancy metabolic status. In early third trimester, several weeks before clinical manifestation, the differences were less influenced by BMI, indicating preeclampsia-specific changes. Near term, women with preeclampsia developed an atherogenic metabolic profile, including elevated total lipids, very-low-density lipoprotein, triglycerides, and total fatty acids.

Decreasing the main maternal and fetal complications in women undergoing in vitro fertilization (IVF) trained by nutrition and healthy eating practices during pregnancy

PURPOSE

In vitro fertilization (IVF) can lead to undesirable consequences for pregnant women and their newborns. Reducing the adverse maternal (mainly, gestational diabetes mellitus (GDM) and preeclampsia (PE)), and fetal outcomes in IVF-pregnant women (IVF-PW) was aimed with the correct training of nutrition principles during pregnancy.

MATERIALS AND METHODS

A quasi-experimental clinical trial with 170 IVF-PW in intervention and control groups was conducted. The subjects before the dietary intervention completed questionnaires of nutritional and lifestyle and 24-h food recall. The intervention group was trained with the diet modification programs from early (12-16 weeks) to late (week 34) pregnancy in six weekly, 15-20-min sessions. The GDM diagnosis was based on 75-g OGTT and FBS tests, respectively, in 24-28 weeks' gestation. Other adverse maternal (e.g. PE, cesarean delivery, and preterm delivery (<37 weeks)), and fetal (e.g. intrauterine growth retardation (IUGR), birth weight, and fetal viability) outcomes were also monitored. The dataset was assessed using both inferential and descriptive statistics.

RESULTS

A diet modification program with an increased intake of lactose, fiber, and some minerals (e.g. magnesium and zinc) and vitamins (e.g. B3 and B5) in conjunction with a lower intake rate of glucose and lipid could control the prevalence of adverse maternal and neonatal outcomes in IVF-PW. Although the GDM reduction in the two intervention (8.2%) and control (20.0%) groups was statistically insignificant, there was a significant difference in PE prevalence at a lower rate (39.0%) in the intervention group than the control. No significant difference in cesarean delivery (94.1-95.2%), and preterm delivery (45.9%) between the two groups was found. The IUGR (24.7-25.9%), birth weight (2.791-2.820 kg), and fetal viability (95.3-97.6%) also did not change significantly after the healthy eating practices during pregnancy.

CONCLUSIONS

Diet-based interventions in IVF-PW during pregnancy were efficient in improving the outcomes for both mother and baby.

Metabolic syndrome in pregnancy and risk for adverse pregnancy outcomes: A prospective cohort of nulliparous women

BACKGROUND

Obesity increases the risk for developing gestational diabetes mellitus (GDM) and preeclampsia (PE), which both associate with increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) associates with T2DM and CVD. The impact of maternal MetS on pregnancy outcomes, in nulliparous pregnant women, has not been investigated.

METHODS AND FINDINGS

Low-risk, nulliparous women were recruited to the multi-centre, international prospective Screening for Pregnancy Endpoints (SCOPE) cohort between 11 November 2004 and 28 February 2011. Women were assessed for a range of demographic, lifestyle, and metabolic health variables at 15 ± 1 weeks' gestation. MetS was defined according to International Diabetes Federation (IDF) criteria for adults: waist circumference ≥80 cm, along with any 2 of the following: raised trigycerides (≥1.70 mmol/l [≥150 mg/dl]), reduced high-density lipoprotein cholesterol (<1.29 mmol/l [<50 mg/dl]), raised blood pressure (BP) (i.e., systolic BP ≥130 mm Hg or diastolic BP ≥85 mm Hg), or raised plasma glucose (≥5.6 mmol/l). Log-binomial regression analyses were used to examine the risk for each pregnancy outcome (GDM, PE, large for gestational age [LGA], small for gestational age [SGA], and spontaneous preterm birth [sPTB]) with each of the 5 individual components for MetS and as a composite measure (i.e., MetS, as defined by the IDF). The relative risks, adjusted for maternal BMI, age, study centre, ethnicity, socioeconomic index, physical activity, smoking status, depression status, and fetal sex, are reported. A total of 5,530 women were included, and 12.3% (n = 684) had MetS. Women with MetS were at an increased risk for PE by a factor of 1.63 (95% CI 1.23 to 2.15) and for GDM by 3.71 (95% CI 2.42 to 5.67). In absolute terms, for PE, women with MetS had an adjusted excess risk of 2.52% (95% CI 1.51% to 4.11%) and, for GDM, had an adjusted excess risk of 8.66% (95% CI 5.38% to 13.94%). Diagnosis of MetS was not associated with increased risk for LGA, SGA, or sPTB. Increasing BMI in combination with MetS increased the estimated probability for GDM and decreased the probability of an uncomplicated pregnancy. Limitations of this study are that there are several different definitions for MetS in the adult population, and as there are none for pregnancy, we cannot be sure that the IDF criteria are the most appropriate definition for pregnancy. Furthermore, MetS was assessed in the first trimester and may not reflect pre-pregnancy metabolic health status.

CONCLUSIONS

We did not compare the impact of individual metabolic components with that of MetS as a composite, and therefore cannot conclude that MetS is better at identifying women at risk. However, more than half of the women who had MetS in early pregnancy developed a pregnancy complication compared with just over a third of women who did not have MetS. Furthermore, while increasing BMI increases the probability of GDM, the addition of MetS exacerbates this probability. Further studies are required to determine if individual MetS components act synergistically or independently.

Preeclampsia: What Does the Father Have to Do with It?

