Meta-analysis of the association between cigarette smoking and peripheral arterial disease

Smoking as a risk factor for lower extremity peripheral artery disease in women compared to men: A systematic review and meta-analysis

BACKGROUND

To investigate whether the relationship between smoking and peripheral artery disease (PAD) differs by sex (PROSPERO CRD42022352318).

METHODS

PubMed, EMBASE, and CINAHL were searched (3 March 2024) for studies reporting associations between smoking and PAD in both sexes, at least adjusted for age. Data were pooled using random effects. Between-study heterogeneity was examined using I2 statistic and Cochran's Q test. Newcastle-Ottowa Scale was adopted for quality assessment.

RESULTS

Four cohort studies (n = 2,117,860, 54.4% women) and thirteen cross-sectional studies (n = 230,436, 59.9% women) were included. In cohort studies, former and current smokers had higher risk of PAD than never smokers. Compared to those who never or previously smoked, women current smokers (relative risk (RR) 5.30 (95% confidence interval 3.17, 8.87)) had higher excess risk of PAD than men (RR 3.30 (2.46, 4.42)), women-to-men ratio of RR 1.45 (1.30, 1.62)(I2 = 0%, p = 0.328). In cross-sectional studies, risk of PAD was higher among former and current compared to never smokers, more so in men, women-to-men ratios of odds ratio: 0.64 (0.46, 0.90)(I2 = 30%, p = 0.192), 0.63 (0.50, 0.79)(I2 = 0%, p = 0.594), respectively. For both sexes, risk of PAD was higher among current smokers compared to those who were not currently smoking. Cohort studies and five cross-sectional studies were of good quality, scoring 6 to 8 of a possible maximum 9 points. Eight cross-sectional studies scored 2 to 5.

DISCUSSIONS

Further research is required to elucidate sex differences in the relationships between smoking and PAD, as the current evidence is limited and mixed. Tobacco-control programs should consider both sexes.

Role of noninvasive ocular imaging as a biomarker in peripheral artery disease (PAD): A systematic review

This study aimed to review the current literature exploring the utility of noninvasive ocular imaging for the diagnosis of peripheral artery disease (PAD). Our search was conducted in early April 2022 and included the databases Medline, Scopus, Embase, Cochrane, and others. Five articles were included in the final review. Of the five studies that used ocular imaging in PAD, two studies used retinal color fundus photography, one used optical coherence tomography (OCT), and two used optical coherence tomography angiography (OCTA) to assess the ocular changes in PAD. PAD was associated with both structural and functional changes in the retina. Structural alterations around the optic disc and temporal retinal vascular arcades were seen in color fundus photography of patients with PAD compared to healthy individuals. The presence of retinal hemorrhages, exudates, and microaneurysms in color fundus photography was associated with an increased future risk of PAD, especially the severe form of the disease. The retinal nerve fiber layer (RNFL) was significantly thinner in the nasal quadrant in patients with PAD compared to age-matched healthy individuals in OCT. Similarly, the choroidal thickness in the subfoveal region was significantly thinner in patients with PAD compared to controls. Patients with PAD also had a significant reduction in the retinal and choroidal circulation in OCTA compared to healthy controls. As PAD causes thinning and ischemic changes in retinal vessels, examination of the retinal vessels using retinal imaging techniques can provide useful information about early microvascular damage in PAD. Ocular imaging could potentially serve as a biomarker for PAD. PROSPERO ID: CRD42022310637.

Peripheral artery disease: an underdiagnosed condition in familial hypercholesterolemia? A systematic review

PURPOSE

Familial hypercholesterolemia (FH) is one of the most common inherited diseases characterized by elevated LDL-cholesterol levels, leading to early-onset atherosclerosis. While the association between FH and coronary and carotid artery disease is well-established, its association with peripheral artery disease (PAD) is less robust. This systematic review aims at exploring existing evidence on PAD prevalence and incidence in FH individuals.

METHODS

A comprehensive search was conducted on MEDLINE and Embase databases, for studies published between January 2013 and December 2023, evaluating prevalence and incidence of PAD in FH patients. Literature reviews, case reports, responses to editors and non-English language articles were excluded.

RESULTS

The initial research provided 53 results. After article screening, 28 articles were fully reviewed and 24 were finally included in the analysis. Among these, 19 reported PAD prevalence, while 5 PAD incidence over a mean follow-up time of 8.7 years. PAD prevalence and incidence ranged from 0.3 to 60% and from 0.5 to 4.2% respectively, probably reflecting the heterogeneity in PAD definition criteria.

CONCLUSION

This systematic review sheds light on the limited number of studies on PAD in FH patients. Particularly, considering the potential positive effects of newly available lipid-lowering strategies on PAD outcomes, addressing this research gap is pivotal for a more comprehensive understanding of peripheral vascular manifestations in FH patients and for optimal management of this population.

Lifestyle Medicine: An Antidote to Cardiovascular Diseases

Despite numerous advances in basic understanding of cardiovascular disease pathophysiology, pharmacology, therapeutic procedures, and systems improvement, there hasn't been much decline in heart disease related mortality in the US since 2010. Hypertension and diet induced risk continue to be the leading causes of cardiovascular morbidity. Even with the excessive mortality associated with the COVID-19 pandemic, in 2020, heart disease remained the leading cause of death. Given the degree of disease burden, morbidity, and mortality, there is an urgent need to redirect medical professionals' focus towards prevention through simple and cost effective lifestyle strategies. However, current practice paradigm and financial compensation systems are mainly centered disease management and not health promotion. For example, the financial value placed on 3-10 min smoking cessation counseling (.24RVUs) is 47-fold lower than an elective PCI (11.21 RVUs). The medical community seems to be enamored with the latest and greatest technology, new devices, and surgical procedures. What if the greatest technology of all was simply the way we live every day? Perhaps when this notion is known by enough, we will switch to this lifestyle medicine technology to prevent disease in the first place.

Gender Bias in Diagnosis, Prevention, and Treatment of Cardiovascular Diseases: A Systematic Review

Cardiovascular disease (CVDs) has been perceived as a 'man's disease', and this impacted women's referral to CVD diagnosis and treatment. This study systematically reviewed the evidence regarding gender bias in the diagnosis, prevention, and treatment of CVDs. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. We searched CINAHL, PubMed, Medline, Web of Science, British Nursing Index, Scopus, and Google Scholar. The included studies were assessed for quality using risk bias tools. Data extracted from the included studies were exported into Statistical Product and Service Solutions (SPSS, v26; IBM SPSS Statistics for Windows, Armonk, NY), where descriptive statistics were applied. A total of 19 studies were analysed. CVDs were less reported among women who either showed milder symptoms than men or had their symptoms misdiagnosed as gastrointestinal or anxiety-related symptoms. Hence, women had their risk factors under-considered by physicians (especially by male physicians). Subsequently, women were offered fewer diagnostic tests, such as coronary angiography, ergometry, electrocardiogram (ECG), and cardiac enzymes, and were referred to less to cardiologists and/or hospitalisation. Furthermore, if hospitalised, women were less likely to receive a coronary intervention. Similarly, women were prescribed cardiovascular medicines than men, with the exception of antihypertensive and anti-anginal medicines. When it comes to the perception of CVD, women considered themselves at lower risk of CVDs than men. This systematic review showed that women were offered fewer diagnostic tests for CVDs and medicines than men and that in turn influenced their disease outcomes. This could be attributed to the inadequate knowledge regarding the differences in manifestations among both genders.

A high burden of diabetes and ankle brachial index abnormalities exists in Mexican Americans in South Texas

Ethnic differences exist in the United States in the interrelated problems of diabetes (DM), peripheral arterial disease (PAD), and leg amputations. The purpose of this study was to determine the prevalence and risk factor associations for subclinical PAD in a population sample of Mexican Americans using the ankle brachial (ABI) index. The ABI-High (higher of the two ankle pressures/highest brachial pressure) and ABI-Low (lower of the two ankle pressures/highest brachial pressure) were calculated to define PAD. Toe brachial index (TBI) was also calculated. 746 participants were included with an age of 53.4 ± 0.9 years, 28.3 % had diabetes mellitus (DM), 12.6 % were smokers, and 51.2 % had hypertension (HTN). Using ABI-High ≤ 0.9, the prevalence of PAD was 2.7 %. This rose to 12.7 % when an ABI-Low ≤ 0.9 was used; 4.0 % of the population had an ABI-High > 1.4. The prevalence of TBI < 0.7 was 3.9 %. DM was a significant risk factor for ABI-High ≤ 0.9 and ABI-High > 1.4, and TBI < 0.7. Increased age, HTN, smoking was associated with ABI-High ≤ 0.9, while being male was associated with ABI-High > 1.4. Increased age, smoking, and lower education were all associated with abnormal TBI. Despite relatively younger mean age than other studied Hispanic cohorts, the present population has a high burden of ABI abnormalities. DM was a consistent risk factor for PAD. These abnormalities indicate an important underlying substrate of vascular and metabolic disease that may predispose this population to the development of symptomatic PAD and incident amputations.

