Prospective study on the effect of smoking and nicotine substitution on leucocyte blood counts and relation between blood leucocytes and lung function

Impact of switching from cigarette smoking to tobacco heating system use on biomarkers of potential harm in a randomized trial

BACKGROUND

Smoking cessation reduces the risk of developing smoking-related diseases. Although smoking prevalence has declined, many continue smoking cigarettes. Switching completely to smoke-free alternatives like the Tobacco Heating System (THS) 2.2-a heated tobacco product for which there is evidence demonstrating significantly reduced formation and exposure to harmful chemicals compared to cigarettes-has the potential to reduce the harm caused by continuing to smoke cigarettes.

METHODS

We conducted a 6-month clinical study (NCT02396381) with a 6-month extension (NCT02649556), initially randomizing 984 adult smokers to continue smoking or switch to THS (non-mentholated), of which 672 continued into the extension study. Endpoints were evaluated at baseline and at 3, 6, and 12 months. We longitudinally assessed biomarkers of potential harm (BoPHs) known to be reversible upon smoking cessation as indicators of pathways involved in the pathogenesis of cardiovascular or respiratory diseases and carcinogenicity. The need to cough and safety profile were also assessed. Impact on eight key BoPHs was used as a proxy to evaluate harm reduction potential.

RESULTS

At 12 months, comparison of BoPH levels between the predominant THS use and cigarette smoking groups showed a positive effect in favor of switching, partially or in full, to THS.

CONCLUSION

These results provide additional evidence of the harm reduction potential of THS for smokers who would otherwise continue smoking, but they need to be verified in long-term confirmatory studies.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT0264955. Date of registration: January 7, 2016 https://clinicaltrials.gov/ct2/show/NCT02649556.

Association of immune cell composition with the risk factors and incidence of acute coronary syndrome

BACKGROUND

Although immune cells are involved in acute coronary syndrome (ACS), few studies have explored the association of incident ACS with the relative immune cell proportions. We aimed to investigate the association of immune cell proportions with the incidence and risk factors of ACS in the Dongfeng-Tongji cohort.

METHODS

We conducted the analyses with 38,295 subjects from the first follow-up of the Dongfeng-Tongji cohort, including DNA methylation profiles for 1570 individuals. The proportions of immune cell types were observed from routine blood tests or estimated from DNA methylation profiles. For both observed and estimated immune cell proportions, we tested their associations with risk factors of ACS by multivariable linear regression models. In addition, the association of each immune cell proportion with incident ACS was assessed by the Cox regression model and conditional logistic regression model, respectively, adjusting for the risk factors of ACS.

FINDINGS

The proportions of lymphocytes, monocytes, and neutrophils showed strong associations with sex, followed by diabetes. Moreover, sex and current smoking were the two factors with strongest association with the proportions of lymphocyte subtypes. The hazard ratio (HR) and 95% confidence interval (CI) of incident ACS per standard deviation (SD) increase in proportions of lymphocytes and neutrophils were 0.91 (0.85-0.96) and 1.10 (1.03-1.16), respectively. Furthermore, the OR (95% CI) of incident ACS per SD increase in proportions of NK cells, CD4⁺ T cells, and B cells were 0.88 (0.78-0.99), 1.15 (1.03-1.30), and 1.13 (1.00-1.26), respectively.

INTERPRETATION

The proportions of immune cells were associated with several risk factors of ACS, including sex, diabetes, and current smoking. In addition, proportion of neutrophils had a risk effect, while proportion of lymphocytes had a protective effect on the incidence of ACS. The protective effect of lymphocytes was probably driven by NK cells.

Biomarkers of Exposure and Potential Harm in Two Weeks of Smoking Abstinence: Changes in Biomarkers of Platelet Function, Oxidative Stress, and Inflammation

: Chronic cigarette smoking is a major risk factor for many serious diseases. While complete cessation of smoking is the best option to reduce harm from smoking, adverse impacts of smoking on health could persist for several years after cessation. Therefore, Biomarkers of Potential Harm (BoPH) are useful in interim evaluations of the beneficial effects of smoking cessation or switching to potentially lower-risk tobacco products. A 14-day smoking abstinence study was conducted under clinical confinement conditions and enrolled 70 subjects into younger (24–34 years, n = 33) and older (35–60 years, n = 37) age cohorts. Biomarkers of Exposure (BoE), which indicate exposure to nicotine and other toxicants, were measured at baseline, 7 and 14 days. Several BoPH including previously identified eicosanoids (leukotriene 4 (LTE4) and 2,3-dinor thromboxane 2 (2,3-d-TXB2) and others were evaluated. Significant declines in BoE, LTE4, 2,3-d-TXB2, neutrophils, WBC and select RBC, and arterial blood gas parameters were observed in both age cohorts at Days 7 and 14 compared to baseline, while other BoPH (e.g., FeNO) showed age-related effects. Rapid and reproducible reductions in LTE4, 2,3-d-TXB2 WBC, and neutrophil counts were consistently detected following smoking abstinence, indicating the value of these markers as useful BoPH.

Elevated Neutrophil to Lymphocyte Ratio in Older Adults with Cocaine Use Disorder as a Marker of Chronic Inflammation

Objective

The neutrophil to lymphocyte ratio (NLR) is a non-specific, easy-to-obtain marker of inflammation associated with morbidity and mortality in systemic, psychiatric, and age-related inflammatory conditions. Given the growing trend of substance use disorder (SUD) in older adults, and the relationship between inflammation and SUD elevated NLR may serve as a useful inflammatory biomarker of the combined burden of aging and SUD. The present study focused on cocaine use disorder (CUD) to examine if cocaine adds further inflammatory burden among older adults, by comparing NLR values between older adults with CUD and a non-cocaine using, aged-matched, nationally representative sample.

