Urine sodium excretion is related to extracellular water volume but not to blood pressure in 510 normotensive and never-treated hypertensive subjects

PURPOSE

High sodium intake is an accepted risk factor for hypertension, while low Na⁺ intake has also been associated with increased risk of cardiovascular events. In this cross-sectional study, we examined the association of 24-h urinary Na⁺ excretion with haemodynamics and volume status.

MATERIALS AND METHODS

Haemodynamics were recorded in 510 normotensive and never-treated hypertensive subjects using whole-body impedance cardiography and tonometric radial artery pulse wave analysis. The results were examined in sex-specific tertiles of 24-h Na⁺ excretion, and comparisons between normotensive and hypertensive participants were also performed. Regression analysis was used to investigate factors associated with volume status. The findings were additionally compared to 28 patients with primary aldosteronism.

RESULTS

The mean values of 24-h urinary Na⁺ excretion in tertiles of the 510 participants were 94, 148 and 218 mmol, respectively. Average tertile age (43.4-44.7 years), office blood pressure and pulse wave velocity were corresponding in the tertiles. Plasma electrolytes, lipids, vitamin D metabolites, parathyroid hormone, renin activity, aldosterone, creatinine and insulin sensitivity did not differ in the tertiles. In supine laboratory recordings, there were no differences in aortic systolic and diastolic blood pressure, heart rate, cardiac output and systemic vascular resistance. Extracellular water volume was higher in the highest versus lowest tertile of Na⁺ excretion. In regression analysis, body surface area and 24-h Na⁺ excretion were independent explanatory variables for extracellular water volume. No differences in urine Na⁺ excretion and extracellular water volume were found between normotensive and hypertensive participants. When compared with the 510 participants, patients with primary aldosteronism had 6.0% excess in extracellular water (p = .003), and 24-h Na⁺ excretion was not related with extracellular water volume.

CONCLUSION

In the absence of mineralocorticoid excess, Na⁺ intake, as evaluated from 24-h Na⁺ excretion, predominantly influences extracellular water volume without a clear effect on blood pressure.

The characteristics of elevated blood pressure in abdominal obesity correspond to primary hypertension: a cross-sectional study

BACKGROUND

Obesity-related hypertension and the associated metabolic abnormalities are considered as a distinct hypertensive phenotype. Here we examined how abdominal fat content, as judged by waist:height ratio, influenced blood pressure and hemodynamic profile in normotensive subjects and never-treated hypertensive patients.

METHODS

The 541 participants (20-72 years) underwent physical examination and laboratory analyses and were divided into age and sex-adjusted quartiles of waist:height ratio. Supine hemodynamics were recorded using whole-body impedance cardiography, combined with analyses of radial tonometric pulse wave form and heart rate variability.

RESULTS

Mean waist:height ratios in the quartiles were 0.46, 0.51, 0.55 and 0.62. Radial and aortic blood pressure, systemic vascular resistance, pulse wave velocity, markers of glucose and lipid metabolism, leptin levels and C-reactive protein were higher in quartile 4 when compared with quartiles 1 and 2 (p < 0.05 for all). Cardiac index was lower in quartile 4 versus quartile 1, while no differences were seen in heart rate variability, augmentation index, plasma renin activity, and aldosterone concentration between the quartiles. Linear regression analyses showed independent associations of abdominal obesity with higher aortic systolic and diastolic blood pressure, systemic vascular resistance, and pulse wave velocity (p < 0.05 for waist:height ratio in all regression models).

CONCLUSION

Higher waist:height ratio was associated with elevated blood pressure, systemic vascular resistance, and arterial stiffness, but not with alterations in cardiac sympathovagal modulation or activation of the circulating renin-angiotensin-aldosterone system. Although obesity-related elevation of blood pressure has distinct phenotypic features, these results suggest that its main characteristics correspond those of primary hypertension.

TRIAL REGISTRATION

ClinicalTrails.gov NCT01742702 (date of registration 5th December 2012).

Team-based "Get-a-Grip" lifestyle management programme in the treatment of obesity

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Team-based one-year lifestyle programme led to mean weight loss of 4.8 kg.

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Among the participants 44% lost ≥ 5%, while 21% lost ≥ 10% of their initial weight.

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Beneficial changes were detected in muscle mass, body fat, and visceral fat.

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Systolic and diastolic blood pressure was reduced significantly.

This study examined weight loss during an extensive 1-year lifestyle programme in primary care in Finland in overweight subjects (n = 134, age 18–69 years; BMI > 30, or BMI > 25 with a comorbidity that would benefit from weight loss) between 2009 and 2013 in a single arm design. The programme included four medical doctor visits, five sessions by a dietitian (advice on diet and on-location shopping behaviour), cooking classes, exercise supervised by personal trainer, and group discussions. A motivational interview method was applied.