Systematic replication of smoking disease associations using survey responses and EHR data in the All of Us Research Program

OBJECTIVE

The All of Us Research Program (All of Us) aims to recruit over a million participants to further precision medicine. Essential to the verification of biobanks is a replication of known associations to establish validity. Here, we evaluated how well All of Us data replicated known cigarette smoking associations.

MATERIALS AND METHODS

We defined smoking exposure as follows: (1) an EHR Smoking exposure that used International Classification of Disease codes; (2) participant provided information (PPI) Ever Smoking; and, (3) PPI Current Smoking, both from the lifestyle survey. We performed a phenome-wide association study (PheWAS) for each smoking exposure measurement type. For each, we compared the effect sizes derived from the PheWAS to published meta-analyses that studied cigarette smoking from PubMed. We defined two levels of replication of meta-analyses: (1) nominally replicated: which required agreement of direction of effect size, and (2) fully replicated: which required overlap of confidence intervals.

RESULTS

PheWASes with EHR Smoking, PPI Ever Smoking, and PPI Current Smoking revealed 736, 492, and 639 phenome-wide significant associations, respectively. We identified 165 meta-analyses representing 99 distinct phenotypes that could be matched to EHR phenotypes. At P < .05, 74 were nominally replicated and 55 were fully replicated. At P < 2.68 × 10-5 (Bonferroni threshold), 58 were nominally replicated and 40 were fully replicated.

DISCUSSION

Most phenotypes found in published meta-analyses associated with smoking were nominally replicated in All of Us. Both survey and EHR definitions for smoking produced similar results.

CONCLUSION

This study demonstrated the feasibility of studying common exposures using All of Us data.

Peripheral artery disease: Update on etiology, pathophysiology, diagnosis and treatment

Peripheral artery disease (PAD) is a condition related to atherosclerosis affecting >200 million people worldwide, and it increases cardiovascular morbidity (mainly from myocardial infarction and stroke) and mortality. Indeed, PAD patients are classified as patients at very high cardiovascular risk. The most common manifestation of PAD is intermittent claudication, which is associated with reduced mobility and leg pain. Nevertheless, asymptomatic PAD is the most frequent form of PAD worldwide; therefore, it remains underdiagnosed and undertreated. The major risk factors for PAD are smoking, diabetes mellitus, hyperlipidemia, hypertension, overweight/obesity, age, male sex, and black race. Hence, the first and most relevant approach in PAD treatment is lifestyle management, with measures such as smoking cessation, healthy diet, weight loss, and regular physical exercise. This should also be supported by an optimal pharmacological approach including lipid-lowering drugs, antihypertensive drugs, antidiabetic agents, and antithrombotics.

Sex differences in risk factors for incident peripheral artery disease hospitalisation or death: Cohort study of UK Biobank participants

BACKGROUND

Women with peripheral artery disease (PAD) often have atypical symptoms, late hospital presentations, and worse prognosis. Risk factor identification and management are important. We assessed sex differences in associations of risk factors with PAD.

METHODS

500,207 UK Biobank participants (54.5% women, mean age 56.5 years) without prior hospitalisation of PAD at baseline were included. Examined risk factors included blood pressure, smoking, diabetes, lipids, adiposity, history of stroke or myocardial infarction (MI), socioeconomic status, kidney function, C-reactive protein, and alcohol consumption. Poisson and Cox regressions were used to estimate sex-specific incidence of PAD hospitalisation or death, hazard ratios (HRs), and women-to-men ratios of HRs (RHR) with confidence intervals (CIs).

RESULTS

Over a median of 12.6 years, 2658 women and 5002 men had a documented PAD. Age-adjusted incidence rates were higher in men. Most risk factors were associated with a higher risk of PAD in both sexes. Compared with men, women who were smokers or had a history of stroke or MI had a greater excess risk of PAD (relative to those who never smoked or had no history of stroke or MI): RHR 1.18 (95%CI 1.04, 1.34), 1.26 (1.02, 1.55), and 1.50 (1.25, 1.81), respectively. Higher high-density lipoprotein cholesterol (HDL-C) was more strongly associated with a lower risk of PAD in women than men, RHR 0.81 (0.68, 0.96). Compared to HDL-C at 40 to 60 mg/dL, the lowest level of HDL-C (≤40 mg/dL) was related to greater excess risk in women, RHR 1.20 (1.02, 1.41), whereas the highest level of HDL-C (>80 mg/dL) was associated with lower risk of PAD in women, but higher risk in men, RHR 0.50 (0.38, 0.65).

CONCLUSIONS

While the incidence of PAD was higher in men, smoking and a history of stroke or MI were more strongly associated with a higher risk of PAD in women than men. HDL-C was more strongly associated with a lower risk of PAD in women than men.

Acute effects of cigarette smoke on Endothelial Nitric Oxide synthase, vascular cell adhesion molecule 1 and aortic intima media thickness

Background. Cigarette smoking could induce endothelial dysfunction and the increase of circulating markers of inflammation by activation of monocytes. This can lead to increased intima media thickness (IMT) of entire blood vessels and result in acceleration of the atherosclerosis process. However, to our knowledge, little is known about the role of cigarette smoking in this atherosclerotic inflammatory process. The aim of this study is to explore the link between cigarette smoking and its effect on endothelial nitric oxide synthase (e-NOS) and vascular cell adhesion molecule 1 (VCAM-1). Methods. An experimental study with a post-test only controlled group design was used. We used 18 Wistar rats ( Rattus norvegicus) randomly subdivided into two groups: group K (-) were not exposed to tobacco smoke, whereas group K (+) were exposed to smoke equivalent of more than 40 cigarettes for 28 days daily. After 28 days, samples were analyzed for e-NOS, VCAM-1 and aortic IMT. Results . Our results indicate that tobacco smoke can enhance the expression of VCAM-1 on rat cardiac vascular endothelial cells, resulting in a decreased expression of e-NOS level and increase of aortic IMT. Linear regression model found that eNOS level negatively correlated wiith aortic IMT ( r 2 = 0.584, β = -0.764, p < 0.001), whereas VCAM-1 expression did not correlate with aortic IMT ( r 2 = 0.197, p = 0.065). Conclusion. Low e-NOS level and high VCAM-1 level observed after cigarette smoke exposure which may increase aortic IMT.

Association of smoking and dietary polycyclic aromatic hydrocarbon exposure on the prevalence of metabolic syndrome in Korean adults

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that are potentially hazardous to human health. Dietary exposure is recognized as one of the major pathways of exposure to PAHs among humans. While some PAH exposures have been associated with metabolic syndrome (MetS) in the general population, most epidemiological studies are based on urinary metabolites of a few noncarcinogenic PAHs.

OBJECTIVE

To investigate the association between estimates of dietary exposure to major carcinogenic PAHs and MetS in Korean adults.

METHODS

Multi-cycle Korean National Health and Nutrition Examination Survey (KNHANES) database (n = 16,015) and PAH measurement data from the total diet survey were employed to estimate daily PAH intake for each participating adult. After adjusting for potential confounders, multinomial logistic regression analysis was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) between PAHs and MetS of the participating adults.

RESULTS

Benzo(a)pyrene exposure was associated with an increased risk of MetS in men (OR = 1.30; 95% Cl: 1.03-1.63; P-trend = 0.03). In women, however, only chrysene and low high-density lipoprotein (HDL-c) were positively associated with an increased risk of MetS (OR = 1.24; 95% CI: 1.03-1.48; P-trend = 0.0172). Among men, smokers were at an increased risk for MetS, regardless of whether they were exposed to low or high total PAHs and benzo(a)pyrene levels.

SIGNIFICANCE

Our findings suggested that PAHs are associated with the risk of MetS and MetS components in Korean adults. In particular, it was confirmed that smoking may influence the relationship between PAH exposure and MetS.Further prospective cohort studies are required to confirm the causal relationship between PAHs and MetS.

IMPACT STATEMENT

Epidemiological studies on PAH exposure are often hampered by a lack of reliable exposure estimates, as biomonitoring of urine does not capture exposure to more toxic PAHs. Using multi-cycle KNHANES data and the measurement data from a total diet survey of Korea, we could develop a personalized PAH intake estimate for each participating adult and assessed the association with MetS.

Association of sex and cardiovascular risk factors with atherosclerosis distribution pattern in lower extremity peripheral artery disease

Objective

Atherosclerosis expression varies across not only coronary, cerebrovascular, and peripheral arteries but also within the peripheral vascular tree. The underlying pathomechanisms of distinct atherosclerosis phenotypes in lower extremity peripheral artery disease (PAD) is poorly understood. We investigated the association of cardiovascular risk factors (CVRFs) and atherosclerosis distribution in a targeted approach analyzing symptomatic patients with isolated anatomic phenotypes of PAD.

