Effects of smoking regular or light cigarettes on brachial artery flow-mediated dilation

Acute Effects of Cannabis Inhalation on Arterial Stiffness, Vascular Endothelial Function, and Cardiac Function

BACKGROUND

The cardiovascular impact of cannabis use is incompletely understood. Although evidence links chronic use to an increased risk of disease and adverse cardiovascular events, few studies have investigated the acute effects of cannabis inhalation on subclinical dysfunction. Furthermore, it remains unknown how method of inhalation and cannabinoid profile modify risk. While controlling for inhalation method and the effects of either Δ-9-tetrahydrocannabinol (THC) or cannabidiol (CBD), we examined the acute cardiovascular effects of cannabis use on arterial stiffness, vascular endothelial responsiveness, and cardiac function, as markers of cardiovascular impairment.

METHODS AND RESULTS

Twenty-two young, healthy, cannabis users were assessed for arterial stiffness via pulse wave velocity, vascular endothelial function via brachial artery flow mediated dilation, and cardiac function via echocardiography, before and after (1) smoking THC-predominant cannabis (S-THC), (2) vaporizing THC-predominant THC (V-THC), and (3) vaporizing cannabidiol-predominant cannabis (V-CBD). S-THC and V-THC increased heart rate (S-THC: ∆17±15 bpm, V-THC: ∆16±16 bpm;both P<0.0001) and mean arterial pressure (S-THC: ∆7±6 mm Hg, V-THC: ∆5±5 mm Hg;both P<0.0001) whereas V-CBD did not (∆1±4 bpm, ∆3±4 mm Hg;both P>0.05). After inhalation, pulse wave velocity increased (S-THC: ∆0.29±0.75 m/s, V-THC: ∆0.42±0.74 m/s, V-CBD: ∆0.10±0.44 m/s; P=0.002) and diastolic function was reduced ([early/late ratio] S-THC: ∆-0.2±0.53, V-THC: ∆-0.33±58, V-CBD: ∆0.01±66; P=0.03). Differences in heart rate were related to changes in pulse wave velocity (r2=0.2; P=0.0002) and diastolic function (r2=0.26; P<0.0001). Inhalation method did not alter these cannabinoid-dependent responses.

CONCLUSIONS

THC predominant, but not cannabidiol predominant, cannabis elicits increases in heart rate and blood pressure irrespective of inhalation method, which may increase arterial stiffness and reduce diastolic function. These findings implicate THC as a relevant factor for cannabis-related subclinical cardiovascular dysfunction.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04693884.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

Persistent Endothelial Dysfunction in Post-Acute COVID-19 Syndrome: A Case-Control Study

Background: Endothelial dysfunction has a key role in the pathogenesis of coronavirus disease 2019 (COVID-19) and its disabling complications. We designed a case-control study to assess the alterations of endothelium-dependent flow-mediated dilation (FMD) among convalescent COVID-19 patients. Methods: COVID-19 patients referred to a Pulmonary Rehabilitation Unit within 2 months from swab test negativization were consecutively evaluated for inclusion and compared to controls matched for age, gender, and cardiovascular risk factors. Results: A total of 133 convalescent COVID-19 patients (81.2% males, mean age 61.6 years) and 133 matched controls (80.5% males, mean age 60.4 years) were included. A significantly lower FMD was documented in convalescent COVID-19 patients as compared to controls (3.2% ± 2.6 vs. 6.4% ± 4.1 p < 0.001), confirmed when stratifying the study population according to age and major clinical variables. Among cases, females exhibited significantly higher FMD values as compared to males (6.1% ± 2.9 vs. 2.5% ± 1.9, p < 0.001). Thus, no significant difference was observed between cases and controls in the subgroup analysis on females (6.1% ± 2.9 vs. 5.3% ± 3.4, p = 0.362). Among convalescent COVID-19 patients, FMD showed a direct correlation with arterial oxygen tension (rho = 0.247, p = 0.004), forced expiratory volume in 1 s (rho = 0.436, p < 0.001), forced vital capacity (rho = 0.406, p < 0.001), and diffusing capacity for carbon monoxide (rho = 0.280, p = 0.008). Overall, after adjusting for major confounders, a recent COVID-19 was a major and independent predictor of FMD values (β = −0.427, p < 0.001). Conclusions: Post-acute COVID-19 syndrome is associated with a persistent and sex-biased endothelial dysfunction, directly correlated with the severity of pulmonary impairment.

