Increased salt sensitivity of ambulatory blood pressure in women with a history of severe preeclampsia

Diet quality and blood pressure among pregnant women with overweight or obesity: A secondary analysis of two randomized controlled trials

INTRODUCTION

Maternal obesity is a significant risk factor for hypertensive disorders of pregnancy. High diet quality may protect against this, yet data regarding the relationship between diet quality and blood pressure among pregnant women with raised body mass index (BMI) is limited.

MATERIAL AND METHODS

This is a secondary analysis (n = 543) of women with BMI ≥25 kg/m2 from two randomized controlled trials; PEARS (Pregnancy Exercise and nutrition Research Study with smartphone application support) and ROLO (Randomized cOntrol trial of LOw glycemic index diet to prevent macrosomia in euglycemic women). Blood pressure was measured at 10-18 weeks and 28 weeks of pregnancy. Mean arterial pressure was calculated as (diastolic blood pressure+ 1 3 × [systolic blood pressure -  diastolic blood pressure]). Diet quality was assessed using 3-day food diaries, and Alternative Healthy Eating Index for Pregnancy (AHEI-P) scores were generated, quantifying alignment of food intakes with dietary guidelines in first and early third trimesters. The cohort was divided based on AHEI-P tertiles to explore differences at an alpha significance value of <0.05.

RESULTS

The mean age of the group was 32.21 ± 4.39 years with a median body mass index (BMI) of 28.13 (IQR 3.47) kg/m2. Mean arterial pressures in the first and third trimesters were 81.07 ± 9.00 mmHg and 82.33 ± 7.53 mmHg, respectively. Rates of elevated blood pressure (≥120/80 mmHg) were 22.33% in trimester 1 and 24.48% in early trimester 3. Mean AHEI-P scores in trimester 1 and early trimester 3 were 53.90 ± 10.43 and 54.05 ± 10.76, respectively. There was no correlation between AHEI-P score and blood pressure and no differences in blood pressure between AHEI-P tertiles at either timepoint (all P-values <0.05). A higher proportion of those with elevated early third trimester blood pressure had a BMI of ≥30 kg/m2 compared with those with normal blood pressure (40.31% vs 28.64%, P = 0.016).

CONCLUSIONS

While diet remains an important factor in maternal health and wellbeing, we did not find a relationship between diet quality as measured by AHEI-P and blood pressure among pregnant women with BMI ≥25 kg/m2. High BMI remains a risk factor for hypertensive disorders of pregnancy.

Nutrition Interventions for Lowering Cardiovascular Risk After Hypertensive Disorders of Pregnancy: A Systematic Review

Background

Hypertension is one of the most common medical problems during pregnancy. Hypertensive disorders of pregnancy (HDP) increase the risk of premature cardiovascular disease (CVD) 2- to 4-fold within 10 years after delivery. Early health behaviour modifications may prevent or manage several cardiovascular risk factors. Importantly, compared with women without HDP, fewer women with HDP achieve national dietary guidelines to prevent CVD. This highlights an opportunity for programs tailored for women post-HDP to support their nutritional behaviours as a key component of postpartum CVD preventive care. This systematic review investigated the impacts of nutrition modifications on lowering measures of CVD risk after HDP.

Methods

Four electronic databases (MEDLINE, EMBASE, CINAHL, Cochrane Library) were searched in October 2022 with a search strategy focused on nutrition programs/interventions and women post-HDP. Additional inclusion criteria were original research and reported outcome of CVD risk or cardiovascular risk factors.

Results

Six studies were included: 4 experimental trials and 2 prospective cohort studies. Of the nutrition interventions, 4 were embedded within comprehensive health behaviour intervention programs. Outcome measures varied, but all studies reported blood pressure. A narrative synthesis found that the range of changes in blood pressure varied from no change to clinically meaningful change.

Conclusions

This review found statistically nonsignificant yet clinically important improvements in measures of cardiovascular risk across a range of nutritional interventions in women after HDP. Further high-quality evidence is needed to inform the design and implementation of nutritional preventive cardiovascular care targeting this high CVD-risk population.

