Smoking intensity (pack/day) is a better measure than pack-years or smoking status for modeling cardiovascular disease outcomes

Cigarette Smoking and Risk of Hospitalization With Acute Kidney Injury: The Atherosclerosis Risk in Communities (ARIC) Study

RATIONALE & OBJECTIVE

Smoking is a modifiable risk factor for various adverse events. However, little is known about the association of smoking with the incidence of acute kidney injury (AKI) in the general population. This study investigated the association of cigarette smoking with the risk of AKI.

STUDY DESIGN

Prospective observational study.

SETTING & PARTICIPANTS

14,571 participants (mean age 55±6 years, 55% women, and 25% Black participants) from the ARIC study visit 1 (1987-1989) followed through December 31, 2019.

EXPOSURE

Smoking parameters (status, duration, pack-years, intensity, and years since cessation).

OUTCOME

Incident hospitalization with AKI, defined by a hospital discharge with a diagnostic code relevant to AKI.

ANALYTICAL APPROACH

Multivariable Cox regression models.

RESULTS

Over a median follow-up period of 26.3 years, 2,984 participants had an incident hospitalization with AKI. Current and former smokers had a significantly higher risk of AKI compared to never smokers after adjusting for potential confounders (HR, 2.22 [95% CI, 2.02-2.45] and 1.12 [1.02-1.23], respectively). A dose-response association was consistently seen for each of smoking duration, pack-years, and intensity with AKI (eg, HR, 1.19 [95% CI, 1.16-1.22] per 10 years of smoking). When years since cessation were considered as a time-varying exposure, the risk of AKI associated with smoking compared with current smokers began to decrease after 10 years, and became similar to never smokers at 30 years (HR for≥30 years, 1.07 [95% CI, 0.97-1.20] vs never smokers).

LIMITATIONS

Self-reported smoking measurements and missing outpatient AKI cases.

CONCLUSIONS

In a community-based cohort, all smoking parameters were robustly associated with the risk of AKI. Smoking cessation was associated with decreased risk of AKI, although the excess risk lasted up to 30 years. Our study supports the importance of preventing smoking initiation and promoting smoking cessation for the risk of AKI.

PLAIN-LANGUAGE SUMMARY

Smoking is a behavior that is associated with many negative health effects. It is not well understood how smoking relates to the occurrence of acute kidney injury (AKI) in the community. In this study, we looked at data from a group of 14,571 adults who were followed for 26 years to see how different aspects of smoking (such as whether someone smoked, how long they smoked for, how many cigarettes they smoked per day, and whether they quit smoking) were related to AKI. We found that smoking was strongly linked to an increased risk of AKI. This risk decreased after 5-10 years of quitting smoking, but the excess risk lasted up to 30 years. This study shows the importance of preventing people from starting smoking and to encourage smokers to quit to reduce their risk of AKI.

Evidence relating cigarettes, cigars and pipes to cardiovascular disease and stroke: Meta-analysis of recent data from three regions

BACKGROUND

More recent data are required relating to disease risk for use of various smoked products and of other products containing nicotine. Earlier we published meta-analyses of recent results for chronic obstructive pulmonary disease and lung cancer on the relative risk (RR) of current compared to never product use for cigarettes, cigars and pipes based on evidence from North America, Europe and Japan. We now report corresponding up-to-date evidence for acute myocardial infarction (AMI), ischaemic heart disease (IHD) and stroke.

AIM

To estimate, using recent data, AMI, IHD and stroke RRs by region for current smoking of cigarettes, cigars and pipes.

METHODS

Publications in English from 2015 to 2020 were considered that, based on epidemiological studies in the three regions, estimated the current smoking RR of AMI, IHD or stroke for one or more of the three products. The studies should involve at least 100 cases of stroke or cardiovascular disease (CVD), not be restricted to populations with specific medical conditions, and should be of cohort or nested case-control study design or randomized controlled trials. A literature search was conducted on MEDLINE, examining titles and abstracts initially, and then full texts. Additional papers were sought from reference lists of selected papers, reviews and meta-analyses. For each study identified, we entered the most recent available data on current smoking of each product, as well as the characteristics of the study and the RR estimates. Combined RR estimates were derived using random-effects meta-analysis for stroke and, in the case of CVD, separately for IHD and AMI. For cigarette smoking, where far more data were available, heterogeneity was studied by a wide range of factors. For cigar and pipe smoking, a more limited heterogeneity analysis was carried out. A more limited assessment of variation in risk by daily number of cigarettes smoked was also conducted. Results were compared with those from previous meta-analyses published since 2000.