Habitual cannabis use is associated with altered cardiac mechanics and arterial stiffness, but not endothelial function in young healthy smokers

Cigarette smoking is among the most detrimental behaviors to cardiovascular health, resulting in arterial stiffening, endothelial dysfunction, and structural/functional alterations to the myocardium. Similar to cigarettes, cannabis is commonly smoked, and next to alcohol, is the most commonly used recreational substance in the world. Despite this, little is known about the long-term cardiovascular effects of smoking cannabis. This study explored the associations of cardiovascular structure and function with cannabis use in ostensibly healthy young participants (n = 35). Using echocardiography, carotid-femoral pulse wave velocity (cfPWV), and brachial flow-mediated dilation (FMD), we performed a cross-sectional assessment of cardiovascular function in cannabis users (n = 18) and controls (n = 17). There were no differences in cardiac morphology or traditional resting measures of systolic or diastolic function between cannabis users and controls (all P > 0.05), whereas cannabis users demonstrated reduced peak apical rotation compared with controls (cannabis users: 5.5 ± 3.8, controls: 9.6 ± 1.5; P = 0.02). Cannabis users had higher cfPWV compared with controls (cannabis users: 5.8 ± 0.6 m/s, controls: 5.3 ± 0.7 m/s; P = 0.05), whereas FMD was similar between cannabis users and controls (cannabis users: 8.3 ± 3.3%, controls: 6.8 ± 3.6%; P = 0.7). Young, healthy, and cannabis users demonstrate altered cardiac mechanics and greater aortic stiffness. Further studies should explore causal links between cannabis smoking and altered cardiovascular function.NEW & NOTEWORTHY Recreational cannabis is the most widely used substance in the world, other than alcohol. Yet, the effects of cannabis use on cardiovascular function and health are not well understood. Our cross-sectional data demonstrate that young, ostensibly healthy cannabis users have greater arterial stiffness and altered cardiac mechanics compared to nonusers. These findings suggest that cannabis users may be at greater risk of the development of future cardiovascular disease.

Habitual cigarette smoking attenuates shear-mediated dilation in the brachial artery but not in the carotid artery in young adults

In the present study, we hypothesized that habitual cigarette smoking attenuates endothelial function in the cerebral circulation as well as that of the peripheral circulation in young adults. To test this hypothesis, we measured cerebrovascular and peripheral flow‐mediated dilation (FMD) in young smokers and nonsmokers in the present study. Ten healthy nonsmokers and 10 smokers participated in the study. We measured blood velocity and diameter in the brachial artery and internal carotid artery (ICA) using Doppler ultrasound. We identified shear‐mediated dilation in the brachial artery and ICA by the percentage change in peak diameter during hyperemia stimulation (reactive hyperemia and hypercapnia). We measured the baseline diameter and the shear rate area under the curve from the onset of hyperemia to peak dilation in the brachial artery and ICA, finding the measurements of the smokers and those of the nonsmokers did not differ (p > .05). In contrast to brachial FMD (5.07 ± 1.79% vs. 7.92 ± 3.01%; smokers vs. nonsmokers, p = .019), FMD in the ICA was not attenuated in the smokers compared with that of the nonsmokers (5.46 ± 2.32% vs. 4.57 ± 2.70%; p = .442). These findings indicate that in young healthy smokers, cerebral endothelial function was preserved, and the response of cerebral endothelial function to smoking was different from that of peripheral vasculature.

Effects of tobacco cigarettes, e-cigarettes, and waterpipe smoking on endothelial function and clinical outcomes

Tobacco smoking is a leading cause of non-communicable disease globally and is a major risk factor for cardiovascular disease (CVD) and lung disease. Importantly, recent data by the World Health Organizations (WHO) indicate that in the last two decades global tobacco use has significantly dropped, which was largely driven by decreased numbers of female smokers. Despite such advances, the use of e-cigarettes and waterpipes (shisha, hookah, narghile) is an emerging trend, especially among younger generations. There is growing body of evidence that e-cigarettes are not a harm-free alternative to tobacco cigarettes and there is considerable debate as to whether e-cigarettes are saving smokers or generating new addicts. Here, we provide an updated overview of the impact of tobacco/waterpipe (shisha) smoking and e-cigarette vaping on endothelial function, a biomarker for early, subclinical, atherosclerosis from human and animal studies. Also their emerging adverse effects on the proteome, transcriptome, epigenome, microbiome, and the circadian clock are summarized. We briefly discuss heat-not-burn tobacco products and their cardiovascular health effects. We discuss the impact of the toxic constituents of these products on endothelial function and subsequent CVD and we also provide an update on current recommendations, regulation and advertising with focus on the USA and Europe. As outlined by the WHO, tobacco cigarette, waterpipe, and e-cigarette smoking/vaping may contribute to an increased burden of symptoms due to coronavirus disease 2019 (COVID-19) and to severe health consequences.