Sex differences in blood pressure regulation and hypertension: renal, hemodynamic, and hormonal mechanisms

The teleology of sex differences has been argued since at least as early as Aristotle's controversial Generation of Animals more than 300 years BC, which reflects the sex bias of the time to contemporary readers. Although the question "why are the sexes different" remains a topic of debate in the present day in metaphysics, the recent emphasis on sex comparison in research studies has led to the question "how are the sexes different" being addressed in health science through numerous observational studies in both health and disease susceptibility, including blood pressure regulation and hypertension. These efforts have resulted in better understanding of differences in males and females at the molecular level that partially explain their differences in vascular function and renal sodium handling and hence blood pressure and the consequential cardiovascular and kidney disease risks in hypertension. This review focuses on clinical studies comparing differences between men and women in blood pressure over the life span and response to dietary sodium and highlights experimental models investigating sexual dimorphism in the renin-angiotensin-aldosterone, vascular, sympathetic nervous, and immune systems, endothelin, the major renal sodium transporters/exchangers/channels, and the impact of sex hormones on these systems in blood pressure homeostasis. Understanding the mechanisms governing sex differences in blood pressure regulation could guide novel therapeutic approaches in a sex-specific manner to lower cardiovascular risks in hypertension and advance personalized medicine.

Smooth Muscle Mineralocorticoid Receptor Promotes Hypertension After Preeclampsia

BACKGROUND

Preeclampsia is a syndrome of high blood pressure (BP) with end organ damage in late pregnancy that is associated with high circulating soluble VEGF receptor (sFlt1 [soluble Fms-like tyrosine kinase 1]). Women exposed to preeclampsia have a substantially increased risk of hypertension after pregnancy, but the mechanism remains unknown, leaving a missed interventional opportunity. After preeclampsia, women have enhanced sensitivity to hypertensive stress. Since smooth muscle cell mineralocorticoid receptors (SMC-MR) are activated by hypertensive stimuli, we hypothesized that high sFlt1 exposure in pregnancy induces a postpartum state of enhanced SMC-MR responsiveness.

METHODS

Postpartum BP response to high salt intake was studied in women with prior preeclampsia. MR transcriptional activity was assessed in vitro in sFlt1-treated SMC by reporter assays and PCR. Preeclampsia was modeled by transient sFlt1 expression in pregnant mice. Two months post-partum, mice were exposed to high salt and then to AngII (angiotensin II) and BP and vasoconstriction were measured.

RESULTS

Women exposed to preeclampsia had significantly enhanced salt sensitivity of BP verses those with a normotensive pregnancy. sFlt1 overexpression during pregnancy in mice induced elevated BP and glomerular endotheliosis, which resolved post-partum. The sFlt1 exposed post-partum mice had significantly increased BP response to 4% salt diet and to AngII infusion. In vitro, SMC-MR transcriptional activity in response to aldosterone or AngII was significantly increased after transient exposure to sFlt1 as was aldosterone-induced expression of AngII type 1 receptor. Post-partum, SMC-MR-KO mice were protected from the enhanced response to hypertensive stimuli after preeclampsia. Mechanistically, preeclampsia mice exposed to postpartum hypertensive stimuli develop enhanced aortic stiffness, microvascular myogenic tone, AngII constriction, and AngII type 1 receptor expression, all of which were prevented in SMC-MR-KO littermates.

CONCLUSIONS

These data support that sFlt1-induced vascular injury during preeclampsia produces a persistent state of enhanced sensitivity of SMC-MR to activation. This contributes to postpartum hypertension in response to common stresses and supports testing of MR antagonism to mitigate the increased cardiovascular risk in women after PE.

Levels of blood pressure, cardiovascular biomarkers and their correlations in women with previous pre-eclamptic pregnancy within 7 years postpartum: a cross-sectional study in Thailand

OBJECTIVE

To assess the levels of blood pressure, cardiovascular biomarkers and their correlations measured within 7 years postpartum in women with previous pre-eclamptic pregnancies compared with women with previous normotensive pregnancies.

DESIGN

Cross-sectional study.

SETTING

Two tertiary hospitals in the southern region of Thailand.

PARTICIPANTS

Women with pre-eclamptic and normotensive pregnancies in the past 7 years were enrolled from 1 October 2019 to 30 April 2021. Eligible women were interviewed, examined for body mass index (BMI) and blood pressure, and donated morning spot urine and blood samples.