Methods

The dataset included 107 (86% male) participants (aged 50-65 years) with cocaine use disorder. NLR was derived from complete blood count tests by dividing the absolute value of peripheral neutrophil concentration by lymphocyte concentration. For comparison, we extracted data from age-matched adults without CUD using the National Health and Nutrition Examination Survey. Individuals with immunocompromising conditions were excluded (e.g., rheumatoid arthritis and sexually transmitted infections such as HIV). A doubly-robust inverse probability-weighted regression adjustment (IPWRA) propensity score method was used to estimate group differences on NLR while controlling for potential confounding variables (age, gender, race, income, nicotine, marijuana and alcohol use).

Results

The IPWRA model revealed that the CUD sample had significantly elevated NLR in comparison to non-cocaine users, with a moderate effect size (β weight = 0.67).

Conclusion

Although non-specific, NLR represents a readily obtainable inflammatory marker for SUD research. CUD may add further inflammatory burden to aging cocaine users.

White Blood Cell Count and Risk of Incident Lung Cancer in the UK Biobank

Background

The contribution of measurable immunological and inflammatory parameters to lung cancer development remains unclear, particularly among never smokers. We investigated the relationship between total and differential white blood cell (WBC) counts and incident lung cancer risk overall and among subgroups defined by smoking status and sex in the United Kingdom (UK).

Methods

We evaluated 424 407 adults aged 37-73 years from the UK Biobank. Questionnaires, physical measurements, and blood were administered and collected at baseline in 2006-2010. Complete blood cell counts were measured using standard methods. Lung cancer diagnoses and histological classifications were obtained from cancer registries. Multivariable Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals of incident lung cancer in relation to quartiles (Q) of total WBC and subtype-specific counts, with Q1 as the reference.

Results

There were 1493 incident cases diagnosed over an average 7-year follow-up. Overall, the highest quartile of total WBC count was statistically significantly associated with elevated lung cancer risk (HR_Q4 = 1.67, 95% CI = 1.41 to 1.98). Among women, increased risks were found in current smokers (n _cases / n = 244 / 19 464, HR_Q4 = 2.15, 95% CI = 1.46 to 3.16), former smokers (n _cases / n = 280 / 69 198, HR_Q4 = 1.75, 95% CI = 1.24 to 2.47), and never smokers without environmental tobacco smoke exposure (n_cases / n = 108 / 111 294, HR_Q4 = 1.93, 95% CI = 1.11 to 3.35). Among men, stronger associations were identified in current smokers (n_{case s} / n = 329 / 22 934, HR_Q4 = 2.95, 95% CI = 2.04 to 4.26) and former smokers (n_{c ases} / n = 358/71 616, HR_Q4 = 2.38, 95% CI = 1.74 to 3.27) but not in never smokers. Findings were similar for lung adenocarcinoma and squamous cell carcinoma and were driven primarily by elevated neutrophil fractions.

Conclusions

Elevated WBCs could potentially be one of many important markers for increased lung cancer risk, especially among never-smoking women and ever-smoking men.

Total and differential white blood cell count in cannabis users: results from the cross-sectional National Health and Nutrition Examination Survey, 2005-2016

Background

Elevated white blood cell (WBC) count in tobacco cigarette smokers compared to non-smokers has been well documented, but little is known on circulating WBC counts and cannabis use.

Methods

The National Health and Nutrition Examination Survey (2005–2016) is designed to be nationally representative of United States non-institutionalized population. The current study includes adult participants 20–59 years of age (n = 16,430) who underwent a detailed examination in the mobile examination center (MEC). Cannabis use was measured using Audio Computer-Assisted Self-Interview. Cannabis use was classified into never, former, occasional (1–7 days of the past 30 days), and heavy (> 7 days of the past 30 days). WBC count was measured using the Coulter Counter method.

Results

Total WBC count was higher among heavy cannabis users when compared to never users (β = 189; 95% confidence interval: 74, 304, p = 0.001). Among circulating WBC types, modest differences were observed for neutrophil count. Neither former nor occasional cannabis use was associated with total or differential WBC counts.

Conclusions

A modest association between heavy cannabis use and WBC count was detected. Additional research is needed to understand the immune related effects of different modes of cannabis use and to elucidate the role of proinflammatory chemicals generated from smoking cannabis.

Electronic supplementary material

The online version of this article (10.1186/s42238-019-0007-8) contains supplementary material, which is available to authorized users.

Modulation of the extraneuronal cholinergic system on main innate response leukocytes

The expression of elements of the cholinergic system has been demonstrated in non-neuronal cells, such as immune cells, where acetylcholine modulates innate and adaptive responses. However, the study of the non-neuronal cholinergic system has focused on lymphocyte cholinergic mechanisms, with less attention to its role of innate cells. Considering this background, the aims of this review are 1) to review information regarding the cholinergic components of innate immune system cells; 2) to discuss the effect of cholinergic stimuli on cell functions; 3) and to describe the importance of cholinergic stimuli on host immunocompetence, in order to set the base for the design of intervention strategies in the biomedical field.

Total and differential white blood cell count in cannabis users: results from the cross-sectional National Health and Nutrition Examination Survey, 2005-2016

BACKGROUND

Elevated white blood cell (WBC) count in tobacco cigarette smokers compared to non-smokers has been well documented, but little is known on circulating WBC counts and cannabis use.

