Secondhand smoke exposure and intermittent claudication: a Scotland-wide study of 4231 non-smokers

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.

Association between secondhand smoke exposure and hypertension: nearly as large as smoking

: Active smoking is a widely accepted risk factor for cardiovascular disease and is recognized as a major public health problem. Passive smoking, also known as secondhand smoke exposure (SHSE), is thought to have similar cardiovascular consequences and the risk has been postulated to be equivalent to that of active smoking. A major component of this risk involves the connection with chronic hypertension. There are several population-based observational studies investigating the relationship between SHSE and chronic hypertension, all of which demonstrate a positive association. Given that SHSE appears to be a risk factor for chronic hypertension, SHSE should also be a risk factor for hypertensive end-organ disease. Many studies have sought to investigate this relationship, but this has yet to be fully elucidated. In this review, we focus on the current evidence regarding the association between SHSE and hypertension as well as exploration of the links between SHSE and hypertensive end-organ damage.

Peripheral arterial disease in Scottish military veterans: a retrospective cohort study of 57 000 veterans and 173 000 matched non-veterans

BACKGROUND

While traumatic limb loss in military personnel is widely known, the threat posed by peripheral arterial disease (PAD) in those who have served is less well recognized. The aim of our study was to examine the risk of PAD in a Scotland-wide cohort of veterans who served between 1960 and 2012.

METHODS

Retrospective 30-year cohort study of 56 205 veterans born 1945-85, and 172 741 non-veterans, matched for age, sex and area of residence, using Cox proportional hazard models to examine the association between veteran status, birth cohort, length of service and risk of PAD leading to hospitalization or death.

RESULTS

Overall, veterans were at increased risk of PAD compared with non-veterans, unadjusted hazard ratio (HR) = 1.46, 95% confidence intervals (CI): 1.33-1.60, P < 0.001. The highest risk was in veterans born between 1950 and 1954, HR = 1.76, 95% CI: 1.50-2.07, P < 0.001, and in those with the shortest service (early service leavers), HR = 1.84, 95% CI: 1.49-2.27, P < 0.001.

CONCLUSIONS

The findings provide evidence for a hidden burden of life- and limb-threatening PAD in older veterans and are consistent with the higher rates of military smoking which have been reported previously. The study emphasizes the need for vascular preventive measures in this group.

Secondhand smoke exposure and risk of incident peripheral arterial disease and mortality: a Scotland-wide retrospective cohort study of 4045 non-smokers with cotinine measurement

BACKGROUND

Active smoking is an important risk factor for all-cause mortality and peripheral arterial disease (PAD). In contrast, published studies on the associations with secondhand smoke (SHS) are limited. The aim of this study was to examine the associations between SHS exposure and incident PAD, as well as mortality, among middle-aged non-smokers.

METHODS

We undertook a retrospective, cohort study using record linkage of the Scottish Health Surveys between 1998 and 2010 to hospital admissions and death certificates. Inclusion was restricted to participants aged > 45 years. Cox proportional hazard models were used to examine the association between SHS exposure and incident PAD (hospital admission or death) and all-cause mortality, with adjustment for potential confounders.

RESULTS

Of the 4045 confirmed non-smokers (self-reported non-smokers with salivary cotinine concentrations < 15 ng/mL), 1163 (28.8%) had either moderate or high exposure to SHS at baseline. In men, high exposure to SHS (cotinine ≥2.7 ng/mL) was associated with increased risk of all-cause mortality (fully adjusted hazard ratio [HR] 1.54, 95% CI 1.07-2.22, p = 0.020) with evidence of a dose-relationship (p for trend = 0.004). In men, high exposure to SHS was associated with increased risk of incident PAD over the first five years of follow-up (fully adjusted HR 4.29, 95% CI 1.14-16.10, p = 0.031) but the association became non-significant over longer term follow-up.

CONCLUSIONS

SHS exposure was independently associated with all-cause mortality and may be associated with PAD, but larger studies, or meta-analyses, are required to confirm the latter.

Exposure to secondhand smoke and risk of peripheral arterial disease in southern Chinese non-smokers: The Guangzhou Biobank Cohort Study-Cardiovascular Disease Sub-cohort

Objectives

We studied the association between secondhand smoke (SHS) exposure and peripheral arterial disease (PAD) in Chinese non-smokers.

