Cigarette smoking and progression of atherosclerosis: The Atherosclerosis Risk in Communities (ARIC) Study

State of the Heart: An Overview of the Disease Burden of Cardiovascular Disease from an Epidemiologic Perspective

Cardiovascular diseases are prevalent worldwide and have significant impact on morbidity, mortality, and overall health care costs. Common risk factors include obesity, hypertension, hyperlipidemia, diabetes mellitus, chronic kidney disease, and smoking. Both modifiable and nonmodifiable risks should be accounted for when evaluating and managing patients with cardiovascular diseases. The complex nature of cardiovascular disease is not fully understood. Therefore, primary care physicians must balance what is known, what is suspected, and each patient's individual preferences to create an optimal treatment plan.

Circulating levels of P-selectin and E-selectin relate to cardiovascular magnetic resonance-derived aortic characteristics in young adults from the general population, a cross-sectional study

BACKGROUND

Although endothelial cell adhesion molecules (CAMs) are postulated to play a key role in early atherosclerosis, studies on endothelial CAMs are mainly pertained to middle-aged populations and populations with an unfavourable cardiovascular risk burden. Therefore, this study evaluated whether circulating endothelial CAMs are related to cardiovascular magnetic resonance imaging (CMR) derived indicators of arterial wall alterations in a random sample of young adults from the general population.

METHODS

This cross-sectional study is part of the general-population-based Atherosclerosis-Monitoring-and-Biomarker-measurements-In-The-YOuNg (AMBITYON) cohort study. In 131 adults (age: 25-35 years), demography, anthropometry and a lipid spectrum was acquired. Thoracic aortic wall area, wall thickness and pulse wave velocity (PWV) were measured using a 3 T CMR-system. From stored blood samples, four CAMs (E-selectin, P-selectin, vascular CAM-1 and intercellular CAM-1) were measured using dedicated methods. Linear mixed-effects regression analysis was used to evaluate the relation of these CAMs with the selected aortic characteristics.

RESULTS

Of the studied endothelial CAMs, P-selectin related to natural logarithm transformed aortic wall thickness (β = 0.18 mm/(μg/ml), [95% confidence interval: 0.04, 0.31], p = 0.01) whereas E-selectin related to natural logarithm transformed aortic PWV (β = 3.01 (m/s)/(μg/ml), [95% confidence interval: 0.08, 5.95], p = 0.04). Of note, VCAM-1 and ICAM-1 did not relate to the selected aortic characteristics.

CONCLUSIONS

In young adults from the general population, circulating P-selectin and E-selectin levels appear positively related to CMR-derived aortic wall thickness and PWV, possibly pointing towards atherogenic inflammatory arterial wall alterations inflicted by these CAMs already in young adulthood.

TRIAL REGISTRATION

Netherlands National Trial Register (NTR): NTR4742 , Registered 18 August 2014, retrospectively registered.

A critical role for ABC transporters in persistent lung inflammation in the development of emphysema after smoke exposure

Macrophage infiltration is common to both emphysema and atherosclerosis, and cigarette smoke down-regulates the macrophage cholesterol efflux transporter ATP binding cassette (ABC)A1. This decreased cholesterol efflux results in lipid-laden macrophages. We hypothesize that cigarette smoke adversely affects cholesterol transport via an ABCA1-dependent mechanism in macrophages, enhancing TLR4/myeloid differentiation primary response gene 88 (Myd88) signaling and resulting in matrix metalloproteinase (MMP) up-regulation and exacerbation of pulmonary inflammation. ABCA1 is significantly down-regulated in the lung upon smoke exposure conditions. Macrophages exposed to cigarette smoke in vivo and in vitro exhibit impaired cholesterol efflux correlating with significantly decreased ABCA1 expression, up-regulation of the TLR4/Myd88 pathway, and downstream MMP-9 and MMP-13 expression. Treatment with liver X receptor (LXR) agonist restores ABCA1 expression after short-term smoke exposure and attenuates the inflammatory response; after long-term smoke exposure, there is also attenuated physiologic and morphologic changes of emphysema. In vitro, treatment with LXR agonist decreases macrophage inflammatory activation in wild-type but not ABCA1 knockout mice, suggesting an ABCA1-dependent mechanism of action. These studies demonstrate an important association between cigarette smoke exposure and cholesterol-mediated pathways in the macrophage inflammatory response. Modulation of these pathways through manipulation of ABCA1 activity effectively blocks cigarette smoke-induced inflammation and provides a potential novel therapeutic approach for the treatment of chronic obstructive pulmonary disease.-Sonett, J., Goldklang, M., Sklepkiewicz, P., Gerber, A., Trischler, J., Zelonina, T., Westerterp, M., Lemaître, V., Okada, V., D'Armiento, J. A critical role for ABC transporters in persistent lung inflammation in the development of emphysema after smoke exposure.

Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells

BACKGROUND

Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke.

METHODS

Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation.

RESULTS

We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation.

CONCLUSIONS

Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development.

Conventional and electronic cigarettes dysregulate the expression of iron transporters and detoxifying enzymes at the brain vascular endothelium: In vivo evidence of a gender-specific cellular response to chronic cigarette smoke exposure

It is well established that tobacco smoking is associated with vascular endothelial dysfunction in a causative and dose dependent manner primarily related to the tobacco smoke (TS) content of reactive oxygen species (ROS), nicotine, and oxidative stress (OS) -driven inflammation. Preclinical studies have also shown that nicotine (the principal e-liquid's ingredient used in e-cigarettes (e-Cigs) can also cause OS, exacerbation of cerebral ischemia and secondary brain injury. Likewise, chronic e-Cig vaping could be prodromal to vascular endothelial dysfunctions. Herein, we provide direct evidence that similarly to TS, e-Cig promotes mitochondrial depolarization in primary brain vascular endothelial cells as well as the vascular endothelial cell line bEnd3. In addition, both TS and e-Cig exposure upregulated the transmembrane iron exporter Slc40a1 (crucial to maintain cellular iron and redox homeostasis) and that of porphyrin importer Abcb6 (linked to accelerated atherosclerosis). We then investigated in vivo whether gender plays a role in how chronic TS affect vascular endothelial functions. Our results clearly show chronic TS exposure differentially impacts the expression levels of Phase-II enzymes as well as the iron transporters previously investigated in vitro. Although the physiological implications of the gender-specific differential responses to TS are not fully clear, they do demonstrate that gender is a risk factor that needs to be investigated when assessing the potential impact of chronic smoking and perhaps e-Cig vaping.

MicroRNAs as Potential Mediators for Cigarette Smoking Induced Atherosclerosis

Smoking increases the risk of atherosclerosis-related events, such as myocardial infarction and ischemic stroke. Recent studies have examined the expression levels of altered microRNAs (miRNAs) in various diseases. The profiles of tissue miRNAs can be potentially used in diagnosis or prognosis. However, there are limited studies on miRNAs following exposure to cigarette smoke (CS). The present study was designed to dissect the effects and cellular/molecular mechanisms of CS-induced atherosclerogenesis. Apolipoprotein E knockout (ApoE KO) mice were exposed to CS for five days a week for two months at low (two puffs/min for 40 min/day) or high dose (two puffs/min for 120 min/day). We measured the area of atherosclerotic plaques in the aorta, representing the expression of miRNAs after the exposure period. Two-month exposure to the high dose of CS significantly increased the plaque area in aortic arch, and significantly upregulated the expression of atherosclerotic markers (VCAM-1, ICAM-1, MCP1, p22phox, and gp91phox). Exposure to the high dose of CS also significantly upregulated the miRNA-155 level in the aortic tissues of ApoE KO mice. Moreover, the expression level of miR-126 tended to be downregulated and that of miR-21 tended to be upregulated in ApoE KO mice exposed to the high dose of CS, albeit statistically insignificant. The results suggest that CS induces atherosclerosis through increased vascular inflammation and NADPH oxidase expression and also emphasize the importance of miRNAs in the pathogenesis of CS-induced atherosclerosis. Our findings provide evidence for miRNAs as potential mediators of inflammation and atherosclerosis induced by CS.