Novel Strategies to Combat CMV-Related Cardiovascular Disease

Cytomegalovirus (CMV), a ubiquitous human pathogen that is never cleared from the host, has long been thought to be relatively innocuous in immunocompetent adults, but causes severe complications including blindness, end-organ disease, and death in newborns and in immuno-compromised individuals, such as organ transplant recipients and those suffering from AIDS. Yet even in persons with intact immunity, CMV infection is associated with profound stimulation of immune and inflammatory pathways. Carriers of CMV infection also have an elevated risk of developing cardiovascular complications. In this review, we define the proposed mechanisms of how CMV contributes to cardiovascular disease (CVD), describe current approaches to target CMV, and discuss how these strategies may or may not alleviate cardiovascular complications in those with CMV infection. In addition, we discuss the special situation of CMV coinfection in people with HIV infection receiving antiretroviral therapy, and describe how these 2 viral infections may interact to potentiate CVD in this especially vulnerable population.

Differential effects of tobacco cigarettes and electronic cigarettes on endothelial function in healthy young people

Tobacco cigarette (TC) smoking has never been lower in the United States, but electronic cigarette (EC) vaping has reached epidemic proportions among our youth. Endothelial dysfunction, as measured by flow-mediated vasodilation (FMD) is a predictor of future atherosclerosis and adverse cardiovascular events and is impaired in young TC smokers, but whether FMD is also reduced in young EC vapers is uncertain. The aim of this study in otherwise healthy young people was to compare the effects of acute and chronic tobacco cigarette (TC) smoking and electronic cigarette (EC) vaping on FMD. FMD was compared in 47 nonsmokers (NS), 49 chronic EC vapers, and 40 chronic TC smokers at baseline and then after EC vapers (n = 31) and nonsmokers (n = 47) acutely used an EC with nicotine (ECN), EC without nicotine (EC0), and nicotine inhaler (NI) at ~4-wk intervals and after TC smokers (n = 33) acutely smoked a TC, compared with sham control. Mean age (NS, 26.3 ± 5.2 vs. EC, 27.4 ± 5.45 vs. TC, 27.1 ± 5.51 yr, P = 0.53) was similar among the groups, but there were more female nonsmokers. Baseline FMD was not different among the groups (NS, 7.7 ± 4.5 vs. EC:6.6 ± 3.6 vs. TC, 7.9 ± 3.7%∆, P = 0.35), even when compared by group and sex. Acute TC smoking versus control impaired FMD (FMD pre-/postsmoking, -2.52 ± 0.92 vs. 0.65 ± 0.93%∆, P = 0.02). Although the increase in plasma nicotine was similar after EC vapers used the ECN versus TC smokers smoked the TC (5.75 ± 0.74 vs. 5.88 ± 0.69 ng/mL, P = 0.47), acute EC vaping did not impair FMD. In otherwise healthy young people who regularly smoke TCs or ECs, impaired FMD compared with that in nonsmokers was not present at baseline. However, FMD was significantly impaired after smoking one TC, but not after vaping an equivalent "dose" (estimated by change in plasma nicotine) of an EC, consistent with the notion that non-nicotine constituents in TC smoke mediate the impairment. Although it is reassuring that acute EC vaping did not acutely impair FMD, it would be dangerous and premature to conclude that ECs do not lead to atherosclerosis.NEW & NOTEWORTHY In our study of otherwise healthy young people, baseline flow-mediated dilation (FMD), a predictor of atherosclerosis and increased cardiovascular risk, was not different among tobacco cigarette (TC) smokers or electronic cigarette (EC) vapers who had refrained from smoking, compared with nonsmokers. However, acutely smoking one TC impaired FMD in smokers, whereas vaping a similar EC "dose" (as estimated by change in plasma nicotine levels) did not. Finally, although it is reassuring that acute EC vaping did not acutely impair FMD, it would be premature and dangerous to conclude that ECs do not lead to atherosclerosis or increase cardiovascular risk.

