Impaired sodium-dependent adaptation of arterial stiffness in formerly preeclamptic women: the RETAP-vascular study

Postpartum home blood pressure monitoring and lifestyle intervention in overweight and obese individuals the first year after gestational hypertension or pre-eclampsia: A pilot feasibility trial

OBJECTIVE

To test the feasibility of a randomised trial of home blood pressure monitoring paired with a remote lifestyle intervention (Heart Health 4 New Moms) versus home blood pressure monitoring alone versus control in individuals with a hypertensive disorder of pregnancy in the first year postpartum.

DESIGN

Single-blinded three-arm randomised clinical trial.

SETTING

Two tertiary care hospitals and a community organisation.

POPULATION

Postpartum overweight and obese individuals with a hypertensive disorder of pregnancy and without pre-pregnancy hypertension or diabetes.

METHODS

We assessed the feasibility of recruitment and retention of 150 participants to study completion at 1-year postpartum with randomisation 1:1:1 into each arm. Secondary aims were to test effects of the interventions on weight, blood pressure and self-efficacy.

RESULTS

Over 23 months, we enrolled 148 of 400 eligible, screened individuals (37%); 28% black or other race and mean pre-pregnancy body mass index (BMI) of 33.4 ± 6.7 kg/m2 . In total, 129 (87%) participants completed the 1-year postpartum study visit. Overall, 22% of participants developed stage 2 hypertension (≥140/90 mmHg or on anti-hypertensive medications) by 1 year postpartum. There were no differences in weight or self-efficacy across the study arms.

CONCLUSION

In this pilot, randomised trial, we demonstrate feasibility of HBPM paired with a lifestyle intervention in the first year postpartum. We detected high rates of ongoing hypertension, emphasising the need for the development of effective interventions in this population.

Maternal Cardiovascular Function Following a Pregnancy Complicated by Preeclampsia

Preeclampsia is a hypertensive pregnancy complication with an unknown etiology and high maternal burden worldwide. Burgeoning research has linked preeclampsia to adverse maternal health outcomes remote from pregnancy; however, the intermediary mechanisms responsible for this association have not been sufficiently established. In the present narrative review, we summarize leading evidence of structural and functional cardiovascular changes associated with prior preeclampsia, and how these changes may be linked to future maternal disease. KEY POINTS: · Prior preeclampsia is associated with subclinical structural and functional vascular changes remote from pregnancy.. · Maternal cardiac adaptations to preeclampsia may have long-term implications on cardiovascular health.. · Clinicians have an opportunity to minimize maternal disease risk following preeclampsia..

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.

Effect of dietary salt restriction on central blood pressure: A systematic review and meta-analysis of the intervention studies

Central blood pressure (cBP) is highly associated with cardiovascular risk. Although reduction of salt intake leads to lower peripheral blood pressure (BP), the studies on cBP provided inconsistent results. Therefore, we performed a systematic review and a meta-analysis of the available intervention trials of salt reduction on cBP values to reach definitive conclusions. A systematic search of the online databases available (up to December 2018) was conducted including the intervention trials that reported non-invasively assessed cBP changes after two different salt intake regimens. For each study, the mean difference and 95% confidence intervals were pooled using a random-effect model. Sensitivity, heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Fourteen studies met the pre-defined inclusion criteria and provided 17 cohorts with 457 participants with 1-13 weeks of intervention time. In the pooled analysis, salt restriction was associated with a significant reduction in augmentation index (9.3%) as well as central systolic BP and central pulse pressure. There was a significant heterogeneity among studies (I²  = 70%), but no evidence of publication bias. Peripheral BP changes seemed to partially interfere on the relationship between salt restriction and cBP. The results of this meta-analysis indicate that dietary salt restriction reduces cBP. This effect seems to be, at least in part, independent of the changes in peripheral BP.

Current Data on Dietary Sodium, Arterial Structure and Function in Humans: A Systematic Review

Background: Subclinical arterial damage (SAD) (arteriosclerosis, arterial remodeling and atheromatosis) pre-exists decades before cardiovascular disease (CVD) onset. Worldwide, sodium (Na) intake is almost double international recommendations and has been linked with CVD and death, although in a J-shape manner. Studies regarding dietary Na and major types of SAD may provide pathophysiological insight into the association between Na and CVD. Objectives: Systematic review of data derived from observational and interventional studies in humans, investigating the association between dietary Na with (i) atheromatosis (arterial plaques); (ii) arteriosclerosis (various biomarkers of arterial stiffness); (iii) arterial remodeling (intima–media thickening and arterial lumen diameters). Data sources: Applying the PRISMA criteria, the PubMed and Scopus databases were used. Results: 36 studies were included: 27 examining arteriosclerosis, four arteriosclerosis and arterial remodeling, three arterial remodeling, and two arterial remodeling and atheromatosis. Conclusions: (i) Although several studies exist, the evidence does not clearly support a clinically meaningful and direct (independent from blood pressure) effect of Na on arterial wall stiffening; (ii) data regarding the association of dietary Na with arterial remodeling are limited, mostly suggesting a positive trend between dietary Na and arterial hypertrophy but still inconclusive; (iii) as regards to atheromatosis, data are scarce and the available studies present high heterogeneity. Further state-of-the-art interventional studies must address the remaining controversies.