Carotid Atherosclerosis Detected by Ultrasonography: A National Cross-Sectional Study

Background

Carotid atherosclerosis (CA) is a reflector of generalized atherosclerosis that is associated with systemic vascular disease. Data are limited on the epidemiology of carotid lesions in a large, nationally representative population sample. We aimed to evaluate the prevalence of CA detected by carotid ultrasonography and related risk factors based on a national survey in China.

Methods and Results

A total of 107 095 residents aged ≥40 years from the China National Stroke Prevention Project underwent carotid ultrasound examination. Participants with carotid endarterectomy or carotid stenting and those with stroke or coronary heart disease were excluded. Data from 84 880 participants were included in the analysis. CA was defined as increased intima–media thickness (IMT) ≥1 mm or presence of plaques. Of the 84 880 participants, 46.4% were men, and the mean age was 60.7±10.3 years. The standardized prevalence of CA was 36.2% overall, increased with age, and was higher in men than in women. Prevalence of CA was higher among participants living in rural areas than in urban areas. Approximately 26.5% of participants had increased IMT, and 13.9% presented plaques. There was an age‐related increase in participants with increased IMT, plaque presence, and stenosis. In multiple logistic regression analysis, older age, male sex, residence in rural areas, smoking, alcohol consumption, physical inactivity, obesity, hypertension, diabetes mellitus, and dyslipidemia were associated with CA.

Conclusions

CA was highly prevalent in a middle‐aged and older Chinese population. This result shows the potential clinical importance of focusing on primary prevention of atherosclerosis progression.

Partial Mediation by Cadmium Exposure of the Association Between Tobacco Smoking and Atherosclerotic Plaques in the Carotid Artery

Exposure to cadmium confers increased cardiovascular risk. Tobacco smoke contains cadmium, which, hypothetically, may mediate parts of the tobacco-associated risk of developing atherosclerotic plaques. Baseline data from the Swedish Malmö Diet and Cancer cohort (1991-1996) were used to test this hypothesis. Mediation analysis was used to examine associations between smoking and blood cadmium levels and the prevalence of ultrasound-assessed carotid atherosclerotic plaques. The total association with smoking status (never smokers, 2 categories of former smokers, and current smokers) was split into direct and indirect association, and the proportion mediated was estimated. The adjusted estimated plaque prevalence was approximately 27% among never smokers. We identified both a direct and an indirect pathway between smoking and carotid plaques; the indirect association, through cadmium, was observed among current smokers and former smokers who had quit smoking less than 15 years before. For current smokers, the prevalence ratio for plaque was 1.5, with 60%-65% of the association with smoking being mediated through cadmium. Recent former smokers had a prevalence ratio of 1.3, and 40%-45% was mediated through cadmium. Long-time former smokers had a prevalence ratio of 1.2, but none of the association was mediated through cadmium. In conclusion, about two-thirds of the proatherosclerotic association with smoking was mediated by cadmium.

Serum Cotinine and Hemoglobin A1c Among a National Sample of Adolescents Without Known Diabetes

Introduction

National data suggest tobacco smoke is positively associated with higher glycated hemoglobin (HbA1c) among adults. Our objective was to examine the association between serum cotinine and HbA1c among adolescents without known diabetes.

Methods

We assessed adolescents 12-19 years old (N = 11550) who participated in the 1999-2012 National Health and Nutrition Examination Survey. We applied sampling weights while performing multiple linear regression analyses.

Results

The prevalence of serum cotinine indicative of no tobacco smoke exposure (TSE, <0.05 ng/mL) was 43.2%, passive TSE (0.05-2.99 ng/mL) was 38.9%, and active TSE (>3 ng/mL) was 17.9% in our sample. Mean (± standard error) HbA1c in participants with no TSE was 5.16% (±0.01), passive TSE was 5.16% (±0.01), and active TSE was 5.14% (±0.01). No differences in HbA1c were found between TSE groups including sex, age, race/ethnicity, education, income, and physical activity or the fully adjusted model with waist circumference. We found cotinine × sex (p = .01) and cotinine × age (p = .02) interactions. There was an association between cotinine and HbA1c for males but not females. Within males, participants with cotinine ≥3 ng/mL (5.26 ± 0.02) had higher mean HbA1c than those with cotinine 0.05-2.99 ng/mL and <0.05 ng/mL (both 5.20 ± 0.01, p ≤ .02). The negative association between age and HbA1c was stronger for participants with cotinine ≥3 ng/mL than participants with cotinine <0.05 ng/mL.

Conclusion

No linear association was found between HbA1c and serum cotinine in adolescents overall after adjusting for potential confounders. Differences between TSE groups were found in males. Future research in adolescents should examine chronic TSE over time to examine the potential for development of type 2 diabetes.

Implications

TSE has been associated with increased risk for the development of type 2 diabetes among adults. It is unclear if this relationship holds in adolescents. We examined the association between serum cotinine and HbA1c in adolescents without known diabetes who completed the 1999-2012 National Health and Nutrition Examination Survey. Although no association was found between serum cotinine and HbA1c overall while controlling for potential confounding factors, we observed interaction effects that are indicative of TSE influencing HbA1c differentially by sex and age. Reducing TSE in adolescents should be a priority for future tobacco control efforts.

Enhancing the Infrastructure of the Atherosclerosis Risk in Communities (ARIC) Study for Cancer Epidemiology Research: ARIC Cancer

Background: We describe the expansion of the Atherosclerosis Risk in Communities (ARIC) Study into a cancer cohort. In 1987 to 1989, ARIC recruited 15,792 participants 45 to 64 years old to be sex (55% female), race (27% black), and geographically diverse. ARIC has exceptional data collected during 6 clinical visits and calls every 6 months, repeated biospecimens, and linkage to Medicare claims data.Methods: We established a Cancer Coordinating Center to implement infrastructure activities, convened a Working Group for data use, leveraged ARIC staff and procedures, and developed protocols. We initiated a cancer-specific participant contact, added questions to existing contacts, obtained permission to collect medical records and tissue, abstracted records, linked with state cancer registries, and adjudicated cases and characterizing data.Results: Through 2012, we ascertained and characterized 4,743 incident invasive, first, and subsequent primary cancers among 4,107 participants and 1,660 cancer-related deaths. We generated a total cancer incidence and mortality analytic case file, and analytic case files for bladder, breast, colorectal, liver, lung, pancreas, and prostate cancer incidence, mortality, and case fatality. Adjudication of multiple data sources improved case records and identified cancers not identified via registries. From 2013 onward, we ascertain cases from self-report coupled with medical records. Additional cancer registry linkages are planned.Conclusions: Compared with starting a new cohort, expanding a cardiovascular cohort into ARIC Cancer was an efficient strategy. Our efforts yielded enhanced case files with 25 years of follow-up.Impact: Now that the cancer infrastructure is established, ARIC is contributing its unique features to modern cancer epidemiology research. Cancer Epidemiol Biomarkers Prev; 27(3); 295-305. ©2017 AACR.

Association of carotid atherosclerosis and stiffness with abdominal aortic aneurysm: The atherosclerosis risk in communities (ARIC) study

BACKGROUND AND AIMS

Individuals with atherosclerosis and stiffness often have increased abdominal aortic diameters, but prospective evidence linking them to the risk of abdominal aortic aneurysm (AAA) is limited.