Preeclampsia (PE) is one of the leading causes of maternal and fetal morbidity and mortality, with incidence rates ranging between 2 and 5 % in the Western World. The exact causes of the disease remain largely unknown, because of the complex pathophysiologic mechanisms involved in the process. Genetic, environmental, and epigenetic parameters have been implicated by various authors as culprits for the pathogenesis of PE. Recent reports in the literature highlight the paternal role. Still, the exact extent and mechanism remain elusive. In this systematic review, we attempt to present data regarding the paternal role in a concise and comprehensive manner.

The -93T/G LPL Promoter Polymorphism Is Associated With Lower Third-Trimester Triglycerides in Pregnant African American Women

BACKGROUND

Hypertriglyceridemia is a risk factor for cardiovascular disease and several pregnancy complications. Lipoprotein lipase (LPL) genetic variation modulates nonpregnancy plasma triglycerides, but its effects during pregnancy are unknown. The G allele of the LPL -93T/G promoter polymorphism is 16-23 times more prevalent in Blacks than in Whites, contributing to lower triglycerides in nonpregnant African Americans by increasing LPL expression.

PURPOSE

This study investigated whether the triglyceride-lowering effect of -93G is observed in African Americans during pregnancy.

METHODS

Genotyping was performed on 124 African American women with uncomplicated pregnancies for common functional LPL polymorphisms/mutations (-93T/G, D9N, N291S, and S447X). Third-trimester plasma triglyceride, high- and low-density lipoprotein cholesterol, apolipoprotein B, and free fatty acid concentrations were measured with colorimetric assays. Clinical characteristics and lipid values were compared across the -93T/G genotypes.

RESULTS

Triglycerides were significantly lower in women with the -93GG compared to the -93TT genotype, both with (n = 124, p = .02) and without (n = 108, p = .03) inclusion of participants with other LPL variant alleles. Triglyceride differences persisted after adjustment for prepregnancy body mass index, gestational age at delivery, and smoking. There were no significant differences in the other lipids or apolipoprotein B by -93T/G genotype.

CONCLUSIONS

Despite the considerable metabolic changes accompanying pregnancy, the triglyceride-lowering effect associated with the -93GG LPL genotype in African Americans persists during late pregnancy. The -93GG genotype might protect against pregnancy complications stemming from hypertriglyceridemia, but the overall increased risk of pregnancy complications in African American women points to complex, multifactorial relationships among risk factors, race, and adverse pregnancy outcomes.

Lipid profile in nonobese pregnant women with polycystic ovary syndrome: a prospective controlled clinical study

Alterations in lipid pattern and increased risk for obstetric/neonatal complications have been observed in patients with polycystic ovary syndrome (PCOS). Pregnancy leads to physiologic changes in lipoprotein metabolism, and alterations in lipid profile have been related with adverse pregnancy outcomes. Based on these considerations, the aim of the present prospective controlled clinical study was to test the hypothesis that the changes in the lipid profile in patients with PCOS during pregnancy are characteristic and potentially related to the increased risk of obstetric/neonatal complications. One hundred and fifty nonobese PCOS women and 150 age- and body mass index (BMI)-matched healthy controls were enrolled. Serum lipids, glucose, insulin, and androgens levels were serially assayed in all subjects before and throughout pregnancy. Serum low-density lipoprotein (LDL) and triglyceride (TG) concentrations were significantly (P<0.05) higher in PCOS group than in healthy controls at each assessment. Throughout pregnancy, serum LDL and TG levels increased significantly (P<0.05) in both groups, although the change from pre-pregnancy values was significantly (P<0.05) greater in PCOS patients than in healthy controls. A significant (P<0.05) relationship was observed between serum LDL and TG changes and changes in both insulin sensitivity indexes and androgen levels in PCOS patients alone. After adjusting for maternal age, pre-pregnancy BMI and lipid levels, body weight gain, and insulin-resistance markers, serum TG concentrations during pregnancy were directly and independently associated with obstetric complications in both groups, whereas serum LDL levels only in PCOS patients. We can conclude that nonobese PCOS patients had specific changes in lipid profile during pregnancy, and that the lipid pattern typical of PCOS may account for the more frequent adverse pregnancy outcomes. PCOS-related hormonal and metabolic features, such as insulin resistance and high androgen levels, may mediate this phenomenon.

Nonesterified fatty acids and spontaneous preterm birth: a factor analysis for identification of risk patterns

We considered that accumulation of nonesterified (free) fatty acids (NEFAs) in the first trimester of pregnancy would mark women at excess risk of spontaneous preterm birth (sPTB) and examined the interplay between NEFAs, lipids, and other markers to explore pathways to sPTB. In a case-control study nested in the Pregnancy Exposures and Preeclampsia Prevention Study (Pittsburgh, Pennsylvania, 1997-2001), we assayed NEFA levels in nonfasting serum collected at a mean gestational week of 9.4 (range, 4-20 weeks) in 115 women with sPTB (<37 weeks) and 222 women with births occurring at ≥37 weeks. C-reactive protein, total cholesterol, low-density lipoprotein and high-density lipoprotein (HDL) cholesterol, triglycerides, and uric acid were also measured. Polytomous logistic regression models were used to evaluate tertiles of NEFA levels and sPTB at <34 weeks and 34-36 weeks; factor analysis was used to characterize patterns of biomarkers. Women with NEFA levels in the highest tertile versus the lowest were 2.02 (95% confidence interval: 1.13, 3.48) times more likely to have sPTB, after adjustment for covariates. Risk of sPTB before 34 weeks was particularly high among women with high NEFA levels (odds ratio = 3.73, 95% confidence interval: 1.33, 10.44). Six biomarker patterns were identified, and 2 were associated with sPTB: 1) increasing NEFA and HDL cholesterol levels and 2) family history of gestational hypertension. NEFA levels early in pregnancy were independently associated with sPTB, particularly before 34 weeks. We also detected a novel risk pattern suggesting that NEFAs together with HDL cholesterol may be related to sPTB.

