Protocol to assess the impact of tobacco-induced volatile organic compounds on cardiovascular risk in a cross- sectional cohort: Cardiovascular Injury due to Tobacco Use study.

INTRODUCTION: Tobacco use leads to increased mortality, the majority of which is attributed to cardiovascular disease. Despite this knowledge, the early cardiovascular impact of tobacco product use is not well understood. Tobacco use increases exposure to harmful and potentially harmful constituents including volatile organic compounds (VOCs) such as acrolein and crotonaldehyde, which may contribute to cardiovascular risk. The link between exposure patterns, risk profiles and demographic distribution of tobacco product users, particularly users of new and emerging products, are not well known. Therefore, we designed the Cardiovascular Injury due to Tobacco Use (CITU) study to assess population characteristics, demographic features, exposure patterns and cardiovascular risk in relation to tobacco. METHODS AND ANALYSIS: We present the design and methodology of the CITU study, a cross-sectional observational tobacco study conducted in Boston, Massachusetts and Louisville, Kentucky starting in 2014. Healthy participants 21-45 years of age who use tobacco products, including electronic nicotine devices, or who never used tobacco are being recruited. The study aims to recruit an evenly split cohort of African-Americans and Caucasians, that is, sex balanced for evaluation of self-reported tobacco exposure, VOC exposure and tobacco-induced injury profiling. Detailed information about participant's demographics, health status and lifestyle is also collected. ETHICS AND DISSEMINATION: The study protocol was approved institutional review boards at both participating universities. All study protocols will protect participant confidentiality. Results from the study will be disseminated via peer-reviewed journals and presented at scientific conferences.

Endothelial Dysfunction in Human Diabetes Is Mediated by Wnt5a-JNK Signaling.

OBJECTIVE: Endothelial dysfunction is linked to insulin resistance, inflammatory activation, and increased cardiovascular risk in diabetes mellitus; however, the mechanisms remain incompletely understood. Recent studies have identified proinflammatory signaling of wingless-type family member (Wnt) 5a through c-jun N-terminal kinase (JNK) as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. APPROACH AND RESULTS: We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in 85 subjects with type 2 diabetes mellitus (n=42) and age- and sex-matched nondiabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Endothelial cells from patients with diabetes mellitus displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes mellitus. In endothelial cells from nondiabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In human aortic endothelial cells, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. CONCLUSIONS: Our findings demonstrate that noncanonical Wnt5a signaling and JNK activity contribute to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes mellitus.

Effect of almond consumption on vascular function in patients with coronary artery disease: a randomized, controlled, cross-over trial.

OBJECTIVE: Almonds reduce cardiovascular disease risk via cholesterol reduction, anti-inflammation, glucoregulation, and antioxidation. The objective of this randomized, controlled, cross-over trial was to determine whether the addition of 85 g almonds daily to a National Cholesterol Education Program (NCEP) Step 1 diet (ALM) for 6 weeks would improve vascular function and inflammation in patients with coronary artery disease (CAD). RESEARCH DESIGN AND METHODS: A randomized, controlled, crossover trial was conducted in Boston, MA to test whether as compared to a control NCEP Step 1 diet absent nuts (CON), incorporation of almonds (85 g/day) into the CON diet (ALM) would improve vascular function and inflammation. The study duration was 22 weeks including a 6-weeks run-in period, two 6-weeks intervention phases, and a 4-weeks washout period between the intervention phases. A total of 45 CAD patients (27 F/18 M, 45-77 y, BMI = 20-41 kg/m(2)) completed the study. Drug therapies used by patients were stable throughout the duration of the trial. RESULTS: The addition of almonds to the CON diet increased plasma α-tocopherol status by a mean of 5.8%, reflecting patient compliance (P ≤0.05). However, the ALM diet did not alter vascular function assessed by measures of flow-mediated dilation, peripheral arterial tonometry, and pulse wave velocity. Further, the ALM diet did not significantly modify the serum lipid profile, blood pressure, C-reactive protein, tumor necrosis factor-α or E-selectin. The ALM diet tended to decrease vascular cell adhesion molecule-1 by 5.3% (P = 0.064) and increase urinary nitric oxide by 17.5% (P = 0.112). The ALM intervention improved the overall quality of the diet by increasing calcium, magnesium, choline, and fiber intakes above the Estimated Average Requirement (EAR) or Recommended Dietary Allowance (RDA). CONCLUSIONS: Thus, the addition of almonds to a NECP Step 1 diet did not significantly impact vascular function, lipid profile or systematic inflammation in CAD patients receiving good medical care and polypharmacy therapies but did improve diet quality without any untoward effect. TRIAL REGISTRATION: The trial was registered with the ClinicalTrials.Gov with the identifier: NCT00782015.

Relation of mitochondrial oxygen consumption in peripheral blood mononuclear cells to vascular function in type 2 diabetes mellitus.