METHODS

We prospectively examined the relationship of carotid atherosclerosis and stiffness with future risk of AAA in ARIC. At Visits 1 (1987-89) or 2 (1990-1992), we assessed carotid atherosclerosis (represented by greater carotid intima-media thickness [cIMT] or presence of atherosclerotic plaque) and lower carotid distensibility (reflected by a higher carotid Beta Index). We identified incident, clinical AAAs during follow-up through 2011 using hospital discharge codes, Medicare outpatient diagnoses, or death certificates.

RESULTS

Participants' mean age at baseline was 54.2 years (SD 5.8), 45% were male and 73% white. During a median of 22.5 years of follow-up, 542 clinical AAAs were ascertained. After multivariable adjustment, the presence of carotid atherosclerotic plaque at baseline was associated with 1.31 (95% CI: 1.10-1.57; p = 0.003) times higher risk of clinical AAA. Greater cIMT and Beta Index were also associated with clinical AAA with a dose-response across quartiles (p trend for both: 0.006; hazard ratios [95% CI] for the highest vs. lowest quartiles: 1.55 [1.13-2.11] and 1.68 [1.16-2.43], respectively). The associations of cIMT and Beta Index with AAA were independent of each other.

CONCLUSIONS

This prospective population-based study found that indices of greater carotid atherosclerosis and lower carotid distensibility are markers of increased AAA risk.

Transesophageal echocardiographic thromboembolic risk is associated with smoking status in patients with atrial fibrillation

BACKGROUND

Smoking is a risk factor for cardiovascular diseases, but it is unclear whether smoking status, including environmental tobacco smoke, increases stroke risk in patients with atrial fibrillation (AF). Abnormalities of the left atrium (LA) and aortic atherosclerosis, as detected by transesophageal echocardiography (TEE), are risk factors for stroke and thromboembolism in AF patients. We investigated the impact of smoking status on thromboembolic risk by TEE in patients with nonvalvular AF.

METHODS

In 122 patients with AF (mean age, 63 years; chronic AF 50%) who underwent TEE before catheter ablation of AF or for detection of the potential cardioembolic source, urinary concentrations of cotinine and clinical variables including smoking status and the CHA₂DS₂-VASc score were determined.

RESULTS

Severe aortic atherosclerosis and increased aortic wall thickness were more frequently detected by TEE in current smokers than in non-smokers (p<0.05), though these findings did not significantly differ between non-smokers and environmental smokers. Patients in AF rhythm during TEE, who were environmental smokers and at relatively low risk, as stratified by their CHA₂DS₂-VASc score (≤ 2), showed lower LA appendage flow velocity than those without environmental smoking (47±22 vs. 34±13 cm/sec, p<0.05).

CONCLUSIONS

TEE findings indicated that smoking status could be associated with thromboembolic risk in patients with AF.

Cigarette Smoking Triggers Colitis by IFN-γ+ CD4+ T Cells

The increased incidence of Crohn’s disease in smokers has been recently reported, suggesting a strong association of cigarette smoke (CS) with colitis. However, the mechanism of the action of CS on colitis has not yet been explored. Here, we demonstrate that CS exposure is sufficient to induce colitis in mice. Interestingly, the colitis is mainly mediated by Th1, but not Th17, responses. CD4⁺ T-cell depletion or T-bet/IFN-γ deficiency protects against the development of colitis induced by CS. Additionally, IFN-γ-producing CD4⁺ T cells play a substantial role in CS-induced colitis. The adoptive transfer (AT) of effector T cells from CS-exposed WT mice into colitis-prone mice caused these mice to develop colitis, while the AT of effector T cells from IFN-γ knock-out mice did not. These findings have implications for broadening our understanding of CS-induced pathology and for the development of novel therapeutic strategies to treat Crohn’s disease.

Association of Serum 25-hydroxyvitamin D in Carotid Intima-media Thickness: A Study from South India

Background:

Abnormal carotid intima-media thickness (IMT) is a marker of carotid atherosclerosis which is a risk factor for cerebrovascular and cardiovascular diseases. Recent studies have found an association of 25-hydroxyvitamin D deficiency with abnormal carotid IMT.

Purpose:

The purpose of the study was to investigate the association of serum 25-hydroxyvitamin D levels with carotid IMT in Indian participants.

Materials and Methods:

We prospectively recruited 300 participants at Yashoda Hospital, Hyderabad, during the study period between January 2012 and December 2014. All participants were assessed for fasting blood sugar, lipid profile, C-reactive protein (CRP), serum alkaline phosphatase, serum calcium, serum phosphorous, serum 25-hydroxyvitamin D levels, and carotid Doppler examination.

Results:

Among the 300 participants, men were 190 (63.3%) and mean age was 51.9 ± 7.7 years with a range from 35 to 64 years. On risk factors evaluation, 105 (35%) were hypertensive, 79 (26.3%) diabetics, 63 (21%) smokers, and 56 (18.6%) were alcoholics. On evaluation of biochemical parameters, 81 (27%) had dyslipidemia, 120 (40%) had elevated CRP levels, 119 (39.6%) had 25-hydroxyvitamin D deficiency, mean alkaline phosphatase was 93.9 ± 14.9 IU/L, serum calcium (mg/dL) was 9.2 ± 2.3, and serum phosphorous 4.4 ± 1.2 mg/dL. On carotid imaging, 121 (40.3%) had abnormal IMT. After multivariate analysis, 25-hydroxyvitamin D deficiency (odds ratio [OR]: 2.14; 95% confidence interval [CI]: 1.29–3.55), dyslipidemia (OR: 2.53; 95% CI: 1.46–4.40), elevated CRP (OR: 2.27; 95% CI: 1.37–3.76), smoking (OR: 2.09; 95% CI: 1.16–3.77), and diabetes (OR: 1.84; 95% CI: 1.05–3.21) were independently associated with abnormal IMT.

Conclusion:

In our study, we established 25-hydroxyvitamin D deficiency as an independently associated with abnormal IMT in Indian participants.

Current smoking is associated with extracranial carotid atherosclerotic stenosis but not with intracranial large artery disease

Background

Accumulating evidence has shown that cigarette smoking is an important risk factor for ischemic stroke. However, it is not clear about the potential mechanisms through which cigarette smoking affects stroke risk. In the study, we aimed to investigate the relationship between cigarette smoking and the occurrence of extracranial (ECAS) and intracranial atherosclerotic stenosis (ICAS).

Methods

We analyzed patients enrolled in the Chinese intracranial atherosclerosis (CICAS), which was a prospective, multicenter, hospital-based cohort study. Smoking status was classified into never, former and current smoking. For those patients with current smoking, data on time duration (year) and extent (the number of cigarette smoked per day) was recorded and pack year of smoking was calculated. ICAS was evaluated with 3-dimentional time-of-flight MRA and ECAS was evaluated with cervical ultrasonography or contrast-enhanced MRA. Multivariable Logistic regression was performed to identify the association between smoking status and the occurrence of ECAS and ICAS.

Results

A total of 2656 patients (92.7%) of acute ischemic stroke and 208 (7.3%) of transient ischemic attack were analyzed. The mean age was 61.9 ± 11.2 and 67.8% were male. There were 141 (4.9%) patients had only ECAS, 1074 (37.5%) had only ICAS, and 261 (9.1%) had both ECAS and ICAS. Current smoking was significantly associated with the occurrence of ECAS (adjusted OR = 1.47, 95% CI = 1.09–1.99, P < 0.01). In addition, with 1 year of smoking increment, the risk of ECAS increased by 1.1% (adjusted OR = 1.011; 95% CI = 1.003–1.019; P = 0.005); with one cigarette smoked per day increment, the risk of ECAS increased by 1.0% (adjusted OR = 1.010; 95% CI = 1.001–1.020; P = 0.03); and with one pack year of smoking increment, the risk of ECAS increased by 0.7% (adjusted OR = 1.007; 95% CI = 1.002–1.012; P < 0.01). However, no significant association was found between smoking status and the occurrence of ICAS.