Recognizing pregnancy-associated cardiovascular risk factors

Preeclampsia, gestational diabetes, or pregnancy-induced hypertension identify a woman at risk for cardiovascular disease. This information should be incorporated into the routine cardiovascular risk assessment for women, as a basis for appropriate risk factor screening, counseling, and preventive interventions. There is need for development and validation of a clinometric tool to assess cardiovascular risk and guide management.

Serum βhCG and Lipid Profile in Early Second Trimester as Predictors of Pregnancy-Induced Hypertension

OBJECTIVES

A variety of biological, biochemical, and biophysical markers implicated in the pathophysiology of pre-eclampsia during the last two decades have instigated the growing interest in this study to include both βhCG and lipid profile studies in the early second trimester as early predictors of pregnancy-induced hypertension. Early identification of at-risk women may help in taking timely preventive and curative management to prevent or delay complications associated with pregnancy-induced hypertension.

METHOD

A prospective study was performed on 120 patients attending the outpatient department of the Obstetrics and Gynaecology of the Maharaja Agrasen Hospital. All the patients were screened for serum βhCG and serum lipid profile in their early second trimester (14-20 weeks) and followed up till their delivery. Comparative studies of serum βhCG and serum lipid profile were performed between those who remain normotensive (group I) and those who developed pregnancy-induced hypertension (group II).

RESULTS

TG, total cholesterol, VLDL, and LDL values for those women who developed PIH (group II) were significantly higher than those who remain normotensive (group I), with p value of <0.05 which is statistically significant. HDL and βhCG values for group II were not higher than those in group I with p value >0.05 which is statistically insignificant.

CONCLUSION

Maternal lipid profile in second trimester is very good noninvasive test which can be used for prediction of pregnancy-induced hypertension before its clinical onset. However, there is no correlation between maternal serum βhCG and pregnancy-induced hypertension.

Euglycemic hyperinsulinemia increases blood pressure in pregnant rats independent of placental antiangiogenic and inflammatory factors

BACKGROUND

Although pregnancies associated with hyperinsulinemia and altered placental angiogenic and inflammatory factors are at increased risk for developing preeclampsia, the effects of euglycemic hyperinsulinemia on placental factors and blood pressure regulation during pregnancy are unclear. We hypothesized that chronic hyperinsulinemia results in increased placental soluble fms-like tyrosine kinase 1(sFlt-1) and tumor necrosis factor α (TNF- α) levels and hypertension in pregnant rats.

METHODS

On gestational day (GD) 14, Sprague-Dawley rats were assigned as normal pregnant or pregnant + insulin. Insulin was infused subcutaneously by osmotic minipump for 5 days at a dose of 1.5 mU/kg/min. Those rats receiving insulin were supplemented with 20% glucose in drinking water to maintain euglycemia. On GD 19, mean arterial pressure (MAP) and heart rate (HR) were assessed in conscious rats by indwelling carotid catheters, followed by collections of blood, placentas, and fetuses. In addition to placental sFlt-1 and TNF-α levels, circulating insulin, glucose, leptin, cholesterol, triglyceride, and free fatty acid concentrations were measured.

RESULTS

MAP was higher in pregnant + insulin vs. normal pregnant rats; however, HR was similar between groups. Although litter size and placental weight were comparable, fetuses from pregnant + insulin rats were heavier. Importantly, circulating insulin concentration was elevated in the pregnant + insulin group, with no change in glucose level. Moreover, circulating leptin, cholesterol, triglyceride, and free fatty acid concentrations were increased in the pregnant + insulin group. There were no differences in placental sFlt-1 and TNF-α concentrations between groups.

CONCLUSIONS

In summary, sustained euglycemic hyperinsulinemia, comparable with insulin levels in preeclamptic women, can raise blood pressure in pregnancy independent of recognized placental factors associated with preeclampsia.

Is the atherosclerotic phenotype of preeclamptic placentas due to altered lipoprotein concentrations and placental lipoprotein receptors? Role of a small-for-gestational-age phenotype

Atherosis of spiral arteries in uteroplacental beds from preeclamptic women resemble those of atherosclerosis, characterized by increased plasma lipids and lipoproteins. We hypothesized that: 1) lipoprotein receptors/transporters in the placenta would be upregulated in preeclampsia, associated with increased maternal and fetal lipoprotein concentrations; and 2) expression of these would be reduced in preeclamptic placentae from women delivering small-for-gestational-age (SGA) infants. Placental biopsies and maternal and umbilical serum samples were taken from 27 normotensive and 24 preeclamptic women. Maternal/umbilical cord serum LDL, HDL, total cholesterol, and triglycerides were measured. Placental mRNA expression of lipoprotein receptors/transporters were quantified using quantitative RT-PCR. Protein localization/expression of LDL receptor-related protein 1 (LRP-1) in the preeclamptic placentae with/without SGA was measured by immunohistochemistry. Placental mRNA expression of all genes except paraoxonase-1 (PON-1), microsomal triglyceride transfer protein (MTTP), and protein disulfide isomerase family A member 2 (PDIA2) were observed. No differences for any lipoprotein receptors/transporters were found between groups; however, in the preeclamptic group placental LRP-1 expression was lower in SGA delivering mothers (n = 7; P = 0.036). LRP-1 protein was localized around fetal vessels and Hofbauer cells. This is the first detailed study of maternal/fetal lipoprotein concentrations and placental lipoprotein receptor mRNA expression in normotensive and preeclamptic pregnancies. These findings do not support a role of altered lipid metabolism in preeclampsia, but may be involved in fetal growth.