Cardiovascular risk of smoking and benefits of smoking cessation

Smoking increases mortality from all causes and has a crucial role in atherosclerotic cardiovascular disease (ASCVD). Active smoking and secondhand smoke exposure determine more than 30% of coronary heart disease (CHD) mortality. The exact mechanisms of cardiovascular damages are not well known, but the detrimental effect of smoking on endothelial function has long been recognized. Smoking elicits oxidative processes, negatively affects platelet function, fibrinolysis, inflammation and vasomotor function; all these proatherogenic effects double the 10-year risk of fatal events in smokers compared to non smokers. An intriguing issue about smoking is the vulnerability of female gender. The mortality from cardiovascular diseases (CVDs) is higher in female than male smokers and female smokers show a 25% higher risk of developing CHD than men with the same exposure to tobacco smoke. This female vulnerability seems to be related to genes involved in thrombin signaling. The effects of smoking cessation have also been extensively studied. Cessation at an early age (40 years) has an impressive 90% reduction in the excess risk of death. In this review we report recent data about the causal link between smoking and CVDs and about the benefits of smoking cessation.

High Carbon Monoxide Levels from Charcoal Combustion Mask Acute Endothelial Dysfunction Induced by Hookah (Waterpipe) Smoking in Young Adults

BACKGROUND

Hookah smoking is marketed to youth as a harmless alternative to cigarettes. Although cigarette smoking acutely impairs endothelial function, the effect of smoking fruit-flavored hookah tobacco is unknown. Because charcoal traditionally is used to heat the hookah tobacco in the waterpipe, hookah smoke delivers tobacco toxicants and nicotine plus charcoal combustion products: not only carbon-rich nanoparticles, oxidants that may destroy nitric oxide and impair endothelial function, but also large amounts of carbon monoxide (CO), a putative vasodilator molecule.

METHODS

To test the acute effect of hookah smoking on endothelial function, in young adult hookah smokers (n=30, age 26±1 years, mean±SE), we measured plasma nicotine, exhaled CO, and brachial artery flow-mediated dilation (FMD) before and after charcoal-heated hookah smoking. To remove the effect of charcoal combustion, the same measurements were performed when the same flavored hookah tobacco product was heated electrically (n=20). As a positive internal control, we studied age-matched cigarette smokers (n=15) who smoked 1 cigarette. To isolate the effect of the CO boost on FMD, hookah smokers (n=8) inhaled a 0.1% CO gas mixture to approximate their CO boost achieved with charcoal-heated hookah smoking.

RESULTS

Nicotine levels increased similarly with all types of smoking, whereas exhaled CO increased 9- to 10-fold more after charcoal-heated hookah than after either electrically heated hookah or cigarette smoking. FMD did not decrease after smoking charcoal-heated hookah but instead increased by +43±7% ( P<0.001). In contrast, FMD decreased by -27±4% ( P<0.001) after smoking electrically heated hookah, comparable to the decrease after cigarette smoking. FMD increased markedly by 138±71% ( P<0.001) after breathing CO gas, 2.8 times more than the increase induced in the same subjects after smoking charcoal-heated hookah ( P<0.001), despite comparable increases in exhaled CO (24±1 versus 28±3 ppm, hookah versus CO).

CONCLUSIONS

Smoking hookah tobacco, similar to cigarette tobacco, acutely impairs endothelial function. With traditional charcoal-heated hookah smoking, the acute endothelial dysfunction is masked by high levels of carbon monoxide, a potent vasodilator molecule generated by charcoal combustion. With respect to large-artery endothelial function, smoking hookah is not harmless.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifiers: NCT03616002 and NCT03067701.

Endothelial and left ventricular diastolic function in young adults exposed to tobacco

Smoking is associated with endothelial and left ventricular diastolic disfunction. We aimed to determine the endothelial and diastolic function in young adults exposed to tobacco smoke and the effects of acute exposure to it. Smokers were considered as cases and non-smokers as controls. Brachial artery diameter, brachial artery flow velocity, and echocardiographic variables were measured. Mean age of the participants was 21 years. Smokers showed significant endothelial dysfunction compared with non-smokers. Arterial dilation mediated by the endothelium was significantly higher in non-smokers than in smokers (p = 0.005). Non-endothelium-mediated arterial dilation was significantly impaired in smokers compared with non-smokers (p = 0.02). After reactive hyperaemia, there was a significant increase in blood flow in non-smokers (61%) compared with that in smokers (29%). Acute cigarette exposure showed a trend towards left ventricle diastolic disfunction in smokers. Left atrium diameter was significantly higher in smokers than in non-smokers. After acute exposure to cigarette smoke, arterial dilation and brachial flow velocity were lower than those achieved in the abstinence phase (p = 0.005). We concluded that endothelium-dependent arterial dilation is impaired in young smokers and it worsens even after acute exposure to cigarette smoke.

