Dieting and Endothelial Dysfunction

Scientific Updates Sponsored by Endothelix Inc.
****************************************************

 

Atherosclerosis. 2016 22;252:28-31

Long-term effects of weight loss with a very-low carbohydrate, low saturated fat diet on flow mediated dilatation in patients with type 2 diabetes: A randomised controlled trial.

 

Wycherley TP1, Thompson CH2, Buckley JD3, Luscombe-Marsh ND4, Noakes M4, Wittert GA2, Brinkworth GD5.

  • 1Centre for Population Health Research, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia; Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
  • 2Discipline of Medicine, University of Adelaide, Adelaide, Australia.
  • 3Alliance for Research in Exercise, Nutrition and Activity, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
  • 4Commonwealth Scientific and Industrial Research Organisation (CSIRO) – Food and Nutrition, Adelaide, Australia.
  • 5Commonwealth Scientific and Industrial Research Organisation (CSIRO) – Food and Nutrition, Adelaide, Australia. Electronic address: grant.brinkworth@csiro.au.

Abstract

BACKGROUND AND AIMS:

Very-low carbohydrate diets can improve glycaemic control in patients with type 2 diabetes (T2DM). However, compared to traditional higher carbohydrate, low fat (HighCHO) diets, they have been associated with impaired endothelial function (measured by flow mediated dilatation [FMD]) that is possibly related to saturated fat. This study aimed to examine the effects of a 12-month hypocaloric very-low carbohydrate, low saturated fat (LowCHO) diet compared to an isocaloric HighCHO diet.

METHODS:
One hundred and fifteen obese patients with T2DM (age:58.4 ± 0.7 [SEM] yr, BMI:34.6 ± 0.4 kg/m2, HbA1c:7.33 [56.3 mmol/mol] ± 0.10%) were randomised to consume an energy restricted LowCHO diet (Carb:Pro:Fat:Sat-Fat 14:28:58: less than 10% energy; n = 58) or isocaloric HighCHO diet (53:17:30:  less than 10%; n = 57) whilst undertaking exercise (60 min, 3/wk). Bodyweight, HbA1c and FMD were assessed.

RESULTS:
Seventy eight participants completed the intervention (LowCHO = 41, HighCHO = 37). Both groups experienced similar reductions in weight and HbA1c (-10.6 ± 0.7 kg, -1.05 ± 0.10%; p = 0.001 time, p = .48 time × diet). FMD did not change (p = 0.11 time, p = 0.20 time × diet).

CONCLUSIONS:

In patients with obesity and T2DM, HighCHO diet and LowCHO diet have similar effects on endothelial function.

Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Obes Rev. 2016 Jul 28

Eating and arterial endothelial function: a meta-analysis of the acute effects of meal consumption on flow-mediated dilation.

 

Thom NJ1, Early AR2, Hunt BE2, Harris RA3, Herring MP4,5.
  • 1Department of Biology, Wheaton College, Wheaton, IL, USA.
  • 2Applied Health Science Department, Wheaton College, Wheaton, IL, USA.
  • 3Georgia Prevention Institute, August University, Augusta, GA, USA.
  • 4Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.
  • 5Health Research Institute (HRI), University of Limerick, Limerick, Ireland.

Abstract

Given that endothelial dysfunction precedes atherosclerotic cardiovascular disease, exploring the parameters that modify postprandial flow-mediated dilation (FMD) is important for public health. The objectives of the study are to estimate the population effect of meal ingestion on FMD and to determine how the effect varied based on patient characteristics and modifiable methodological features. Articles published before June 2015 were located using MEDLINE, PubMed and Web of Science. One hundred fifty-four effects were derived from 78 articles involving 2,548 subjects were selected. Included articles required measurement of FMD in adults before and after meal ingestion. Effects were analysed using an unstandardized mean gain random effects model, and significant moderators were analysed using meta-regression. Meal consumption significantly reduced FMD by a heterogeneous mean effect size delta (Δ) of -2.03 (95% CI: [-2.28, -1.77]), an ~2% reduction in FMD. FMD reductions were larger among normal weight individuals, males, those with a cardio-metabolic disorder, those with elevated baseline FMD, and individuals with impaired glucose tolerance at baseline.

Macronutrient meal ingestion significantly reduced FMD, an effect that was moderated by body mass index, sex and two-way interactions between disease status and both baseline FMD and baseline blood glucose levels.