Activation of NF-κB in placentas of women with preeclampsia

OBJECTIVE

Placentas are oxidatively stressed during preeclampsia and produce more tumor necrosis factor α (TNFα) and more thromboxane than normal. Oxidative stress may cause these abnormalities by activating nuclear factor-κB (NF-κB). We measured the levels of activated NF-κB in normal and preeclamptic placentas and determined whether oxidative stress activates NF-κB in a trophoblast-like cell line.

METHODS

We used immunohistochemistry to determine the percentage of the total tissue area that stained for the p65 subunit of NF-κB in placentas obtained from normal and preeclamptic pregnancies. In a second set of experiments, we used a reporter plasmid bearing the NF-κB binding site and transfected it into trophoblast-like cells. The cells were incubated with medium control, linoleic acid (LA), an oxidizing solution (Ox), or Ox enriched with LA (OxLA), TNFα, or OxLA plus TNFα for 20 h. Cell lysates were analyzed using a dual luciferase assay kit.

RESULTS

Placentas obtained from women with preeclampsia showed nearly a 10-fold increase in the extent of area stained for activated NF-κB as compared to normal placentas. In cell culture experiments, Ox and OxLA induced a threefold increase in NF-κB activation as compared to medium control or LA. TNFα induced a threefold increase in NF-κB activation. The combination of TNFα with OxLA caused a 10-fold increase in NF-κB activation.

CONCLUSIONS

Placental NF-κB is activated nearly 10-fold in preeclampsia. Oxidative stress causes NF-κB activation in a trophoblast-like cell line, which is enhanced by TNFα. These data suggest that oxidative stress is likely an important in vivo activator of placental NF-κB in preeclampsia.

Triglyceride metabolism in pregnancy

During pregnancy, complex changes occur in lipid profiles. From the 12th week of gestation, phospholipids, cholesterol (total, LDL, HDL), and triglycerides (TG) increase in response to estrogen stimulation and insulin resistance. Transition to a catabolic state favors maternal tissue lipid use as energy sources, thus sparing glucose and amino acids for the fetus. In addition, maternal lipids, that is, cholesterol, are available for fetal use in building cell membranes and as precursor of bile acids and steroid hormones. It is also required for cell proliferation and development of the growing body. Free-fatty acids (FFA), oxidized in the maternal liver as ketone-bodies, represent an alternative fuel for the fetus. Maternal hypertriglyceridemia (vs. other lipids) has many positive effects such as contributing to fetal growth and development and serving as an energy depot for maternal dietary fatty acids. However, increased TG during pregnancy appears to increase risk of preeclampsia and preterm birth. Some have suggested that maternal hypertriglyceridemia has a role in increasing cardiovascular risk later in life. This chapter reviews lipid metabolism during pregnancy to elucidate its effect on fetal growth and its potential role in pregnancy-associated complications and future cardiovascular risk.

Hypertension in pregnancy

Hypertension is a common complication of pregnancy. Preeclampsia, in particular, is associated with substantial risk to both the mother and the fetus. Several risk factors have been recognized to predict risk for preeclampsia. However, at present no biomarkers have sufficient discriminatory ability to be useful in clinical practice, and no effective preventive strategies have yet been identified. Commonly used medications for the treatment of hypertension in pregnancy include methyldopa and labetalol. Blood pressure thresholds for initiating antihypertensive therapy are higher than outside of pregnancy. Women with prior preeclampsia are at increased risk of hypertension, cardiovascular disease, and renal disease.

Early antenatal serum lipid levels and the risk of pre-eclampsia in Trinidad and Tobago

OBJECTIVE

To determine the lipid levels in early pregnancy and the risk for pre-eclampsia in a Trinidad population.

METHODS

Prospective cohort study comprised 156 pregnant women attending antenatal clinic visits prior to 20 weeks at an average of 14 weeks. Blood samples were analysed for lipid levels. Of which 102 participants were followed until delivery and were monitored for pre-eclampsia. Data was analysed using univariate linear and stepwise logistic regression analysis.

RESULTS

In the study 11 women developed pre-eclampsia and 91 remained normal. Mean triglyceride levels were found significantly higher in the pre-eclampsia group (p = 0.001). Mean HDL levels were low and LDL/HDL ratios were high in pre-eclampsia group. Women with triglycerides above 130 mg/dL had increased risk of pre-eclampsia (adjusted OR 14.046; 95% CI 1.254-157.334) compared with those with triglycerides levels 91 mg/dL or less.

CONCLUSION

Increased serum triglyceride levels in early pregnancy before 20 weeks are associated with pre-eclampsia.

Role of nutrition in the risk of preeclampsia

Preeclampsia (PE) accounts for about one-quarter of the cases of maternal mortality and ranks second among the causes of pregnancy-associated maternal deaths in Canada and worldwide. The identification of an effective strategy to prevent PE is a priority and a challenge for research in obstetrics. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet in the etiology of PE has recently received increased attention. The objective of this paper is to provide an overview of the literature concerning 1) the current understanding of the pathogenesis of PE, 2) the biological plausibility and potential mechanisms underlying the associations between maternal dietary exposures, nutrition, and the risk of PE, and 3) the epidemiological findings of maternal nutrient intake in relation to the risk of PE.

Maternal serum dyslipidemia occurs early in pregnancy in women with mild but not severe preeclampsia

OBJECTIVE

We sought to determine whether serum lipids at midgestation differ between normotensive women and women developing mild and severe preeclampsia.

STUDY DESIGN

A case-control study of 50 women with preeclampsia (mild = 26; severe = 24) and 100 women with uncomplicated term deliveries was conducted. Maternal serum collected at 15-20 weeks was used to measure lipid profiles.