RESULTS

Current cigarette smoking: Ten studies gave a random-effects RR for AMI of 2.72 [95% confidence interval (CI): 2.40-3.08], derived from 13 estimates between 1.47 and 4.72. Twenty-three studies gave an IHD RR of 2.01 (95%CI: 1.84-2.21), using 28 estimates between 0.81 and 4.30. Thirty-one studies gave a stroke RR of 1.62 (95%CI: 1.48-1.77), using 37 estimates from 0.66 to 2.91. Though heterogeneous, only two of the overall 78 RRs were below 1.0, 71 significantly (P < 0.05) exceeding 1.0. The heterogeneity was only partly explicable by the factors studied. Estimates were generally higher for females and for later-starting studies. They were significantly higher for North America than Europe for AMI, but not the other diseases. For stroke, the only endpoint with multiple Japanese studies, RRs were lower there than for Western studies. Adjustment for multiple factors tended to increase RRs. Our RR estimates and the variations by sex and region are consistent with earlier meta-analyses. RRs generally increased with amount smoked. Current cigar and pipe smoking: No AMI data were available. One North American study reported reduced IHD risk for non-exclusive cigar or pipe smoking, but considered few cases. Two North American studies found no increased stroke risk with exclusive cigar smoking, one reporting reduced risk for exclusive pipe smoking (RR 0.24, 95%CI: 0.06-0.91). The cigar results agree with an earlier review showing no clear risk increase for IHD or stroke.

CONCLUSION

Current cigarette smoking increases risk of AMI, IHD and stroke, RRs being 2.72, 2.01 and 1.62. The stroke risk is lower in Japan, no increase was seen for cigars/pipes.

Association of Multiple Cardiovascular Risk Factors with Musculoskeletal Function in Acute Coronary Syndrome Ward Inpatients

This study explored the association of multiple risk factors with musculoskeletal function in adults hospitalized for acute coronary syndrome. Sixty-nine inpatients (55 ± 6 years; 67% male) admitted to the cardiology ward within <12 h were assessed regarding stress, smoking, alcoholism, hypertension, diabetes mellitus, and obesity. The musculoskeletal function was assessed by predicted values of handgrip strength of the dominant hand (HGS-D%) and maximal inspiratory and expiratory pressures (MIP% and MEP%, respectively). After adjustment by age and sex, drinking habits showed the strongest linear association with the total number of cardiovascular disease risk factors [standardized ß, p-value] (ß = 0.110, p < 0.001), followed by smoking load (ß = 0.028, p = 0.009). Associations were also observed for HGS-D% with mean blood pressure (ß = 0.019 [0.001; 0.037], p = 0.048); MIP% with mean blood pressure (ß = 0.025 [0.006; 0.043], p = 0.013); and MEP% with drinking habits (ß = 0.009 [0.002; 0.016], p = 0.013) and body mass index (ß = 0.008 [0.000; 0.015], p = 0.035). Peripheral and respiratory muscle strength must be interpreted in the context of its association with cardiovascular disease risk factors in adults hospitalized for acute coronary syndrome.

Effects of Smoking on Optic Nerve Head Microvasculature Density in Glaucoma

PRCIS

Decreased superficial whole image capillary density was observed in open angle glaucoma (OAG) patients with high smoking intensity.

PURPOSE

To investigate the effects of smoking on optic nerve head capillary density measured by optical coherence tomography angiography in patients with OAG.

METHODS

In this retrospective cross-sectional study, perimetric and preperimetric glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) with optical coherence tomography angiography follow-up were included. Univariable and multivariable linear mixed analysis were performed to determine the effects of different variables on the superficial whole image capillary density.

RESULTS

A total of 432 eyes of 271 glaucoma patients comprising 63 preperimetric (106 eyes) and 208 perimetric OAG (326 eyes) were included. A history of tobacco consumption was reported in 105 (38.8%). Among smokers, mean (95% confidence interval) smoking intensity was 12.8 (10.2, 15.5) pack-years. After adjusting for age, glaucoma severity and other confounders, each 10 pack-year increase in smoking intensity (95% confidence interval) was associated with -0.54 (-1.06, -0.02) % lower whole image capillary density ( P =0.041).

CONCLUSIONS

Smoking intensity is associated with reduced optic nerve vessel density in glaucoma.

Pattern of novel psychoactive substance use among patients presented to the poison control centre of Ain Shams University Hospitals, Egypt: A cross-sectional study

Background

Novel psychoactive substances (NPSs) are relatively new substances in the illicit drug market, not previously listed in the United Nations Office on Drugs and Crime (UNDOC). Strox and Voodoo are considered some of the most popular blends of NPS in the Egyptian drug market.

Objectives

The current study was conducted to assess NPS's use pattern: Voodoo and Strox among acutely intoxicated patients presented to the poison control center of Ain Shams University Hospitals (PCC- ASUH).

Methods

A single center based cross-sectional study was carried out in the PCC-ASUH among acutely intoxicated patients presenting to the emergency department (ED) over four months (from January–April 2019. using a previously adopted and validated Fahmy and El-Sherbini socioeconomic scale (SES). Data were presented as mean, median and range as appropriate. Both smoking and crowding indexes were calculated and presented as previously reported.