Effects of Smoking Cessation with Nicotine Replacement Therapy on Vascular Endothelial Function, Arterial Stiffness, and Inflammation Response in Healthy Smokers

The effects of nicotine replacement therapy (NRT)-aided smoking cessation on vascular function are not fully clarified. We investigated 100 healthy smokers who were motivated to quit and received NRT for a 3-month period. Vascular endothelial function (measured by reactive hyperemia-peripheral arterial tonometry [RH-PAT]), arterial stiffness (measured by augmentation index [AI] and brachial-ankle pulse wave velocity [baPWV]), and systemic inflammation markers (including serum soluble intercellular adhesion molecule-1 [sICAM-1] and interleukin-1β [IL-1β]) were assessed at baseline and 3 and 12 months of follow-up. After 3 months of intervention, endothelial function, arterial stiffness, and inflammatory markers significantly improved (RH-PAT increased, AI and baPWV decreased, sICAM-1 and IL-1β decreased, all P < .05) for the participants who abstained from smoking completely, but for those who did not abstained completely, RH-PAT, AI, baPWV, and IL-1β remained unchanged. At 12 months follow-up, endothelial function (RH-PAT), arterial stiffness (AI and baPWV), and inflammatory markers (sICAM-1 and IL-1β) were further improved in participants who abstained from smoking (P < .001), while the above parameters deteriorated in continued smokers (P < .05). In conclusion, vascular dysfunction can be reversible after NRT-aided smoking cessation in healthy smokers and vascular function could be further damaged if they continue smoking.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

CT-Measured Lung Air-Trapping is Associated with Higher Carotid Artery Stiffness in Individuals with Chronic Obstructive Pulmonary Disease

Early stages of chronic obstructive pulmonary disease (COPD) are characterized by the loss and narrowing of terminal bronchioles in the lung resulting in 'air-trapping,' often occurring before overt emphysema manifests. Individuals with an airway-predominant phenotype of COPD display extensive lung air-trapping and are at greater cardiovascular disease (CVD) risk than COPD patients with an emphysema-predominant phenotype. We hypothesized that the degree of computed tomography (CT)-quantified lung air-trapping would be associated with greater aortic and carotid artery stiffness and lower endothelial function, known biomarkers of CVD risk. Lung air-trapping was associated with greater aortic stiffness (carotid femoral pulse wave velocity, CFPWV) (r=0.60, p=0.007) and carotid β-stiffness (r=0.75, p=0.0001) among adults with (n=10) and without (n=9) a clinical diagnosis of COPD and remained significant after adjusting for blood pressure (BP) and smoking history (pack-years) (carotid β-stiffness r=0.68, p<0.01; CFPWV r=0.53, p=0.03). The association between lung air-trapping and carotid β-stiffness remained significant after additionally adjusting for age and FEV₁ (r=0.64, p=0.01). In the COPD group only (n=10), lung air-trapping remained associated with carotid β-stiffness (r=0.82, p=0.05) after adjustment for age, pack-years and FEV₁. In contrast, no association was observed between CFPWV and lung air-trapping after adjustment for BP, pack-years, age and FEV₁ (r=0.12, p=0.83). Lung air-trapping was not associated with endothelial function (brachial artery flow mediated dilation) in the entire cohort (p=0.80) or in patients with COPD only (p=0.71). These data suggest that carotid artery stiffness may be a mechanism explaining the link between airway- predominant phenotypes of COPD and high CVD risk.

Metabolic Pathways and Networks Associated With Tobacco Use in Military Personnel

OBJECTIVE

The aim of this study is to use high-resolution metabolomics (HRM) to identify metabolic pathways and networks associated with tobacco use in military personnel.

METHODS

Four hundred deidentified samples obtained from the Department of Defense Serum Repository were classified as tobacco users or nonusers according to cotinine content. HRM and bioinformatic methods were used to determine pathways and networks associated with classification.

RESULTS

Eighty individuals were classified as tobacco users compared with 320 nonusers on the basis of cotinine levels at least 10 ng/mL. Alterations in lipid and xenobiotic metabolism, and diverse effects on amino acid, sialic acid, and purine and pyrimidine metabolism were observed. Importantly, network analysis showed broad effects on metabolic associations not simply linked to well-defined pathways.

CONCLUSIONS

Tobacco use has complex metabolic effects that must be considered in evaluation of deployment-associated environmental exposures in military personnel.

Associations of Tobacco Smoking with Impaired Endothelial Function: The Circulatory Risk in Communities Study (CIRCS)

Aims: Smoking impairs endothelial function as an acute effect. However, few population-based studies have examined the association between smoking status and endothelial function or the dose-response and duration- response association of smoking with endothelial function. We examined whether smoking habits were associated with impaired endothelial function depending on smoking dose and duration.