METHODS

The National Health and Nutrition Examination Survey (2005-2016) is designed to be nationally representative of United States non-institutionalized population. The current study includes adult participants 20-59 years of age (n= 16,430) who underwent a detailed examination in the mobile examination center (MEC). Cannabis use was measured using Audio Computer-Assisted Self-Interview. Cannabis use was classified into never, former, occasional (1-7 days of the past 30 days), and heavy (>7 days of the past 30 days). WBC count was measured using the Coulter Counter method.

RESULTS

Total WBC count was higher among heavy cannabis users when compared to never users (β = 189; 95% confidence interval: 74, 304, p = 0.001). Among circulating WBC types, modest differences were observed for neutrophil count. Neither former nor occasional cannabis use was associated with total or differential WBC counts.

CONCLUSIONS

A modest association between heavy cannabis use and WBC count was detected. Additional research is needed to understand the immune related effects of different modes of cannabis use and to elucidate the role of proinflammatory chemicals generated from smoking cannabis.

Analysis of Short-Term Smoking Effects in PBMC of Healthy Subjects-Preliminary Study

Early structural changes exist in the small airways before the establishment of Chronic Obstructive Pulmonary Disease (COPD). These changes are believed to be induced by oxidation. The aim of this study was to analyze the influence of short-term smoking on the expression of the genes contributing to airway remodeling and their relationship with the oxidative status of human blood cells. Blood mononuclear cells were isolated from 16 healthy volunteers and treated with cigarette smoke ingredients (CSI): nicotine, 1-Nitrosodimethylamine, N-Nitrosopyrrolidyne, vinyl chloride, acetone, and acrolein. The expression of TGF-β1, TIMP-1, SOD1, and arginase I was determined by qPCR. Additionally, thiol groups and TBARs were assessed. CSI induced TGF and TIMP-1 expression in peripheral blood mononuclear cells (PBMC), and apocynin alleviated this effect. The changes were more noticeable in the smoking group (p < 0.05). TBARs concentrations were higher in smokers, and in this group, apocynin acted more effectively. SOD1 correlated with arginase expression in smokers (p < 0.05). MMP-9 showed a significant correlation with SOD1 in both groups, but only on the protein level. Blood cells appear to mirror the general changes caused by cigarette smoke ingredients, which seem to be connected with the oxidative status of the cell. Our findings indicate that a short period of smoking influences the gene expression and oxidative balance of blood cells, which might result in the development of serious disorders such as COPD.

Unhealthy smokers: scopes for prophylactic intervention and clinical treatment

BACKGROUND

Globally, tobacco use causes approximately 6 million deaths per year, and predictions report that with current trends; more than 8 million deaths are expected annually by 2030. Cigarette smokings is currently accountable for more than 480,000 deaths each year in United States (US) and is the leading cause of preventable death in the US. On average, smokers die 10 years earlier than nonsmokers and if smoking continues at its current proportion among adolescents, one in every 13 Americans aged 17 years or younger is expected to die prematurely from a smoking-related illness. Even though there has been a marginal smoking decline of around 5% in recent years (2005 vs 2015), smokers still account for 15% of the US adult population. What is also concerning is that 41,000 out of 480,000 deaths results from secondhand smoke (SHS) exposure. Herein, we provide a detailed review of health complications and major pathological mechanisms including mutation, inflammation, oxidative stress, and hemodynamic and plasma protein changes associated with chronic smoking. Further, we discuss prophylactic interventions and associated benefits and provide a rationale for the scope of clinical treatment.

CONCLUSIONS

Considering these premises, it is evident that much detailed translational and clinical studies are needed. Factors such as the length of smoking cessation for ex-smokers, the level of smoke exposure in case of SHS, pre-established health conditions, genetics (and epigenetics modification caused by chronic smoking) are few of the criteria that need to be evaluated to begin assessing the prophylactic and/or therapeutic impact of treatments aimed at chronic and former smokers (especially early stage ex-smokers) including those frequently subjected to second hand tobacco smoke exposure. Herein, we provide a detailed review of health complications and major pathological mechanisms including mutation, inflammation, oxidative stress, and hemodynamic and plasma protein changes associated with chronic smoking. Further, we discuss about prophylactic interventions and associated benefits and provide a rationale and scope for clinical treatment.

MicroRNA Signature of Cigarette Smoking and Evidence for a Putative Causal Role of MicroRNAs in Smoking-Related Inflammation and Target Organ Damage

BACKGROUND

Cigarette smoking increases risk for multiple diseases. MicroRNAs regulate gene expression and may play a role in smoking-induced target organ damage. We sought to describe a microRNA signature of cigarette smoking and relate it to smoking-associated clinical phenotypes, gene expression, and lung inflammatory signaling.

METHODS AND RESULTS

Expression profiling of 283 microRNAs was conducted on whole blood-derived RNA from 5023 Framingham Heart Study participants (54.0% women; mean age, 55±13 years) using TaqMan assays and high-throughput reverse transcription quantitative polymerase chain reaction. Associations of microRNA expression with smoking status and associations of smoking-related microRNAs with inflammatory biomarkers and pulmonary function were tested with linear mixed effects models. We identified a 6-microRNA signature of smoking. Five of the 6 smoking-related microRNAs were associated with serum levels of C-reactive protein or interleukin-6; miR-1180 was associated with pulmonary function measures at a marginally significant level. Bioinformatic evaluation of smoking-associated genes coexpressed with the microRNA signature of cigarette smoking revealed enrichment for immune-related pathways. Smoking-associated microRNAs altered expression of selected inflammatory mediators in cell culture gain-of-function assays.