PRIMARY OUTCOME MEASURES

Serum high-sensitivity C reactive protein, creatinine, fasting blood glucose (FBS), glycated haemoglobin (HbA1c), low-density lipoprotein (LDL) cholesterol, urine microalbumin to creatinine ratio (UACR) and sodium were measured. Group differences in biomarkers were tested using unpaired t-test, Wilcoxon rank-sum test or χ² test. The levels of blood pressure and biomarkers between the two study groups at <2 years, 2-4 years and >4 years were also compared. The correlations between blood pressure and biomarkers were analysed using Pearson's correlation and partial correlation methods.

RESULTS

From 206 women included in the analysis, 88 had pre-eclamptic pregnancies and 118 had normotensive pregnancies. Compared with women with previous normotensive pregnancies, women with previous pre-eclamptic pregnancies had significantly increased rates of hypertension (31.8% vs 7.6%, p<0.001) and obesity (55.7% vs 40.7%, p=0.038), as well as higher serum levels of FBS (p<0.001), HbA1c (p<0.001), LDL cholesterol (p=0.03), creatinine (p<0.001) and UACR (p<0.001). Correlation coefficients of BMI, serum creatinine and UACR with blood pressure ranged from 0.27 to 0.31.

CONCLUSION

The risk of hypertension after a pre-eclamptic pregnancy increased. Blood pressure measurement combined with BMI, serum creatinine and UACR screening at least once during 7 years postpartum is suggested for early detection of cardiovascular risk.

Impact of high-salt versus low-salt intake on the response of sympathetic baroreflex sensitivity to orthostasis in women with a history of normal pregnancy

Previous studies have demonstrated that sympathetic baroreflex sensitivity (BRS) increases during orthostatic stress in humans. We recently showed that dietary salt intake affects sympathetic neural control in healthy premenopausal women. This study aimed to determine whether salt loading versus salt reduction would impact sympathetic BRS during orthostasis in premenopausal women with a history of normal pregnancy. Nine healthy women [42 ± 3 (SD) yr] were given a standardized isocaloric high-salt (250 mEq sodium/day) or low-salt (50 mEq sodium/day) diet for 1 wk each (∼2 mo apart with the order randomized), whereas water intake was ad libitum. Laboratory testing was performed following each high- and low-salt period in the midluteal phase of the menstrual cycle. Hemodynamics and muscle sympathetic nerve activity (MSNA) were measured at baseline (supine; 2 min) and during a graded head-up tilt (30° for 5 min and 60° for 20 min). Sympathetic BRS was assessed during baseline and head-up tilt. Hemodynamics were not different between salt conditions during baseline or tilt. Both supine and upright MSNA indices were lower in high salt than low salt (all P < 0.05), however, there was no interaction effect (P = 0.507-0.996). On moving from supine to upright, sympathetic BRS remained unchanged in high salt but increased in low salt (P = 0.028 for interaction). Thus, salt loading diminishes the responsiveness of sympathetic BRS during orthostasis compared with salt reduction in healthy premenopausal women with prior normal pregnancy. Whether this is one underlying mechanism for salt-induced development of hypertension during ambulation remains to be determined.

Dietary Magnesium Insufficiency Induces Salt-Sensitive Hypertension in Mice Associated With Reduced Kidney Catechol-O-Methyl Transferase Activity

[Figure: see text].

Preeclampsia Emerging as a Risk Factor of Cardiovascular Disease in Women

The objective of this literature review was to explore the long-term cardiovascular effects of preeclampsia in women. The primary goal was to determine which organs were most commonly affected in this population. Although it was previously believed that preeclampsia is cured after the delivery of the fetus and the placenta current evidence supports an association between preeclampsia and cardiovascular disease later in life, many years after the manifestation of this hypertensive pregnancy related disorder. Therefore preeclampsia may be emerging as a novel cardiovascular risk factor for women, which requires long-term follow up.