Results

Fifty-one patients were presented to the ED of PCC-ASUH during the study period. A total of 96.1% (n = 49) were males. The mean age was 25 ± 7.5 years. The most common NPS used was Strox: 54.9% (n = 28), followed by Voodoo: 27.4% (n = 14). Neurological and gastrointestinal (GI) symptoms were the most frequent presentations. The most common motive behind NPS use was the desire to give a trial of new psychoactive substances. The mean SES score was 35.1 ± 13.17. Most patients have the preparatory as the highest education 36.0% (n = 18).

Conclusions

NPS use is common among young males in preparatory education from different social classes, starting it most commonly as a means to experiencing a new high. Neurological and GI manifestations are the most common presenting symptoms of NPS intoxication.

Burden of current and past smoking across 28 European countries in 2017: A cross-sectional analysis

INTRODUCTION

Most studies use the prevalence of current smoking as an indicator to quantify the burden of smoking. However, length and intensity of smoking, as well as time since cessation for former smokers are also known to impact smoking-related health risks. The aim of this study was to quantify and compare the burden of smoking across the European Union (EU) using a range of smoking burden indicators.

METHODS

We conducted a cross-sectional analysis using data from the March 2017 Eurobarometer 87.1 (n=27901, people aged ≥15 years) in 28 European Union Member States (EU MS) and the Tobacco Control Scale. We defined five indicators of smoking burden including the prevalence of current and ever smoking, length of smoking, pack-years, and discounted pack-years, and ranked EU MS by each indicator. Two-level linear and logistic regressions were performed to assess the association between these indicators and sociodemographic and tobacco policy factors.

RESULTS

Wide variations across the EU countries were observed in all smoking burden indicators. While some MS ranked consistently high (e.g. Greece, France) or consistently low (e.g. Ireland, United Kingdom) in all indicators, we found substantial discrepancies in ranking depending on the indicator used for MS such as Malta, Denmark, Finland and the Netherlands. All indicators of smoking burden were lower among women and respondents without financial difficulties; however, the magnitude of those inequalities varied two-fold among the different indicators.

CONCLUSIONS

Using a range of smoking burden indicators can be more informative than relying on prevalence alone. Our analysis highlights the limitations of relying solely on prevalence of current smoking to estimate the burden of smoking and the potential value of more nuanced indicators. We recommend that multiple and more nuanced indicators that consider former smokers, intensity and duration of smoking should be utilized to monitor tobacco use and evaluate tobacco control policies.

Tobacco Consumption and High-Sensitivity Cardiac Troponin I in the General Population: The HUNT Study

Background

Cardiac troponins represent a sensitive index of subclinical myocardial injury and are associated with increased risk of cardiovascular events in the general population. Despite positive associations with cardiovascular risk of both cardiac troponins and cigarette smoking, concentrations of cardiac troponin I measured by high‐sensitivity assays (hs‐cTnI) are paradoxically lower in current smokers than in never‐smokers. The impact of smoking intensity and time from smoking cessation on hs‐cTnI remains unknown.

Methods and Results

hs‐cTnI concentrations were measured in 32028 subjects free from cardiovascular disease enrolled in the prospective, population‐based HUNT (Trøndelag Health Study). Tobacco habits were self‐reported and classified as never (n=14 559), former (n=14 248), and current (n=3221) smokers. Current smokers exhibited significantly lower concentrations of hs‐cTnI than never‐smokers (P<0.001). In adjusted models, both current smoking (−17.3%; 95% CI, −20.6 to −13.9%) and former smoking (−6.6%; 95% CI, −8.7 to −4.5%) were associated with significantly lower hs‐cTnI concentrations. Among former smokers, higher smoking burden (>10 pack‐years) were associated with lower concentrations of hs‐cTnI. Time since smoking cessation was associated with increasing concentrations of hs‐cTnI in a dose‐dependent manner (P for trend<0.001), and subjects who quit smoking >30 years ago had concentrations of hs‐cTnI comparable with those of never‐smokers.

Conclusions

In the general population, both current and former cigarette smoking is associated with lower concentrations of hs‐cTnI. In former smokers, there was a dose‐response relationship between pack‐years of smoking, and hs‐cTnI. Time since smoking cessation was associated with increasing concentrations of hs‐cTnI, indicating a continuum of hs‐cTnI from current smoker to never‐smokers.

The effect of short term exposure to outdoor air pollution on fertility

BACKGROUND

There is evidence to suggest that long term exposure to air pollution could be associated with decreased levels of fertility, although there is controversy as to how short term exposure may compromise fertility in IVF patients and what windows of exposure during the IVF process patients could be most vulnerable.

METHODS

This prospective cohort study aimed to evaluate the impact of acute exposure that air pollution have on reproductive outcomes in different moments of the IVF process. Women undergoing IVF living in Barcelona were recruited. Individual air pollution exposures were modelled at their home address 15 and 3 days before embryo transfer (15D and 3D, respectively), the same day of transfer (D0), and 7 days after (D7). The pollutants modelled were: PM_2.5 [particulate matter (PM) ≤2.5 μm], PM_coarse (PM between 2.5 and 10μm), PM₁₀ (PM≤10 μm), PM_2.5 abs, and NO₂ and NOx. Outcomes were analyzed using multi-level regression models, with adjustment for co-pollutants and confouding factors. Two sensitivity analyses were performed. First, the model was adjusted for subacute exposure (received 15 days before ET). The second analysis was based on the first transfer performed on each patient aiming to exclude patients who failed previous transfers.