CONCLUSIONS

We characterized a novel microRNA signature of cigarette smoking. The top microRNAs were associated with systemic inflammatory markers and reduced pulmonary function, correlated with expression of genes involved in immune function, and were sufficient to modulate inflammatory signaling. Our results highlight smoking-associated microRNAs and are consistent with the hypothesis that smoking-associated microRNAs serve as mediators of smoking-induced inflammation and target organ damage. These findings call for further mechanistic studies to explore the diagnostic and therapeutic use of smoking-related microRNAs.

Neutrophil Counts and Initial Presentation of 12 Cardiovascular Diseases: A CALIBER Cohort Study

BACKGROUND

Neutrophil counts are a ubiquitous measure of inflammation, but previous studies on their association with cardiovascular disease (CVD) were limited by small numbers of patients or a narrow range of endpoints.

OBJECTIVES

This study investigated associations of clinically recorded neutrophil counts with initial presentation for a range of CVDs.

METHODS

We used linked primary care, hospitalization, disease registry, and mortality data in England. We included people 30 years or older with complete blood counts performed in usual clinical care and no history of CVD. We used Cox models to estimate cause-specific hazard ratios (HRs) for 12 CVDs, adjusted for cardiovascular risk factors and acute conditions affecting neutrophil counts (such as infections and cancer).

RESULTS

Among 775,231 individuals in the cohort, 154,179 had complete blood counts performed under acute conditions and 621,052 when they were stable. Over a median 3.8 years of follow-up, 55,004 individuals developed CVD. Adjusted HRs comparing neutrophil counts 6 to 7 versus 2 to 3 × 10⁹/l (both within the 'normal' range) showed strong associations with heart failure (HR: 2.04; 95% confidence interval [CI]: 1.82 to 2.29), peripheral arterial disease (HR: 1.95; 95% CI: 1.72 to 2.21), unheralded coronary death (HR: 1.78; 95% CI: 1.51 to 2.10), abdominal aortic aneurysm (HR: 1.72; 95% CI: 1.34 to 2.21), and nonfatal myocardial infarction (HR: 1.58; 95% CI: 1.42 to 1.76). These associations were linear, with greater risk even among individuals with neutrophil counts of 3 to 4 versus 2 to 3 × 10⁹/l. There was a weak association with ischemic stroke (HR: 1.36; 95% CI: 1.17 to 1.57), but no association with stable angina or intracerebral hemorrhage.

CONCLUSIONS

Neutrophil counts were strongly associated with the incidence of some CVDs, but not others, even within the normal range, consistent with underlying disease mechanisms differing across CVDs. (White Blood Cell Counts and Onset of Cardiovascular Diseases: a CALIBER Study [CALIBER]; NCT02014610).

Treatment of hyperthyroidism with antithyroid drugs corrects mild neutropenia in Graves' disease

CONTEXT

Neutropenia secondary to antithyroid drug (ATD) therapy in Graves' disease (GD) is well recognized. However, the effect of hyperthyroidism, prior to and after ATD therapy, on neutrophil counts in patients with GD is unclear.

OBJECTIVE

To study the prevalence of neutropenia in newly diagnosed untreated GD and the effect of ATD on the neutrophil count.

DESIGN

Prospective study from August 2010 to December 2014.

SETTING

Endocrinology outpatient clinic in a single centre.

PATIENTS

Consecutive patients (n = 206) with newly diagnosed GD.

INTERVENTION

ATD therapy.

MAIN OUTCOME MEASURES

Prevalence and factors predicting neutropenia (<2 × 10⁹ /l) and change in neutrophil counts following ATD.

RESULTS

At diagnosis, 29 (14·1%) of GD individuals had neutropenia. Non-Caucasians [odds ratio (95% CI) of 4·06 (1·14-14·45), P = 0·03] and patients with higher serum thyroid hormone levels [OR 1·07 (1·02-1·13), P = 0·002 for serum FT3] were the only independent predictors of neutropenia. All patients with neutropenia had normalized blood neutrophil levels after achieving euthyroidism with ATD therapy. In patients in whom data were available posteuthyroidism (n = 149), change in neutrophil count after achieving euthyroidism was independently related to reduction in thyroid hormone levels (P < 0·01).

CONCLUSIONS

GD is associated with neutropenia in one in seven patients at diagnosis, especially in non-Caucasians and those with higher serum thyroid hormone levels. Neutrophil counts increase with treatment with ATD and are related to reduction in thyroid hormone concentrations. It is therefore important to check neutrophil levels in newly diagnosed patients with GD prior to commencing ATD therapy as otherwise low levels may incorrectly be attributed to ATD therapy.

Human cells involved in atherosclerosis have a sex

The influence of sex has been largely described in cardiovascular diseases. Atherosclerosis is a complex process that involves many cell types such as vessel cells, immune cells and endothelial progenitor cells; however, many, if not all, studies do not report the sex of the cells. This review focuses on sex differences in human cells involved in the atherosclerotic process, emphasizing the role of sex hormones. Furthermore, we report sex differences and issues related to the processes that determine the fate of the cells such as apoptotic and autophagic mechanisms. The analysis of the data reveals that there are still many gaps in our knowledge regarding sex influences in atherosclerosis, largely for the cell types that have not been well studied, stressing the urgent need for a clear definition of experimental conditions and the inclusion of both sexes in preclinical studies.