Salt-sensitive hypertension in chronic kidney disease: distal tubular mechanisms

Chronic kidney disease (CKD) causes salt-sensitive hypertension that is often resistant to treatment and contributes to the progression of kidney injury and cardiovascular disease. A better understanding of the mechanisms contributing to salt-sensitive hypertension in CKD is essential to improve these outcomes. This review critically explores these mechanisms by focusing on how CKD affects distal nephron Na+ reabsorption. CKD causes glomerulotubular imbalance with reduced proximal Na+ reabsorption and increased distal Na+ delivery and reabsorption. Aldosterone secretion further contributes to distal Na+ reabsorption in CKD and is not only mediated by renin and K+ but also by metabolic acidosis, endothelin-1, and vasopressin. CKD also activates the intrarenal renin-angiotensin system, generating intratubular angiotensin II to promote distal Na+ reabsorption. High dietary Na+ intake in CKD contributes to Na+ retention by aldosterone-independent activation of the mineralocorticoid receptor mediated through Rac1. High dietary Na+ also produces an inflammatory response mediated by T helper 17 cells and cytokines increasing distal Na+ transport. CKD is often accompanied by proteinuria, which contains plasmin capable of activating the epithelial Na+ channel. Thus, CKD causes both local and systemic changes that together promote distal nephron Na+ reabsorption and salt-sensitive hypertension. Future studies should address remaining knowledge gaps, including the relative contribution of each mechanism, the influence of sex, differences between stages and etiologies of CKD, and the clinical relevance of experimentally identified mechanisms. Several pathways offer opportunities for intervention, including with dietary Na+ reduction, distal diuretics, renin-angiotensin system inhibitors, mineralocorticoid receptor antagonists, and K+ or H+ binders.

Postpartum Hypertension

PURPOSE OF REVIEW

Hypertension affects approximately 10% of pregnancies and may persist in the postpartum period. Furthermore, de novo hypertension may present after delivery, but its exact prevalence is not verified. Both types of hypertension expose the mother to eventually severe complications like eclampsia, stroke, pulmonary edema, and HELLP (hemolysis, elevated liver enzymes, low platelet) syndrome.

RECENT FINDINGS

Until today, there are limited data regarding the risk factors, pathogenesis, and pathophysiology of postpartum hypertensive disorders. However, there is certain evidence that preeclampsia may in large part be responsible. Women who experienced preeclampsia during pregnancy, although considered cured after delivery and elimination of the placenta, continue to present endothelial and renal dysfunction in the postpartum period. The brain and kidneys are particularly sensitive to this pathological vascular condition, and severe complications may result from their involvement. Large randomized trials are needed to give us the evidence that will allow a timely diagnosis and treatment. Until then, medical providers should increase their knowledge regarding hypertension after delivery because many times there is an underestimation of the complications that can ensue after a misdiagnosed or undertreated postpartum hypertension.

Prior exposure to placental ischemia causes increased salt sensitivity of blood pressure via vasopressin production and secretion in postpartum rats

OBJECTIVES

Women with a history of preeclampsia exhibit increased salt sensitivity of blood pressure at postpartum, which might be responsible for their increased risk of future cardiovascular diseases. However, it is unclear whether preeclampsia can cause increased salt sensitivity at postpartum. Vasopressin may play a role in the pathogenesis of preeclampsia and salt-sensitive hypertension. Therefore, the aim of this study was to determine whether the exposure to preeclampsia, as elicited by placental ischemia, causes increased salt sensitivity at postpartum, and if so, whether vasopressin is involved in its process.

METHODS AND RESULTS

We used a reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. Pregnant Sprague-Dawley rats were categorized into the following two groups: RUPP-operated and sham-operated (SHAM) control groups. A 1-week-long high-salt diet was initiated at 3 weeks postpartum. The high-salt diet-induced increase in mean arterial pressure was significantly greater in the RUPP group than in the SHAM group. In addition, the plasma levels of copeptin, a substitute for plasma vasopressin, increased and serum osmolality decreased in the RUPP group. Double immunostaining revealed that the expression of c-Fos, a marker of neural activity, in vasopressin-producing neurons and presympathetic neurons in the hypothalamic paraventricular nucleus was significantly elevated in the RUPP group. The oral administration of conivaptan, the dual V1a/V2 vasopressin receptor antagonist, during high-salt diet abolished the enhanced increase in mean arterial pressure in RUPP rats.

CONCLUSION

Prior exposure to placental ischemia causes increased salt sensitivity of blood pressure at postpartum probably due to enhanced vasopressin production and secretion.