RESULTS

One hundred ninety-four women were recruited, contributing with data for 486 embryo transfers. Acute and subacute exposure to PMs showed a tendency in increasing miscarriage rate and reducing clinical pregnancy rate, although results were not statistically significant. The first sensitivity analysis, showed a significant risk of miscarriage for PM_2.5 exposure on 3D after adjusting for subacute exposure, and an increased risk of achieving no pregnancy for PM_2.5, PM_coarse and PM₁₀ on 3D. The second sensitivity analysis showed a significant risk of miscarriage for PM_2.5 exposure on 3D, and a significant risk of achieving no pregnancy for PM2.5, PM_coarse and PM10 particularly on 3D. No association was observed for nitrogen dioxides on reproductive outcomes.

CONCLUSIONS

Exposure to particulate matter has a negative impact on reproductive outcomes in IVF patients. Subacute exposure seems to increase the harmful effect of the acute exposure on miscarriage and pregnancy rates. Nitrogen dioxides do not modify significantly the reproductive success.

Environmental Contaminant Body Burdens and the Relationship with Blood Pressure Measures Among Indigenous Adults

Supplemental Digital Content is available in the text.

Blood pressure (BP) increase cardiovascular disease (CVD) risk. Indigenous Canadians experience slightly higher CVD compared with nonIndigenous Canadians. This study examined the role of polychlorinated biphenyls (PCBs), other organic compound concentrations (OCs), and toxic metals on blood pressure measures among Indigenous Canadians.

Xanthine oxidase inhibitors are associated with reduced risk of cardiovascular disease

As previous studies have reported finding an association between hyperuricemia and the development of cardiovascular and chronic kidney disease, hyperuricemia is thought to be an independent risk factor for hypertension and diabetic mellitus. However, we have not been able to determine whether the use of xanthine oxidase inhibitors can reduce cardiovascular disease. The present study used the longitudinal data of the Fukushima Cohort Study to investigate the relationship between the use of xanthine oxidase inhibitors and cardiovascular events in patients with cardiovascular risks. During the 3-year period between 2012 and 2014, a total of 2724 subjects were enrolled in the study and followed. A total of 2501 subjects had hypertension, diabetic mellitus, dyslipidemia, or chronic kidney disease, and were identified as having cardiovascular risks. The effects of xanthine oxidase inhibitor use on the development of cardiovascular events was evaluated in these patients using a time to event analysis. During the observational periods (median 2.7 years), the incidence of cardiovascular events was 20.7 in subjects with xanthine oxidase inhibitor and 11.2 (/1000 person-years, respectively) in those without. Although a univariate Cox regression analysis showed that the risk of cardiovascular events was significantly higher in subjects administered xanthine oxidase inhibitors (HR = 1.87, 95% CI 1.19–2.94, p = 0.007), the risk was significantly lower in subjects administered a xanthine oxidase inhibitor after adjustment for covariates (HR = 0.48, 95% CI 0.26–0.91; p = 0.024) compared to those without. Xanthine oxidase inhibitor use was associated with reduced risk of cardiovascular disease in patients with cardiovascular risk factors.

Modifiable lifestyle factors in women with Takotsubo syndrome: A case-control study

BACKGROUND

There is limited information on the relationship between modifiable lifestyle factors and Takotsubo syndrome (TS).

OBJECTIVES

To determine the association of physical activity, smoking, alcohol use, and caffeinated coffee consumption with TS.

METHODS

This case-control study enrolled women with newly diagnosed TS (n = 45), women post-myocardial infarction (MI; n = 32), and healthy women volunteers (HC; n = 30). Information on physical activity, smoking, alcohol use, and caffeinated coffee consumption was collected 1-month post-discharge for TS and MI, and 1-month post-enrollment for HC.

RESULTS

TS women reported a higher prevalence of lifetime smoking and cigarette packs/day, greater coffee consumption, and less physical activity than HC. Associations with cigarette and coffee use remained significant in adjusted models. Physical activity, smoking, and coffee consumption were similar in TS and MI women.

CONCLUSIONS

Use of psychostimulants (caffeine and cigarettes) may play a role in TS pathophysiology. These findings need to be confirmed in larger, fully powered studies.

Impact of secondhand smoke exposure in former smokers on their subsequent risk of coronary heart disease: evidence from the population-based cohort of the Tehran Lipid and Glucose Study

OBJECTIVES

Cigarette smoking is an established, strong, and modifiable risk factor for coronary heart disease (CHD). However, little research has investigated CHD risk in former smokers who continue to be exposed to others’ cigarette smoke (former & secondhand smokers).