Methods: We conducted a cross-sectional study of 910 men and women aged 30–79 years from 2013 to 2016. Statistical analyses of the data were conducted between 2016 and 2017. Endothelial function was assessed by brachial artery flow-mediated dilation (FMD) measurement. Low FMD was defined in two ways as the cutoff point based on the lowest quartile of %FMD (< 5.1%) and median of %FMD (< 6.8%), regarding as impaired endothelial function. We investigated the smoking status in terms of cigarettes consumed per day and the duration of smoking.

Results: Heavy and chronic smokers were associated with a high prevalence of impaired endothelial function. Those associations did not change substantially after adjustment for other cardiovascular risk factors. Among all participants, the multivariable-adjusted ORs (95% CIs) of low FMD (< 5.1%) with reference to never smokers were 2.23 (1.00–5.14) for current heavy smokers of ≥ 30 cigarettes per day, 1.83 (1.04–3.20) for heavy smokers of ≥ 40 pack-years, and 2.16 (1.15–4.06) for chronic smokers of ≥ 40 years. For low FMD (< 6.8%) those values was 2.17 (1.01–5.05), 1.70 (1.01–2.86), and 1.98 (1.07–3.69), respectively.

Conclusions: Similar associations were observed among only men. Heavy or long-term tobacco smoking may induce impaired endothelial function.

Depletion in LpA-I:A-II particles enhances HDL-mediated endothelial protection in familial LCAT deficiency

The aim of this study was to evaluate the vasoprotective effects of HDL isolated from carriers of LCAT deficiency, which are characterized by a selective depletion of LpA-I:A-II particles and predominance of preβ migrating HDL. HDLs were isolated from LCAT-deficient carriers and tested in vitro for their capacity to promote NO production and to inhibit vascular cell adhesion molecule-1 (VCAM-1) expression in cultured endothelial cells. HDLs from carriers were more effective than control HDLs in promoting eNOS activation with a gene-dose-dependent effect (P_Trend = 0.048). As a consequence, NO production induced by HDL from carriers was significantly higher than that promoted by control HDL (1.63 ± 0.24-fold vs. 1.34 ± 0.07-fold, P = 0.031). HDLs from carriers were also more effective than control HDLs in inhibiting the expression of VCAM-1 (homozygotes, 65.0 ± 8.6%; heterozygotes, 53.1 ± 7.2%; controls, 44.4 ± 4.1%; P_Trend = 0.0003). The increased efficiency of carrier HDL was likely due to the depletion in LpA-I:A-II particles. The in vitro findings might explain why carriers of LCAT deficiency showed flow-mediated vasodilation and plasma-soluble cell adhesion molecule concentrations comparable to controls, despite low HDL-cholesterol levels. These results indicate that selective depletion of apoA-II-containing HDL, as observed in carriers of LCAT deficiency, leads to an increased capacity of HDL to stimulate endothelial NO production, suggesting that changes in HDL apolipoprotein composition may be the target of therapeutic interventions designed to improve HDL functionality.

Decrease in Small Pulmonary Vessels on Chest Computed Tomography in Light Smokers Without COPD: An Early Change, but Correlated with Smoking Index

PURPOSE

The aim of this study was to evaluate the relationship between the amount of smoking and the cross-sectional area (CSA) of small pulmonary vessels in light smokers without a diagnosis of chronic obstructive pulmonary disease (COPD).

METHODS

This retrospective study was approved by our institutional review board, which waived the need for informed consent from patients. The study included 34 current smokers without COPD, who were defined as light smokers based on their smoking history (≤25 pack years). The CSA of small pulmonary vessels (<5 mm² [CSA_<5]) was measured on computed tomography (CT) scans, and the percentage of total CSA of the lung (%CSA_<5) was calculated. The extent of emphysema was also assessed as the percentage of low attenuation area (%LAA, <-950 Hounsfield units). The correlations of %CSA_<5 and %LAA with pack years were determined using the Spearman rank correlation.

RESULTS

There was a significant negative correlation between %CSA_<5 and pack years, whereas no significant correlation was found between %LAA and pack years. The correlations between pack years and percent predicted forced expiratory volume in 1 s (FEV₁) and FEV₁/forced vital capacity were not significant.

CONCLUSIONS

The percentage of total CSA of the lung made up of small pulmonary vessels in light smokers without COPD significantly decreases with increasing amount of smoking, in contrast to emphysema measurements. This suggests that small pulmonary vessels might have been injured or might have degenerated because of smoking, and might represent an initial stage in the development of COPD.