Recent studies have shown mitochondrial dysfunction and increased production of reactive oxygen species in peripheral blood mononuclear cells (PBMCs) and endothelial cells from patients with diabetes mellitus. Mitochondria oxygen consumption is coupled to adenosine triphosphate (ATP) production and also occurs in an uncoupled fashion during formation of reactive oxygen species by components of the electron transport chain and other enzymatic sites. We therefore hypothesized that diabetes would be associated with higher total and uncoupled oxygen consumption in PBMCs that would correlate with endothelial dysfunction. We developed a method to measure oxygen consumption in freshly isolated PBMCs and applied it to 26 patients with type 2 diabetes mellitus and 28 non-diabetic controls. Basal (192 ± 47 vs 161 ± 44 pmoles/min, p = 0.01), uncoupled (64 ± 16 vs 53 ± 13 pmoles/min, p = 0.007), and maximal (795 ± 87 vs 715 ± 128 pmoles/min, p=0.01) oxygen consumption rates were higher in diabetic patients compared to controls. There were no significant correlations between oxygen consumption rates and endothelium-dependent flow-mediated dilation measured by vascular ultrasound. Non-endothelium-dependent nitroglycerin-mediated dilation was lower in diabetics (10.1 ± 6.6 vs 15.8 ± 4.8%, p = 0.03) and correlated with maximal oxygen consumption (r = -0.64, p=0.001). In summary, we found that diabetes mellitus is associated with a pattern of mitochondrial oxygen consumption consistent with higher production of reactive oxygen species. The correlation between oxygen consumption and nitroglycerin-mediated dilation may suggest a link between mitochondrial dysfunction and vascular smooth muscle cell dysfunction that merits further study. Finally, the described method may have utility for the assessment of mitochondrial function in larger scale observational and interventional studies in humans.

Effects of cranberry juice consumption on vascular function in patients with coronary artery disease.

BACKGROUND: Cranberry juice contains polyphenolic compounds that could improve endothelial function and reduce cardiovascular disease risk. OBJECTIVE: The objective was to examine the effects of cranberry juice on vascular function in subjects with coronary artery disease. DESIGN: We completed an acute pilot study with no placebo (n = 15) and a chronic placebo-controlled crossover study (n = 44) that examined the effects of cranberry juice on vascular function in subjects with coronary artery disease. RESULTS: In the chronic crossover study, subjects with coronary heart disease consumed a research preparation of double-strength cranberry juice (54% juice, 835 mg total polyphenols, and 94 mg anthocyanins) or a matched placebo beverage (480 mL/d) for 4 wk each with a 2-wk rest period between beverages. Beverage order was randomly assigned, and participants refrained from consuming other flavonoid-containing beverages during the study. Vascular function was measured before and after each beverage, with follow-up testing ≥12 h after consumption of the last beverage. Mean (±SD) carotid-femoral pulse wave velocity, a measure of central aortic stiffness, decreased after cranberry juice (8.3 ± 2.3 to 7.8 ± 2.2 m/s) in contrast with an increase after placebo (8.0 ± 2.0 to 8.4 ± 2.8 m/s) (P = 0.003). Brachial artery flow-mediated dilation, digital pulse amplitude tonometry, blood pressure, and carotid-radial pulse wave velocity did not change. In the uncontrolled pilot study, we observed improved brachial artery flow-mediated dilation (7.7 ± 2.9% to 8.7 ± 3.1%, P = 0.01) and digital pulse amplitude tonometry ratio (0.10 ± 0.12 to 0.23 ± 0.16, P = 0.001) 4 h after consumption of a single 480-mL portion of cranberry juice. CONCLUSIONS: Chronic cranberry juice consumption reduced carotid femoral pulse wave velocity-a clinically relevant measure of arterial stiffness. The uncontrolled pilot study suggested an acute benefit; however, no chronic effect on measures of endothelial vasodilator function was found. This trial was registered at clinicaltrials.gov as NCT00553904.

Flow-induced arterial remodeling relates to endothelial function in the human forearm.

BACKGROUND: Chronic changes in blood flow stimulate arterial remodeling, which contributes to the maintenance of vascular homeostasis. Experimental studies suggest that remodeling represents a response to local changes in endothelial shear stress and is nitric oxide-dependent. METHODS AND RESULTS: To investigate determinants of outward arterial remodeling in humans, we measured ulnar artery flow, diameter, and flow-mediated dilation before and after removal of the adjacent radial artery in 53 patients who were undergoing coronary bypass surgery (age 60+/-11 years; 13% female). Removal of the radial artery increased ulnar artery blood flow by 35% (P=0.009) and increased ulnar artery diameter by 9% (P<0.001) 4 to 8 weeks after surgery. At 1 week, ulnar artery shear stress was increased by 58% (P<0.001), but it was no longer different from baseline at longer-term follow-up. The contralateral ulnar artery was unaffected, which suggests that these findings were not attributable to the systemic effects of medications or the postoperative state. Extent of outward remodeling correlated with the increase in blood flow (r=0.50, P=0.001) and with flow-mediated dilation at baseline (r=0.50, P=0.001). Remodeling correlated inversely with baseline endothelial expression of P-selectin in the radial artery (r=-0.76, P=0.004, n=14). CONCLUSIONS: A sustained increase in blood flow in the ulnar artery induced outward arterial remodeling despite the presence of risk factors and coronary artery disease. The remodeling response was related to endothelial phenotype, as reflected by flow-mediated dilation and expression of P-selectin. These findings provide evidence that the endothelium plays an important role in the regulation of vascular structure in humans.