© 2016 World Obesity.

 

Trials. 2016 Aug 2;17:378

Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA)

 

Meyer AS1, Ostrowski SR2, Kjaergaard J3, Johansson PI2,4, Hassager C3.

Abstract

BACKGROUND:

Morbidity and mortality following initial survival of cardiac arrest remain high despite great efforts to improve resuscitation techniques and post-resuscitation care, in part due to the ischemia-reperfusion injury secondary to the restoration of the blood circulation. Patients resuscitated from cardiac arrest display evidence of endothelial injury and coagulopathy (hypocoagulability, hyperfibrinolysis), which in associated with poor outcome. Recent randomized controlled trials have revealed that treatment with infusion of prostacyclin reduces endothelial damage after major surgery and AMI. Thus, a study is pertinent to investigate if prostacyclin infusion as a therapeutic intervention reduces endothelial damage without compromising, or even improving, the hemostatic competence in resuscitated cardiac arrest patients. Post-cardiac arrest patients frequently have a need for vasopressor therapy (catecholamines) to achieve the guideline-supported blood pressure goals. To evaluate a possible catecholamine interaction with the primary endpoints of this study, included patients will be randomized into two different blood pressure goals within guideline-recommended targets.

 

A randomized, placebo-controlled, double-blind investigator-initiated pilot trial in 40 out-of-hospital-cardiac-arrest (OHCA) patients will be conducted. Patients will be randomly assigned to either the active treatment group (48 hours of active study drug (iloprost, 1 ng/kg/min) or to the control group [placebo (saline) infusion]. Target mean blood pressure levels will be allocated 1:1 to 65 mmHg or approximately 75 mmHg, which gives four different permutations, namely: (i) iloprost/65 mHg, (ii) iloprost/75 mmHg, (iii) placebo/65 mmHg, and (iv) placebo/75 mmHg. All randomized patients will be treated in accordance with state-of-the art therapy including targeted temperature management. The primary endpoint of this study is change in biomarkers indicative of endothelial activation and damage, [soluble thrombomodulin (sTM), sE-selectin, syndecan-1, soluble vascular endothelial growth factor (sVEGF), nucleosomes] and sympathoadrenal over activation (epinephrine/norepinephrine) from baseline to 48 hours post-randomization. The secondary endpoints of this trial will include: (1) the hemostatic profile [change in functional hemostatic blood test (thrombelastography (TEG) and whole blood platelet aggregometry (multiplate)) blood cell and endothelial cell-derived microparticles]; (2) feasibility of blood pressure target intervention (target 90 %); (3) interaction of primary endpoints and blood pressure target; (4) levels of neuron-specific enolase at 48 hours post-inclusion according to blood pressure targets.

 

DISCUSSION:

The ENDO-RCA study is a pilot study trial that investigates safety and efficacy of low-dose infusion of prostacyclin administration as compared to standard therapy in post-cardiac arrest syndrome patients.

 

Hypertensive response to exercise: mechanisms and clinical implication.

Kim D1, Ha JW1

 1Cardiology Division, Severance Cardiovascular Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752 Republic of Korea.

A hypertensive response to exercise (HRE) is frequently observed in individuals without hypertension or other cardiovascular disease. However, mechanisms and clinical implication of HRE is not fully elucidated. Endothelial dysfunction and increased stiffness of large artery contribute to development of HRE. From neurohormonal aspects, excess stimulation of sympathetic nervous system and augmented rise of angiotensin II seems to be important mechanism in HRE. Increasing evidences indicates that a HRE is associated with functional and structural abnormalities of left ventricle, especially when accompanied by increased central blood pressure. A HRE harbors prognostic significance in future development of hypertension and increased cardiovascular events, particularly if a HRE is documented in moderate intensity of exercise. As supported by previous studies, a HRE is not a benign phenomenon, however, currently, whether to treat a HRE is controversial with uncertain treatment strategy. Considering underlying mechanisms, angiotensin receptor blockers and beta blockers can be suggested in individuals with HRE, however, evidences for efficacy and outcomes of treatment of HRE in individuals without hypertension is scarce and therefore warrants further studies.

 Exercise and Hypertension.png

Exercise-induced hypertension, cardiovascular events, and mortality in patients undergoing exercise stress testing: a systematic review and meta-analysis.