Influence of sleep duration on cortical oxygenation in elderly individuals

AIM

Short sleep duration is a risk factor for cardiovascular diseases. Cerebral blood flow and its regulation are affected by pathological conditions commonly observed in the elderly population, such as dementia, atherosclerosis, diabetes mellitus (DM), stroke, and hypertension. The purpose of this study was to examine the influence of sleep duration on cortical oxygenated hemoglobin (OxyHb) using near-infrared spectroscopy (NIRS).

METHODS

Seventy-three individuals (age, 70.1 ± 3.9 years, 51 men and 22 women) participated in this study. Cortical OxyHb levels were measured with NIRS. We evaluated age, body mass index (BMI), smoking status, alcohol intake, sleep duration, hypertension, DM, and hyperlipidemia using a questionnaire. Blood pressure was measured using plethysmography.

RESULTS

Peak OxyHb and area under the NIRS curve significantly decreased in participants with sleep duration <7 h compared with those with sleep duration ≥7 h (0.136 ± 0.212 mM·mm vs 0.378 ± 0.342 mM·mm, P = 0.001; 112.0 ± 243.6 vs 331.7 ± 428.7, P  = 0.012, respectively). Sleep duration was significantly correlated with peak OxyHb level and area under the NIRS curve (r = 0.378, P  = 0.001; r = 0.285, P  = 0.015, respectively). Multiple regression analysis, including age, BMI, sex, smoking status, alcohol intake, sleep duration, hypertension, DM, and hyperlipidemia revealed that sleep duration was the only significant independent factor associated with peak OxyHb and area under the NIRS curve (β = 0.343, P  = 0.004; β = 0.244, P  = 0.049, respectively), and smoking status was independently correlated with time to the peak OxyHb (β = -0.319, P  = 0.009).

CONCLUSION

Sleep duration may be an important factor that influences cortical oxygenation in the elderly population.

Greater γ-tocopherol status during acute smoking abstinence with nicotine replacement therapy improved vascular endothelial function by decreasing 8-iso-15(S)-prostaglandin F2α

Nicotine replacement therapy (NRT) improves the long-term success rate of smoking cessation, but induces oxidative stress and inflammatory responses that may delay the restoration of vascular endothelial function (VEF). No studies have examined co-therapy of NRT-assisted smoking abstinence with γ-tocopherol (γ-T), a vitamin E form with antioxidant and anti-inflammatory activities, on improvements in VEF. In a randomized, double-blind, placebo-controlled study, healthy smokers (25 ± 1 y old; mean ± SEM) received NRT and abstained from smoking for 24 h with placebo (n = 12) or oral administration of γ-T-rich mixture of tocopherols (γ-TmT; n = 11) that provided 500 mg γ-T. Brachial artery flow-mediated dilation (FMD), and biomarkers of nitric oxide metabolism, antioxidant status, inflammation, and lipid peroxidation [8-iso-prostaglandin F2α stereoisomers (8-iso-15(R)-PGF2α and 8-iso-15(S)-PGF2α)] were measured prior to and after 24 h of smoking abstinence. Smoking abstinence with NRT regardless of γ-TmT similarly decreased urinary naphthol (P < 0.05) without affecting plasma cotinine. γ-TmT increased plasma γ-T by 4-times and the urinary metabolite of γ-T, γ-carboxyethyl-chromanol, by three times. Smoking abstinence with γ-TmT, but not smoking abstinence alone, increased FMD without affecting plasma nitrate/nitrite or the ratio of asymmetric dimethylarginine/arginine. Urinary 8-iso-15(S)-PGF2α decreased only in those receiving γ-TmT and was inversely correlated to FMD (R = -0.43, P < 0.05). Circulating markers of inflammation were unaffected by smoking abstinence or γ-TmT. Short-term NRT-assisted smoking abstinence with γ-TmT, but not NRT-assisted smoking abstinence alone, improved VEF by decreasing 8-iso-15(S)-PGF2α, a vasoconstrictor that was otherwise unaffected by NRT-assisted smoking abstinence.

Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Objective: Endocan, a dermatan sulphate proteoglycan produced by endothelial cells, is considered a biomarker for endothelial cell activation/dysfunction. Preeclampsia is characterized by systemic vascular inflammation, and endothelial cell activation/dysfunction. Therefore, the objectives of this study were to determine whether: (1) plasma endocan concentrations in preeclampsia differ from those in uncomplicated pregnancies; (2) changes in plasma endocan concentration relate to the severity of preeclampsia, and whether these changes are specific or observed in other obstetrical syndromes such as small-for-gestational age (SGA), fetal death (FD), preterm labor (PTL) or preterm prelabor rupture of membranes (PROM); (3) a correlation exists between plasma concentration of endocan and angiogenic (placental growth factor or PlGF)/anti-angiogenic factors (soluble vascular endothelial growth factor receptor or sVEGFR-1, and soluble endoglin or sEng) among pregnancies complicated by preeclampsia; and (4) plasma endocan concentrations in patients with preeclampsia and acute pyelonephritis (both conditions in which there is endothelial cell activation) differ.