Current cigarette smoking is a reversible cause of elevated white blood cell count: Cross-sectional and longitudinal studies

While cigarette smoking is a well-recognized cause of elevated white blood cell (WBC) count, studies on longitudinal effect of smoking cessation on WBC count are limited. We attempted to determine causal relationships between smoking and elevated WBC count by retrospective cross-sectional study consisting of 37,972 healthy Japanese adults who had a health check-up between April 1, 2008 and March 31, 2009 and longitudinal study involving 1730 current smokers who had more than four consecutive annual health check-ups between April 1, 2007 and March 31, 2012. In the cross-sectional study, younger age, male gender, increased body mass index, no alcohol habit, current smoking, and elevated C-reactive protein level were associated with elevated WBC count. Among these factors, current smoking had the most significant association with elevated WBC count. In subgroup analyses by WBC differentials, smoking was significantly associated with elevated counts of neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Ex-smoking was not associated with elevated WBC count. In the longitudinal study, both WBC and neutrophil counts decreased significantly in one year after smoking cessation and remained down-regulated for longer than next two years. There was no significant change in either WBC or neutrophil count in those who continued smoking. These findings clearly demonstrated that current smoking is strongly associated with elevated WBC count and smoking cessation leads to recovery of WBC count in one year, which is maintained for longer than subsequent two years. Thus, current smoking is a significant and reversible cause of elevated WBC count in healthy adults.

Smoking and the Association Between Depressive Symptoms and Absolute Neutrophil Count in the Investigations Préventives et Cliniques Cohort Study

OBJECTIVES

Depressive symptoms have been associated with chronic low-grade inflammation, including elevated neutrophil count. Smokers often have both high neutrophil count and depressive symptoms. Thus, smoking could explain the cross-sectional association between depressive symptoms and neutrophil count.

METHODS

Total white blood cell count and subtypes, including absolute neutrophil, lymphocyte, monocyte, basophil, and eosinophil counts, were measured in 44,806 participants (28,534 men; mean [standard deviation] age = 38.9 [11.4] years), without a history of chronic disease or current medication. Depressive symptoms were assessed with the Questionnaire of Depression, Second Version, Abridged. Smoking status was self-reported and categorized in five classes. Sex, age, alcohol intake, self-rated health, body mass index, glycemia, physical activity, household composition, occupational status, and education were included as covariates. Associations were examined with general linear models and causal mediation analyses.

RESULTS

After adjustment for all covariates except smoking, depressive symptoms were positively associated with neutrophil count only (β = 5.83, standard error [SE] = 2.41, p = .014). After further adjustment for a semiquantitative measure of smoking, this association was no longer significant (β = 2.40, SE = 2.36, p = .30). Causal mediation analyses revealed that smoking mediated the association (p < .001), accounting for 57% of its total variance. In contrast, depressive symptoms were negatively associated with lymphocyte count in fully adjusted model only (β = -3.21, SE = 1.11, p = .004).

CONCLUSIONS

Smoking may confound or mediate the association between depressive symptoms and neutrophil count. These results advocate for including an accurate measure of smoking in future studies addressing this association. When considering the link between depression and inflammation, one should not overlook the noxious effects of smoking.

Do circulating blood cell types correlate with modifiable risk factors and outcomes in patients with acute coronary syndrome (ACS)?

AIMS

Atherosclerosis is an inflammatory process with different cardiovascular risk factors (CVRFs) contributing to its pathogenesis. We aimed to evaluate the specific relationship between circulating blood leukocytes, troponin I and CVRFs.

METHODS

We prospectively enrolled 959 patients with evidence of acute coronary syndrome either in form of unstable angina or STEMI or NSTEMI. Details demographic characteristics, CVRF and biochemical parameters such as total white blood cells (WBC), neutrophil, lymphocytes, platelet, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and troponin I were collected.

RESULTS

The results indicated that patients having either hypertension, diabetes or smoking habit had significantly higher levels of total WBC (p=0.013), neutrophil (p=0.029), NLR (p=0.029) and PLR (p=0.009). The level of troponin I was unaffected by these risk factors. Significant association of hypertension was found with total WBC (p=0.0392), lymphocytes (p=0.0384) and PLR (p=0.0027), whereas in diabetes and females all other leukocyte subtypes were significantly altered except for platelet and troponin I. Smokers had higher level of total WBC count (p=0.0033) and PLR (p=0.0464). No relationship between CVRFs and leukocytes was observed in males. The age independent effect was observed with PLR, whereas association with total WBC, lymphocytes, NLR, platelet was specific in older population. In younger patients NLR (p=0.0453) is more likely to be elevated. Mortality was significantly associated with changes in the leukocytes but not with the CVRF presence.

CONCLUSION

We demonstrate that the neutrophils, lymphocytes and total WBC along with its ratios predict mortality and are more likely to be elevated in presence of CVRFs.

Effect of intensity of cigarette smoking on haematological and lipid parameters

BACKGROUND

Smoking is the single largest preventable cause of disease and premature death and major tobacco related diseases like cancer costs India more than Rs.308.33 billion per year. Cigarette smoking increases the total peripheral blood leukocyte count but its effect on other haematological parameters is largely unexplored..

OBJECTIVE

To study the effect of smoking and its intensity on hematological and lipid parameters.

MATERIALS AND METHODS

This cross sectional study included 40 cigarette smokers and 40 non-smokers in the age range of 25 and 40 years at SRM Medical College, Kattangulathur, Tamilnadu, India. In this study the volunteers were otherwise healthy and the smokers were enquired about their intensity of smoking using smoking index. Common hematological and lipid parameters were measured in all subjects. Comparison of smoking status and its intensity among the study subjects were analysed using t-test and ANOVA..