Preeclampsia beyond pregnancy: long-term consequences for mother and child

Preeclampsia is defined as new-onset hypertension after the 20th wk of gestation along with evidence of maternal organ failure. Rates of preeclampsia have steadily increased over the past 30 yr, affecting ∼4% of pregnancies in the United States and causing a high economic burden (22, 69). The pathogenesis is multifactorial, with acknowledged contributions by placental, vascular, renal, and immunological dysfunction. Treatment is limited, commonly using symptomatic management and/or early delivery of the fetus (6). Along with significant peripartum morbidity and mortality, current research continues to demonstrate that the consequences of preeclampsia extend far beyond preterm delivery. It has lasting effects for both mother and child, resulting in increased susceptibility to hypertension and chronic kidney disease (45, 54, 115, 116), yielding lifelong risk to both individuals. This review discusses recent guideline updates and recommendations along with current research on these long-term consequences of preeclampsia.

Prediction and prevention of pre-eclampsia in Asian subpopulation

The benefit of the early administration of aspirin to reduce preterm pre-eclampsia among screened positive European women from multivariate algorithmic approach (ASPRE trial) has opened an intense debate on the feasibility of universal screening. This review aims to assess the new perspectives in the combined screening of pre-eclampsia in the first trimester of pregnancy and the chances for prevention using low-dose aspirin with special emphasis on the particularities of the Asian population. PubMed, CENTRAL and Embase databases were searched from inception until 15 November 2017 using combinations of the search terms: preeclampsia, Asian, prenatal screening, early prediction, ultrasonography, pregnancy, biomarker, mean arterial pressure, soluble fms-like tyrosine kinase-1, placental growth factor, pregnancy-associated plasma protein-A and pulsatility index. This is not a systematic review or meta-analysis, so the risk of bias of the selected published articles and heterogeneity among the studies need to be considered. The prevalence of pre-eclampsia and serum levels of biochemical markers in Asian are different from Caucasian women; hence, Asian ethnicity needs to be corrected for in the algorithmic assessment of multiple variables to improve the screening performance. Aspirin prophylaxis may still be viable in Asian women, but resource implication needs to be considered. Asian ethnicity should be taken into account before implementing pre-eclampsia screening strategies in the region. The variables included can be mixed and matched to achieve an optimal performance that is appropriate for economical restriction in individual countries.

Sex-specific differences in hypertension and associated cardiovascular disease

Although intrinsic mechanisms that regulate arterial blood pressure (BP) are similar in men and women, marked variations exist at the molecular, cellular and tissue levels. These physiological disparities between the sexes likely contribute to differences in disease onset, susceptibility, prevalence and treatment responses. Key systems that are important in the development of hypertension and cardiovascular disease (CVD), including the sympathetic nervous system, the renin-angiotensin-aldosterone system and the immune system, are differentially activated in males and females. Biological age also contributes to sexual dimorphism, as premenopausal women experience a higher degree of cardioprotection than men of similar age. Furthermore, sex hormones such as oestrogen and testosterone as well as sex chromosome complement likely contribute to sex differences in BP and CVD. At the cellular level, differences in cell senescence pathways may contribute to increased longevity in women and may also limit organ damage caused by hypertension. In addition, many lifestyle and environmental factors - such as smoking, alcohol consumption and diet - may influence BP and CVD in a sex-specific manner. Evidence suggests that cardioprotection in women is lost under conditions of obesity and type 2 diabetes mellitus. Treatment strategies for hypertension and CVD that are tailored according to sex could lead to improved outcomes for affected patients.

Prevalence of Hypertensive Phenotypes After Preeclampsia: A Prospective Cohort Study

Preeclampsia is associated with increased cardiovascular and renal risk. The aim of this prospective cohort study was to characterize the early postpartum blood pressure (BP) profile after preeclampsia. We enrolled 115 women with preeclampsia and 41 women with a normal pregnancy in a prospective cohort study. At 6 to 12 week postpartum, we assessed the prevalence of different hypertensive phenotypes using 24-hour ambulatory BP monitoring (ABPM), as well as the risk of salt sensitivity and the variability of BP derived from ABPM parameters. Among patients with preeclampsia, 57.4% were still hypertensive at the office. Daytime ABP was significantly higher in the preeclampsia group (118.9±15.0/83.2±10.4 mm Hg) than in controls (104.8±7.9/71.6±5.3 mm Hg; P<0.01). Differences between groups were similar for nocturnal BP values. Fifty percent of preeclampsia women remained hypertensive on ABPM in the postpartum, of whom 24.3% were still under antihypertensive treatment; 17.9% displayed a white-coat hypertension and 11.6% had masked hypertension. In controls, 2.8% had white-coat hypertension; none had masked hypertension or needed hypertensive treatment. The prevalence of nondippers was similar 59.8% in the preeclampsia group versus 51.4% in controls. High-risk class of salt sensitivity of BP was increased in preeclampsia women (48.6%) compared with controls (17.1%); P<0.01. In conclusion, ABPM 6 to 12 weeks after delivery reveals a high rate of sustained ambulatory, nocturnal, and masked hypertension after preeclampsia. This finding may help identify women who should be included in a postpartum cardiovascular risk management program.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01095939.