Methods

In a cross-sectional analysis of consecutive patients undergoing first-time endovascular recanalization for symptomatic PAD, data of patients with isolated anatomic phenotypes of either proximal (iliac) or distal (infrageniculate) atherosclerosis segregation were extracted. We performed a multivariable logistic regression model with backward elimination to investigate the association of proximal and distal PAD with CVRFs.

Results

Of the 637 patients (29% females) with endovascular recanalization, 351 (55%) had proximal and 286 (45%) had distal atherosclerosis. Female sex [odds ratio (OR) 0.33, 95% confidence interval (CI) 0.20-0.54, p = 0.01], active smoking (OR 0.16, 95% CI 0.09-0.28, p < 0.001), and former smoking (OR 0.33, 95% CI 0.20-0.57, p < 0.001) were associated with proximal disease. Diabetes mellitus (DM) (OR 3.25, 95% CI 1.93-5.46, p < 0.001), chronic kidney disease (CKD) (OR 1.18, 95% CI 1.08-1.28, p < 0.001), and older age (OR 1.31, 95% CI 1.06-1.61, p = 0.01) were associated with distal disease.

Conclusion

Female sex, particularly in the context of smoking, is associated with clinically relevant, proximal atherosclerosis expression. Our additional findings that distal atherosclerosis expression is associated with DM, CKD, and older age suggest that PAD has at least two distinct atherosclerotic phenotypes with sex-specific and individual susceptibility to atherogenic risk factors.

Medical Management of Peripheral Artery Disease

Peripheral artery disease (PAD) is a common type of atherosclerotic disease of the lower extremities associated with reduced quality of life and ambulatory capacity. Major adverse cardiovascular events and limb amputations are the leading cause of morbidity and mortality in this population. Optimal medical therapy is therefore critical in these patients to prevent adverse events. Risk factor modifications, including blood pressure control and smoking cessation, in addition to antithrombotic agents, peripheral vasodilators, and supervised exercise therapy are key pillars of medical therapy. Revascularization procedures represent key touch points between patients and health care providers and serve as opportunities to optimize medical therapy and improve long-term patency rates and outcomes. This review summarizes the aspects of medical therapy that all providers should be familiar with when caring for patients with PAD in the peri-revascularization period.

Development and validation of a prediction model for the prolonged length of stay in Chinese patients with lower extremity atherosclerotic disease: a retrospective study

OBJECTIVES

This study aims to develop and internally validate a prediction model, which takes account of multivariable and comprehensive factors to predict the prolonged length of stay (LOS) in patients with lower extremity atherosclerotic disease (LEAD).

DESIGN

This is a retrospective study.

SETTING

China.

PARTICIPANTS, PRIMARY AND SECONDARY OUTCOMES

Data of 1694 patients with LEAD from a retrospective cohort study between January 2014 and November 2021 were analysed. We selected nine variables and created the prediction model using the least absolute shrinkage and selection operator (LASSO) regression model after dividing the dataset into training and test sets in a 7:3 ratio. Prediction model performance was evaluated by calibration, discrimination and Hosmer-Lemeshow test. The effectiveness of clinical utility was estimated using decision curve analysis.

RESULTS

LASSO regression analysis identified age, gender, systolic blood pressure, Fontaine classification, lesion site, surgery, C reactive protein, prothrombin time international normalised ratio and fibrinogen as significant predictors for predicting prolonged LOS in patients with LEAD. In the training set, the prediction model showed good discrimination using a 500-bootstrap analysis and good calibration with an area under the receiver operating characteristic of 0.750. The Hosmer-Lemeshow goodness of fit test for the training set had a p value of 0.354. The decision curve analysis showed that using the prediction model both in training and tests contributes to clinical value.

CONCLUSION

Our prediction model is a valuable tool using easily and routinely obtained clinical variables that could be used to predict prolonged LOS in patients with LEAD and help to better manage these patients in routine clinical practice.

Risk profiles, access to care, and outcomes in Hispanics hospitalized for lower extremity peripheral artery disease

OBJECTIVE

Previous studies have shown that Hispanics have worse clinical outcomes for lower extremity peripheral artery disease (PAD) than non-Hispanic White (NHWs). Using a national database, this study aimed to document the contemporary burden of PAD in Hispanics by evaluating their risk profiles, access to care, and outcomes compared with NHWs.

METHODS

Hospitalizations of Hispanics and NHWs with a primary diagnosis of PAD were identified using 2011-2017 National Inpatient Sample data. Patient sociodemographic characteristics, comorbidities, whether the admission was through the emergency department (ED) or elective, length of stay, and costs accrued were compared by ethnicity. Temporal trends in revascularizations, amputations, and ED admissions by year were evaluated with the Cochran-Mantel-Haenszel test and stratified by ethnicity. Data were combined across years and multivariable logistic regression was used to evaluate the association of ethnicity with inpatient revascularization, amputation, and mortality, adjusting for sociodemographic and cardiovascular risk factors.

RESULTS

From 2011 to 2017, there were a total of 1,018,220 PAD hospitalizations among Hispanics (13.9%) and NHWs (86.1%) between 2011 and 2017. Hispanics were more often low income and uninsured and presented with higher burden of comorbidities including diabetes, renal failure, prior amputations, and chronic limb-threatening ischemia compared with NHWs. Most Hispanics were admitted via the ED compared with NHWs (58.0% vs 36.7%; d = 0.48), and median length of stay was almost a day longer (4.5 days vs 3.7 days). Hispanic ethnicity was associated with lower odds of surgical (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.57-0.67) and endovascular revascularization (OR, 0.94; 95% CI, 0.89-0.996) and mortality (OR, 0.83; 95% CI, 0.75-0.93), but higher odds of minor (OR, 1.25; 95% CI, 1.20-1.31) and major (OR, 1.08; 95% CI, 1.03-1.14) amputation.

CONCLUSIONS

Two tiers of health care consumption for inpatient PAD care and outcomes manifested among Hispanics and NHWs. First, Hispanics with PAD had a more vulnerable socioeconomic profile and presented with more severe PAD than NHWs. Second, they sought care more disproportionately through the ED and underwent more amputations than NHWs. To eradicate these inequities in PAD care and risk, strategies that improve access to outpatient care and expand health care coverage, as well as targeted management of risk factors in these vulnerable minority groups are needed.

Comparative evaluation of socioeconomic insecurity in peripheral and coronary artery disease patients

BACKGROUND

Cardiovascular disease represents the leading cause of death worldwide. Socioeconomic deprivation is a risk factor for cardiovascular disease. We have previously shown that precariousness was more frequent in symptomatic peripheral artery disease (PAD) patients than in the general population. According to a previous study, coronary artery disease (CAD) patients have a higher level of education than CAD with PAD, but no study directly compared the level of precariousness in PAD and CAD patients.

AIM

To measure and compare the level of socioeconomic insecurity in patients suffering from symptomatic PAD with those suffering from isolated CAD, i.e without symptomatic PAD.

METHODS

We conducted an observational, cohort, prospective, multicenter study. Patients suffering from symptomatic PAD or CAD were recruited through the medical or surgical vascular or cardiology departments, or the vascular rehabilitation center. The EPICES score and the INSEE parameters were used for analysis. The individual is considered precarious when his or her score is greater than or equal to 30. Cardiovascular risk factors and peripheral arterial disease stages were also collected.

RESULTS

In total, 230 patients were included. According to the EPICES score, 47.8% [95%CI, 38.7-56.7] of patients with symptomatic PAD were in a precarious situation compared to 17.4% [95%CI, 10.5-24.3] of patients suffering from isolated CAD (P<0.001). The mean EPICES score was 33.3 (SD 22.5) in the PAD and 16.9 (SD 17.02) in the CAD population, respectively (P<0.001). In the PAD population, the level of education was low, with an under-representation of patients with a baccalaureate or higher education degree: 21.7% [95%CI, 14.2-29.3] vs. 41.7% [95%CI, 32.7-50.7] in the PAD and CAD populations, respectively. There was also an under-representation of executives and intellectual and intermediate professions in the PAD population, 18.3% [95%CI, 11.2-25.3], compared to the CAD population, 31.3% [95%CI, 22.8-39.8].

CONCLUSION

PAD patients are more precarious than patients suffering from CAD. A better detection of socioeconomic deprivation in patients suffering from peripheral arterial disease could allow comprehensive care and thus hope for an improvement in terms of morbidity and mortality.

Editor's Choice - Effect of Physical Activity and Tobacco Use on Mortality and Morbidity in Patients with Peripheral Arterial Disease After Revascularisation: A Korean Nationwide Population Based Cohort Study

OBJECTIVE

To investigate the effects of physical activity (PA) and tobacco use on adverse clinical outcomes after revascularisation for peripheral arterial disease (PAD) in the Western Pacific region, where PAD cases and tobacco use are among the highest in the world.

METHODS

This was a retrospective cohort study using the Korean National Health Insurance Service (NHIS) database and included patients who had received revascularisation for PAD between 2010 and 2015. They were categorised as active or inactive based on the number of days per week they engaged in PA and as current or non-tobacco users (self report). The primary outcome was all cause mortality. Secondary outcomes included major adverse outcome (a composite of all cause mortality, myocardial infarction, and stroke) and major adverse limb event (MALE, a composite of amputation and recurrent revascularisation).