RESULTS

The groups were similar with respect to demographic characteristics. Women with mild preeclampsia had higher triglyceride levels and a higher total cholesterol to high-density lipoprotein ratio than control subjects (200 +/- 79.5 mg/dL vs 164 +/- 56.2 mg/dL; P = .02; and 3.31 +/- 1.06 mg/dL vs 2.91 +/- 0.59; P = .02). Women with severe preeclampsia had lower levels of low-density lipoprotein than control subjects (85.5 +/- 21.3 mg/dL vs 102 +/- 30.0 mg/dL; P = .04) and a less atherogenic lipid profile than control subjects.

CONCLUSION

Midgestation dyslipidemia is associated with mild but not severe preeclampsia. These findings may aid in elucidating the different pathologic processes between mild and severe preeclampsia.

Trp64Arg polymorphism of the β3-adrenergic receptor gene, pre-pregnancy obesity and risk of pre-eclampsia

OBJECTIVE

Trp64Arg polymorphism of the beta3-adrenergic receptor (beta3-AR) gene was reported to be associated with increased risk of obesity and insulin resistance. Both traits have been implicated in the epidemiology and pathogenesis of pre-eclampsia. We investigated the relation of the beta3-AR gene to pre-pregnancy obesity and risk of pre-eclampsia. The present study is a case-control study of 87 Caucasian pre-eclampsia cases and 214 controls.

METHODS

Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusted for maternal age and parity. Normotensive carriers of the variant allele (i.e. Arg64 allele) were 3.6 times more likely to be obese (body mass index (BMI) > or = 30 kg/m2) as compared with women not carrying the variant allele (OR = 3.6, 95% CI 0.8-15.0).

RESULTS

Arg64 allele was more frequent in controls as compared with pre-eclampsia cases (11.7 vs. 5.3%, p < 0.01). After adjusting for age and parity, carriers experienced a 60% reduction in risk of pre-eclampsia (OR = 0.4, 95% CI 0.2, 0.9) as compared with women not carrying this allele. The association between carriage of the variant allele and risk of pre-eclampsia appeared to be modified by maternal BMI. Compared with lean carriers, lean women without the variant allele experienced only a small increase in the risk of pre-eclampsia (OR = 1.5; 95% CI: 0.6, 3.9). The OR for overweight women without the variant allele was 7.3 (95% CI 2.7-19.2).

CONCLUSIONS

Our results suggest a puzzling relationship between the polymorphism and the risk of pre-eclampsia. Future studies are needed to confirm these findings.

Free fatty acid profiles in preeclampsia

Preeclampsia has many characteristics similar to the metabolic syndrome. One of these is aberrant lipid metabolism. We studied free fatty acid (FFA) profiles at baseline and after oral glucose load in 21 preeclamptic and 11 normotensive pregnant women. Insulin sensitivity was measured by intravenous glucose tolerance test. We found that serum total FFA concentrations at baseline were 67% higher in preeclamptic than in normotensive pregnancies (P=0.0002). The difference between the two groups was largest in the concentrations of oleic (75%), linoleic (129%) and arachidonic (315%) acids. Oral intake of glucose suppressed total FFA in preeclamptic women by 40% (95% CI 32.1-46.1%, P<0.0001) but only 24% in control women (95% CI 0.01-42.0%, P=0.045). Insulin sensitivity, which in preeclamptic women was 37% lower (P=0.009), was unrelated to total or any individual FFA concentration. We concluded that preeclamptic women have higher circulating FFA concentrations, which despite insulin resistance are suppressed by oral glucose loading.

Circulating levels of adiponectin and leptin at 23-25 weeks of pregnancy in women with impaired placentation and in those with established fetal growth restriction

Adiponectin and leptin, two adipose-tissue-derived proteins, have been reported to be elevated in women with established PE (pre-eclampsia). The aim of the present study was to investigate whether alterations in adiponectin and leptin levels predate the development of PE and FGR (fetal growth restriction) in women at increased risk of these complications, as assessed by Doppler examination of the uterine arteries during the second trimester of pregnancy. We also sought to investigate the circulating levels of adiponectin and leptin in women with established severe early-onset FGR. The study included three groups of pregnant women at 23-25 weeks: Group A (n=44) with normal uterine artery Doppler waveforms, Group B (n=49) with abnormal Doppler waveforms and normal fetal growth at the time of the examination, and Group C (n=15) with established severe FGR and abnormal Doppler waveforms. All women had plasma adiponectin and leptin measured by sensitive immunoassays. In Group B, 19 women had a normal outcome, 17 delivered infants with FGR and 13 developed PE. The women who developed PE delivered smaller babies earlier than women with a normal outcome (P<0.001). There were no significant differences in adiponectin levels between any of the groups (overall P=0.3). Leptin concentrations, expressed as MoM (multiples of the median) of Group A, were higher in women in Group C, i.e. established severe FGR at 2.5 (1.2-2.7) MoMs (overall P<0.001), compared with all of the other groups and subgroups. In conclusion, we found that, in pregnancies complicated by severe early-onset FGR, the maternal plasma concentration of leptin is twice as high as in normal pregnancies. However, the second trimester levels of maternal plasma adiponectin and leptin in pregnancies that subsequently develop PE and/or FGR are not significantly different from normal and, consequently, it is unlikely that these markers will be useful as predictors of these pregnancy complications.