Methods

We conducted a cross-sectional study using baseline data from the Guangzhou Biobank Cohort Study: Cardiovascular Disease Sub-cohort Study (GBCS-CVD). Guangzhou residents aged ≥ 50 years were recruited between 2003 and 2008. Baseline data included measurement of ankle brachial pressure index (ABPI) and self-reported smoking status and SHS exposure. Univariate and multivariate logistic regression analyses were used to analyze the association between SHS and PAD (defined as ABPI < 0.9).

Results

Of the 1507 non-smokers, 24 (1.6%) had PAD. Of these, 12 were men and 12 were women. Exposure to SHS at home of ≥25 h per week was reported by 16.7% of PAD cases compared with 3.8% of those without PAD (χ2 test, p = 0.003). After adjustment for potential confounders, exposure to ≥25 h per week at home was still associated with PAD (adjusted OR 7.86, 95% CI 2.00–30.95, p = 0.003), with suggestion of a dose-response relationship.

Conclusions

Our results extend the US Surgeon General’s 2006 report that SHS exposure is an independent risk factor for PAD. National smoke-free legislation is needed to protect all people from exposure.

Legislative smoking bans for reducing harms from secondhand smoke exposure, smoking prevalence and tobacco consumption

BACKGROUND

Smoking bans have been implemented in a variety of settings, as well as being part of policy in many jurisdictions to protect the public and employees from the harmful effects of secondhand smoke (SHS). They also offer the potential to influence social norms and the smoking behaviour of those populations they affect. Since the first version of this review in 2010, more countries have introduced national smoking legislation banning indoor smoking.

OBJECTIVES

To assess the effects of legislative smoking bans on (1) morbidity and mortality from exposure to secondhand smoke, and (2) smoking prevalence and tobacco consumption.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialised Register, MEDLINE, EMBASE, PsycINFO, CINAHL and reference lists of included studies. We also checked websites of various organisations. Date of most recent search; February 2015.

SELECTION CRITERIA

We considered studies that reported legislative smoking bans affecting populations. The minimum standard was having an indoor smoking ban explicitly in the study and a minimum of six months follow-up for measures of smoking behaviour. Our search included a broad range of research designs including: randomized controlled trials, quasi-experimental studies (i.e. non-randomized controlled studies), controlled before-and-after studies, interrupted time series as defined by the Cochrane Effective Practice and Organisation of Care Group, and uncontrolled pre- and post-ban data.

DATA COLLECTION AND ANALYSIS

One author extracted characteristics and content of the interventions, participants, outcomes and methods of the included studies and a second author checked the details. We extracted health and smoking behaviour outcomes. We did not attempt a meta-analysis due to the heterogeneity in design and content of the studies included. We evaluated the studies using qualitative narrative synthesis.

MAIN RESULTS

There are 77 studies included in this updated review. We retained 12 studies from the original review and identified 65 new studies. Evidence from 21 countries is provided in this update, an increase of eight countries from the original review. The nature of the intervention precludes randomized controlled trials. Thirty-six studies used an interrupted time series study design, 23 studies use a controlled before-and-after design and 18 studies are before-and-after studies with no control group; six of these studies use a cohort design. Seventy-two studies reported health outcomes, including cardiovascular (44), respiratory (21), and perinatal outcomes (7). Eleven studies reported national mortality rates for smoking-related diseases. A number of the studies report multiple health outcomes. There is consistent evidence of a positive impact of national smoking bans on improving cardiovascular health outcomes, and reducing mortality for associated smoking-related illnesses. Effects on respiratory and perinatal health were less consistent. We found 24 studies evaluating the impact of national smoke-free legislation on smoking behaviour. Evidence of an impact of legislative bans on smoking prevalence and tobacco consumption is inconsistent, with some studies not detecting additional long-term change in existing trends in prevalence.

AUTHORS' CONCLUSIONS

Since the first version of this review was published, the current evidence provides more robust support for the previous conclusions that the introduction of a legislative smoking ban does lead to improved health outcomes through reduction in SHS for countries and their populations. The clearest evidence is observed in reduced admissions for acute coronary syndrome. There is evidence of reduced mortality from smoking-related illnesses at a national level. There is inconsistent evidence of an impact on respiratory and perinatal health outcomes, and on smoking prevalence and tobacco consumption.