Method: This cross-sectional study included the following groups: (1) uncomplicated pregnancy (n = 130); (2) preeclampsia (n = 102); (3) pregnant women without preeclampsia who delivered an SGA neonate (n = 51); (4) FD (n = 49); (5) acute pyelonephritis (AP; n = 35); (6) spontaneous PTL (n = 75); and (7) preterm PROM (n = 64). Plasma endocan concentrations were determined in all groups, and PIGF, sEng and VEGFR-1 plasma concentrations were measured by ELISA in the preeclampsia group.

Results: (1) Women with preeclampsia had a significantly higher median plasma endocan concentration than those with uncomplicated pregnancies (p = 0.004); (2) among women with preeclampsia, the median plasma endocan concentration did not differ significantly according to disease severity (p = 0.1), abnormal uterine artery Doppler velocimetry (p = 0.7) or whether diagnosis was made before or after 34 weeks gestational age (p = 0.3); (3) plasma endocan concentration in women with preeclampsia correlated positively with plasma anti-angiogenic factor concentrations [sVEGFR-1: Spearman rho 0.34, p = 0.001 and sEng: Spearman rho 0.30, p = 0.003]; (4) pregnancies complicated by acute pyelonephritis with bacteremia had a lower median plasma endocan concentration than pregnancies complicated by acute pyelonephritis without bacteremia (p = 0.004), as well as uncomplicated pregnancies (p = 0.001); and (5) there was no significant difference in the median plasma endocan concentration between uncomplicated pregnancies and those complicated by FD, delivery of an SGA neonate, PTL or preterm PROM (other members of the “great obstetrical syndromes”; each p > 0.05).

Conclusion: Median maternal plasma endocan concentrations were higher preeclampsia and lower in acute pyelonephritis with bacteremia than in uncomplicated pregnancy. No significant difference was observed in the median plasma endocan concentration between other great obstetrical syndromes and uncomplicated pregnancies. The difference in the direction of change of endocan in preeclampsia and acute pyelonephritis with bacteremia may be consistent with the view that both disease entities differ in pathogenic mechanisms, despite their associations with systemic vascular inflammation and endothelial cell activation/dysfunction.

Potentially spurious correlations between arterial size, flow-mediated dilation, and shear rate

The use of indices formed from the ratio of 2 variables often generates spurious correlations with other variables that are mathematically coupled. In this context, we examined the correlations between percent flow-mediated dilation, baseline diameter, and shear rate. In a sample of 315 participants, with and without substantial vascular risk factors, the observed correlation coefficients between the variables were of a similar magnitude to those reported in the literature. We then applied a Monte Carlo procedure based on random permutations to remove any physical or physiological explanation for these correlations. We found that the median residual correlation coefficients were comparable with those observed in our original sample. When the confounding influence of artery size was adjusted for, the mean difference in percent flow-mediated dilation between high-risk and low-risk samples was halved. These findings indicate that the widely reported correlations between flow-mediated dilation, basal artery diameter, and shear rate have a substantial spurious component. This is because percent flow-mediated dilation and shear rate are mathematically coupled to artery size.

Smoking and Cardiovascular Disease

Smoking represents one of the most important preventable risk factors for the development of atherosclerosis. The present review aims at providing a comprehensive summary of published data from clinical and animal studies, as well as results of basic research on the proatherogenic effect of smoking. Extensive search and review of literature revealed a vast amount of data on the influence of cigarette smoke and its constituents on early atherogenesis, particularly on endothelial cells. Vascular dysfunction induced by smoking is initiated by reduced nitric oxide (NO) bioavailability and further by the increased expression of adhesion molecules and subsequent endothelial dysfunction. Smoking-induced increased adherence of platelets and macrophages provokes the development of a procoagulant and inflammatory environment. After transendothelial migration and activation, macrophages take up oxidized lipoproteins arising from oxidative modifications and transdifferentiate into foam cells. In addition to direct physical damage to endothelial cells, smoking induces tissue remodeling, and prothrombotic processes together with activation of systemic inflammatory signals, all of which contribute to atherogenic vessel wall changes. There are still great gaps in our knowledge about the effects of smoking on cardiovascular disease. However, we know that smoking cessation is the most effective measure for reversing damage that has already occurred and preventing fatal cardiovascular outcomes.