The impact of salt intake during and after pregnancy

Although high blood pressure before pregnancy is associated with a risk of gestational hypertension and preeclampsia, no convincing evidence has been produced to show that dietary salt reduction helps in the prevention and treatment of hypertension during pregnancy. Thus the current guidelines do not recommend a sodium restriction during pregnancy to prevent gestational hypertension and the development of preeclampsia. However, the long-term impact of hypertensive disorders of pregnancy for life-threatening diseases later in life is a critical issue. Gestational hypertension could contribute to the risk of developing hypertension later in life, and recent studies have suggested that gestational hypertension and preeclampsia are linked to cardiovascular complications. In this article, we provide an overview of the current perspectives on the salt intake of pregnant women and consider both the short-term influence and the impact beyond the perinatal period.

Low Calcium Intake in Midpregnancy Is Associated with Hypertension Development within 10 Years after Pregnancy: The Norwegian Mother and Child Cohort Study

Background: Low dietary calcium intake may be a risk factor for hypertension, but studies conflict.Objective: We evaluated the ability to predict hypertension within 10 y after delivery based on calcium intake during midpregnancy.Methods: The Norwegian Mother and Child Cohort Study of women delivering in 2004-2009 was linked to the Norwegian Prescription Database (2004-2013) to ascertain antihypertensive medication usage >90 d after delivery. Women with hypertension before pregnancy were excluded, leaving 60,027 mothers for analyses. Age and energy-adjusted cubic splines evaluated dose-response curves, and Cox proportional hazard analyses evaluated HR and 95% CIs by calcium quartiles adjusting for 7 covariates. Analyses were stratified by gestational hypertension and by sodium-to-potassium intake ratio (<0.76 compared with ≥0.76).Results: Participants had a mean ± SD age of 30.5 ± 4.6 y, a body mass index (in kg/m²) of 24.0 ± 4.3 before pregnancy, and a mean follow-up duration of 7.1 ± 1.6 y. Cubic spline graphs identified a threshold effect of low calcium intake only within the range of dietary inadequacy related to increased risk. The lowest calcium quartile (≤738 mg/d; median: 588 mg/d), relative to the highest quartile (≥1254 mg/d), had an HR for hypertension of 1.34 (95% CI: 1.05, 1.70) among women who were normotensive during pregnancy, and an HR of 1.62 (95% CI: 1.14, 2.35) among women who had gestational hypertension, after adjusting for covariates. Women with gestational hypertension, who were in the lowest quartile of calcium intake, and who had a high sodium-to-potassium intake ratio had a risk of hypertension more than double that of their counterparts with a calcium intake in the highest quartile. Results were attenuated by adjusting for covariates (HR: 1.92; 95% CI: 1.09, 3.39).Conclusions: The results suggest that low dietary calcium intake may be a risk factor or risk marker for the development of hypertension, particularly for women with a history of gestational hypertension.