Sodium Intake and Hypertension

The close relationship between hypertension and dietary sodium intake is widely recognized and supported by several studies. A reduction in dietary sodium not only decreases the blood pressure and the incidence of hypertension, but is also associated with a reduction in morbidity and mortality from cardiovascular diseases. Prolonged modest reduction in salt intake induces a relevant fall in blood pressure in both hypertensive and normotensive individuals, irrespective of sex and ethnic group, with larger falls in systolic blood pressure for larger reductions in dietary salt. The high sodium intake and the increase in blood pressure levels are related to water retention, increase in systemic peripheral resistance, alterations in the endothelial function, changes in the structure and function of large elastic arteries, modification in sympathetic activity, and in the autonomic neuronal modulation of the cardiovascular system. In this review, we have focused on the effects of sodium intake on vascular hemodynamics and their implication in the pathogenesis of hypertension.

Role of endogenous digitalis-like factors in the clinical manifestations of severe preeclampsia: a sytematic review

Endogenous digitalis-like factor(s), originally proposed as a vasoconstrictor natriuretic hormone, was discovered in fetal and neonatal blood accidentally because it cross-reacts with antidigoxin antibodies (ADAs). Early studies using immunoassays with ADA identified the digoxin-like immuno-reactive factor(s) (EDLF) in maternal blood as well, and suggested it originated in the feto-placental unit. Mammalian digoxin-like factors have recently been identified as at least two classes of steroid compounds, plant derived ouabain (O), and several toad derived bufodienolides, most prominent being marinobufagenin (MBG). A synthetic pathway for MBG has been identified in mammalian placental tissue. Elevated maternal and fetal EDLF, O and MBG have been demonstrated in preeclampsia (PE), and inhibition of red cell membrane sodium, potassium ATPase (Na, K ATPase (NKA)) by EDLF is reversed by ADA fragments (ADA-FAB). Accordingly, maternal administration of a commercial ADA-antibody fragment (FAB) was tested in several anecdotal cases of PE, and two, small randomized, prospective, double-blind clinical trials. In the first randomized trial, ADA-FAB was administered post-partum, in the second antepartum. In the post-partum trial, ADA-FAB reduced use of antihypertensive drugs. In the second trial, there was no effect of ADA-FAB on blood pressure, but the fall in maternal creatinine clearance (CrCl) was prevented. In a secondary analysis using the pre-treatment maternal level of circulating Na, K ATPase (NKA) inhibitory activity (NKAI), ADA-FAB reduced the incidence of pulmonary edema and, unexpectedly, that of severe neonatal intraventricular hemorrhage (IVH). The fall in CrCl in patients given placebo was proportional to the circulating level of NKAI. The implications of these findings on the pathophysiology of the clinical manifestations PE are discussed, and a new model of the respective roles of placenta derived anti-angiogenic (AAG) factors (AAGFs) and EDLF is proposed.

Adiposity, but not Obesity, Is Associated With Arterial Stiffness in Young Nulliparous Women

Subclinical vascular dysfunction is increasingly recognized as an independent risk factor for cardiovascular events and adverse pregnancy outcomes. The evidence linking indices of obesity and vascular dysfunction is mixed. As an example, some data suggest that adiposity may be a better predictor of endothelial dysfunction than body mass index (BMI). The aim of the current study is to compare the association of obesity, as evaluated by BMI, and a direct measure of body fat to biophysical parameters of vascular function including flow-mediated vasodilation and pulse wave velocity (PWV) in healthy nulliparous reproductive-age women. This is a secondary analysis of data collected as a prospective study of prepregnancy physiology in healthy, nulliparous women. Body mass index was calculated as weight (kg)/height (m²). Total and android body fat were calculated by dual-energy X-ray absorptiometry. Brachial PWV and flow-mediated vasodilation were assessed ultrasonographically. Seventy-nine women were evaluated. Mean BMI was 24.4 (5.4) kg/m², and 15% of women were obese (BMI ≥ 30 kg/m²). In contrast, 39% were considered to have excess adiposity, with ≥39% android body fat. Brachial PWV was associated with increased adiposity, but not obesity. We found no differences in flow-mediated dilation associated with either BMI or body fat. Adiposity may be superior to BMI in identifying women with vascular dysfunction at increased risk of adverse pregnancy outcome and cardiovascular disease. Proper identification may allow implementation of prevention strategies to improve perinatal outcomes and maternal health.