RESULTS

The relatively healthy cohort comprised 8 324 patients (mean age 64.7 years; 76.9% male) following revascularisation for PAD. Among them, 32.7% were inactive and 26.4% were tobacco users. Active patients had better outcomes than inactive patients (all cause mortality adjusted hazard ratio [adjHR] 0.766; 95% CI 0.685 - 0.855, major adverse outcome adjHR 0.795; 95% CI 0.719 - 0.878, MALE adjHR 0.858; 95% CI 0.773 - 0.953). Tobacco users had poorer outcomes than non-users (all cause mortality adjHR 1.279; 95% CI 1.124 - 1.456, major adverse outcome adjHR 1.263; 95% CI 1.124 - 1.418, MALE adjHR 1.291; 95% CI 1.143 - 1.458).

CONCLUSION

Even after receiving revascularisation for PAD, a sizable proportion of patients were physically inactive and used tobacco, leading to adverse clinical outcomes such as death, cardiovascular morbidity, and amputation in Korea. These modifiable risk factors should be addressed systematically, and a comprehensive approach including supervised exercise programmes and tobacco cessation is needed in patients with PAD.

Mortality and Conversion to Transfemoral Amputation After Transtibial Amputation in the Veterans Affairs Health System

INTRODUCTION

Transtibial below-knee amputation (BKA) is associated with considerable morbidity, particularly in the vasculopathic population. The purpose of this study was to determine the cumulative probability of undergoing transfemoral above-knee amputation (AKA) conversion within 5 years of BKA and associated risk factors while accounting for the competing risk of death.

METHODS

This is a retrospective, national database study with structured query of the Veterans Affairs (VA) database for patients who underwent BKA from 1999 to 2020, identified by Current Procedural Terminology codes. Above-knee amputation conversion was identified using Current Procedural Terminology codes in combination with natural language processing to match procedure laterality. After internally validating our patient identification method, risk factors were collected. Competing risk analysis estimated the cumulative incidence rate of AKA conversion and associated risk factors with death as a competing risk.

RESULTS

Our query yielded 19,875 patients (19,640 men, 98.8%) who underwent BKA with a median age of 66 years (interquartile range, 60 to 73). The median follow-up was 951 days (interquartile range, 275 to 2,026). The crude cumulative probabilities of AKA conversion and death at 5 years were 15.4% (95% confidence interval [CI], 14.9% to 16.0%) and 47.7% (95% CI, 46.9% to 48.4%), respectively. In the Fine and Gray subdistribution hazard model, peripheral vascular disease had the highest AKA conversion risk (hazard ratio [HR] 2.66; 95% CI, 2.22 to 3.20; P < 0.001). Other factors independently associated with AKA conversion included urgent operation (HR 1.32; 95% CI, 1.23 to 1.42), cerebrovascular disease (HR 1.19; 95% CI, 1.11 to 1.28), chronic obstructive pulmonary disease (HR 1.15; 95% CI, 1.07 to 1.24), and previous myocardial infarction (HR 1.10; 95% CI, 1.02 to 1.19) (All P < 0.02).

DISCUSSION

Within this predominantly male, VA population, BKA carries a high risk of conversion to AKA within 5 years, without reaching a steady risk of AKA conversion within 5 years. Peripheral vascular disease, chronic obstructive pulmonary disease, cerebrovascular disease, previous myocardial infarction, and urgent BKA increase the risk of AKA conversion.

LEVEL OF EVIDENCE

Level III.

Swedish snuff (snus) dipping, cigarette smoking, and risk of peripheral artery disease: a prospective cohort study

Tobacco smoking is an important risk factor for peripheral artery disease (PAD), but it remains unknown whether smokeless tobacco, such as Swedish snuff (snus), is also associated with this disease. We used data from the Cohort of Swedish Men including 24,085 men. Individuals were grouped into never, past, and current snus dippers as well as never, past quitting ≥ 10 years, past, quitting < 10 years, and current smokers. Incident PAD cases were defined by linkage of the cohort with the Swedish National Patient Register. Cox proportional hazards regression was used to analyze the data. Over a mean follow-up period of 9.1 years (from July 1, 2009 to December 31, 2019), 655 incident PAD cases were ascertained. Cigarette smoking but not Swedish snus dipping was associated with an increased risk of PAD. Compared with never snus dippers, the hazard ratio of PAD was 0.95 (95% confidence interval [CI] 0.73–1.24) for past snus dippers and 0.88 (95% CI 0.66–1.17) for current snus dippers. Compared to never smokers, the hazard ratio of PAD was 1.38 (95% CI 1.14–1.68) for past smoker who stopped smoking for ≥ 10 years, 2.61 (95% CI 1.89–3.61) for past smoker who stopped smoking for < 10 years, and 4.01 (95% CI 3.17, 5.08) for current smoker. In conclusion, cigarette smoking but not Swedish snus dipping increases the risk of PAD.

The Plasma Oxylipidome Links Smoking Status to Peripheral Artery Disease

Peripheral artery disease (PAD) is prevalent among individuals with a history of tobacco smoking. Although oxidation of lipids may contribute to atherogenesis in vascular disease, enzymatically and nonenzymatically produced oxidized lipids can have varying and contrasting physiological effects. The underlying mechanisms of atherogenic vulnerability can be better elucidated with the recent advances in oxylipidome quantification using HPLC-MS/MS technology. In a randomized, controlled clinical trial, the plasma oxylipidome was analyzed in participants living with PAD by smoking status (n = 98) and in nonsmoking comparators without chronic disease (n = 20). Individuals with PAD had approximately a four-fold higher level of total plasma oxylipins versus the comparator. Cessation of smoking in individuals with PAD was associated with significantly lower levels of linoleic acid-derived TriHOMEs, greater levels of omega-3 fatty acid-derived oxylipins, and greater levels of nonfragmented oxidized phosphatidylcholines (OxPCs). Individuals living with PAD but without a history of smoking, exhibited higher levels of the putative atherogenic fragmented OxPCs versus individuals who currently or previously smoked. These data implicate the plasma oxylipidome in PAD and that smoking cessation is associated with a less inflammatory profile. Furthermore, fragmented OxPCs may play a more significant role in the pathophysiology of PAD in individuals without a history of smoking.

Nonfreezing Cold Injury and Cold Intolerance in Paddlesport

INTRODUCTION

Nonfreezing cold injury (NFCI) occurs when tissues are subjected to prolonged cooling that causes tissue damage, but not freezing. Long-term effects include cold intolerance, with allodynia, pain, or numbness of the affected limb. Those who participate in outdoor paddlesports are at particular risk.

METHODS

This is an epidemiological study that aimed to determine the risk factors for paddlesport athletes developing NFCI and chronic cold intolerance in their hands. Secondary outcomes were to correlate cumulative cold exposure with the development of cold intolerance and to identify risk factors for developing NFCI or cold intolerance. Six hundred nine athletes responded to a survey distributed by their national governing body obtaining demographic and activity details, symptoms of NFCI, and a cold intolerance severity score (CISS).

RESULTS

Twenty-three percent reported symptoms consistent with acute NFCI. The median CISS was 31 y (interquartile range 25-43), and 15% had a pathological CISS defined as >50. Females and individuals with Raynaud's phenomenon or migraines had a significantly higher CISS (P<0.05). Regression analysis found that females, smokers, and those with Raynaud's phenomenon or a previous nerve injury had a significantly higher risk of developing pathological cold intolerance (CISS >50). There was no correlation between cumulative cold exposure and CISS.

CONCLUSIONS

A large proportion of paddlesport athletes undertaking activity in cold conditions have a pathological CISS or episodes consistent with NFCI. Cumulative cold exposure was not associated with a pathologically high CISS. The risk factors were female sex, smokers, and those suffering from either Raynaud's phenomenon or nerve injury.

Association of Plasma Bilirubin Levels With Peripheral Arterial Disease in Chinese Hypertensive Patients: New Insight on Sex Differences

Background and aims: Previous studies have indicated that Plasma total bilirubin (TBiL) might play an essential role in peripheral arterial disease (PAD). However, the effects of different levels of TBiL on PAD development remain uncertain. We aimed to examine the TBiL and the prevalence of PAD among Chinese adults with hypertension, with particular attention paid to sex differences.

Methods: A total of 10,900 hypertensive subjects were included in the current study. The mean age of our study participants was 63.86 ± 9.25 years, and there were 5,129 males and 5,771 females. The outcome was peripheral arterial disease (PAD), defined as present when the ankle-brachial index (ABI) of either side was ≤0.90. The association between TBiL and PAD was examined using multivariate logistic regression analysis and the restricted cubic spline.