Interactions between smoking and weight in pregnancies complicated by preeclampsia and small-for-gestational-age birth

Cigarette smoking protects against preeclampsia but increases the risk of small-for-gestational-age birth (SGA). Regarding body weight, the converse is true: obesity elevates rates of preeclampsia but reduces rates of SGA. The authors assessed the combined effects of smoking and weight among US women developing preeclampsia or SGA, studying 7,757 healthy, primigravid women with singleton pregnancies in 1959-1965. Smoking (never, light, heavy), stratified by prepregnancy body mass index (BMI (weight (kg)/height (m)(2)); underweight, overweight, obese), was examined in relation to preeclampsia and SGA. Among underweight (BMI <18.5) and normal-weight (BMI 18.5-24.9) women, smoking decreased the risk of preeclampsia (for heavy smoking, light smoking, nonsmoking, test for trend p = 0.002 for underweight and p = 0.009 for normal weight) after adjustment for age, race, and socioeconomic status. However, among overweight/obese women (BMI >or=25), this trend was not apparent (p = 0.4). Among both underweight and overweight women, smoking significantly increased SGA risk (trend p < 0.001 for underweight and p = 0.02 for overweight/obese). Obesity eliminated the inverse association between smoking and preeclampsia but did not substantially alter the positive association between smoking and SGA. A possible unifying biologic explanation is discussed in this paper.

Preeclampsia recurrence and prevention

Women with a previous pregnancy complicated by preeclampsia have an increased risk for recurrence in subsequent pregnancies. For severe preeclamptic women in an initial pregnancy, recurrence rates for any type of preeclampsia are very high, approaching 50% in some studies. Significant maternal and fetal complications are more common in recurrent preeclampsia compared with an initial episode. For women who have experienced a pregnancy complicated by preeclampsia, a systematic evaluation for underlying risk factors may identify a specific pathway suitable for a specific intervention. Although some progress has been made in developing potential therapeutic options to prevent preeclampsia recurrence, there is a great need for better data to determine who will benefit most from any specific therapy.

Placental-related diseases of pregnancy: Involvement of oxidative stress and implications in human evolution

Miscarriage and pre-eclampsia are the most common disorders of human pregnancy. Both are placental-related and exceptional in other mammalian species. Ultrasound imaging has enabled events during early pregnancy to be visualized in vivo for the first time. As a result, a new understanding of the early materno-fetal relationship has emerged and, with it, new insight into the pathogenesis of these disorders. Unifying the two is the concept of placental oxidative stress, with associated necrosis and apoptosis of the trophoblastic epithelium of the placental villous tree. In normal pregnancies, the earliest stages of development take place in a low oxygen (O2) environment. This physiological hypoxia of the early gestational sac protects the developing fetus against the deleterious and teratogenic effects of O2 free radicals (OFRs). In miscarriage, development of the placento-decidual interface is severely impaired leading to early and widespread onset of maternal blood flow and major oxidative degeneration. This mechanism is common to all miscarriages, with the time at which it occurs in the first trimester depending on the aetiology. In contrast, in pre-eclampsia the trophoblastic invasion is sufficient to allow early pregnancy phases of placentation but too shallow for complete transformation of the arterial utero-placental circulation, predisposing to a repetitive ischaemia-reperfusion (I/R) phenomenon. We suggest that pre-eclampsia is a three-stage disorder with the primary pathology being an excessive or atypical maternal immune response. This would impair the placentation process leading to chronic oxidative stress in the placenta and finally to diffuse maternal endothelial cell dysfunction.

Shared and disparate components of the pathophysiologies of fetal growth restriction and preeclampsia

Intrauterine growth restriction (IUGR) and preeclampsia differ in their association with maternal disease but share a similar placental pathology. Moreover, mothers who have had pregnancies complicated by preeclampsia or IUGR are at elevated later-life cardiovascular risk. Why, then, do some women develop IUGR and others develop preeclampsia? In this clinical opinion, based on a review of the literature, we hypothesize that both women experiencing preeclampsia and IUGR enter pregnancy with some degree of endothelial dysfunction, a lesion that predisposes to shallow placentation. In our opinion, preeclampsia develops when abnormal placentation, through the mediator of elevated circulating cytokines, interacts with maternal metabolic syndrome, comprised of adiposity, insulin resistance/hyperglycemia, hyperlipidemia, and coagulopathy. IUGR develops in the absence of antenatal metabolic syndrome. Among these women, the baby is affected by shallow placentation but the mother does not develop clinically apparent disease. This conceptualization provides a testable framework for future etiologic studies of preeclampsia and IUGR.

Serum lipid levels at 28-32 weeks gestation and hypertensive disorders

BACKGROUND

The etiology and pathogenesis of hypertensive disorders complicating pregnancy are poorly understood, and the definition of these disorders is controversial.

METHODS

In a prospective study, 470 primigravida women between 28 and 32 weeks of pregnancy were evaluated for serum levels of total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglyceride. Afterward, they were observed for any symptoms of preeclampsia and gestational hypertension until 40 weeks of gestational age. We than compared the serum lipid levels among women with preeclampsia and gestational hypertension with those of matched women with normal pregnancies.

RESULTS

The numbers of patients developing preeclampsia and gestational hypertension were 25 (5.3%) and 32 (6.8%), respectively. At the beginning of the study, the mean values of serum triglyceride levels between women who later experienced preeclampsia or gestational hypertension and those who did not differed significantly (p < 0.0001, p < 0.03).

CONCLUSION

Although many cases of gestational hypertension represent latent essential hypertension based on the lipid levels, some of these women display true pregnancy-induced hypertension or nonproteinuric preeclampsia.