RESULTS

There is a significant increase in levels of haemoglobin, hematocrit, total leukocyte count, total cholesterol, triglycerides, low density lipoprotein (LDL), very low density lipoprotein (VLDL) and reduced levels of high density lipoprotein (HDL) among the smokers. Heavy smokers showed significant dyslipidemia,increase in red blood cell count, total leukocyte count and neutrophil count.

CONCLUSION

Increase in hemoglobin, hematocrit, total leucocyte count and dyslipidemia were found significant among smokers and in heavy smokers there is dyslipidemia with increased RBC count, total leukocyte count with specific increase in neutrophils. As per the existing literature, these changes may lead to future fatal cardiac diseases among the smokers.

Differences in smoking associated DNA methylation patterns in South Asians and Europeans

BACKGROUND

DNA methylation is strongly associated with smoking status at multiple sites across the genome. Studies have largely been restricted to European origin individuals yet the greatest increase in smoking is occurring in low income countries, such as the Indian subcontinent. We determined whether there are differences between South Asians and Europeans in smoking related loci, and if a smoking score, combining all smoking related DNA methylation scores, could differentiate smokers from non-smokers.

RESULTS

Illumina HM450k BeadChip arrays were performed on 192 samples from the Southall And Brent REvisited (SABRE) cohort. Differential methylation in smokers was identified in 29 individual CpG sites at 18 unique loci. Interaction between smoking status and ethnic group was identified at the AHRR locus. Ethnic differences in DNA methylation were identified in non-smokers at two further loci, 6p21.33 and GNG12. With the exception of GFI1 and MYO1G these differences were largely unaffected by adjustment for cell composition. A smoking score based on methylation profile was constructed. Current smokers were identified with 100% sensitivity and 97% specificity in Europeans and with 80% sensitivity and 95% specificity in South Asians.

CONCLUSIONS

Differences in ethnic groups were identified in both single CpG sites and combined smoking score. The smoking score is a valuable tool for identification of true current smoking behaviour. Explanations for ethnic differences in DNA methylation in association with smoking may provide valuable clues to disease pathways.

Smoking cessation and COPD mortality among Japanese men and women: the JACC study

OBJECTIVE

To investigate an effect of smoking cessation on chronic obstructive pulmonary disease (COPD) mortality in Asians.

METHODS

The data was obtained from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). A total of 41465 Japanese men and 52662 Japanese women aged 40-79 years who had no history of COPD, asthma, other chronic lung diseases, cardiovascular disease or cancer were followed between 1988 and 2008.

RESULTS

During median 18-year of follow-up, there were 285 (251 men and 34 women) documented deaths from COPD. Multivariable-adjusted hazard ratios with 95% confidence intervals of COPD death were 4.46 (2.72-7.29) and 9.26 (4.19-20.5), respectively for current male and female smokers when compared to never smokers. Compared with current smokers, the multivariable HRs for 5-9 years and 10 years or more smoking cessation prior to baseline were 0.44 (0.22-0.87) and 0.36 (0.22-0.58) in men, respectively while the HR for never smokers was 0.30 (0.16-0.57). There were an insufficient number of COPD deaths in women to clarify this association.

CONCLUSION

Smoking cessation for ten years or more prior to enrollment reverses the excess risk of COPD mortality to a level similar to that observed among never smokers in men.

Ion channels in hematopoietic and mesenchymal stem cells

Hematopoietic stem cells (HSCs) reside in bone marrow niches and give rise to hematopoietic precursor cells (HPCs). These have more restricted lineage potential and eventually differentiate into specific blood cell types. Bone marrow also contains mesenchymal stromal cells (MSCs), which present multilineage differentiation potential toward mesodermal cell types. In bone marrow niches, stem cell interaction with the extracellular matrix is mediated by integrin receptors. Ion channels regulate cell proliferation and differentiation by controlling intracellular Ca(2+), cell volume, release of growth factors, and so forth. Although little evidence is available about the ion channel roles in true HSCs, increasing information is available about HPCs and MSCs, which present a complex pattern of K(+) channel expression. K(+) channels cooperate with Ca(2+) and Cl(-) channels in regulating calcium entry and cell volume during mitosis. Other K(+) channels modulate the integrin-dependent interaction between leukemic progenitor cells and the niche stroma. These channels can also regulate leukemia cell interaction with MSCs, which also involves integrin receptors and affects the MSC-mediated protection from chemotherapy. Ligand-gated channels are also implicated in these processes. Nicotinic acetylcholine receptors regulate cell proliferation and migration in HSCs and MSCs and may be implicated in the harmful effects of smoking.