Of the 134 participants, 92 (69%) completed the 1-year programme. Among the participants 44% lost ≥ 5%, while 21% lost ≥ 10% of their initial body weight. In intention-to-treat-analyses, the mean weight loss during one year was 4.8 kg (p < 0.001). Mean BMI decreased by 1.7 kg/m² (p < 0.001) and waist circumference by 5.6 cm (p < 0.001). Mean muscle mass increased by 3.3% (p < 0.001), and body fat decreased by 5.0% (p < 0.001). After the programme mean visceral fat content was reduced by 6.4%, systolic blood pressure by 8 mmHg (p < 0.001), and diastolic blood pressure by 6 mmHg (p < 0.001).

In conclusion, retention to the team-based lifestyle management programme resulted in moderate but significant weight loss with beneficial changes in body composition, and the trend to lose weight was maintained throughout the year.

Trial registration: Clinicaltrials.gov identifier NCT04003259.

Prospective, randomized, double-blinded, placebo-controlled study on safety and tolerability of the krill powder product in overweight subjects with moderately elevated blood pressure

Background

Krill powder is rich in bioactive ingredients such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), phospholipids, protein and astaxanthin. Containing dominantly EPA, it is considered to be effective in lowering lipids, foremost serum triglycerides and LDL cholesterol. Krill-derived protein hydrolysates/peptides may have positive effect on blood pressure and astaxanthin has anti-oxidative and anti-inflammatory properties. Thus, krill powder has a lot of potential in improving lipid and metabolic profile and reinforcing the activity of the antioxidant system. However, randomized clinical trials on krill powder are scarce and systematic data of krill meal on human safety is limited. Some of the earlier studies have reported several, non-serious adverse events, mostly related to gastrointestinal tract, but systematic sufficiently powered study on safety is lacking. The aim of this study was to collect data on safety and tolerability of krill powder in humans and simultaneously gain efficacy data by measuring the risk factors for cardiovascular disease.

Methods

The study was a randomised, double-blinded, placebo-controlled intervention study with 35 overweight subjects with mildly or moderately elevated blood pressure, who took 4 g krill oil powder or 4 g of placebo during an 8-week follow-up period. The study consisted of a pre-screening, screening, day 0 baseline (randomization visit) and three follow-up visits on days 14, 28 and 56. The reported adverse events in the groups were compared as primary endpoint and haematological safety parameters and changes in systolic and diastolic pressure and blood total and lipoprotein lipids were measured as secondary end points.

Results

There were in total 80 reported adverse events during the follow-up; 50 in placebo and 30 in krill powder group. Gastrointestinal symptoms (flatulence, heartburn and diarrhea) were the most commonly reported among those probably related to the test products. No serious adverse events were reported. The mean value of all measured hematology variables remained within the reference values in all study subject and no significant changes were observed in blood pressure or lipid values.

Conclusions

The results seem to indicate that using krill powder as a source for EPA and DHA is safe in therapeutic dose and the risk of adverse events, let alone serious ones, is low.

Trial registration

ClinicalTrials.gov, NCT03112083, retrospectively registered.

Efficacy and Safety of Dapagliflozin in Patients With Inadequately Controlled Type 1 Diabetes: The DEPICT-1 52-Week Study

OBJECTIVE

This study evaluated the long-term safety and efficacy of dapagliflozin as an adjunct to adjustable insulin in patients with type 1 diabetes and inadequate glycemic control.

RESEARCH DESIGN AND METHODS

DEPICT-1 (Dapagliflozin Evaluation in Patients With Inadequately Controlled Type 1 Diabetes) was a randomized (1:1:1), double-blind, placebo-controlled phase 3 study of dapagliflozin 5 mg and 10 mg in patients with type 1 diabetes (HbA_1c 7.5-10.5% [58-91 mmol/mol]) (NCT02268214). The results of the 52-week study, consisting of the 24-week short-term and 28-week extension period, are reported here.

RESULTS

Of the 833 patients randomized into the study, 708 (85%) completed the 52-week study. Over 52 weeks, dapagliflozin 5 mg and 10 mg led to clinically significant reductions in HbA_1c (difference vs. placebo [95% CI] -0.33% [-0.49, -0.17] [-3.6 mmol/mol (-5.4, -1.9)] and -0.36% [-0.53, -0.20] [-3.9 mmol/mol (-5.8, -2.2)], respectively) and body weight (difference vs. placebo [95% CI] -2.95% [-3.83, -2.06] and -4.54% [-5.40, -3.66], respectively). Serious adverse events were reported in 13.4%, 13.5%, and 11.5% of patients in the dapagliflozin 5 mg, 10 mg, and placebo groups, respectively. Although hypoglycemia events were comparable across treatment groups, more patients in the dapagliflozin groups had events adjudicated as definite diabetic ketoacidosis (DKA; 4.0%, 3.4%, and 1.9% in dapagliflozin 5 mg, 10 mg, and placebo groups, respectively).

CONCLUSIONS

Over 52 weeks, dapagliflozin led to improvements in glycemic control and weight loss in patients with type 1 diabetes, while increasing the risk of DKA.