Inflammation and triglycerides partially mediate the effect of prepregnancy body mass index on the risk of preeclampsia

The objective of this study was to quantify the mediating role of inflammation and triglycerides in the association between prepregnancy body mass index (weight (kg)/height (m)2) and preeclampsia. The authors conducted a nested case-control study of 55 preeclamptic women and 165 pregnant controls from the Pregnancy Exposures and Preeclampsia Prevention Study (Pittsburgh, Pennsylvania, 1997-2001). Serum samples collected at < or = 20 weeks' gestation were analyzed for levels of C-reactive protein and triglycerides. The adjusted odds ratio (AOR) from a multivariable conditional logistic regression model assessing the total effect of body mass index on preeclampsia risk was compared with the AOR from the same model after results were controlled for C-reactive protein, triglycerides, and confounding factors (direct-effects model). The percentage of the total effect that was mediated through inflammation and triglycerides was calculated as 100 - [ln(direct-effects AOR)/ln(total-effects AOR)]. In the total-effects model, 4- and 8-unit increases in body mass index were associated with 1.7-fold (95% confidence interval (CI): 1.3, 2.3) and 2.9-fold (95% CI: 1.6, 5.2) increases in preeclampsia risk, whereas in the direct-effects model, these AORs were 1.4 (95% CI: 1.0, 1.9) and 2.0 (95% CI: 1.0, 3.8), respectively. Inflammation was a more important mediator than triglycerides. These findings suggest that approximately one third of the total effect of body mass index on preeclampsia risk is mediated through inflammation and triglyceride levels.

Preeclampsia

Preeclampsia is a pregnancy complication with serious consequences for mother and infant. The disorder is diagnosed by gestational hypertension and proteinuria but is far more than pregnancy induced hypertension. Preeclampsia is proposed to occur in 2 stages. Stage 1 reduced placental perfusion is postulated as the root cause and to lead to the maternal syndrome, Stage 2. Why perfusion is reduced, how this translates to a maternal disease in some but not all women and what is the linkage of the 2 stages are topics of intense study. In the last decade such studies have provided valuable insights into pathophysiology that now guide ongoing clinical trials.

Risk for Coronary Artery Disease and Morbid Preeclampsia: A Commentary

PURPOSE

A predisposition to coronary artery disease (CAD) may put women at risk for preeclampsia. Morbid preeclampsia (early, severe, recurrent, and with neonatal morbidity) represents the subset of preeclampsia of greatest public health concern.

METHODS

We review here the published links between preeclampsia and CAD.

RESULTS

Many risk factors are common to both CAD and preeclampsia. These include obesity; elevated blood pressure; dyslipidemia; insulin resistance; and hyperglycemia, together termed "Syndrome X"; as well as endothelial dysfunction; hyperuricemia; hyperhomocysteinemia; and abnormalities of inflammation, thrombosis, and angiogenesis. After pregnancy, women with preeclampsia are more likely to experience later life CAD.

CONCLUSIONS

Both the association between CAD risk factors and preeclampsia and the association between preeclampsia and later CAD appears to be more pronounced among the subset of women with morbid preeclampsia. Thus, women at elevated risk for CAD may be at particularly high risk for morbid preeclampsia and women with morbid preeclampsia may be those at highest risk for later life CAD.

Lack of proinflammatory effects of free fatty acids on human umbilical cord vein endothelial cells and leukocytes

AIM

To determine whether the free fatty acids (FFAs), oleic, linoleic, and palmitic acid, found elevated before 20 weeks of pregnancy in those women who later develop preeclampsia, induced changes in expression of the vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), or E-selectin in cultured human umbilical cord vein endothelial cells (HUVEC), and integrin subunit CD11b, L-selectin or intracellular reactive oxygen species (ROS) in leukocytes.

METHODS

The VCAM-1, ICAM-1, and E-selectin expression were measured using ELISA in HUVEC after incubation with 100 micromol of either oleic, linoleic, or palmitic acid for 6 hr and 24 hr. The co-reactivity with lipopolysaccharide (LPS), the amount of VCAM-1 mRNA in the cells, and soluble VCAM-1 in the incubation medium were measured as well. Leukocyte adhesion molecules and ROS were measured after incubation with 750 microm of either of the FFAs in a whole blood model using flow cytometry.

RESULTS

No effects of the FFAs tested were found on the HUVEC or leukocyte adhesion molecule expression or intracellular ROS. The only exception to this was palmitic acid incubation, which significantly lowered the VCAM-1 expression in HUVEC after 24-hr incubation and also slowed the decay of VCAM-1 expressed after stimulation with LPS.

CONCLUSIONS

The lack of significant proinflammatory changes of the FFAs tested might indicate that the elevated plasma levels of FFAs seen in preeclampsia most probably are products of the preeclamptic process rather than a causative factor.

Lipoprotein(a) levels in women with pre-eclampsia and in normotensive pregnant women

AIM

To determine if plasma lipoprotein(a) levels are elevated in pre-eclampsia and if so, their association with the severity of the disease.

METHODS

Ninety-one pre-eclamptic (48 mild, 43 severe) and 40 healthy normotensive pregnant women at more than 32 gestational weeks were recruited into study. Plasma levels of lipoprotein(a), lipids, total protein, albumin and fibrinogen were measured in all subjects.

RESULTS

All groups were comparable with respect to maternal age, maternal weight, gravidity and parity. Platelet count, total serum protein and albumin levels were significantly decreased, whereas fibrinogen levels significantly increased in the pre-eclamptic group. There was no difference between the groups with respect to total cholesterol and low-density lipoprotein levels. In the pre-eclampsic group, triglyceride and very-low-density lipoprotein concentrations were significantly higher, whereas high-density lipoprotein levels were significantly lower. No difference in serum lipoprotein(a) levels was found between the three groups.

CONCLUSIONS

No statistically significant difference existed between normotensive pregnant, and pre-eclamptic women, with regard to plasma lipoprotein(a) levels. It is improbable that high serum lipoprotein(a) levels are risk factors for the development of pre-eclampsia; however, elevated triglyceride-rich lipoproteins might cause endothelial damage leading to pre-eclampsia.