METHODS

In the Tehran Lipid and Glucose Study, a prospective population-based cohort (n=20,069) was followed up for a median period of 14.6 years. A subset of 8,050 participants of 30 years of age and older was analyzed, with first CHD events as the study outcome. Participants were categorized as never, former, current, secondhand, and former & secondhand smokers. Data on smoking intensity (cigarette/d) were also collected. A Cox proportional hazards regression model was applied to estimate the risk of CHD, taking into account the main potential confounders.

RESULTS

The mean age of participants was 46.10 ±11.38 years, and they experienced 1,118 first CHD events (with most CHD cases in former smokers) during the follow-up period. The risk of CHD was highest in current smokers, followed in order by former & secondhand, former, and secondhand smokers (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.65 to 2.39; HR, 1.55; 95% CI, 1.15 to 2.08; HR, 1.39; 95% CI, 1.12 to 1.72; HR, 1.27; 95% CI, 1.07 to 1.51, respectively), compared to never smokers. The risk of CHD increased with smoking intensity, which has been proposed as a preferable measure of smoking, indicating a dose-response pattern.

CONCLUSIONS

The elevated risk of CHD in former & secondhand smokers was a noteworthy finding, with possible implications for health policy; however, further research is needed.

Association of smoking and right ventricular function in middle age: CARDIA study

Objective

To evaluate the association of cigarette smoking and right ventricular (RV) systolic and diastolic functions in a population-based cohort of individuals at middle age.

Methods

This cross-sectional study included participants who answered the smoking questionnaire and underwent echocardiography at the Coronary Artery Risk Development in Young Adulthood year 25 examination. RV systolic function was assessed by echocardiographic-derived tricuspid annular plane systolic excursion (TAPSE) and by right ventricular peak systolic velocity (RVS'), while RV diastolic function was evaluated by early right ventricular tissue velocity (RVE'). Multivariable linear regression models assessed the relationship of smoking with RV function, adjusting for age, sex, race, body mass index, systolic blood pressure, total cholesterol, high-density lipoprotein (HDL) cholesterol, diabetes mellitus, alcohol consumption, pulmonary function, left ventricular systolic and diastolic function and coronary artery calcium score.

Results

A total of 3424 participants were included. The mean age was 50±4 years; 57% were female; and 53% were black. There were 2106 (61%) never smokers, 750 (22%) former smokers and 589 (17%) current smokers. In the multivariable analysis, current smokers had significantly lower TAPSE (β=-0.082, SE=0.031, p=0.008), RVS' (β=-0.343, SE=0.156, p=0.028) and RVE' (β=-0.715, SE=0.195, p<0.001) compared with never smokers. Former smokers had a significantly lower RVE' compared with never smokers (β=-0.414, SE=0.162, p=0.011), whereas no significant difference in RV systolic function was found between former smokers and never smokers.

Conclusions

In a large multicenter community-based biracial cohort of middle-aged individuals, smoking was independently related to both worse RV systolic and diastolic functions.

Smoking behavior and smoking index as prognostic indicators for patients with esophageal squamous cell carcinoma who underwent surgery: A large cohort study in Guangzhou, China

INTRODUCTION

This study aimed to evaluate the association between smoking and smoking index with clinical outcomes of esophageal squamous cell carcinoma patients.

METHODS

This is a retrospective analysis conducted on consecutive patients with esophageal carcinoma who underwent esophagectomy from January 2005 to December 2010. All patients had pathologically confirmed esophageal squamous cell carcinoma. The association between smoking and sociodemographic characteristics with overall survival and disease-free survival was analyzed. Serum carcinoembryonic antigen was measured using an electrochemiluminescence immunoassay.

RESULTS

A total of 944 patients were enrolled. Kaplan-Meier analysis indicated that esophageal squamous cell carcinoma patients who smoked had a significantly worse prognosis in terms of both overall survival (p=0.007) and disease-free survival (p= 0.010). Multivariate analysis demonstrated that age (p=0.001), carcinoembryonic antigen (p=0.012), tumor-node-metastasis (TNM) staging (p<0.001) and smoking (p=0.048) were independently correlated with overall survival, while only TNM stage (p<0.001) and smoking (p=0.041) were identified as independent factors of disease-free survival. We divided the smoking population into two groups (smoking index <400 and ≥400). Kaplan-Meier survival analysis indicated that a smoking index <400 was associated with a significantly better prognosis in terms of both overall survival (p=0.003) and favorable disease-free survival (p=0.032). Multivariate analysis showed that age (p<0.001), TNM staging (p<0.001), and smoking index (p=0.025) were independent factors of overall survival, whereas for disease-free survival, only TNM stage (p=0.001) and smoking index (p=0.025) were identified.

CONCLUSIONS

Overall survival was significantly associated with smoking in esophageal squamous cell carcinoma patients. For esophageal squamous cell carcinoma patients who smoke, a higher smoking index is associated with worse clinical outcomes. Therefore, smoking may be used as a predictive indicator for pretreatment evaluation and adjustment of treatment regimen.

Effects of Cigarette Smoking on Retinal and Choroidal Thickness: A Systematic Review and Meta-Analysis

Background

Cigarette smoking has been regarded as a risk factor for the incidence of a wide variety of chronic illness; however, its effect on thickness of the retina or choroid is still unknown.