Conclusion

A dose–response relationship was identified between cigarette smoking and the occurrence of ECAS, but not ICAS. Further studies on molecular mechanisms were warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-017-0873-7) contains supplementary material, which is available to authorized users.

Offsetting the impact of smoking and e-cigarette vaping on the cerebrovascular system and stroke injury: Is Metformin a viable countermeasure?

Recently published in vitro and in vivo findings strongly suggest that BBB impairment and increased risk for stroke by tobacco smoke (TS) closely resemble that of type-2 diabetes (2DM) and develop largely in response to common key modulators such oxidative stress (OS), inflammation and alterations of the endogenous antioxidative response system (ARE) regulated by the nuclear factor erythroid 2-related factor (Nrf2). Preclinical studies have also shown that nicotine (the principal e-liquid's ingredient used in e-cigarettes) can also cause OS, exacerbation of cerebral ischemia and secondary brain injury. Herein we provide evidence that likewise to TS, chronic e-Cigarette (e-Cig) vaping can be prodromal to the loss of blood-brain barrier (BBB) integrity and vascular inflammation as well as act as a promoting factor for the onset of stroke and worsening of post-ischemic brain injury. In addition, recent reports have shown that Metformin (MF) treatment before and after ischemic injury reduces stress and inhibits inflammatory responses. Recent published data by our group revealead that MF promotes the activation of counteractive mechanisms mediated by the activation of Nrf2 which drastically reduce TS toxicity at the brain and cerebrovascular levels and protect BBB integrity. In this study we provide additional in vivo evidence showing that MF can effectively reduce the oxidative and inflammatory risk for stroke and attenuate post-ischemic brain injury promoted by TS and e-Cig vaping. Our data also suggest that MF administration could be extended as prophylactic care during the time window required for the renormalization of the risk levels of stroke following smoking cessation thus further studies in that direction are warrated.

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Chronic cigarette and e-cigarette exposure downregulate throbomodulin and Nrf2.

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Chronic CS and e-Cig exposure worsen stroke outcome in mice undergoing tMCAO.

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Metformin ameliorate stroke outcomes in CS and e-Cig exposed mice undergoing tMCAO.

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MF protective effect correlates with renormalization of Nrf2 levels.

Diabetes status modifies the association between carotid intima-media thickness and incident heart failure: The Atherosclerosis Risk in Communities study

AIMS

Increasing carotid intima-media thickness (CIMT) is associated with incident heart failure (HF). We investigated whether this association differs by diabetes status.

METHODS

We characterized 13,590 Atherosclerosis Risk in Communities Study participants free of baseline HF into normal fasting glucose (NFG, glucose <100mg/dl), impaired fasting glucose (IFG, glucose 100-125mg/dl), and type 2 diabetes (T2D, glucose ≥126mg/dl, self-report, or use of diabetes drugs). CIMT was assessed by B-mode ultrasound. Incident HF was defined using ICD-9 or 10 codes from hospitalizations and death certificates. Cox regression was used to estimate hazard ratios (HR) for incident HF, adjusting for age, sex, race, education, hypertension medication, blood pressure, BMI, waist circumference, HDL, LDL, triglycerides, lipid-lowering medication, smoking, alcohol, serum creatinine, and interim CHD.

RESULTS

T2D participants had higher mean CIMT (0.79±0.20mm), compared to IFG (0.75±0.19mm) and NFG (0.70±0.17mm) (p<0.0001). Over 20.6years of median follow-up, 15% developed HF. Rates of HF (per 1000 person-years) were substantially higher for those with T2D (24.7), compared to IFG (7.7) and NFG (5.8). In adjusted analyses, the CIMT-HF association was significantly modified by diabetes status (P_interaction=0.015): for NFG (HR per SD increase in CIMT: 1.27; 95%CI: 1.20-1.34), IFG (HR 1.18; 95%CI: 1.11-1.25) and T2D (HR 1.12; 95%CI: 1.05-1.21).

CONCLUSIONS

CIMT is associated with increased risk of HF, particularly among persons without diabetes. Due to a high absolute risk of HF among adults with T2D, CIMT may be a less reliable predictor.

[Effects of chronic tabacco smoking on the cerebral blood flow]

AIM

To study an effect of chronic smoking on cerebral hemodynamics and cerebrovascular reactivity in different segments of the arterial system of the brain in men.

MATERIAL AND METHODS

Male patients enrolled in the study were divided into two groups: controls (n=11) and smokers (n=24) with index 30.7 pack-year smoking history. Haemorheological parameters: viscosity of blood, aggregation of erythrocytes, hematocrit, fibrinogen were evaluated in both groups. Using carotid duplex ultrasound (MyLab 50 Esaote, Italy), intima-media thickness (IMT) of common carotid arteries (CCA) was measured. Parameters of cerebral hemodynamics were evaluated using transcranial Doppler ultrasound (Nicolet Companion Biomedikal, USA). Tests of the cerebrovascular reactivity were used to study arteries of three levels: common carotid arteries, middle cerebral arteries (MCA) and pial arteries.

RESULTS

An increase in erythrocytes, hemoglobin, hematocrit, viscosity of blood, aggregation of erythrocytes and fibrinogen was found in the group of smokers compared to the control group. There were an increase in IMT of CCA by more than 50% and a decrease in the mean flow velocity in CCA in smokers. Also smoking decreased MCA mean flow velocity, but this decrease was 2-3 times smaller than in the common carotid arteries. Vasoconstrictor reactions prevailed in MCA, as indicated by the increase in the peripheral vascular resistance index. An increase in vasospastic reactions in pial arteries in smokers was discovered. At the same time, the vasodilatation reaction was maintained or not significantly reduced in pial arteries.

CONCLUSION

Chronic smoking is one of the significant factors causing changes in haemorheological parameters, damage of vascular wall, initiation of atherogenesis and disturbance of cerebral hemodynamics. The study of velocity characteristics and peripheral vascular resistance indices in the group of smokers revealed different reactions of different segments of the brain arterial system.

Influence of Epidemiologic and Patient Behavior–Related Predictors on Amputation Rates in Diabetic Patients

Amputation of patients with diabetic foot is a major issue worldwide, particularly from a medical and economic standpoint. This meta-analysis aimed to identify significant risk factors of high amputation rate among epidemiologic and patient behavior–related predictors in diabetic patients. A systematic literature review and meta-analysis were performed using MEDLINE, EMBASE, and Cochrane databases. Seven variables were extracted from the included studies and evaluated based on amputation rate. The Newcastle-Ottawa scale was used to assess the quality of the studies. The search strategy identified 101 publications. After screening, 33 articles were selected for review. Male sex and smoking were identified as significant risk factors of high amputation rate of diabetic foot. Although further investigation of long-term and randomized controlled studies is needed, we identified 2 variables as significant risk factors for high amputation rate in diabetic patients in this meta-analysis.

Association between carotid atherosclerosis and different subtypes of hypertension in adult populations: A multiethnic study in Xinjiang, China

Background

Ethnic differences in non-invasive measurements of carotid atherosclerosis are being increasingly reported, but the association between carotid atherosclerosis and different subtypes of hypertension in adult populations is not fully understood in different ethnicities. We aimed to investigate the association of carotid atherosclerosis with different subtypes of hypertension in different ethnicities in Xinjiang, a northwestern province in China.