[Recent Knowledge of Smoking and Peripheral Arterial Disease in Lower Extremities]

Peripheral arterial disease (PAD) is an atherosclerotic obstructive disease of the arteries in lower extremities. Patients with PAD show high rates of mortality from coronary artery disease (CAD) and stroke. Smoking as well as diabetes is an important risk factor for PAD. A lesion of PAD in the lower extremities tends to be more proximal in smokers than in nonsmokers and to be more distal in patients with diabetes than in nondiabetics. By a systematic review, the odds ratio for PAD of smokers vs nonsmokers has been reported to be in the range of 1.7-7.4. Previous epidemiological studies suggest a stronger association of smoking with PAD than that with CAD. Nitric oxide (NO) is an important molecule suppressing the progression of atherosclerosis, but this function is compromised by smoking. Smoking decreases the bioactivity of NO and the expression level of NO synthase. In addition, smoking results in deteriorations of risk factors for atherosclerosis such as decreases in blood HDL (high-density lipoprotein) cholesterol and tissue plasminogen activator levels and increases in the levels of blood triglycerides, LDL (low-density lipoprotein) cholesterol, fibrinogen and the von Willebrand factor. Thus, smoking increases blood coagulability and deteriorates the blood lipid profile, resulting in thrombogenetic proneness and dyslipidemia. Smoking also increases the generation of atherogenic oxidized LDL in blood and decreases antiatherogenic prostacyclin production in the vascular endothelium. Smoking cessation is important for the prevention and therapy of PAD, and to this end, counseling by physicians and nicotine replacement therapy are useful and strongly recommended for patients with PAD.

The anti-inflammatory activities of ethanol extract from Dan-Lou prescription in vivo and in vitro

Background

Although, Dan-Lou prescription (DLP) is used for antagonizing check discomfort and heartache, the pharmacological mechanism has not been clearly illustrated. Our present study aimed to design inflammatory models induced by LPS in vivo and in vitro to investigate the anti-inflammation of DLP ethanol extract (EEDL) and the potential mechanisms.

Methods

EEDL was prepared and then analyzed by high performance liquid chromatography (HPLC). Further, the anti-inflammatory effects of EEDL in vivo was evaluated by measuring inflammation-associated factors includingcytokines, chemokines and acute phase proteins in lipopolysaccharide (LPS)-induced mice serum and liver. The anti-inflammatory mechanism exploration of EEDL was performed in LPS-stimulated RAW 264.7 cells. Different effects of EEDL on nitric oxide (NO) and prostaglandin (PG)E₂ secretion were investigated by Griess reagent method and enzyme-linked immunosorbent assay (ELISA) respectively. Then the mRNA and protein expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 were measured by real-time reverse-transcription polymerase chain reaction (RT-PCR), ELISA and Western blot. Other chemokines and acute phase proteins were determined by proteome profile array. Finally, the ELISA based transcription factor assay was applied to measure the DNA-binding activity of nuclear transcription factor (NF)-κB p65.

Results

Eight compounds from EEDL have been identified as gallic acid, salvianic acid, puerarin, daidzin, paeoniflorin, salvianolic acid B, cryptotanshinone, and tanshinone IIA, with amounts of 0.26, 9.84, 10.41, 2.55, 9.44, 3.82, 0.24 and 0.3 mg/kg, respectively. In vivo, EEDL administration antagonized the up-regulation of more than 17 kinds of cytokines, chemokines and acute phase proteins in LPS-treated mice serum, and inhibited LPS-induced IL-6 mRNA and protein expression in mice liver tissue. In vitro, LPS-induced NO and PGE₂ over-productions were decreased by EEDL treatment. The mRNA and protein expression of iNOS, COX-2 and IL-6 were similarly inhibited by EEDL treatment, which might be attributed to decrease the DNA-binding activity of NF-κB p65.

Conclusion

EEDL was valid for anti-inflammation and the potential molecular mechanisms might be due to the inhibition of of LPS-induced iNOS/NO, COX-2/PGE₂ and cytokines expression by antagonizing the activation of NF-κB p65.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-015-0848-4) contains supplementary material, which is available to authorized users.