Gluten-free diet and autoimmune thyroiditis in patients with celiac disease. A prospective controlled study

OBJECTIVE

Early diagnosis and dietary treatment with a gluten-free diet might slow down the progression of associated autoimmune diseases in celiac disease, but the data are contradictory. We investigated the course of autoimmune thyroid diseases in newly diagnosed celiac disease patients before and after gluten-free dietary treatment.

MATERIAL AND METHODS

Twenty-seven consecutive adults with newly diagnosed celiac disease were investigated at the time of diagnosis and after 1 year on gluten-free diet. Earlier diagnosed and subclinical autoimmune thyroid diseases were recorded and examined. Thyroid gland volume and echogenicity were measured by ultrasound. Autoantibodies against celiac disease and thyroiditis, and thyroid function tests were determined. For comparison, 27 non-celiac controls on normal gluten-containing diet were examined.

RESULTS

At the time of diagnosis, the celiac disease patients had more manifest (n = 7) or subclinical (n = 3) thyroid diseases than the controls (10/27 vs. 3/27, p = 0.055). During the follow-up, the thyroid volume decreased significantly in the patients with celiac disease compared with the controls, indicating the progression of thyroid gland atrophy despite the gluten-free diet.

CONCLUSIONS

Celiac patients had an increased risk of thyroid autoimmune disorders. A gluten-free diet seemed not to prevent the progression of autoimmune process during a follow-up of 1 year.

Increased wall tension in response to vasoconstrictors in isolated mesenteric arterial rings from patients with high blood pressure

Essential hypertension is associated with several alterations in arterial function. A wealth of information from animal models is available concerning hypertensive changes in the mesenteric circulation, while only few studies have examined human mesenteric arterial function. The tone of isolated mesenteric arterial segments (outer diameter 0.7-0.9 mm) was examined from individuals with high (n=17) or normal (n=22) blood pressure, grouped using the current definition of elevated blood pressure (140/90 mmHg). Since the majority of them were operated because of malignancies, we evaluated whether functional vascular properties provided information about patient prognosis. Wall tension development (mN/mm) in response to vasoconstrictors (noradrenaline, 5-hydroxy tryptamine, potassium chloride) was higher in mesenteric arterial rings from patients with high than normal blood pressure. There was no difference in vasoconstrictor sensitivity, or endothelium-dependent and endothelium-independent vasorelaxation. Arterial segment weight was higher in hypertensive subjects, suggesting vascular wall hypertrophy. The 10-year follow-up showed no differences in the control of arterial tone between the surviving (n=14) or deceased (n=25) patients. In conclusion, isolated mesenteric arterial segments from hypertensive patients showed increased wall tension in response to vasoconstrictors. Since the mesenteric circulation is an important regulator of peripheral arterial resistance, possible functional alterations in this vascular bed should be further investigated in hypertensive patients.

Control of vascular tone in isolated mesenteric arterial segments from hypertensive patients

1. Experimental hypertension is associated with several functional alterations of vascular endothelium and smooth muscle, but relatively few studies have examined the control of arterial tone in isolated vascular preparations from patients with essential hypertension. Therefore, we compared functional characteristics in vitro of distal ring segments of the mesenteric artery from 17 hypertensive and 22 normotensive humans. 2. Arterial constrictor responses induced by cumulative addition of Ca(2+) in the presence of noradrenaline (NA) were more effectively inhibited by the Ca(2+) entry blocker nifedipine (0.5 nM) in hypertensive than normotensive subjects (by 55.4+/-4.9, n=17 and 35.0+/(-5.2%), n=22, respectively). Also the contractions elicited by high concentrations of KCl were more effectively inhibited by nifedipine in arterial rings from hypertensive than normotensive patients (by 38.9+/(-3.7), n=17 and 20. 2+/(-4.6%), n=22, respectively). However, the concentration-response curves of contractions to NA, serotonin and KCl in the absence of nifedipine were similar between the study groups. 3. The concentration-response curves of endothelium-dependent relaxations to acetylcholine and Ca(2+) ionophore A23187, as well as of endothelium-independent relaxations to the nitric oxide donor nitroprusside, beta-adrenoceptor agonist isoprenaline and K+ channel opener cromakalim did not show any differences between the groups. Moreover, the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (0.1 mM) almost abolished the relaxations to acetylcholine and Ca(2+) ionophore in both groups, indicating that these responses were largely mediated by nitric oxide. The function of arterial sodium pump was evaluated by relaxations elicited by the return of K+ upon contractions induced by K+-free solution. The rate of K+-relaxation was similar in hypertensive and normotensive arteries (for all these responses n=20 - 22 in the normotensive and 15 - 17 in the hypertensive group). 4. These results suggest abnormal function of voltage-dependent Ca(2+) channels in arterial smooth muscle of hypertensive patients, whereas vascular responses to endothelium-dependent and -independent vasodilators and classical contractile agents were similar between hypertensive and normotensive subjects. The present findings support the view that blockade of voltage-dependent Ca(2+) channels is an effective means of reducing arterial tone in essential hypertension.