Methods

A total of 14,618 participants (5,757 Hans, 4,767 Uygurs, and 4,094 Kazakhs) from 26 villages of seven cities in Xinjiang were randomly selected from the Cardiovascular Risk Survey conducted during 2007 and 2010. A standard questionnaire, a physical examination and biochemical tests were employed.

Results

The mean common carotid intima-media thickness (CIMT) for the 14,618 participants was 0.86±0.003 mm. The CIMT gradually increased with age. Men (0.92±0.005 mm) had a higher CIMT than women (0.81±0.004 mm). The Uygur participants (0.82±0.006 mm) had a lower CIMT than the Han (0.88±0.005 mm) and Kazakh participants (0.88±0.005 mm). The overall prevalences of carotid intimal thickening and carotid plaques were 12.4% and 9.7%, respectively. The prevalence of CIMT varied for the different subtypes of hypertension. Multivariate logistic regression analysis showed different risk factors for abnormal CIMT in different ethnicities. The associations between abnormal CIMT and the different subtypes of hypertension within different ethnic backgrounds were also different. The risk factors for abnormal CIMT included systolic-diastolic hypertension (SDH) in Han participants (OR: 1.323, 95% CI: 1.100–1.590), SDH (OR: 1.426, 95% CI: 1.160–1.753) and isolated-systolic hypertension (ISH) (OR: 1.844, 95% CI: 1.470–2.313) in Uygur participants, and isolated-diastolic hypertension (IDH) (OR: 1.536, 95% CI: 1.170–2.016) in Kazakh participants.

Conclusion

There was an ethnic difference in the prevalence of abnormal CIMT in Xinjiang, a northwestern province in China. The associations between abnormal CIMT and the subtypes of hypertension varied among the different ethnic groups. Among the studied populations, Han participants with SDH, Uygur participants with SDH and ISH, and Kazakh with IDH were more likely to suffer carotid atherosclerosis than those with other subtypes of hypertension. Participants with different ethnic backgrounds had different sets of risk factors for abnormal CIMT.

Association between HbA1c and carotid atherosclerosis among elderly Koreans with normal fasting glucose

Aim

We examined whether glycated haemoglobin (HbA1c) is associated to carotid atherosclerosis in an elderly Korean population with normal fasting glucose.

Methods

Using data from the Korean Urban Rural Elderly study, we conducted a cross-sectional analysis of 1,133 participants (335 men and 798 women) with a mean age of 71.8 years. All participants had fasting blood glucose less than 100mg/dL (5.6 mmol/L) and HbA1c level below 6.5% (48 mmol/mol). They were also free from a history of cardiovascular disease, known type 2 diabetes mellitus or use of anti-diabetes medications. Carotid atherosclerosis was assessed by intima-media thickness (IMT) using ultrasonography. The association between HbA1c and carotid IMT was investigated using multivariable linear regression analysis.

Results

HbA1c levels were independently and positively associated with carotid IMT (β = 0.020, p = 0.045) after adjusting for sex, age, body mass index, systolic blood pressure, diastolic blood pressure, triglyceride, LDL cholesterol, smoking and alcohol intake. However, fasting insulin and glucose levels were not associated with carotid IMT.

Conclusion

HbA1c levels were positively associated with carotid atherosclerosis, as assessed by carotid IMT, in an elderly population with normoglycemia. Our study suggested that higher HbA1c level is an effective and informative marker of carotid atherosclerosis in an elderly population.

Sex-Related Cochlear Impairment in Cigarette Smokers

Background

A number of studies have documented the influence of cigarette smoking on hearing. However, the association between sex and hearing impairment in smokers as measured by otoacoustic emissions (OAEs) has not been clearly established. The aim of this study was to analyze sex-specific effects of smoking on hearing via conventional and ultra-high-frequency pure tone audiometry (PTA), and OAEs, specifically spontaneous OAEs, click-evoked OAEs, and distortion-product OAEs.

Material/Methods

The study included 84 healthy volunteers aged 25–45 years (mean 34), among them 46 women (25 non-smokers and 21 smokers) and 38 men (16 non-smokers and 22 smokers). The protocol of the study included otoscopic examination, tympanometry, low-, moderate-, and ultra-high-frequency PTA, evaluation of spontaneous click-evoked (CEAOEs) and distortion-product otoacoustic emissions (DPOAEs), assessment of the DP-grams for 2f₁-f₂ (f₁ from 977 to5 164 Hz), and input/output function at L₂ primary tone level of 40–70 dB SPL.

Results

Smokers and non-smokers did not differ significantly in terms of their hearing thresholds assessed with tone audiometry. Male smokers presented with significantly lower levels of CEAOEs and DPOAEs than both male non-smokers and female smokers.

Conclusions

Smoking does not modulate a hearing threshold determined with PTA at low, moderate, and ultra-high frequencies, but causes a significant decrease in OAE levels. This effect was observed only in males, which implies that they are more susceptible to smoking-induced hearing impairment. Sex-specific differences in otoacoustic emissions level may reflect influences of genetic, hormonal, behavioral, and/or environmental factors.

Secondhand Smoke Exposure and Subclinical Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Few studies have evaluated the association between secondhand smoke (SHS) and subclinical cardiovascular disease among ethnically diverse populations. This study assesses the impact of SHS on inflammation and atherosclerosis (carotid intima-media thickness, coronary artery calcification, and peripheral arterial disease).

METHODS AND RESULTS

We examined 5032 nonsmoking adults aged 45 to 84 years without prior cardiovascular disease participating in the Multi-Ethnic Study of Atherosclerosis (MESA) from 2000 to 2002. SHS exposure was determined by self-report, and urinary cotinine was measured in a representative subset (n=2893). The multi-adjusted geometric mean ratios (95% CIs) for high-sensitivity C-reactive protein and interleukin-6 comparing 407 participants with SHS ≥12 h/wk versus 3035 unexposed participants were 1.13 (1.02-1.26) and 1.04 (0.98-1.11), respectively. The multi-adjusted geometric mean ratio for carotid intima-media thickness was 1.02 (0.97-1.07). Fibrinogen and coronary artery calcification were not associated with SHS. The prevalence of peripheral arterial disease (ankle-brachial index ≤0.9 or ≥1.4) was associated with detectable urinary cotinine (odds ratio, 2.10; 95% CI, 1.09-4.04) but not with self-reported SHS. Urinary cotinine was not associated with inflammation or carotid intima-media thickness.

CONCLUSIONS

Despite limited exposure assessment, this study supports the association of SHS exposure with inflammation and peripheral arterial disease.

Smoking Behaviors and Arterial Stiffness Measured by Pulse Wave Velocity in Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Though smoking is strongly associated with peripheral vascular disease and arteriosclerosis, smoking's association with arterial stiffness has been inconsistent and mostly limited to a single arterial segment. We examined the relationship between smoking behaviors with arterial stiffness in multiple arterial segments among community dwelling older adults.

METHODS

The cross-sectional relationship between smoking behavior with carotid-femoral (cfPWV) and femoral-ankle pulse wave velocity (faPWV) was examined in 5,002 men and women, separately, of the Atherosclerosis Risk in Communities (ARIC) cohort study. Brachial-ankle PWV was also assessed and presented in Supplementary Material. Heckman selection models were used to control for selective attrition and death in the ARIC cohort.

RESULTS

In women, faPWV was lower in current smokers compared to never smokers (-66.0cm/s; 95% confidence interval (95% CI): -94.6, -37.4), and was 1.0cm/s lower (95% CI: -1.8, -0.2) for every additional year a woman smoked, after adjustment for confounders. Among women, cfPWV was not associated with smoking status or cigarette pack-years. Additionally, no associations of smoking status and cigarette pack-years with PWV were observed among men. Years since smoking cessation was not associated with PWV in either gender.