Methods

A consummate literature search was conducted in PubMed and Embase up to January, 2018. The quantitative synthesis was conducted by Stata 12.0.

Results

A total of 13 observational studies were included in this meta-analysis. In this meta-analysis of all available observational studies, no significant effect of tobacco smoking on retinal or choroidal thickness change was detected. However, advanced analyses showed that smoking would influence the thickness of RNFL (average: SMD, −0.332; 95% CI, −0.637 to −0.027; inferior: SMD, −0.632; 95% CI, −1.092 to −0.172; and superior: SMD, −0.720; 95% CI, −0.977 to −0.463) and GCL (superior: SMD, −0.549; 95% CI, −0.884 to −0.215; inferior: SMD, −0.602; 95% CI, −0.938 to −0.265). Meanwhile, subgroup analyses demonstrated that the results based on studies in some regions (America and Africa) and cross-sectional studies showed a reduced choroidal thickness in smokers. No publication bias was detected in this study.

Conclusion

In conclusion, no significant effect of tobacco smoking on retinal or choroidal thickness change was detected. However, smoking would influence the thickness of RNFL and GCL. Future research on this field would help in the prevention and treatment of smoking-associated disorders.

Cigarette Smoking, Smoking Cessation, and Long-Term Risk of 3 Major Atherosclerotic Diseases

BACKGROUND

Public statements about the effect of smoking on cardiovascular disease are predominantly based on investigations of coronary heart disease (CHD) and stroke, although smoking is recognized as a strong risk factor for peripheral artery disease (PAD). No study has comprehensively compared the long-term association of cigarette smoking and its cessation with the incidence of 3 major atherosclerotic diseases (PAD, CHD, and stroke).

OBJECTIVES

The aim of this study was to quantify the long-term association of cigarette smoking and its cessation with the incidence of the 3 outcomes.

METHODS

A total of 13,355 participants aged 45 to 64 years in the ARIC (Atherosclerosis Risk In Communities) study without PAD, CHD, or stroke at baseline (1987 to 1989) were included. The associations of smoking parameters (pack-years, duration, intensity, and cessation) with incident PAD were quantified and contrasted with CHD and stroke using Cox models.

RESULTS

Over a median follow-up of 26 years, there were 492 PAD cases, 1,798 CHD cases, and 1,106 stroke cases. A dose-response relationship was identified between pack-years of smoking and 3 outcomes, with the strongest results for PAD. The pattern was consistent when investigating duration and intensity separately. A longer period of smoking cessation was consistently related to lower risk of PAD, CHD, and stroke, but a significantly elevated risk persisted up to 30 years following smoking cessation for PAD and up to 20 years for CHD.

CONCLUSIONS

All smoking measures showed significant associations with 3 major atherosclerotic diseases, with the strongest effect size for incident PAD. The risk due to smoking lasted up to 30 years for PAD and 20 years for CHD. Our results further highlight the importance of smoking prevention and early smoking cessation, and indicate the need for public statements to take PAD into account when acknowledging the impact of smoking on overall cardiovascular health.

Depressed Mood, Perceived Health Competence and Health Behaviors: aCross-Sectional Mediation Study in Outpatients with Coronary Heart Disease

BACKGROUND

Identifying potential mechanisms that link depressed mood with worse health behaviors is important given the prevalence of depressed mood in patients with coronary heart disease (CHD) and its relationship with subsequent mortality. Perceived health competence is an individual's confidence in his/her ability to successfully engineer solutions to achieve health goals and may explain how depressed mood affects multiple health behaviors.

OBJECTIVE

Examine whether or not perceived health competence mediates the relationship between depressed mood and worse health behaviors.

DESIGN

A cross-sectional study conducted by the Patient-Centered Outcomes Research Institute-funded Mid-South Clinical Data Research Network between August 2014 and September 2015. Bootstrapped mediation was used.

PARTICIPANTS

Patients with coronary heart disease (n = 2334).

MAIN MEASURES

Two items assessing perceived health competence, a single item assessing depressed mood, and a Health Behaviors Index including: the International Physical Activity Questionnaire (IPAQ); select items from the National Adult Tobacco Survey and the Alcohol Use Disorder Inventory Test; and single items assessing diet and medication adherence.

KEY RESULTS

Depressed mood was associated with lower perceived health competence (a = - 0.21, p < .001) and lower perceived health competence was associated with worse performance on a Health Behaviors Index(b = 0.18, p < .001). Perceived health competence mediated the influence of depressed mood on health behaviors (ab = - 0.04, 95% CI = - 0.05 to - 0.03). The ratio of the indirect effect to the total effect was used as a measure of effect size (P_M = 0.26, 95% CI: 0.18 to 0.39).

CONCLUSIONS

Depressed mood is associated with worse health behaviors directly and indirectly via lower perceived health competence. Interventions to increase perceived health competence may lessen the deleterious impact of depressed mood on health behaviors and cardiovascular outcomes.

