Central Blood Pressure Responses to Dietary Sodium and Potassium Interventions

Arterial Health After Preeclampsia: Role of Chronic Hypertension in the Early Vascular Aging (EVA) Study

BACKGROUND

Preeclampsia (PE) is associated with increased cardiovascular risk. Recent data have shown worse left ventricular remodeling and diastolic function in women with PE and persistent hypertension (HTN). We performed a comprehensive arterial hemodynamic assessment to evaluate the contribution of persistent HTN on arterial health after PE.

METHODS

We recruited 40 women with PE history and 40 age-matched controls (6 months to 6 years postpartum). We evaluated arterial hemodynamics with validated techniques combining applanation tonometry and transthoracic echocardiography, comparing three groups: previous PE with persistent HTN (PE-HTN), previous PE with normalized blood pressure (PE-noHTN) and controls, using multivariable linear regression adjusted for age, body surface area, heart rate, diabetes, smoking history, creatinine, and gravidity.

RESULTS

Eight (20%) of the post-PE women had persistent HTN. Mean age was 35.8 ± 3.9 years, median number of pregnancies was 2 (range 1-7), and time since last pregnancy 2.1 (range 0.5-5.7) years (not different between groups, P > 0.05). Compared to controls and to PE-noHTN, PE-HTN had higher aortic stiffness, wave reflections, pulsatile, and steady arterial load (P < 0.05 for each). Among PE-noHTN, aortic stiffness, wave reflections and steady arterial load were worse than controls (P < 0.05 for each), with smaller effect sizes.

CONCLUSIONS

This is the most comprehensive assessment of arterial hemodynamics and first to demonstrate the contribution of persistent HTN on worse arterial health following PE. Since measures of arterial health are associated with cardiovascular events in the population, the combination of previous PE and chronic HTN may represent a higher risk subgroup who could benefit from targeted prevention strategies.

Urinary potassium excretion and mortality risk in community-dwelling individuals with and without obesity

BACKGROUND

Potassium intake has been shown to be inversely associated with blood pressure and premature mortality. Previous studies have suggested that the association between potassium intake and blood pressure is modified by obesity, but whether obesity similarly influences the association between potassium intake and mortality is unclear.

OBJECTIVES

We investigated whether potassium intake, reflected by 24-h urinary excretion, is associated with all-cause mortality, and explored potential effect modification by obesity.

METHODS

We performed a prospective cohort study in community-dwelling individuals. The association between urinary potassium excretion and all-cause mortality was investigated by using multivariable Cox regression. We performed multiplicative interaction analysis and subgroup analyses according to BMI and waist circumference.

RESULTS

In 8533 individuals (50% male), the mean age was 50 ± 13 y, mean urinary potassium excretion was 71 ± 21 mmol/24 h, median BMI (in kg/m2) was 25.6 (IQR: 23.1, 28.4) and mean waist circumference was 89 ± 13 cm. During median follow-up of 18.4 (IQR: 13.5, 18.8) y, 1663 participants died. Low urinary potassium excretion (first compared with third sex-specific quintile) was associated with an increased mortality risk (fully adjusted HR: 1.38; 95% CI: 1.18, 1.61), P < 0.001, irrespective of body dimensions (HR range for all body dimensions: 1.36-1.70, all P < 0.05). High urinary potassium excretion (fifth compared with third quintile) was associated with increased mortality risk in participants with obesity (BMI ≥30; HR: 1.52; CI: 1.00, 2.30), but not in participants without obesity (BMI: <25; HR: 0.89; 95% CI: 0.62, 1.26; P-interaction = 0.001).

CONCLUSIONS

Low potassium intake was associated with increased mortality risk in community-dwelling individuals. In individuals with obesity, high potassium intake was also associated with increased mortality risk.

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.