CONCLUSION

Both smoking status and cumulative smoking exposure were associated with lower peripheral arterial stiffness among women, but not among men. We did not observe an association between central arterial stiffness and smoking status in either gender. The profound and well-documented adverse effects of cigarette smoking on the vasculature may not include a sustained stiffening of the arteries measured at older age.

Association of Secondhand Smoke With Stroke Outcomes

Background and Purpose—

Approximately half of never smokers are exposed to secondhand smoke (SHS). Smoking is a well-established stroke risk factor, yet associations between SHS, stroke, and poststroke mortality remain uncertain. We aimed to determine the prevalence of exposure to SHS among those with and without stroke and its impact on mortality.

Methods—

Data were obtained from the US National Health and Nutrition Examination Surveys for 27 836 never smokers with/without self-reported stroke aged ≥18 years, sampled from 1988 to 1994 and 1999 to 2012, with linked mortality through 2010. Household exposure to SHS was determined by self-report; exposure severity was quantified by serum cotinine level. Independent relationships between SHS and all-cause mortality were assessed using Cox regression models, before and after adjusting for sociodemographics and comorbidities.

Results—

From 1988 to 1994 to 1999 to 2012, age-adjusted prevalence of exposure to SHS declined from 11.5% to 6.6% among survivors of stroke ( P =0.08), and 14.6% to 5.9% among persons without stroke ( P <0.01). Factors associated with high exposure to SHS were male sex, black race, ≤12th-grade education, poverty income ratio ≤200%, high alcohol intake, and history of myocardial infarction (all P <0.05). High exposure to SHS was associated with higher odds of previous stroke (odds ratio, 1.46; P =0.026). There was a dose-dependent relationship between exposure to SHS and all-cause mortality after stroke.

Conclusions—

Individuals with previous stroke have 50% greater odds to have been exposed to SHS; SHS is associated with a 2-fold increase in mortality after stroke. This study highlights the importance of obtaining exposure to SHS history and counseling patients and their families on the potential impact of SHS on poststroke outcomes.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Effect of Smoking on Infarct Size and Major Adverse Cardiac Events in Patients With Large Anterior ST-Elevation Myocardial Infarction (from the INFUSE-AMI Trial)

We sought to investigate the effect of smoking on infarct size (IS) and major adverse cardiac events (MACE) in patients with large anterior ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Participants from the Intracoronary Abciximab and Aspiration Thrombectomy in Patients with Large Anterior Myocardial Infarction study were categorized according to smoking status (current or previous smoking vs no history of smoking). The primary imaging outcome was cardiac magnetic resonance imaging-assessed IS of left ventricular mass (%) at 30 days. The primary clinical outcome was the rate of MACE at 30 days and 1 year, defined as the composite of death, reinfarction, new-onset heart failure, or rehospitalization. Of 447 patients enrolled in Intracoronary Abciximab and Aspiration Thrombectomy in Patients with Large Anterior Myocardial Infarction, 271 (60.6%) were current or past smokers. Compared with nonsmokers, smokers were almost 10 years younger and had a lower prevalence of clinical co-morbidities. Smokers had better procedural success and angiographic reperfusion compared with nonsmokers. At 30 days, there were no differences between smokers and nonsmokers in median IS (16.8% vs 17.4%, p = 0.67) or metrics of left ventricular function. By multivariable linear regression analysis, smoking was not significantly associated with IS at 30 days (beta coefficient: 0.83, p = 0.42). At 1 year, smokers had lower crude rates of MACE (7.6% vs 15%, p = 0.01). After multivariable adjustment, there were no significant differences in 1-year MACE between smokers and nonsmokers (adjusted hazard ratio 0.73, 95% CI 0.40 to 1.33, p = 0.30). In conclusion, smoking history had no significant effect on IS at 30 days. Although current or previous smokers had lower rates of 1-year MACE than those with no history of smoking, adjustment for baseline characteristics rendered this association nonsignificant. These findings support the hypothesis that the smoker's paradox is largely attributable to differences in demographic and clinical baseline risk, rather than differences in IS after primary percutaneous coronary intervention.

A Japanese cross-sectional multicentre study of biomarkers associated with cardiovascular disease in smokers and non-smokers

We performed a cross-sectional, multicentre study in Japan to detect the differences in biomarkers of exposure and cardiovascular biomarkers between smokers and non-smokers. Several clinically relevant cardiovascular biomarkers differed significantly between smokers and non-smokers, including lipid metabolism (high-density lipoprotein cholesterol concentrations – lower in smokers), inflammation (fibrinogen and white blood cell count – both higher in smokers), oxidative stress (8-epi-prostaglandin F_2α – higher in smokers) and platelet activation (11-dehydro-thromboxane B₂ – higher in smokers) (p ≤ 0.0001). These results provide further evidence showing that cardiovascular biomarkers can discriminate smokers from non-smokers, and could be used to evaluate the risks associated with tobacco products.

Cardiorespiratory Fitness and Atherosclerosis: Recent Data and Future Directions

Historically, the relationship between exercise and the cardiovascular system was viewed as unidirectional, with a disease resulting in exercise limitation and hazard. This article reviews and explores the bidirectional nature, delineating the effects, generally positive, on the cardiovascular system and atherosclerosis. Exercise augments eNOS, affects redox potential, and favorably affects mediators of atherosclerosis including lipids, glucose homeostasis, and inflammation. There are direct effects on the vasculature as well as indirect benefits related to exercise-induced changes in body composition and skeletal muscle. Application of aerobic exercise to specific populations is described, with the hope that this knowledge will move the science forward and improve individual patient outcome.

Secondary prevention of coronary artery disease in patients undergoing elective surgery for peripheral arterial disease

The purpose of the study was to assess the implementation of secondary prevention guidelines of coronary artery disease (CAD) in patients undergoing peripheral revascularization surgery. The design was a descriptive study of the prevalence of cardiac risk factors and preventive pharmacological therapy in vascular surgical patients set in an academic medical center between July 1996 and February 1999. A total of 237 patients were recruited, 82 (35%) having carotid surgery and 155 (65%) having lower extremity bypass. Data were collected from an existing database of a study examining perioperative cardiac events in vascular surgery patients. The majority of patients were hypertensive and 58% of patients had a blood pressure.140/90 mmHg. Most patients (81%) reported a history of tobacco use and 23% were active smokers. Of the 41% of patients who were diabetic, 46% had a random glucose .140 mg/dl. Half of the patients took aspirin, 35% a lipid-lowering medication, 30% a beta-blocker. Patients with lower extremity disease were less likely than patients with carotid disease to be on aspirin (45% vs. 62%), a lipid-lowering agent (30% vs. 45%), or a beta-blocker (26% vs. 39%) (all p,0.05). Of patients with heart disease, more men than women were on aspirin (62% vs. 45%) (p,0.05). In conclusion, our findings suggest that patients presenting for vascular surgery have a high prevalence of modifiable CAD risk factors that are not being adequately managed. Preoperative examination of vascular patients is an important opportunity to assess and implement neglected secondary prevention measures.

Smoking and red blood cell phospholipid membrane fatty acids

Smoking is associated with lower n-3 long chain polyunsaturated fatty acids (LCPUFA) concentrations; however, limited studies have accounted for dietary PUFA intake or whether tobacco dose or smoking duration influences this association. We measured red blood cell phospholipid (RBC) membrane concentrations of fatty acids in 126 current smokers, 311 former smokers, and 461 never smokers using gas liquid chromatography and tandem mass spectrometry. Smokers had lower RBC membrane percentages of total n-3 LCPUFAs compared to former smokers or never smokers (median percent: 5.46, [interquartile range (IQR) 4.52, 6.28] versus 6.39; [IQR: 5.18, 7.85] versus 6.59; [IQR 5.34, 8.01]) (p<0.001) and this association remained after adjusting for dietary PUFA intake. Duration of smoking and cigarettes per day were not associated with RBC membrane n-3 LCPUFA differences. Smoking is associated with lower n-3 LCPUFA RBC membrane percentages and this association was not influenced by diet or smoking dose or duration.