Cigarette smoking intensity informs outcomes after open revascularization for peripheral artery disease

OBJECTIVE

Cigarette smoking is the leading risk factor for peripheral artery disease (PAD). Existing literature often defines smoking history in broad categories of current, former, and never smokers, which may not sufficiently identify patients at the highest risk for poor outcomes. The purpose of this study was to examine the use of more informative categorization of smoking and to determine the association with important revascularization outcomes.

METHODS

We conducted a retrospective review of all patients undergoing open lower extremity revascularization for symptomatic PAD, defined as claudication (Rutherford 3) or critical limb ischemia (Rutherford 4-6), during a 5-year period (2013-2017). Smoking history, demographics, and comorbidities were abstracted from electronic health records from seven hospitals within our health care system. Smoking history was defined by intensity (packs/day), duration (years), pack-year history, and cessation time. Outcomes included major adverse limb events (MALEs), death, limb loss, and amputation-free survival. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals (CIs) for each parameter adjusted for patients' demographics and comorbidities. Cumulative incidence is reported for outcomes at 30, 180, and 365 days of follow-up.

RESULTS

We identified 693 patients undergoing open lower extremity revascularization for PAD (66% critical limb ischemia; 46% diabetes). The 1-year cumulative incidence of MALEs was 29.9% (95% CI, 26.4-33.9), whereas the 1-year incidence of death was 9.8% (95% CI, 7.5-12.7). The broad classification of current and former smokers identified no statistically significant differences in any measured outcomes. Patients who smoked more than one pack/day had 1.48 (95% CI, 1.01-2.16) times increase in risk of MALEs at 1 year compared with patients who smoked one or fewer packs/day. Patients who smoked more than one pack/day also had the highest 1-year amputation incidence (12.7%). Each of the four parameters was associated with increased risk of poor outcomes, although small sample size limited the precision of our estimates.

CONCLUSIONS

We found that smoking intensity is particularly informative of outcomes of patients undergoing open lower extremity revascularization for symptomatic PAD. These findings lay the groundwork for future research on relevant smoking history parameters and benefits of smoking reduction and cessation for clinicians to discuss with patients and to better understand and inform patients of intervention risks and expected outcomes.

Dose-dependent effect of smoking on risk of coronary heart disease, heart failure and stroke in individuals with type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to assess the potential dose-dependent effects of smoking on the risk of CHD, heart failure and stroke in individuals with type 1 diabetes.

METHODS

The study included 4506 individuals with type 1 diabetes who were participating in the Finnish Diabetic Nephropathy (FinnDiane) study. Intensity of smoking was estimated by packs per day and cumulative smoking by pack-years. Cox regression analyses were used to estimate the risk of incident CHD, heart failure or stroke during follow-up.

RESULTS

One pack per day significantly increased the risk of incident CHD in current smokers compared with never smokers (HR 1.45 [95% CI 1.15, 1.84]), after adjustment for age, sex, HbA_1c, hypertension, duration of diabetes and BMI. The risk of CHD in former smokers was similar to the risk in never smokers. The risk of incident heart failure was 1.43 (95% CI 1.03, 1.97) in current smokers per one pack per day and 1.37 (95% CI 1.05, 1.77) in former smokers, while the risk of incident stroke was 1.70 (95% CI 1.26, 2.29) and 1.49 (95% CI 1.14, 1.93), respectively. After further adjustments for lipids, however, the difference in the risk of heart failure in current and former smokers was no longer significant. Cumulative smoking data were similar to smoking intensity data.

CONCLUSIONS/INTERPRETATION

There is a dose-dependent association between smoking and cardiovascular disease in individuals with type 1 diabetes. In men in particular, the risk of incident stroke remains high even after smoking cessation and is increased in current and former smokers independently of other risk factors.

Usefulness of Lipoprotein-Associated Phospholipase A2 Activity and C-Reactive Protein in Identifying High-Risk Smokers for Atherosclerotic Cardiovascular Disease (from the Atherosclerosis Risk in Communities Study)

Despite the causal role of cigarette smoking in atherosclerotic cardiovascular disease (ASCVD), the underlying mechanisms are not fully understood. We evaluated the joint relation between smoking and inflammatory markers with ASCVD risk. We tested cross-sectional associations of self-reported smoking status (never, former, current) and intensity (packs/day) with lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and high-sensitivity C-reactive protein (hsCRP) in 10,506 Atherosclerosis Risk in Communities participants at Visit 4 (1996 to 1998). Using Cox hazard models adjusted for demographic and traditional ASCVD risk factors, we examined the associations of smoking status and intensity with incident adjudicated ASCVD events (n = 1,745 cases) over an average of 17 years, stratified by Lp-PLA2 and hsCRP categories. Greater packs/day smoked was linearly associated with higher levels of both Lp-PLA2 and hsCRP among current smokers. Compared with never smokers, the hazard ratio for incident ASCVD in current smokers was 2.04 (95% CI 1.76 to 2.35). Among current smokers, the risk for ASCVD per 1 pack/day greater was 1.39 (1.10 to 1.76). Both Lp-PLA2 activity ≥253 nmol/min/ml and hsCRP >3 mg/L identified current smokers at the highest risk for incident ASCVD, with similar hazard ratios. hsCRP risk-stratified current smokers better based on intensity. Among current smokers, hsCRP improved ASCVD prediction beyond traditional risk factors better than Lp-PLA2 (C-statistic 0.675 for hsCRP vs 0.668 for Lp-PLA2, p = 0.001). In this large cohort with long follow-up, we found a dose-response relation between smoking intensity with Lp-PLA2 activity, hsCRP, and ASCVD events. Although both Lp-PLA2 activity and hsCRP categories identified high risk among current smokers, hsCRP may better stratify risk of future ASCVD.