Exposure to placental ischemia impairs postpartum maternal renal and cardiac function in rats

Women with a history of preeclampsia (PE) have an increased risk to develop cardiovascular and renal diseases later in life, but the mechanisms underlying this effect are unknown. In rats, we assessed whether placental ischemia results in long-term effects on the maternal cardiovascular and renal systems using the reduced uterine perfusion pressure (RUPP) model for PE. Sprague-Dawley rats received either a Sham or RUPP operation at gestational day 14 The rats were followed for 8 wk after delivery (Sham n = 12, RUPP n = 21) at which time mean arterial pressure (MAP; conscious), 24-h albuminuria, glomerular filtration rate (GFR; transcutaneous, FITC-sinistrin), and cardiac function (Vevo 770 system) were assessed. Subsequently, all rats were euthanized for mesenteric artery vasorelaxation and histology of heart and kidney. At 8 wk after delivery, there was no difference in MAP and albuminuria. However, RUPP rats showed a significantly reduced GFR [2.61 ± 0.53 vs. 3.37 ± 0.74 ml/min; P = 0.01]. Ultrasound showed comparable cardiac structure, but RUPP rats had a lower left ventricular ejection fraction (62 ± 7 vs. 69 ± 10%; P = 0.04). Heart and kidney histology was not different between Sham or RUPP rats. Furthermore, there were no differences in endothelial-dependent or -independent vasorelaxation. We show that exposure to placental ischemia in rats is accompanied by functional disturbances in maternal renal and cardiac function 8 wk after a preeclamptic pregnancy. However, these changes were not dependent on differences in blood pressure, small artery vasorelaxation, or cardiac and renal structure at this time point postpartum.

Pregnancy as a critical window for blood pressure regulation in mother and child: programming and reprogramming

Pregnancy is a critical time for long-term blood pressure regulation in both mother and child. Pregnancies complicated by placental insufficiency, resulting in pre-eclampsia and intrauterine growth restriction, are associated with a threefold increased risk of the mother to develop hypertension later in life. In addition, these complications create an adverse intrauterine environment, which programmes the foetus and the second generation to develop hypertension in adult life. Female offspring born to a pregnancy complicated by placental insufficiency are at risk for pregnancy complications during their own pregnancies as well, resulting in a vicious circle with programmed risk for hypertension passing from generation to generation. Here, we review the epidemiology and mechanisms leading to the altered programming of blood pressure trajectories after pregnancies complicated by placental insufficiency. Although the underlying mechanisms leading to hypertension remain the subject of investigation, several abnormalities in angiotensin sensitivity, sodium handling, sympathetic activity, endothelial function and metabolic pathways are found in the mother after exposure to placental insufficiency. In the child, epigenetic modifications and disrupted organ development play a crucial role in programming of hypertension. We emphasize that pregnancy can be viewed as a window of opportunity to improve long-term cardiovascular health of both mother and child, and outline potential gains expected of improved preconceptional, perinatal and post-natal care to reduce the development of hypertension and the burden of cardiovascular disease later in life. Perinatal therapies aimed at reprogramming hypertension are a promising strategy to break the vicious circle of intergenerational programming of hypertension.

Long-term renal and cardiovascular risk after preeclampsia: towards screening and prevention

Preeclampsia (PE) is a hypertensive pregnancy disorder complicating up to 1-5% of pregnancies, and a major cause of maternal and fetal morbidity and mortality. In recent years, observational studies have consistently shown that PE carries an increased risk for the mother to develop cardiovascular and renal disease later in life. Women with a history of PE experience a 2-fold increased risk of long-term cardiovascular disease (CVD) and an approximate 5-12-fold increased risk of end-stage renal disease (ESRD). Recognition of PE as a risk factor for renal disease and CVD allows identification of a young population of women at high risk of developing of cardiovascular and renal disease. For this reason, current guidelines recommend cardiovascular screening and treatment for formerly preeclamptic women. However, these recommendations are based on low levels of evidence due to a lack of studies on screening and prevention in formerly preeclamptic women. This review lists the incidence of premature CVD and ESRD observed after PE and outlines observed abnormalities that might contribute to the increased CVD risk with a focus on kidney-related disturbances. We discuss gaps in current knowledge to guide optimal screening and prevention strategies. We emphasize the need for research on mechanisms of late disease manifestations, and on effective screening and therapeutic strategies aimed at reducing the late disease burden in formerly preeclamptic women.

Dietary sodium and health: more than just blood pressure

Sodium is essential for cellular homeostasis and physiological function. Excess dietary sodium has been linked to elevations in blood pressure (BP). Salt sensitivity of BP varies widely, but certain subgroups tend to be more salt sensitive. The mechanisms underlying sodium-induced increases in BP are not completely understood but may involve alterations in renal function, fluid volume, fluid-regulatory hormones, the vasculature, cardiac function, and the autonomic nervous system. Recent pre-clinical and clinical data support that even in the absence of an increase in BP, excess dietary sodium can adversely affect target organs, including the blood vessels, heart, kidneys, and brain. In this review, the investigators review these issues and the epidemiological research relating dietary sodium to BP and cardiovascular health outcomes, addressing recent controversies. They also provide information and strategies for reducing dietary sodium.