Epidemiology of peripheral artery disease

New data on the epidemiology of peripheral artery disease (PAD) are available, and they should be integrated with previous data. We provide an updated, integrated overview of the epidemiology of PAD, a focused literature review was conducted on the epidemiology of PAD. The PAD results were grouped into symptoms, diagnosis, prevalence, and incidence both in the United States and globally, risk factors, progression, coprevalence with other atherosclerotic disease, and association with incident cardiovascular morbidity and mortality. The most common symptom of PAD is intermittent claudication, but noninvasive measures, such as the ankle-brachial index, show that asymptomatic PAD is several times more common in the population than intermittent claudication. PAD prevalence and incidence are both sharply age-related, rising >10% among patients in their 60s and 70s. With aging of the global population, it seems likely that PAD will be increasingly common in the future. Prevalence seems to be higher among men than women for more severe or symptomatic disease. The major risk factors for PAD are similar to those for coronary and cerebrovascular disease, with some differences in the relative importance of factors. Smoking is a particularly strong risk factor for PAD, as is diabetes mellitus, and several newer risk markers have shown independent associations with PAD. PAD is strongly associated with concomitant coronary and cerebrovascular diseases. After adjustment for known cardiovascular disease risk factors, PAD is associated with an increased risk of incident coronary and cerebrovascular disease morbidity and mortality.

Pharmacology in peripheral arterial disease: what the interventional radiologist needs to know

Peripheral arterial disease (PAD) is a progressive disease with significant morbidity and mortality. Risk factor control, using diet and lifestyle modification, exercise, and pharmacological methods, improves symptoms and reduces associated cardiovascular events in these patients. Antiplatelet agents and anticoagulants may be used to reduce the incidence of acute events related to thrombosis. The armamentarium available for symptom relief and disease modification is discussed. Novel treatments such as therapeutic angiogenesis are in their evolutionary phase with promising preclinical data.

Association between salivary cotinine and cardiovascular biomarkers among nonsmokers and current smokers: cross-sectional study of 10,081 participants

OBJECTIVE

Both active smoking and exposure to secondhand smoke (SHS) are associated with cardiovascular disease, but sidestream smoke contains higher levels of small particles and toxic gases than mainstream smoke. The relationship between the concentration of cotinine and a number of cardiovascular biomarkers among nonsmokers and active smokers was examined.

METHODS

A cross-sectional study using the Scottish Health Surveys conducted between 1998 and 2010 was undertaken. Inclusion was restricted to participants aged ≥16 years who had provided saliva and blood samples. Uni- and multivariate regression models were used to examine the relationships between the concentration of cotinine and C-reactive protein (CRP), high-density lipoprotein (HDL) cholesterol, and fibrinogen concentrations, as well as total:HDL cholesterol ratios.

RESULTS

Of the 10,018 eligible participants, 7,345 (73.3%) were confirmed to be nonsmokers (cotinine <15.0 ng/mL) and 2,673 (26.7%) were confirmed to be current smokers (cotinine ≥15.0 ng/mL). CRP and total:HDL cholesterol increased, and HDL cholesterol decreased, with increasing cotinine concentration across nonsmokers and smokers (all p < .001). However, there were step changes at the interface, whereby nonsmokers with a high exposure to SHS had lower concentrations of cotinine than light active smokers but comparable concentrations of CRP (p = .709), HDL cholesterol (p = .931), and total:HDL cholesterol (p = .405). Fibrinogen concentrations were significantly raised in moderate and heavy active smokers only (both p < .001).

CONCLUSION

Exposure to SHS is associated with disproportionately higher biomarkers of cardiovascular risk compared with active smoking. Protection from exposure to SHS should be a public health priority.

Modeling the effects of indoor passive smoking at home, work, or other households on adult cardiovascular and mental health: the Scottish Health Survey, 2008-2011

Passive smoking has contributed increased risks of cardiovascular disease, mental health, and mortality, but the cumulative effects from work or other households were less studied. Therefore, it was aimed to model the effects of indoor passive smoking from own home, work, and other households in a country-wide, population-based setting. Data in the Scottish Health Survey between 2008 and 2011 after the law banning smoking in public places were analyzed. Information including demographics, lifestyle factors, and self-reported cardiovascular disease and mental health was obtained by household interview. Analyses included chi-square test and survey-weighted logistic regression modeling. After full adjustment, it was observed that being exposed to indoor passive smoking, in particular in more than two places of exposure, was significantly associated with risks of stroke, angina, heart attack, abnormal heart rhythms, and GHQ ≥ 12. The significance remained for angina, GHQ ≥ 12 and probably heart attack in never smokers. The cumulative risks also impacted on sleep problems, self-recognition, making decisions, self-confidence, under strain constantly, depressed, happiness and self-worth. The significance remained for sleep problems, self-confidence, under strain constantly, depressed, and happiness in never smokers. Elimination of indoor passive smoking from different sources should still be a focus in future public health programs.