Associations of Cigarette Smoking With Subclinical Inflammation and Atherosclerosis: ELSA-Brasil (The Brazilian Longitudinal Study of Adult Health)

Background

There is a need to identify sensitive biomarkers of early tobacco‐related cardiovascular disease. We examined the association of smoking status, burden, time since quitting, and intensity, with markers of inflammation and subclinical atherosclerosis.

Methods and Results

We studied 14 103 participants without clinical cardiovascular disease in ELSA‐Brasil (Brazilian Longitudinal Study of Adult Health). We evaluated baseline cross‐sectional associations between smoking parameters and inflammation (high‐sensitivity C‐reactive protein [hsCRP]) and measures of subclinical atherosclerosis (carotid intima–media thickness, ankle‐brachial index, and coronary artery calcium [CAC]). The cohort included 1844 current smokers, 4121 former smokers, and 8138 never smokers. Mean age was 51.7±8.9 years; 44.8% were male. After multivariable adjustment, compared with never smokers, current smokers had significantly higher levels of hsCRP (β=0.24, 0.19–0.29 mg/L; P<0.001) and carotid intima–media thickness (β=0.03, 0.02–0.04 mm; P<0.001) and odds of ankle‐brachial index ≤1.0 (odds ratio: 2.52; 95% confidence interval, 2.06–3.08; P<0.001) and CAC >0 (odds ratio: 1.83; 95% confidence interval, 1.46–2.30; P<0.001). Among former and current smokers, pack‐years of smoking (burden) were significantly associated with hsCRP (P<0.001 and P=0.006, respectively) and CAC (P<0.001 and P=0.002, respectively). Among former smokers, hsCRP and carotid intima–media thickness levels and odds of ankle‐brachial index ≤1.0 and CAC >0 were lower with increasing time since quitting (P<0.01). Among current smokers, number of cigarettes per day (intensity) was positively associated with hsCRP (P<0.001) and CAC >0 (P=0.03) after adjusting for duration of smoking.

Conclusions

Strong associations were observed between smoking status, burden, and intensity with inflammation (hsCRP) and subclinical atherosclerosis (carotid intima–media thickness, ankle‐brachial index, CAC). These markers of early cardiovascular disease injury may be used for the further study and regulation of traditional and novel tobacco products.

The relationship between smoking intensity and subclinical cardiovascular injury: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Modern tobacco regulatory science requires an understanding of which biomarkers of cardiovascular injury are most sensitive to cigarette smoking exposure.

METHODS

We studied self-reported current smokers from the Multi-Ethnic Study of Atherosclerosis. Smoking intensity was defined by number of cigarettes/day and urinary cotinine levels. Subclinical cardiovascular injury was assessed using markers of inflammation [high-sensitivity C-reactive protein (hsCRP), interleukin 6 & 2 (IL-2 & IL-6), tumor necrosis factor alpha (TNF-α)], thrombosis (fibrinogen, D-dimer, homocysteine), myocardial injury (troponin T; TnT), endothelial damage (albumin: creatinine ratio), and vascular function [aortic & carotid distensibility, flow-mediated dilation (FMD)]. Biomarkers were modeled as absolute and percent change using multivariable-adjusted linear regression models adjusted for cardiovascular risk factors and smoking duration.

RESULTS

Among 843 current smokers, mean age was 58 (9) years, 53% were men, 39% were African American, mean number of cigarettes per day was 13 (10), and median smoking duration was 39 (15) years. Cigarette count was significantly associated with higher hsCRP, IL-6 and fibrinogen (β coefficients: 0.013, 0.011, 0.60 respectively), while ln-transformed cotinine was associated with the same biomarkers (β coefficients: 0.12, 0.04, 5.3 respectively) and inversely associated with aortic distensibility (β coefficient: -0.13). There was a limited association between smoking intensity and homocysteine, D-dimer, and albumin:creatinine ratio in partially adjusted models only, while there was no association with IL-2, TNF-α, carotid distensibility, FMD, or TnT in any model. In percent change analyses, relationships were strongest with hsCRP.

CONCLUSIONS

Smoking intensity was associated with early biomarkers of CVD, particularly, markers of systemic inflammation. Of these, hsCRP may be the most sensitive.