Results: Of 10,900 hypertensive participants, 350 (3.21%) had PAD, and the mean plasma total bilirubin was 14.66 (6.86) μmol/L. The mean TBiL was 15.67 μmol/L in men and 13.76 μmol/L in women. The smoothing curve showed that a U-shaped curve association existed between TBiL and the prevalence of PAD in Chinese adults with hypertension. When stratified by sex, TBiL was significantly U-shaped associated with PAD among men but not women. Among males, the inflection point was 11.48 μmol/L; to the left inflection point, the effect size and 95% CI were 0.08, 0.01, 0.66, respectively; to the right inflection point, OR, 5.16; 95% CI,1.64, 16.25.

Conclusions: We found an independent U-shaped association between TBiL and the prevalence of PAD among hypertensive subjects and a differential association between men and women. We further revealed a turning point by threshold effect analysis.

Association between secondhand smoke and peripheral arterial disease: a meta-analysis of cross-sectional studies

PURPOSE

The association between secondhand smoke (SHS) and peripheral arterial disease (PAD) was inconsistent and the studies were relatively scarce, hence, we conducted a meta-analysis of the association between SHS and PAD.

MATERIALS AND METHODS

We systematically searched three electronic databases (PubMed, EMBASE, and Web of Science), and calculated the pooled prevalence risk ratio (RR) and estimated standard error by random effect model from the meta-analysis. Furthermore, we performed a subgroup meta-analysis according to the location of SHS exposure.

RESULTS

We initially identified 502 articles from the electronic database, and 6 articles, cross-sectional data from 4 cross-sectional studies and 2 prospective cohort studies, were included in the meta-analysis. Among these six articles, two studies showed a significant correlation between SHS exposure and PAD, whereas no study showed a negative correlation between SHS exposure and PAD. In the meta-analysis, pooled prevalence showed a significant association between SHS exposure and PAD (RR = 1.23; 95% confidence interval [CI] 1.08-1.41; z = 3.02, p = 0.003). In the subgroup analysis based on location of SHS exposure, the prevalence RR of PAD at home was 1.30 (95% CI 1.14-1.49, Z-3.99, p < 0.0001). The prevalence RR in the subgroup of SHS exposure at work was not significant (RR = 0.89; 95% CI 0.55-1.44; z = 0.48, p = 0.63).

CONCLUSION

Exposure to SHS was significantly and positively associated with PAD. Moreover, we found a significant association between exposure to SHS and PAD at home, but the association was not significant at work.

Associations of lower-limb atherosclerosis and arteriosclerosis with cardiovascular risk factors and disease in older adults: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND & AIMS

Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femoral-ankle pulse wave velocity (faPWV), but no studies have identified whether ABI and faPWV similarly associate with overt CVD and risk factors, nor whether faPWV confers additional information. The aims of this study were to (i) compare associations of ABI and faPWV with traditional CVD risk factors, including age, sex, systolic blood pressure (SBP), high-density lipoprotein (HDL), total cholesterol (TC), smoking, and diabetes; and (ii) determine the independent and additive associations of ABI and faPWV with a composite measure of prevalent CVD.

METHODS

We evaluated ABI and faPWV in 4330 older-aged (75.3 ± 5.0 years) adults using an oscillometric screening device. Associations between ABI and faPWV with CVD risk factors and CVD were determined using mixed-model linear- and logistic-regression.

RESULTS

ABI and faPWV were associated with age, HDL, and smoking. ABI was associated with sex, TC, diabetes. faPWV was associated with SBP. Both ABI and faPWV were inversely associated with CVD. Low ABI (≤0.9 vs. >0.9) and low faPWV (≤9.94 vs. >9.94) increased the odds of CVD by 2.41-fold (95% CI:1.85,3.17) and 1.46-fold (95% CI:1.23,1.74), respectively. The inverse association between faPWV and CVD was independent of ABI and CVD risk factors.

CONCLUSIONS

ABI and faPWV, measures of lower-limb atherosclerosis and arteriosclerosis, are independently associated with CVD risk factors and prevalent CVD. Assessment of faPWV may confer additional risk information beyond ABI.

Urinary pteridines as a discriminator of atherosclerotic risk in patients with diabetes

Background and aims

We have recently proposed urinary pteridine level as a useful biomarker of oxidative stress in a general population. However, the significance of urinary pteridines in patients with diabetes is unknown.

Methods

The relationships of the level of urinary pteridine derivatives with d-dimer, ankle-brachial pressure index (ABI), and known cardiovascular risk factors were investigated in patients with type 2 diabetes.

Results

Urinary pteridine level showed significant positive correlations with urinary15-isoprostane F2t, female gender, history of smoking and d-dimer and significant inverse correlations with history of alcohol drinking, body mass index (BMI) and ABI. ABI was significantly lower and d-dimer was significantly higher in the highest tertile group of pteridines than in the lowest tertile group. The odds ratios of the highest vs. lowest tertiles for low ABI and high d-dimer were significantly higher than the reference level. The above relationships of urinary pteridines with ABI and d-dimer were not altered when age, gender, BMI, hemoglobin A1c and history of alcohol drinking were used as explanatory variables in multivariable analyses. History of smoking confounded the relation of pteridines with ABI but not that with d-dimer. However, in logistic regression analysis, the association between pteridines and ABI remained significant with adjustment for history of smoking.

Conclusion

Urinary pteridine level was associated with d-dimer and ABI, which reflect blood coagulability and arterial flow to the lower extremities, respectively, and is thus thought to be a useful discriminator of thromboatherosclerotic risk in patients with diabetes.

Principal predictors of major adverse limb events in diabetic peripheral artery disease: A narrative review

Background and aims

The increasing prevalence of diabetes mellitus is causing a massive growth of peripheral artery disease incidences, a disabling complication of diabetic atherosclerosis, which leads often to the amputation of the affected limb. Critical limb ischemia is the terminal disease stage, which requires a prompt intervention to relieve pain and save limbs. However, patients undergoing revascularization often suffer from cardiovascular, cerebrovascular and major adverse limb events with poor outcomes. Furthermore, the same procedure performed in apparently similar patients has various outcomes and lack of an outcome predictive support causes a high lower limb arterial revascularization rate with disastrous effects for patients. We collected the main risk factors of major adverse limb events in a more readable and immediate format of the topic, to propose an overview of parameters to manage effectively peripheral artery disease patients and to propose basics of a new predictive tool to prevent from disabling vascular complications of the disease.

Methods

Most recent and updated literature about the prevalence of major adverse limb events in peripheral artery disease was reviewed to identify possible main predictors.

Results

In this article, we summarized major risk factors of limb revascularization failure and disabling vascular complications collecting those parameters principally responsible for major adverse limb events, which provides physio-pathological explanation of their role in peripheral artery disease.

Conclusion

We evaluated and listed a panel of possible predictors of MALE (Major Adverse Limb Event) in order to contribute to the development of a predictive score, based on a summary of the main risk factors reported in scientific articles, which could improve the management of peripheral artery disease by preventing vascular accidents.

Development and validation of a risk score model for prediction of lower extremity arterial disease in Chinese with type 2 diabetes aged over 50 years

BACKGROUND

Lower extremity arterial disease (LEAD) is highly prevalent in people with diabetes in China, but half of cases are underdiagnosed due to diversities of clinical presentations and complexities of diagnosis approaches. The purpose of this study was to develop a risk score model for LEAD to facilitate early screening among type 2 diabetes (T2DM) patients.

METHODS

A total of 8313 participants with T2DM from the China DIA-LEAD study, a multicenter, cross-sectional epidemiological study, were selected as the training dataset to develop a risk score model for LEAD by logistic regression. The area under receiver operating characteristic curve (AUC) and bootstrapping were utilized for internal validation. A dataset of 287 participants consecutively enrolled from a teaching hospital between July 2017 and November 2017 was used as external validation for the risk score model.

RESULTS

A total of 931 (11.2%) participants were diagnosed as LEAD in the training dataset. Factors including age, current smoking, duration of diabetes, blood pressure control, low density lipoprotein cholesterol, estimated glomerular filtration rate, and coexistence of cardio and/or cerebrovascular disease correlated with LEAD in logistic regression analysis and resulted in a weighed risk score model of 0-13. A score of ≥5 was found to be the optimal cut-off for discriminating moderate-high risk participants with AUC of 0.786 (95% CI: 0.778-0.795). The bootstrapping validation showed that the AUC was 0.784. Similar performance of the risk score model was observed in the validation dataset with AUC of 0.731 (95% CI: 0.651-0.811). The prevalence of LEAD was 3.4, 12.1, and 27.6% in the low risk (total score 0-4), moderate risk (total score 5-8), and high risk (total score 9-13) groups of LEAD in the training dataset, respectively, which were 4.3, 19.6, and 30.2% in the validation dataset.

CONCLUSION

The weighed risk score model for LEAD could reliably discriminate the presence of LEAD in Chinese with T2DM aged over 50 years, which may be helpful for a precise risk assessment and early diagnosis of LEAD.