Salt and miscarriage: Is there a link?

Salt is a major mineral element that plays fundamental roles in health and disease. Excessive salt intake is a major cause of hypertension, cardiovascular disease and stroke. Miscarriage and preeclampsia are the most common pregnancy complications with multiple etiological factors, including inflammatory and autoimmune conditions. More recently, different studies indicated that excessive salt intake is involved in the development of inflammatory processes through induction of T helper-17 pathway and their inflammatory cytokines. On the other hand, several studies indicated the pivotal role of inflammation in the etiology of miscarriage, preeclampsia and adverse pregnancy outcome. Here, it is hypothesized that excessive salt intake around the time of conception or during pregnancy can trigger inflammatory processes, which consequently associated with increased risk of miscarriage, preeclampsia or adverse pregnancy outcome. Thus, this hypothesis suggests that low salt intake around the time of conception or during pregnancy can decrease the risk of miscarriage or adverse pregnancy outcome. This hypothesis also offers new insights about the role of salt in the etiology of miscarriage and preeclampsia.

Cardiovascular disease in women: the significance of hypertension and gestational diabetes during pregnancy

PURPOSE OF REVIEW

Cardiovascular disease (CVD) remains the major killer of women around the globe. Complications during pregnancy, including hypertensive disorders of pregnancy and gestational diabetes mellitus, are now recognized as risk factors for future CVD.

RECENT FINDINGS

Studies of diverse populations demonstrate the links between these complications of pregnancy and a woman's future risk of CVD including atherosclerosis, hypertension, stroke, coronary artery disease, and heart failure. Markers that persist in these women following pregnancy continue to be identified and include microalbuminuria, proteinuria, elevated homocysteine levels, C-reactive protein, and salt sensitivity. Efforts are now being placed on establishing specialized clinics to monitor women beyond pregnancy to help reduce the burden of future disease.

SUMMARY

Pregnancy offers a unique window through which women at risk of future CVD may be identified. Clinicians have an opportunity to implement health monitoring, lifestyle modifications, and other interventions during this period, and beyond, that will help reduce the burden of CVD. Research should continue to focus on identifying and understanding the mechanisms that lead to future CVD in these women; deciphering whether pregnancy unmasks an existing predisposition to disease, compounds the risk of future disease, or is the direct cause of future disease.

Higher filtration fraction in formerly early-onset preeclamptic women without comorbidity

Formerly preeclamptic women have an increased risk for developing end-stage renal disease, which has been attributed to altered renal hemodynamics and abnormalities in the renin-angiotensin-aldosterone system. Whether this is due to preeclampsia itself or to comorbid conditions is unknown. Renal hemodynamics and responsiveness to ANG II during low Na(+) intake (7 days, 50 mmol Na(+)/24 h) and high Na(+) (HS) intake (7 days, 200 mmol Na(+)/24 h) were studied in 18 healthy normotensive formerly early-onset preeclamptic women (fPE women) and 18 healthy control subjects (fHP women), all selected for absence of comorbidity. At the end of each diet, renal hemodynamics and blood pressure were measured before and during graded ANG II infusion. Both HS intake and former preeclampsia increased filtration fraction (FF) without an interaction between the two. FF was highest during HS intake in fPE women [0.31 ± 0.12 vs. 0.29 ± 0.11 in fHP women, generalized estimating equation analysis (body mass index corrected), P = 0.03]. The renal response to ANG II infusion was not different between groups. In conclusion, fPE women have a higher FF compared with fHP women. As this was observed in the absence of comorbidity, preeclampsia itself might exert long-term effects on renal hemodynamics. However, we cannot exclude the presence of prepregnancy alterations in renal function, which, in itself, lead to an increased risk for preeclampsia. In experimental studies, an elevated FF has been shown to play a pathogenic role in the development of hypertension and renal damage. Future studies, however, should evaluate whether the subtle differences in renal hemodynamics after preeclampsia contribute to the increased long-term renal risk after preeclampsia.