Environmental Tobacco Smoke and Atrial Fibrillation: The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study

OBJECTIVE

This study examines the association between environmental tobacco smoke (ETS) exposure and atrial fibrillation (AF).

METHODS

We examined the cross-sectional association between ETS exposure and AF in 12,021 participants (mean age: 65 ± 9.9 years; 60% women; 40% blacks) from the REasons for Geographic And Racial Differences in Stroke study who self-identified as never smokers between 2003 and 2007.

RESULTS

A total of 2503 (21%) participants reported ETS exposure. In a multivariate logistic regression model adjusted for sociodemographics and potential confounders, ETS exposure was significantly associated with AF (odds ratio = 1.27, 95% confidence interval = 1.08, 1.50).

CONCLUSIONS

Our findings suggest that the harmful effects of ETS exposure extend to sustained arrhythmias such as AF.

Young smoker "ABCD" vascular assessment: a four-step ultrasound examination for detecting peripheral, extra and intra-cranial early arterial damage

Background

Cigarette smoking is known as a major risk factor in the pathogenic mechanisms of stroke, coronary and peripheral artery disease (CAD and PAD), even in young subjects. The aim of this study is the creation of a four-step ultrasound examination to evaluate and monitor the peripheral, the extra and the intra-cranial assessment of the arterial early damage in smokers. The evaluations of A, the Ankle-brachial index, ABI, B, the Breath holding index, BHI, C, the Carotid intima media thickness, CIMT, and D, the Diameter of the abdominal aorta represent the “ABCD” assessment.

Methods

Thirty-eight healthy smokers and 43 controls underwent A, calculated for each leg. B was calculated after determination of subjects’ flow velocity of middle cerebral artery (MCA) by trans-cranial colour Doppler (TCCD) before and after 30 s of apnoea at baseline and just after smoking a cigarette, to simulate the chronic and acute effects of smoking. Finally, C and D evaluation were assessed using a high-resolution B-mode ultrasound.

Results

Smokers presented higher values of CIMT (mean and maximal), and lower BHI both at baseline and just after smoking (p < 0.01), though in the normal range. No significant differences were found for A and D between smokers and non- smokers.

Conclusions

Our results underline the importance of the assessment of B and C, that, though in the normal range, present significant differences between smokers and non-smokers. These data could drive the screening between smokers in age-related manner. Moreover, the “ABCD” examination could represent a valid method to detect and then monitor smokers’ vascular damage. Although it is far to be considered a screening and routine tool, it should be contemplated in a wider context of possible not-invasive practical screening and follow-up modalities. This would be designed to implement preventive strategies and tools aimed at discouraging tobacco addiction and monitoring cardiovascular risk patients.

Subtotal Gastrectomy With Billroth II Anastomosis Is Associated With a Low Risk of Ischemic Stroke in Peptic Ulcer Disease Patients: A Nationwide Population-Based Study

Duodenal diversion can ameliorate lipid and glucose metabolism. We assessed the risk of stroke after subtotal gastrectomy with Billroth II anastomosis (SGBIIA) in peptic ulcer disease (PUD). We identified 6425 patients who received SGBIIA for PUD between 1998 and 2010 from the Taiwan National Health Insurance Research Database as the study cohort; we frequency-matched them with 25,602 randomly selected controls from the PUD population who did not receive SGBIIA according to age, sex, index year, and comorbidities including hypertension, diabetes mellitus, hyperlipidemia, coronary artery disease, congestive heart failure, chronic kidney disease, chronic obstructive pulmonary disease (COPD), and obesity. All patients were followed until the end of 2011 to determine the incidence of stroke. The incidence of stroke was lower in patients in the SGBIIA cohort than in those in the non-SGBIIA cohort (18.9 vs 22.9 per 1000 person-years, adjusted hazard ratio [aHR] 0.80, 95% confidence interval [CI] 0.72-0.89, P < 0.001). The risk of ischemic stroke (aHR 0.77, 95% CI 0.69-0.86, P < 0.001), rather than hemorrhagic stroke (aHR 1.00, 95% CI 0.78-1.28), was lower for the SGBIIA cohort than for the non-SGBIIA cohort according to the multivariable Cox proportional hazard regression analysis. The relative risk of ischemic stroke after SGBIIA was lower in men (aHR 0.77, 95% CI 0.69-0.86) than in women (aHR 0.80, 95% CI 0.65-0.99) and in patients aged ≥65 years (aHR 0.72, 95% CI 0.63-0.81) than in those of other age groups (≤49 years, aHR 0.82, 95% CI 0.48-1.39; 50-64 years, aHR 1.01, 95% CI 0.79-1.28). The relative risk of ischemic stroke after SGBIIA was also reduced in patients with comorbidities (aHR 0.84, 5% CI 0.75-0.95) rather than in those without comorbidities (aHR 0.81, 95% CI 0.59-1.12). SGBIIA is associated with a low risk of ischemic stroke for PUD patients, and its protective effect is prominent in men, patients aged ≥65 years, and those with comorbidities.

Twelve-Year Cardiovascular and Mortality Risk in Relation to Smoking Habits in Type 2 Diabetic and Non-Diabetic Men: Tehran Lipid and Glucose Study

INTRODUCTION

To examine the associations between smoking and cardiovascular disease (CVD) / coronary heart disease (CHD) and all-cause mortality events in men with and without type 2 diabetes (T2D) in a Middle Eastern cohort during a median follow-up of 12 years.

METHODS

The study population included 2230 subjects aged ≥ 40 years, free from CVD, comprised of 367 participants with diabetes (21.2% current smokers) and 1863 without (27.3% current smokers). Multivariate Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for smoking (considering different definitions) for those with and without diabetes. Potential confounding factors including age, body mass index, estimated Glomerular Filtration Rate, hypertension, hypercholesterolemia and educational level were entered in the multivariate analysis.

RESULTS

In men with diabetes, the HR (95% CI) of comparing current and non-smokers was 1.25 (0.74-2.12) for incident CHD, 1.52 (0.96-2.40) for CVD and 2.10 (1.27-3.47) for mortality events; the corresponding values for men without diabetes were 1.65 (1.24-2.20), 1.70 (1.30-2.22) and 1.72 (1.14-2.58), respectively (all P values for interactions > 0.46). After pooling past smokers with current smokers, among diabetic individuals there was no significant risk for CVD [1.29 (0.89-1.86)] or mortality events [1.25 (0.81-1.92)]; however, among non-diabetic individuals the HRs of current/past smokers reached significant levels for CVD [1.53 (1.23-1.91)] but not for mortality outcomes (all P values for interactions > 0.51).

CONCLUSIONS

The strength of the associations between smoking habits and incident CVD/CHD and mortality events from all causes did not differ significantly among diabetic and non-diabetic participants. Therefore, a comprehensive community-based smoking prevention program is important, given the increasing trend of smoking among the Iranian population regardless of diabetes status.

The effect of smoking on carotid intima-media thickness progression rate and rate of lumen diameter reduction

OBJECTIVE

The purpose of the study was to investigate the long-term associations between smoking habits, environmental tobacco smoke exposure (ETS), carotid intima-media thickness (IMT) progression rate, and rate of lumen diameter reduction in the carotid artery during a 16-year follow-up. Another objective was to investigate if an effect of smoking on progression rate could be explained by increased low grade inflammation.