Peripheral Artery Disease as a Risk Factor for Myocardial Infarction

Introduction: Atherosclerosis contributes to the underlying pathophysiology for peripheral arterial disease (PAD), coronary artery disease (CAD), and cerebrovascular disease. Several studies have been conducted to demonstrate PAD as a major risk factor for cardiovascular (CV) events, however, the regional data are limited. This study aims to highlight PAD as a major risk factor in CV events in a local setting.

Methods: In this longitudinal study, 400 hypertensive patients with a confirmed diagnosis of PAD were enrolled from the outpatient department of the cardiology unit. Diagnosis of PAD was made using the ankle brachial index (ABI). ABI less than 0.9 was labeled as participants with PAD. Another group of 400 without PAD was also enrolled as the control group from the outpatient department of cardiology unit. Patients were followed up for 12 months or for the development of myocardial infarction (MI).

Result: Participants with PAD had a significant increased risk of total MI events with a relative risk (RR) of 1.67 (confidence interval, CI 95%: 1.05-2.66; p-value: 0.02). The RR for fatal MI was 2.62 (CI 95%: 0.94-7.29; p-value: 0.06) compared to the participants without PAD, however, it was not significant.

Conclusion: This study has focused on the risk factors of PAD and has suggested that the patients who have any of the mentioned risk factors should be treated with caution under strict instructions given by doctors. A variety of treatment options is available, but the initial changes should be made in the lifestyle of these patients, making sure the risk factors are being treated.

Similarities and differences in peripheral artery disease between China and Western countries

OBJECTIVE

Peripheral artery disease (PAD) affects more than 200 million people worldwide, among whom more than two-thirds reside in low- and middle-income countries. China, as the largest low- and middle-income country, faces a challenge from the burden of PAD as the country undergoes economic expansion. We compared the patterns of PAD between China and Western countries to determine if there are differences in risk factors, awareness, or treatment of PAD.

METHODS

Literature searches were performed both in English databases and Chinese databases covering January 1, 1995, to March 1, 2020. Both landmark and high-quality articles were evaluated.

RESULTS

The prevalence of PAD in high-income countries increases linearly with age, whereas PAD increases slowly until the middle 60s and exponentially thereafter in China. In contrast with Western countries, the prevalence of PAD in China is reported to be higher in women than in men. There is a higher prevalence of risk factors in China, but the rates of awareness and treatment of these risk factors are low.

CONCLUSIONS

The lack of awareness and lower rates of treatment and control of PAD and its risk factors in China may be underlying the higher prevalence of PAD in women than in men as well as the steep increase in PAD after the middle 60s. In all countries, more attention should be paid to the planning and implementation of preventative strategies and clinical services. The societal and economic effects of PAD are considerable and ongoing studies are needed to help curtail the burden of this disease.

Evidence-Based Recommendations for Medical Management of Peripheral Artery Disease

Patients with lower limb artery stenosis or occlusion (peripheral artery disease; PAD) have been determined to be at very high risk of both major adverse cardiovascular events, such as myocardial infarction and stroke, and major adverse limb events, such as amputation and requirement for artery surgery.

Effective medical management has been identified as key in reducing this risk; however, this is often poorly implemented in clinical practice. Thus, the aim of this narrative review was to summarize the current evidence on the medical management of PAD in order to inform clinicians and highlight recommendations for clinical practice. International guidelines, randomized controlled trials, and relevant systematic reviews and meta-analyses have been included in this study. The focus was the management of the key modifiable risk factors to mitigate possible adverse events through prescription of anti-platelet and anticoagulation drugs and medications to control low-density lipoprotein cholesterol, blood pressure, and diabetes and aid smoking cessation. The available evidence from randomized clinical trials provide a strong rationale for the need for holistic medical management programs that are effective in achieving uptake of these medical therapies in patients with PAD. In conclusion, people with PAD have some of the highest adverse event rates among those with cardiovascular diseases. Secondary preventive measures have been proven effective in reducing these adverse events; however, they remain to be adequately implemented. Thus, the need for an effective implementation program has emerged to reduce adverse events in this patient group.

Conventional and Novel Lipid Measures and Risk of Peripheral Artery Disease

OBJECTIVE

The aim of this study was to comprehensively assess the association of multiple lipid measures with incident peripheral artery disease (PAD). Approach and Results: We used Cox proportional hazards models to characterize the associations of each of the fasting lipid measures (total cholesterol, LDL-C [low-density lipoprotein cholesterol], HDL-C [high-density lipoprotein cholesterol], triglycerides, RLP-C [remnant lipoprotein cholesterol], LDL-TG [LDL-triglycerides], sdLDL-C [small dense LDL-C], and Apo-E-HDL [Apo-E-containing HDL-C]) with incident PAD identified by pertinent International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) hospital discharge codes (eg, 440.2) among 8330 Black and White ARIC (Atherosclerosis Risk in Communities) participants (mean age 62.8 [SD 5.6] years) free of PAD at baseline (1996-1998) through 2015. Since lipid traits are biologically correlated to each other, we also conducted principal component analysis to identify underlying components for PAD risk. There were 246 incident PAD cases with a median follow-up of 17 years. After accounting for potential confounders, the following lipid measures were significantly associated with PAD (hazard ratio per 1-SD increment [decrement for HDL-C and Apo-E-HDL]): triglycerides, 1.21 (95% CI, 1.08-1.36); RLP-C, 1.18 (1.08-1.29); LDL-TG, 1.18 (1.05-1.33); HDL-C, 1.39 (1.16-1.67); and Apo-E-HDL, 1.27 (1.07-1.51). The principal component analysis identified 3 components (1: mainly loaded by triglycerides, RLP-C, LDL-TG, and sdLDL-C; 2: by HDL-C and Apo-E-HDL; and 3: by LDL-C and RLP-C). Components 1 and 2 showed independent associations with incident PAD.

CONCLUSIONS

Triglyceride-related and HDL-related lipids were independently associated with incident PAD, which has implications on preventive strategies for PAD. However, none of the novel lipid measures outperformed conventional ones. Graphic Abstract: A graphic abstract is available for this article.

Electronic Cigarette Use and Blood Pressure Endpoints: a Systematic Review

PURPOSE OF REVIEW

E-cigarettes (e-cigs) release toxic chemicals known to increase blood pressure (BP) levels. The effects of e-cigs on BP, however, remain unknown. Studying BP may help characterize potential cardiovascular risks of short- and long-term e-cig use. We summarized published studies on the association of e-cig use with BP endpoints.

RECENT FINDINGS

Thirteen e-cig trials (12 cross-over designs) and 1 observational study evaluated systolic and diastolic blood pressure (SBP and DBP). All trials included at least one e-cig arm with nicotine, 6 a no-nicotine e-cig arm, and 3 a placebo arm. SBP/DBP increased in most nicotine e-cig arms, in some non-nicotine e-cig arms, and in none of the placebo arms. The observational study followed e-cig users and nonsmokers for 3.5 years with inconsistent findings. The use of e-cigs with and without nicotine may result in short-term elevations of both SBP and DBP. Prospective studies that investigate the long-term cardiovascular impact of e-cig use are needed.

Genetic predisposition to smoking in relation to 14 cardiovascular diseases

AIMS

The aim of this study was to use Mendelian randomization (MR) to determine the causality of the association between smoking and 14 different cardiovascular diseases (CVDs).

METHODS AND RESULTS

Our primary genetic instrument comprised 361 single-nucleotide polymorphisms (SNPs) associated with smoking initiation (ever smoked regularly) at genome-wide significance. Data on the associations between the SNPs and 14 CVDs were obtained from the UK Biobank study (N = 367 643 individuals), CARDIoGRAMplusC4D consortium (N = 184 305 individuals), Atrial Fibrillation Consortium (2017 dataset; N = 154 432 individuals), and Million Veteran Program (MVP; N = 190 266 individuals). The main analyses were conducted using the random-effects inverse-variance weighted method and complemented with multivariable MR analyses and the weighted median and MR-Egger approaches. Genetic predisposition to smoking initiation was most strongly and consistently associated with higher odds of coronary artery disease, heart failure, abdominal aortic aneurysm, ischaemic stroke, transient ischaemic attack, peripheral arterial disease, and arterial hypertension. Genetic predisposition to smoking initiation was additionally associated with higher odds of deep vein thrombosis and pulmonary embolism in the UK Biobank but not with venous thromboembolism in the MVP. There was limited evidence of causal associations of smoking initiation with atrial fibrillation, aortic valve stenosis, thoracic aortic aneurysm, and intracerebral and subarachnoid haemorrhage.

CONCLUSION

This MR study supports a causal association between smoking and a broad range of CVDs, in particular, coronary artery disease, heart failure, abdominal aortic aneurysm, ischaemic stroke, transient ischaemic attack, peripheral arterial disease, and arterial hypertension.

