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.

Exposure to second hand smoke and 10-year (2002-2012) incidence of cardiovascular disease in never smokers: The ATTICA cohort study

BACKGROUND

Despite WHO Framework Convention of Tobacco Control (FCTC) adoption, effective implementation of national smoking bans remains pending in several countries. This study quantified the association of second hand smoke (SHS) exposure and 10-year cardiovascular disease (CVD) among never smokers in such settings.

METHODS

In 2001-2002, a sample of 1514 males and 1528 females (range: 18-89 years old) were randomly selected in Greece. Frequency and duration of SHS exposure (i.e. exposure extending >30 min/day) within the home and/or workplace were assessed by interview. Following a 10-year follow-up period (2002-2012), incidence of non-fatal and fatal CVD (ICD-10) was evaluated among n = 2020 participants. The analytic study sample consisted of all never smokers (n = 910).

RESULTS

Despite national smoking ban implementation (2009), 44.6% (n = 406) of never smokers reported SHS exposure. While SHS exposed never smokers exhibited a more favorable profile of CVD-related risk factors at baseline, they subsequently developed similar 10-year CVD incidence rates, at a younger mean age (p = 0.001), than their non-exposed counterparts. Following adjustment for several lifestyle and clinical factors, SHS exposed never smokers exhibited a two-fold elevated 10-year CVD risk (adj. HR: 2.04, 95% CI: 1.43-2.92), particularly among women (adj. HR: 2.45, 95% CI: 1.45-4.06). SHS exposure accounted for 32% excess Population Attributable Risk (PAR) for 10-year CVD events in never smokers, with highest rates (PAR: 52%) being among those exposed in the workplace.

CONCLUSION

The prevention of SHS associated CVD and related healthcare costs mandates additional strategies for securing the effective implementation of comprehensive WHO FCTC based national smoking bans.

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.