BACKGROUND:

The prognostic relevance of a hypertensive response to exercise (HRE) is ill-defined in individuals undergoing exercise stress testing. The study described here was intended to provide a systematic review and meta-analysis of published literature to determine the value of exercise-related blood pressure (BP) (independent of office BP) for predicting cardiovascular (CV) events and mortality.

METHODS:
Online databases were searched for published longitudinal studies reporting exercise-related BP and CV events and mortality rates.

RESULTS:
We identified for review 12 longitudinal studies with a total of 46,314 individuals without significant coronary artery disease, with total CV event and mortality rates recorded over a mean follow-up of 15.2±4.0 years. After adjustment for age, office BP, and CV risk factors, an HRE at moderate exercise intensity carried a 36% greater rate of CV events and mortality (95% CI, 1.02-1.83, P = 0.039) than that of subjects without an HRE. Additionally, each 10mm Hg increase in systolic BP during exercise at moderate intensity was accompanied by a 4% increase in CV events and mortality, independent of office BP, age, or CV risk factors (95% CI, 1.01-1.07, P = 0.02). Systolic BP at maximal workload was not significantly associated with the outcome of an increased rate of CV, whether analyzed as a categorical (HR=1.49, 95% CI, 0.90-2.46, P = 0.12) or a continuous (HR=1.01, 95% CI, 0.98-1.04, P = 0.53) variable.

CONCLUSIONS:
An HRE at moderate exercise intensity during exercise stress testing is an independent risk factor for CV events and mortality. This highlights the need to determine underlying pathophysiological mechanisms of exercise-induced hypertension

 

Skin Endothelial Function: A Window to Heart and Kidney

endothelial_dysfunction_guy_small.PNG

BMC Nephrol. 2016 Jul 13;17(1):82

[Skin] Microvascular endothelial dysfunction is associated with albuminuria and CKD in older adults

Seliger SL, Salimi S, Pierre V, Giffuni J, Katzel L, Parsa A

Abstract

BACKGROUND: Impairment in glomerular endothelial function likely plays a major role in the development of albuminuria and CKD progression. Glomerular endothelial dysfunction may reflect systemic microvascular dysfunction, accounting in part for the greater cardiovascular risk in patients with albuminuria. Prior studies of vascular function in CKD have focused on conduit artery function or those with ESRD, and have not examined microvascular endothelial function with albuminuria.

METHODS: We conducted a cross-sectional study among older hypertensive male veterans with stage 1-4 CKD, and hypertensive controls without CKD. Microvascular function was quantified by two distinct Laser-Doppler flowmetry (LDF) measures: peak responses to 1) post-occlusive reactive hyperemia (PORH) and 2) thermal hyperemia (TH), measured on forearm skin. Associations of each LDF measure with albuminuria, eGFR, and CKD status were estimated using correlation coefficients and multiple linear regression, accounting for potential confounders.

RESULTS: Among 66 participants (mean age 69.2 years), 36 had CKD (mean eGFR 46.1 cc/min/1.73 m(2); 30.6 % with overt albuminuria). LDF responses to PORH and TH were 43 and 39 % significantly lower in multivariate analyses among those with macroalbuminuria compared to normoalbuminuria, (β= – 0.42, p = 0.009 and β= -0.37, p = 0.01, respectively). Those with CKD had a 23.9 % lower response to PORH compared to controls (p = 0.02 after adjustment). In contrast, TH responses did not differ between those with and without CKD.

CONCLUSIONS:

Microvascular endothelial function was strongly associated with greater albuminuria and CKD, independent of diabetes and blood pressure.
These findings may explain in part the excess systemic cardiovascular risk associated with albuminuria and CKD.

 

Scientific Updates Sponsored by Endothelix Inc.
****************************************************

Evaluate Endothelial Function with VENDYS Digital Thermal Monitoring of
Vascu
lar Reactivity

Cartoon guy_captions2_Sept2014-1.jpg

new-slideshow-image-patientdoc2.JPG 


An innovative, inexpensive, noninvasive office-based test to enhance your practice and improve patient care.

        easy.JPG   

Endothelix_HomePageSlider_1.png

Leave a Reply

LATEST SCIENTIFIC UPDATES

Enhance your patient care with the new office-based vascular function test.

Sign Up for our Webinar Series

Why Should We Measure Endothelial Function?