3 min read

New studies show Endothelial Dysfunction precedes HTN,

and Microvascular ED is a more sensitive marker than Macrovascular ED

Arq Bras Cardiol. 2018;110(6):558-567. doi: 10.5935/abc.20180086. Endothelial Dysfunction and Inflammation Precedes Elevations in Blood Pressure Induced by a High-Fat Diet. [Article in English, Portuguese] Oishi JC1, Castro CA1, Silva KA1, Fabricio V1, Cárnio EC2, Phillips SA3, Duarte ACGO1, Rodrigues GJ1. Author information 1Universidade Federal de São Carlos (UFSCar), São Paulo, SP – Brazil.2Universidade de São Paulo (USP), Ribeirão Preto, SP – Brazil.3University of Chicago Medical Center, Chicago, Illinois – USA. Abstract BACKGROUND: Obesity leads to a chronic inflammatory state, endothelial dysfunction and hypertension. OBJECTIVE: To establish the time-course of events regarding inflammatory markers, endothelial dysfunction, systolic blood pressure (SBP) in obesity in only one experimental model. METHODS: We fed male Wistar rats (eight-week age) with a standard diet (Control – CT, n = 35), or palatable high-fat diet (HFD, n = 35) for 24 weeks. Every six weeks, 7 animals from each group were randomly selected for euthanasia. SBP and serum levels of interleukin-6, tumor necrosis factor-α, C-reactive protein, adiponectin and nitric oxide were determined. Endothelial and vascular smooth muscle functions were determined in dissected aorta and lipid peroxidation was measured. Statistical significance was set at p < 0.05. RESULTS: Levels of pro-inflammatory cytokines began to increase after six weeks of a high-fat diet, while those of the anti-inflammatory cytokine adiponectin decreased. Interestingly, the endothelial function and serum nitric oxide began to decrease after six weeks in HFD group. The SBP and lipid peroxidation began to increase at 12 weeks in HFD group. In addition, we showed that total visceral fat mass was negatively correlated with endothelial function and positively correlated with SBP. CONCLUSION: Our results show the time-course of deleterious effects and their correlation with obesity. Full-text

Obes Res Clin Pract. 2018 Sep – Oct;12(5):452-458.

Adverse effects of long-term weight gain on microvascular endothelial function. Coutinho T1, Turner ST2, Kullo IJ3. Author information 1Department of Medicine, Division of Cardiology and Division of Cardiac Prevention and Rehabilitation, University of Ottawa Heart Institute, 40 Ruskin St. Ottawa, ON K1Y 4W7, Canada. Electronic address: tcoutinho@ottawaheart.ca.2Department of Medicine, Division of Nephrology and Hypertension, USA. Electronic address: sturner@mayo.edu.3Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, 200 First St. SW. Rochester, MN 55901, USA. Electronic address: kullo.iftikhar@mayo.edu. Abstract BACKGROUND: Endothelial dysfunction is the first stage of the atherosclerotic cascade, and independently associated with cardiovascular events. We evaluated the associations of longitudinal changes in weight, waist circumference, body fat percentage and lean mass index with changes in endothelial function. METHODS: 521 community-based subjects who belonged to hypertensive sibships and had no history of myocardial infarction or stroke had their anthropometric measures and endothelial function assessed a mean of 8.5 years apart. Endothelial function was assessed with brachial artery ultrasound, yielding measures of flow-mediated dilation and reactive hyperemia. We used multivariable linear regression with generalised estimating equations to assess the associations of longitudinal changes (Δ) in anthropometric measures with Δ flow-mediated dilation and reactive hyperemia, adjusting for potential confounders. RESULTS: Mean±standard deviation age was 57.6±8.7years, 58% were women, and 72% were hypertensive. Most (84%) were overweight or obese at baseline. At end of follow-up, flow-mediated dilation and reactive hyperemia increased by 1.9±7.6% and 51.2±605.8% on average, respectively. In multivariable linear regression, changes in anthropometric measures were not associated with changes in flow-mediated dilation. However, Δ weight (β±SE: -9.00±2.35), Δ waist circumference (-6.78±2.21) and Δ body fat percentage (-19.72±5.62, P<0.0001 for each) were inversely associated with Δ reactive hyperemia. Δ lean mass index was not associated with Δ reactive hyperemia. CONCLUSIONS: Long-term increases in weight, waist circumference and body fat percentage are associated with progressive worsening of microvascular endothelial function, but not conduit vessel endothelial function, in subjects without a history of cardiovascular events, independently of risk factors. Copyright © 2018 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.