Association of Carboxyhemoglobin Levels with Peripheral Arterial Disease in Chronic Smokers Managed at Dr George Mukhari Academic Hospital

Chronic cigarette smokers (CCS) are known to have elevated levels of carboxyhemoglobin (COHb). However, it is not known whether increased levels of COHb are associated with endothelial dysfunction (ED), and therefore the development of peripheral arterial disease (PAD). The aim of the study was to investigate the association of blood COHb and plasma nitric oxide (NO) levels, and whether it is an independent risk factor in the development of PAD among CCS at Dr George Mukhari Academic Hospital (DGMAH). A sample of 120 CCS with PAD and a convenience sample of 100 CCS without PAD were recruited into the study. Blood COHb levels were measured using the ABL 90 FLEX CO-oximeter automated spectroscopy. Plasma nitric oxide (NO) levels were measure using ELISA. Logistic regression analysis was used to investigate the association of blood COHb and plasma NO with PAD. Blood COHb levels of CCS with PAD were significantly higher than those of CCS without PAD, and the NO levels of CCS with PAD were significantly lower than those of CCS without PAD. Although both the blood COHb and plasma NO in CCS were significantly associated with PAD in bivariate logistic analysis, only plasma NO was independently associated with PAD in multivariate logistic analysis. This finding is consistent with the hypothesis that COHb is a cause of arterial damage in PAD, leading to reduced NO, and therefore reduced arterial dilation.

Free Radical and Nicotine Yields in Mainstream Smoke of Chinese Marketed Cigarettes: Variation with Smoking Regimens and Cigarette Brands

Free radicals and nicotine are components of cigarette smoke that are thought to contribute to the development of smoking-induced diseases. China has the largest number of smokers in the world, yet little is known about the yields of tobacco smoke constituents in different Chinese brands of cigarettes. In this study, gas-phase and particulate-phase free radicals as well as nicotine yields were quantified in mainstream cigarette smoke from five popular Chinese brands and two research cigarettes (3R4F and 1R6F). Mainstream smoke was generated under International Organization of Standardization (ISO) and Canadian Intense (CI) smoking regimens using a linear smoking machine. Levels of free radicals and nicotine were measured by electron paramagnetic resonance spectroscopy (EPR) and gas chromatography with flame-ionization detection, respectively. Under the ISO puffing regimen, Chinese brand cigarettes produced an average of 3.0 ± 1.2 nmol/cig gas-phase radicals, 118 ± 44.7 pmol/cig particulate-phase radicals, and 0.6 ± 0.2 mg/cig nicotine. Under the CI puffing regimen, Chinese brand cigarettes produced an average of 5.6 ± 1.2 nmol/cig gas-phase radicals, 282 ± 92.1 pmol/cig particulate-phase radicals, and 2.1 ± 0.4 mg/cig nicotine. Overall, both gas- and particulate-phase free radicals were substantially lower compared to the research cigarettes under both regimens, whereas no significant differences were observed for nicotine levels. When Chinese brands were compared, the highest free radical and nicotine yields were found in "LL" and "BS" brands, while lowest levels were found in "YY". These results suggested that the lower radical delivery by Chinese cigarettes compared to United States reference cigarettes may be associated with reductions in oxidant-related harm.

Simple-to-use nomogram for evaluating the incident risk of moderate-to-severe LEAD in adults with type 2 diabetes: A cross-sectional study in a Chinese population

This study aimed to analyze the clinical characteristics of lower extremity atherosclerotic disease (LEAD) in Chinese adult type 2 diabetes (T2D) patients, and also explored the risk factors for LEAD and developed simple-to-use nomograms for LEAD and lesion degree in these patients. We retrospectively studied 4422 patients (male = 2084; female = 2338) with T2D who were ≥50. Based on lower extremity arterial ultrasound findings, we divided the patients into three groups: normal, mild, and moderate-to-severe group. The factors related to LEAD in patients with T2D were analyzed by logistic regression analysis. The risk factors for moderate-to-severe LEAD included: high HbA1c (OR = 1.07 95% CI 1.02–1.13), diabetic peripheral neuropathy (OR = 1.93 95% CI 1.57–2.37), and diabetic retinopathy (OR = 1.26 95%CI 1.01–1.57). The overall areas under the receiver operating characteristic curves for the nomograms for predicting the risks of LEAD and moderate-to-severe LEAD in adult T2D patients were 0.793 (95%CI 0.720, 0.824) and 0.736 (95%CI 0.678, 0.795), respectively. The developed nomograms are simple to use and enable preliminary visual prediction of the risk and degree of LEAD in Chinese T2D patients over 50 years. The nomograms are accurate to a certain degree and provide a clinical basis for predicting the occurrence and progression of LEAD.

Underutilization of Evidence-Based Smoking Cessation Support Strategies Despite High Smoking Addiction Burden in Peripheral Artery Disease Specialty Care: Insights from the International PORTRAIT Registry

Background

Smoking is the most important risk factor for peripheral artery disease (PAD). Smoking cessation is key in PAD management. We aimed to examine smoking rates and smoking cessation interventions offered to patients with PAD consulting a vascular specialty clinic; and assess changes in smoking behavior over the year following initial visit.

Methods and Results

A total of 1272 patients with PAD and new or worsening claudication were enrolled at 16 vascular specialty clinics (2011–2015, PORTRAIT (Patient‐Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) registry). Interviews collected smoking status and cessation interventions at baseline, 3, 6, and 12 months. Among smokers, transition state models analyzed smoking transitions at each time point and identified factors associated with quitting and relapse. On presentation, 474 (37.3%) patients were active, 660 (51.9%) former, and 138 (10.8%) never smokers. Among active smokers, only 16% were referred to cessation counseling and 11% were prescribed pharmacologic treatment. At 3 months, the probability of quitting smoking was 21%; among those continuing to smoke at 3 months, the probability of quitting during the next 9 months varied between 11% and 12% (P<0.001). The probability of relapse among initial quitters was 36%. At 12 months, 72% of all smokers continued to smoke.

Conclusions

More than one third of patients with claudication consulting a PAD provider are active smokers and few received evidence‐based cessation interventions. Patients appear to be most likely to quit early in their treatment course, but many quickly relapse and 72% of all patients smoking at baseline are still smoking at 12 months. Better strategies are needed to provide continuous cessation support.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01419080.

Associations between habitual flavonoid intake and hospital admissions for atherosclerotic cardiovascular disease: a prospective cohort study

BACKGROUND

Flavonoids, compounds found in plant-based foods and beverages, might ameliorate vascular damage and atherosclerosis. Therefore, our aim was to assess the association between flavonoid intake and hospital admissions due to atherosclerotic cardiovascular disease.

METHODS

In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study were cross-linked with Danish nationwide registries. Eligible participants were aged 50-65 years, had no previous history of atherosclerotic cardiovascular disease, and had completed a food-frequency questionnaire at baseline. We examined associations between flavonoid intake (calculated from food-frequency questionnaires with use of the Phenol-Explorer database) and hospital admissions for atherosclerotic cardiovascular disease, ischaemic heart disease, ischaemic stroke, or peripheral arterial disease. We obtained hazard ratios (HRs) using restricted cubic splines based on Cox proportional hazards models.

FINDINGS

Of the participants recruited to the Danish Diet, Cancer, and Health study between 1993 and 1997, our study population was comprised of 53 552 participants, with a median follow-up of 21 years (IQR 15-22). During follow-up, 8773 participants were admitted to hospital for atherosclerotic cardiovascular disease. We observed non-linear associations between flavonoid intake and hospital admissions, plateauing at total flavonoid intakes of approximately 1000 mg per day. Compared with an intake of 175 mg per day, an intake of 1000 mg per day was associated with a 14% lower risk of atherosclerotic cardiovascular disease (HR 0·86, 95% CI 0·81-0·91). For disease subtypes, we observed a 9% lower risk of ischaemic heart disease (0·91, 0·85-0·98), a non-significant 9% lower risk of ischaemic stroke (0·91, 0·82-1·01), and a 32% lower risk of peripheral artery disease (0·68, 0·60-0·78). The overall associations were stronger in smokers than in non-smokers, as well as stronger in consumers of high (>20 g per day) quantities of alcohol than in those consuming low-to-moderate (≤20 g per day) quantities.

INTERPRETATION

Our results suggest that ensuring an adequate consumption of flavonoid-rich foods, particularly in subpopulations at risk of atherosclerosis such as smokers and consumers of high quantities of alcohol might mitigate some of the risk of atherosclerotic cardiovascular disease. More studies are needed to support and validate these data.

FUNDING

Danish Cancer Society.

Determinants of frailty development and progression using a multidimensional frailty index: Evidence from the English Longitudinal Study of Ageing

Objective

To identify modifiable risk factors for development and progression of frailty in older adults living in England, as conceptualised by a multidimensional frailty index (FI).

Methods

Data from participants aged 50 and over from the English Longitudinal Study of Ageing (ELSA) was used to examine potential determinants of frailty, using a 56-item FI comprised of self-reported health conditions, disabilities, cognitive function, hearing, eyesight, depressive symptoms and ability to carry out activities of daily living. Cox proportional hazards regression models were used to measure frailty development (n = 7420) and linear regression models to measure frailty progression over 12 years follow-up (n = 8780).