METHODS

The study population included 2992 middle-aged men and women in the 1991-1994 (baseline) and the 2007-2012 (re-examination) investigation of the Malmö Diet and Cancer Study cardiovascular cohort. Associations between smoking, progression of carotid IMT and lumen diameter reduction due to plaque protrusion were assessed by linear regression.

RESULTS

IMT progression rates and rate of lumen diameter reduction increased from never smokers with no ETS through former, moderate and heavy smokers, even after adjustment for traditional risk factors (e.g., differences in yearly progression rates (mm/year) of maximal IMT in the carotid bifurcation compared to never smokers; former smokers 0.0074 (95% CI: 0.0018-0.0129), moderate smokers 0.0106 (95% CI: 0.0038-0.0175), and heavy smokers 0.0146 (95% CI: 0.0061-0.0230)). Former smokers showed distinct lowering of progression rates after more than five years since smoking cessation. Smoking and former smoking was associated with increased low grade inflammation, however, the effect of smoking on atherosclerotic progression rate remained fairly unchanged after such adjustment.

CONCLUSION

The effect of smoking and former smoking on carotid IMT progression rates and change in lumen reduction due to plaque protrusion could not be explained by differences in traditional risk factors or low grade inflammation.

Smoking Induced Hemolysis: Spectral and microscopic investigations

Smoking is one of the major causes of lifestyle associated mortality and morbidity such as cancer of the oral cavity and lungs, and also cardiovascular diseases. In this study, we have provided evidences for the smoking-induced hemolysis using two methods: spectra of blood components and atomic force microscopic analysis of surface morphology. A total of 62 subjects (control = 31; smoker = 31: 21 male; 10 female in each set) were considered for the study. The findings indicate that smoking leads to potholes on the surface, swelling of shape, rupturing of erythrocytes, removal of hematoporphyrin and flushing into the plasma as metabolites of the erythrocyte. The overall morphology of the erythrocytes of the smoker group appears more like a Mexican hat. The mean surface roughness was 5.5 ± 3 nm for the smoker group, but 1.2 ± 0.2 nm for the control group. Such damages might help the toxins, (CO, peroxidants, aldehydes etc.,) to gain easy access and get strongly absorbed by the hemoglobin, leading to enhanced rates of hemolysis as shown by the spectral features of metabolites. This indicates that the average life span of the smoker's erythrocytes is significantly less than that of the control group.

Prevalence and risk factors of carotid intima-media thickness in asymptomatic individual subjects in a tertiary care center in India

BACKGROUND

Carotid intima-media thickness (IMT) is increasingly identified as a marker of atherosclerosis and increased risk of cerebrovascular disease.

AIM

We aimed to investigate the prevalence of carotid IMT in asymptomatic Indian individuals, more than 40 years of age, and correlate it with other risk factors for cerebrovascular ischemia.

MATERIALS AND METHODS

Individuals attending outpatient services of Nizam's Institute of Medical Sciences, who were asymptomatic for cerebrovascular ischemia underwent detailed history and carotid Doppler examination. IMT on mid common carotid artery (CCA) was measured. All subjects' blood was taken for biochemical estimation of fasting blood sugar and total cholesterol levels.

RESULTS

Out of 1,392 subjects, 571 (41%) had abnormal IMT and 821 (59%) had normal IMT. On comparison of the two groups, the factors significantly associated with abnormal IMT were mean older age (59 vs 50.7 years; P < 0.0001) and higher prevalence of hypertension (257 (45%) vs 236 (28.7%); P < 0.0001), diabetes (159 (27.8%) vs 139 (16.9%); P < 0.0001), and hypercholesterolemia (124 (21.7%) vs113 (13.7%); P = 0.0001). After adjustment with multiple logistic regression, significant predictors were age (odds 3.2; 95% confidence interval (CI) 2.5-4.1), male gender (odds 1.5; 95% CI 1.1-1.9), hypercholesterolemia (odds 1.5; 95% CI 1.1-2.0), hypertension (odds 1.4; 95% CI 1.1-1.8), and diabetes (odds 1.3; 95% CI 1.0-1.7).

CONCLUSION

We found age, sex, hypertension, diabetes, and hypercholesterolemia to be independent risk factor for abnormal IMT in asymptomatic subjects over 40 years of age.

Secondhand Smoke Exposure and Stroke: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

INTRODUCTION

Stroke is a major public health concern worldwide given the associated morbidity and mortality. Smoking is a risk factor for stroke, but the relationship between secondhand smoke (SHS) exposure and stroke has been inconsistent to date. The aim of the current study was to examine the association of SHS exposure and risk of stroke and its subtypes (ischemic and hemorrhagic stroke) among nonsmokers.

METHODS

Demographic and clinical characteristics were compared by SHS exposure status for African American and white nonsmokers aged ≥45 years in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study in 2014. Hazard ratios (HRs) and corresponding 95% CIs were calculated by Cox proportional hazards models to assess the relationship between SHS exposure and stroke risk.

RESULTS

Of the 21,743 participants (38% African American, 45% male), SHS exposure in the past year was reported by 23%. Compared with those without SHS exposure, exposed participants were more likely to be female, white, younger, and reside with a smoker (all p<0.001). A total of 428 incident strokes were observed from April 2003 to March 2012 during a mean follow-up of 5.6 years. The risk of overall stroke was increased 30% among those with SHS exposure after adjustment for other stroke risk factors (95% CI=2%, 67%). This relationship appeared to be driven by ischemic strokes.

CONCLUSIONS

SHS exposure is independently associated with an increased risk of stroke. Future studies are needed to confirm these findings and examine the role of long-term effects of SHS exposure on stroke outcomes.

Long-Term Consequences of Early Trauma on Coronary Heart Disease: Role of Familial Factors

Early childhood trauma has been associated with increased risk for subsequent coronary heart disease (CHD), but little is known regarding what role genetic and shared familial factors play in this relationship. Early trauma was measured retrospectively in 562 male middle-aged twins with the Early Trauma Inventory. CHD was assessed by history and by myocardial perfusion imaging with positron emission tomography [(13)N] ammonia. Coronary flow reserve, a measure of coronary microcirculatory function, was defined as the ratio of myocardial blood flow at rest to flow during stress. Early trauma was associated with a higher prevalence of CHD by clinical history, OR = 1.48 per early trauma inventory quartile increase, 95% CI [1.18, 1.86]. When within- and between-pair effects were estimated, only the between-pair association was significant, OR = 1.76, 95% CI [1.30, 2.40], showing that the odds of CHD in the twin pair increased as the average early trauma exposure in the pair increased. A marginal between-pair (but not within-pair) relationship was also found between early trauma and coronary flow reserve (n = 416, unstandardized B = -0.04, SE B = 0.02, p = .036). In conclusion, early trauma was associated with CHD and familial factors played a key role.

Association of serum cotinine levels and the parameters of vascular structure and function in never-smoking adults

Passive smoking is now recognized to be associated with early arterial damage. The aim of this study was to assess the relationship between secondhand smoke (SHS) exposure, measured objectively by serum cotinine level, and the parameters used to assess vascular structure and function among never smokers in North China. From January 2008 to August 2008, 652 adults aged 20-70 years were enrolled. Brachial-ankle pulse wave velocity (baPWV), ankle-brachial index, and carotid intima-media thickness measurements were performed in all patients. All participants were required to respond to an interviewer-led questionnaire including medical histories and demographic data and to receive blood tests on biochemical indicators. We found that in nonsmokers, higher levels of serum cotinine were positively associated with higher baPWV and brachial pulse pressure after adjusting for heart rate, body mass index, and other confounders. Tests for linear trends for this association were statistically significant. In contrast, no association was present with ankle-brachial index and carotid intima-media thickness. In never smokers, higher SHS exposure measured objectively by serum cotinine levels was found to be associated with brachial pulse pressure and baPWV after adjusting for confounders.