Calprotectin plasma level is elevated in preeclampsia

BACKGROUND

Calprotectin is a protein found in myelomonocytic cells and plays a role in various physiological functions such as inflammatory processes and antiproliferation of cells, and in the neutrophil defense against bacterial infections. Preeclampsia is characterized by maternal endothelial dysfunction and by insufficient trophoblast invasion into the maternal endometrium (decidua). In addition, preeclampsia is associated with maternal leukocyte activation and we therefore wanted to investigate whether calprotectin levels in plasma from women with preeclampsia differed from the levels in normotensive pregnant and nonpregnant women.

METHOD

Calprotectin measurements were included in a case-control study of 20 preeclamptic women matched with 20 normotensive pregnant women regarding age, pregnancy length, parity and body mass index (BMI). We also measured calprotectin in 12 nonpregnant women. Calprotectin plasma levels were analyzed using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

We discovered significantly elevated plasma calprotectin levels in preeclamptic patients compared to matched normotensive pregnancies: 768 (612-1016) microg/L vs. 445 (276-598) microg/L (medians, 25, 75 percentiles, respectively), p = 0.002.

CONCLUSIONS

The elevated plasma calprotectin levels demonstrated in the preeclampsia group supports the notion that leukocytes are activated in preeclampsia. The elevated calprotectin level might constitute a part of the innate defense in myelomonocytic cells against microorganisms in pregnancy. We suggest further elucidation of a role for calprotectin in the development of pregnancy disorders such as preeclampsia.

Clinical characteristics of young-onset hypertension-implications for different genders

BACKGROUND

Hypertension may develop early, before the age of 40 years, in both genders, so-called young-onset hypertension. The clinical characteristics of young-onset hypertension have not been well defined.

METHODS

The personal history and clinical characteristics were evaluated in a series of patients with young-onset hypertension. With the individual-matching, case-controlled design, patients were initially matched for age, gender and residence with the first control (C1) group in either 2:1 or 1:1 fashion. They were then additionally matched for body mass index (BMI) with the second control (C2) group in 1:1 fashion. To elucidate the possible difference between genders, all the comparisons were conducted in males and females separately.

RESULTS

A total of 82 consecutive patients, 56 males and 26 females, with young-onset hypertension were included. Compared with the 148 subjects in C1 group, hypertensive patients were relatively highly educated and had less alcohol drinking in either gender. BMI (25.10+/-0.49 vs. 22.34+/-0.31 kg/m(2), P<0.001) and serum triglyceride level (153.35+/-10.71 vs. 98.76+/-5.12 mg/dl, P<0.001) were significantly increased in male patients, while serum uric acid (5.74+/-0.34 vs. 4.78+/-0.17 mg/dl, P=0.006) and triglyceride level (121.39+/-12.71 vs. 76.58+/-4.88 mg/dl, P=0.002) were increased in female ones. Compared to that in C2 group, serum triglyceride level was still increased in patients of either gender. Interestingly, serum cholesterol level in female patients was lower than that in either C1 or C2 group. Further, serum triglyceride level was significantly correlated to BMI, serum cholesterol and glucose level in male patients but only to serum uric acid level in female ones.

CONCLUSIONS

Clinical characteristics of young-onset hypertension were unique and different by gender. Though consistently increased in patients of either gender, serum triglyceride level was correlated to BMI, serum cholesterol and glucose level only in males, suggesting the gender-specific presence of metabolic syndrome in young-onset hypertension.

Avancées dans la physiopathologie de la pré-éclampsie : place de la réponse inflammatoire

Inflammatory response is a major component in physiopathology of preeclampsia and intra-uterine growth retardation. Endothelium is a main connection between placental ischemia and clinical manifestations during vascular pregnancy complications. In this review recent findings concerning inflammatory response and its links with endothelium are reported. Studies concerning isolated intra-uterine growth retardation confirm the hypothesis of a similar pathophysiology with an activation confined to utero-placental bed or at a lower level. Current information on oxidative stress, atherosclerosis, and apoptosis in vascular pregnancy complications are available in this review. These concepts offer innovative possibilities of treatment.

Maternal birth weight in relation to plasma lipid concentrations in early pregnancy

OBJECTIVE

The purpose of this study was to determine the extent to which, if at all, maternal weight at birth is related to dyslipidemia during early pregnancy, which is a risk factor for preeclampsia.

STUDY DESIGN

This hospital-based prospective cohort study included 1000 women who initiated prenatal care before 16 weeks of gestation. Participants provided information about their birth weight and other sociodemographic and reproductive covariates. Plasma triglyceride, high-density lipoprotein cholesterol, and total cholesterol concentrations were measured at approximately 13 weeks of gestation. beta coefficients and standard errors were estimated by multiple linear regression; odds ratios and 95% confidence intervals were estimated by logistic regression.

RESULTS

Maternal birth weight was correlated negatively with triglycerides (r =-0.12; P =.001) and was correlated positively with high-density lipoprotein cholesterol (r =0.08; p =.02) but not statistically significantly related with total cholesterol (r =-0.004; P=.91). After adjusting for potential confounders, women who weighed <2500 g at birth had higher triglyceride and total cholesterol concentrations (beta=23.4 mg/dL [P<.001]; beta =2.6 mg/dL [P =.585], respectively) and lower high-density lipoprotein cholesterol concentrations (beta =-3.2 mg/dL; P=.105), when compared with women who weighed 3000 to 3499 g at birth. Women who were born small (<2500 g) and became overweight (body mass index, >or=25 kg/m(2)) in adulthood had less favorable lipid profiles than their counterparts who weighed >or=2500 g at birth and remained lean (body mass index, <25 kg/m(2)).

CONCLUSION

Our findings suggest that factors that are related to growth in utero may help to predict the subsequent risk of altered lipid metabolism during pregnancy, which may, in turn, be causally related to the occurrence of preeclampsia.