Results

Increasing age (HR: 1.08 (CI: 1.08–1.09)), being in the lowest wealth quintile (HR: 1.79 (CI: 1.54–2.08)), lack of educational qualifications (HR: 1.19 (CI: 1.09–1.30)), obesity (HR: 1.33 (CI: 1.18–1.50) and a high waist-hip ratio (HR: 1.25 (CI: 1.13–1.38)), being a current or previous smoker (HR: 1.29 (CI: 1.18–1.41)), pain (HR: 1.39 (CI: 1.34–1.45)), sedentary behaviour (HR: 2.17 (CI: 1.76–2.78) and lower body strength (HR: 1.07 (CI: 1.06–1.08)), were all significant risk factors for frailty progression and incidence after simultaneous adjustment for all examined factors.

Conclusion

The findings of this study suggest that there may be scope to reduce both frailty incidence and progression by trialling interventions aimed at reducing obesity and sedentary behaviour, increasing intensity of physical activity, and improving success of smoking cessation tools. Furthermore, improving educational outcomes and reducing poverty may also reduce inequalities in frailty.

Common risk factors for major noncommunicable disease, a systematic overview of reviews and commentary: the implied potential for targeted risk reduction

Noncommunicable disease now contributes to the World Health Organization top 10 causes of death in low-, middle- and high-income countries. Particular examples include stroke, coronary heart disease, dementia and certain cancers. Research linking clinical and lifestyle risk factors to increased risk of noncommunicable disease is now well established with examples of confirmed risk factors, including smoking, physical inactivity, obesity and hypertension. However, despite a need to target our resources to achieve risk reduction, relatively little work has examined the overlap between the risk factors for these main noncommunicable diseases. Our high-level review draws together the evidence in this area. Using a systematic overview of reviews, we demonstrate the likely commonality of established risk factors having an impact on multiple noncommunicable disease outcomes. For example, systematic reviews of the evidence on physical inactivity and poor diet found each to be associated with increased risk of cancers, coronary heart disease, stroke, diabetes mellitus and dementia. We highlight the potential for targeted risk reduction to simultaneously impact multiple noncommunicable disease areas. These relationships now need to be further quantified to allow the most effective development of public health interventions in this area.

Oxidative Stress in Peripheral Arterial Disease (PAD) Mechanism and Biomarkers

Hemodynamic dysfunction mainly characterizes pathophysiology of peripheral arterial disease (PAD) leading to chronic ischemia. Hemodynamic dysfunction is the origin of intermittent claudication (chronic PAD) or of critical limb ischemia (very severe PAD). Notably, it is well known that oxidative stress (OxS) plays a pathophysiological role in PAD. The higher production of reactive oxygen species (ROS) from OxS and reduced redox capability are two crucial players in initiating and progressing PAD. A number of biomarkers highlight OxS and monitor it in PAD. The present review summarizes data on OxS, on biomarkers available to mark OxS occurrence and to monitor on PAD progression, as well as to evaluate the effects treatments in PAD patients. In conclusion, by detailing OxS and its biomarkers, we hope to encourage more studies to focus on drugs which combat OxS and inflammation.

Observational study of the medical management of patients with peripheral artery disease

BACKGROUND

Previous research has suggested that patients with peripheral artery disease (PAD) are not offered adequate risk factor modification, despite their high cardiovascular risk. The aim of this study was to assess the cardiovascular profiles of patients with PAD and quantify the survival benefits of target-based risk factor modification.

METHODS

The Vascular and Endovascular Research Network (VERN) prospectively collected cardiovascular profiles of patients with PAD from ten UK vascular centres (April to June 2018) to assess practice against UK and European goal-directed best medical therapy guidelines. Risk and benefits of risk factor control were estimated using the SMART-REACH model, a validated cardiovascular prediction tool for patients with PAD.

RESULTS

Some 440 patients (mean(s.d.) age 70(11) years, 24·8 per cent women) were included in the study. Mean(s.d.) cholesterol (4·3(1·2) mmol/l) and LDL-cholesterol (2·7(1·1) mmol/l) levels were above recommended targets; 319 patients (72·5 per cent) were hypertensive and 343 (78·0 per cent) were active smokers. Only 11·1 per cent of patients were prescribed high-dose statin therapy and 39·1 per cent an antithrombotic agent. The median calculated risk of a major cardiovascular event over 10 years was 53 (i.q.r. 44-62) per cent. Controlling all modifiable cardiovascular risk factors based on UK and European guidance targets (LDL-cholesterol less than 2 mmol/l, systolic BP under 140 mmHg, smoking cessation, antiplatelet therapy) would lead to an absolute risk reduction of the median 10-year cardiovascular risk by 29 (20-38) per cent with 6·3 (4·0-9·3) cardiovascular disease-free years gained.

CONCLUSION

The medical management of patients with PAD in this secondary care cohort was suboptimal. Controlling modifiable risk factors to guideline-based targets would confer significant patient benefit.

Inflammation and Peripheral Arterial Disease

Peripheral arterial disease (PAD) is an atherosclerotic disease closely associated with high morbidity and mortality in cardiac events. Inflammation is crucial in atherosclerosis both at triggering and in progression. Numerous inflammatory biomarkers (cytokines, matrix metalloproteinases (MMPs), selectin, intracellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM) C-reactive protein (CRP), fibrinogen) have been measured in atherosclerotic diseases including PAD. This paper summarizes the data on the inflammatory biomarkers for PAD pathophysiology and highlights the most useful markers in monitoring PAD outcomes.

Cigarette Smoking and Subclinical Peripheral Arterial Disease in Blacks of the Jackson Heart Study

Background Prevalence of peripheral artery disease ( PAD ) is significantly higher among blacks as compared with non-Hispanic whites, but the role of cigarette smoking in PAD is understudied in blacks. We aimed to evaluate the relationship between cigarette smoking and PAD in blacks in the (JHS) Jackson Heart Study. Methods and Results JHS participants (n=5306) were classified by self-reported baseline smoking status into current, past (smoked at least 400 cigarettes/life), or never smokers. We examined multivariable logistic and robust linear regression models to estimate the associations between baseline smoking status, smoking intensity, and measures of subclinical PAD (ankle-brachial index [visit 1] and aortic calcium by computed tomography [visit 2]) to yield odds ratios and β-coefficients (estimated adjusted difference) to compare each smoking status with never smokers (reference group). There were 3579 (68%) never smokers, 986 (19%) past smokers, and 693 (13%) current smokers self-identified at baseline. After adjustment for covariates, current smokers had increased risk of ankle-brachial index <1 (odds ratio, 2.2, 95% CI, 1.5-3.3) and increased risk of abdominal aortic (odds ratio, 8.4, 95% CI, 5.8-12.0) and aortoiliac calcium (odds ratio, 9.6, 95% CI, 6.7-13.7). When stratifying by smoking intensity, those smoking more than 20 cigarettes daily (1 pack) had higher likelihood of subclinical PAD by all of these measures compared with lower-intensity use, suggesting a dose-dependent relationship. Conclusions In a large black cohort, cigarette smoking was associated with measures of subclinical PAD in a dose-dependent manner. These findings highlight the association between smoking and PAD in blacks and support further research exploring the impact of interventions on smoking cessation to reduce PAD in this population.

Nicotine dependence as an independent risk factor for atherosclerosis in the National Lung Screening Trial

Background

Atherosclerosis and COPD are systemic inflammatory diseases that share common risk factors including cigarette smoking. A high level of nicotine dependence is emerging as a recently identified risk factor for pulmonary impairment, chronic obstructive pulmonary disease and tobacco-related cancers. We hypothesized that nicotine dependence is associated with the risk of atherosclerosis in long-term cigarette smokers.

Methods

A nested case-control study was conducted within the National Lung Cancer Screening Trial- American College of Radiology Imaging Network. Cases were defined as having a new diagnosis of any type of atherosclerosis. Controls were matched on a 2:1 basis by age, sex, race, study center, smoking status, years of smoking, and frequency of smoking. Dependence was measured by the time to first cigarette after awakening (TTFC).

Results

The study included 166 cases and 286 controls. Compared to participants who smoked within 5 min after waking, the risk of atherosclerosis for participants who smoked an hour or more after waking was borderline non-significant (odds ratio = 0.49, 95% confidence intervals [CI] 0.23, 1.00). Findings were similar for men and women. For aortic atherosclerosis, the corresponding odds ratio was 0.24 (95% CI 0.08, 0.69). Hypertension was associated with an increased risk and body mass index was associated with a decreased risk of aortic atherosclerosis. The TTFC was unrelated to coronary atherosclerosis.

Conclusions

Compared to smoking immediately after waking, delaying an hour or more reduces the risk of aortic atherosclerosis even among long-term heavy smokers. Possible mechanisms that explain this association are intensity of smoking, inflammation and oxidative stress, and elevated lipid levels.