Lung function and respiratory symptoms in a 1-year randomized smoking cessation trial of varenicline in COPD patients

There are few data concerning changes in lung function and respiratory symptoms in smokers with chronic obstructive pulmonary disease (COPD) weeks to months after quitting smoking. We examined serial changes in spirometry and Clinical COPD Questionnaire (CCQ) scores (measuring respiratory symptoms and health-related quality of life) in COPD participants by smoking status during a smoking cessation trial. In this randomized, double-blind trial, smokers with mild-to-moderate COPD were treated with varenicline 1 mg b.i.d. or placebo for 12 weeks and followed to Week 52. Primary endpoints of abstinence were previously reported. Secondary endpoints were mean changes from baseline in post-bronchodilator forced expired volume in 1 s (FEV(1)) and CCQ scores. Change from baseline in post-bronchodilator FEV(1) was significantly improved in continuous abstainers (121.8 mL) vs. continuous smokers (37.9 mL) at Week 12 (P = 0.0069), but not at Weeks 24 or 52. Mean change from baseline at Week 12 in CCQ Total Score was significantly better in continuous abstainers (-1.04) vs. continuous smokers (-0.53; P < 0.0001): this improvement was sustained at Weeks 24 and 52. In a 1-year cessation trial of smokers with COPD, continuous abstinence compared with continuous smoking significantly improved post-bronchodilator FEV(1) at Week 12 (although the difference narrowed subsequently) and CCQ Total Scores at Week 12, with sustained improvement thereafter. (

TRIAL REGISTRY

http://www.clinicaltrials.gov; trial identifier: NCT00285012).

Cholinergic activation of hematopoietic stem cells: role in tobacco-related disease?

Tobacco use is associated with an increase in the white blood cell (WBC) count. This association has been attributed to bronchopulmonary inflammation and/or infection. It is not known if nicotine itself may play a role. The objective of this study was to determine whether nicotine itself could affect the WBC count, and to determine whether this was due to a direct effect on hematopoietic stem cells (HSC). C57Bl6J mice received nicotine orally, and measurements of the WBC count, bone marrow and spleen cellularity, and HSC count were made. To determine the functionality of HSCs, irradiated animals received bone marrow transplants from vehicle or nicotine-treated mice. Nicotine increased leukocytes in the peripheral blood, bone marrow and spleen. The peripheral red cell and platelet count were unaffected. Nicotine increased the frequency of HSC in the bone marrow. Isolated long-term HSCs from nicotine-treated mice transplanted into irradiated mice regenerated all hematopoietic cell lineages, demonstrating the functional competence of those HSCs. HSCs expressed nicotinic acetylcholine receptors (nAChRs), as documented by FITC-conjugated alpha-bungarotoxin binding. Nicotine increased soluble Kit ligand, consistent with stem cell activation. In conclusion, the data suggest a new mechanism for the increased WBC associated with tobacco use. The effect of nicotine to activate hematopoiesis may contribute to tobacco-related diseases.

Systematic review of the evidence relating FEV1 decline to giving up smoking

BACKGROUND

The rate of forced expiratory volume in 1 second (FEV1) decline ("beta") is a marker of chronic obstructive pulmonary disease risk. The reduction in beta after quitting smoking is an upper limit for the reduction achievable from switching to novel nicotine delivery products. We review available evidence to estimate this reduction and quantify the relationship of smoking to beta.

METHODS

Studies were identified, in healthy individuals or patients with respiratory disease, that provided data on beta over at least 2 years of follow-up, separately for those who gave up smoking and other smoking groups. Publications to June 2010 were considered. Independent beta estimates were derived for four main smoking groups: never smokers, ex-smokers (before baseline), quitters (during follow-up) and continuing smokers. Unweighted and inverse variance-weighted regression analyses compared betas in the smoking groups, and in continuing smokers by amount smoked, and estimated whether beta or beta differences between smoking groups varied by age, sex and other factors.

RESULTS

Forty-seven studies had relevant data, 28 for both sexes and 19 for males. Sixteen studies started before 1970. Mean follow-up was 11 years. On the basis of weighted analysis of 303 betas for the four smoking groups, never smokers had a beta 10.8 mL/yr (95% confidence interval (CI), 8.9 to 12.8) less than continuing smokers. Betas for ex-smokers were 12.4 mL/yr (95% CI, 10.1 to 14.7) less than for continuing smokers, and for quitters, 8.5 mL/yr (95% CI, 5.6 to 11.4) less. These betas were similar to that for never smokers. In continuing smokers, beta increased 0.33 mL/yr per cigarette/day. Beta differences between continuing smokers and those who gave up were greater in patients with respiratory disease or with reduced baseline lung function, but were not clearly related to age or sex.

CONCLUSION

The available data have numerous limitations, but clearly show that continuing smokers have a beta that is dose-related and over 10 mL/yr greater than in never smokers, ex-smokers or quitters. The greater decline in those with respiratory disease or reduced lung function is consistent with some smokers having a more rapid rate of FEV1 decline. These results help in designing studies comparing continuing smokers of conventional cigarettes and switchers to novel products.

White cells count in smokers affected by rheumatic diseases

Evidence shows that tobacco smoking interacts with development of rheumatic diseases. Increase in white cells count (leukocytosis) is frequently present, and in smokers, it is considered a biomarker of cardiovascular risk. Aim of the study is to evaluate this biomarker in smokers with rheumatic diagnosis. We carried out an observational study on 115 rheumatic outpatients (26 men and 89 women) divided into two groups according to their smoking habit: one composed of 56 smokers, the other of 59 not smokers. Diagnosis and common routinary clinical parameters were collected. In the total sample, smokers were 48.69%. Most common diagnosis was osteoarthritis (OA) (40.87% of the total); smokers in OA women were 36.11%, smokers in OA men were 54.55%. Second most common diagnosis was rheumatoid arthritis (RA) (23.48% of the total); smokers in RA women were 40.91%; smokers in RA men were 80%. OA smokers showed a significant increase (P < 0.05) in white cells count when compared with OA not smokers. Between RA smokers and not smokers, any clinical difference was found. RA subjects following regular pharmacological treatment in the last 2 months were 84.61%. OA patients treated with drugs in the last 2 months were only 22.2%. Results seem to confirm that smoking habit may influence the development as well as gender distribution of rheumatic diseases. They show also that in absence of pharmacological treatment in smokers affected by OA leukocytosis (biomarker of cardiovascular risk) is observed.

Occupational health hazards in women beedi rollers in Bihar, India

We studied the health problems of 197 female beedi rollers in Patna, Bihar, India to ascertain the effects of beedi rolling on health. The study found that more than 70% of the beedi rollers suffered from eye, gastrointestinal and nervous problems while more than 50% of the respondents suffered from respiratory problems, mostly throat burning and cough. More than 75% of the respondents faced osteological problems. Total RBC, WBC and platelet counts of the beedi rollers were significantly lower in comparison to the control subjects. Differential leucocyte count showed significantly risen lymphocytes and eosinophils and lowered neutrophils and monocytes in the beedi rollers as compared to the control group. Haemoglobin levels were lower among beedi rollers compared to the control group. SGPT (ALT) enzyme concentration, a parameter of liver dysfunction was significantly higher in the beedi rollers as compared to the control group. Thus, the study concluded that beedi rolling may cause significant health hazards.

Deciphering normal blood gene expression variation--The NOWAC postgenome study

There is growing evidence that gene expression profiling of peripheral blood cells is a valuable tool for assessing gene signatures related to exposure, drug-response, or disease. However, the true promise of this approach can not be estimated until the scientific community has robust baseline data describing variation in gene expression patterns in normal individuals. Using a large representative sample set of postmenopausal women (N = 286) in the Norwegian Women and Cancer (NOWAC) postgenome study, we investigated variability of whole blood gene expression in the general population. In particular, we examined changes in blood gene expression caused by technical variability, normal inter-individual differences, and exposure variables at proportions and levels relevant to real-life situations. We observe that the overall changes in gene expression are subtle, implying the need for careful analytic approaches of the data. In particular, technical variability may not be ignored and subsequent adjustments must be considered in any analysis. Many new candidate genes were identified that are differentially expressed according to inter-individual (i.e. fasting, BMI) and exposure (i.e. smoking) factors, thus establishing that these effects are mirrored in blood. By focusing on the biological implications instead of directly comparing gene lists from several related studies in the literature, our analytic approach was able to identify significant similarities and effects consistent across these reports. This establishes the feasibility of blood gene expression profiling, if they are predicated upon careful experimental design and analysis in order to minimize confounding signals, artifacts of sample preparation and processing, and inter-individual differences.

As a major defence and transport system, blood cells are capable of adjusting gene expression in response to various clinical, biochemical, and pathological conditions. Here, we expand our understanding about the nature and extent of variation in gene expression from blood among healthy individuals. Using a large representative sample of postmenopausal women (N = 286) in the Norwegian Women and Cancer (NOWAC) postgenome study, we investigated blood gene expression changes due to normal inter-individuality (age, body mass index, fasting status), and exposure variables (smoking, hormone therapy, and medication use) at proportions and levels found in real life situations. Host genes were found to vary by inter-individual (i.e. fasting, BMI) and exposure (i.e. smoking) factors, and these gene lists may be used as a basis for further hypothesis development. Our study also establishes the feasibility of blood gene expression profiling for disease prediction, diagnosis, or prognosis, but underscores the necessity of care in study design and analysis to account for inter-individual differences and confounding signals.

Cardiovascular biomarkers in groups of established smokers after a decade of smoking

To investigate tools for evaluation of smoking-associated disease initiation and progression, we examined basic clinical parameters and biomarkers of cardiovascular disease risk, in a group of healthy volunteers with an average 10-year smoking history. A small cross-sectional study of never-smokers, moderate smokers and smokers was performed. Caucasians were recruited to match pre-defined cigarette tar yields and cigarettes smoked per day. For haematological parameters, significant differences between never-smokers and all female smokers combined were seen for haemoglobin concentration, haematocrit, total leucocyte count, neutrophil count and lymphocyte count. For all male smokers combined, only total leucocyte count was statistically different. Analysis of exhaled CO and other smoke exposure biomarker (nicotine and its metabolites) data showed a statistically significant increase in all groups of smokers with a trend related to the number of cigarettes smoked per day. Thromboxane urinary metabolites 11-dehydro-thromboxane B(2) and 2,3-dinor-thromboxane B(2) were statistically significantly elevated in smokers. Significant statistical differences between smokers with approximately 10 years of smoking history and non-smokers in white cells count, hemoglobin and thromboxane turnover were seen, although they did not reach levels associated with overt diseases. These data could provide insight into early biomarkers predictive of risk for coronary and vascular disease.

Variation in blood levels of inflammatory markers related and unrelated to smoking cessation in women

This study assessed the influence of short-term changes in smoking habit on blood levels of inflammatory markers, which have been associated with increased cardiovascular risk. Five inflammatory markers were measured before and 6 weeks after attempting smoking cessation in 138 healthy women. In the 48 participants who stopped smoking, white blood cell count (-0.7+/-1.2 x 10(9)/L; P<.001) and fibrinogen (-0.6+/-1.5 micromol/L; P<.01) decreased, but there was no significant (P>.1) change in the plasma level of C-reactive protein (median change +0.1; interquartile range -0.2, 0.9 mg/L), intercellular adhesion molecule 1 (+17+/-75 ng/mL), or CD40 ligand (+0.4+/-2.1 ng/mL). Most of the individual variation in inflammatory marker levels was unrelated to changes in smoking habit.

Cigarette smoke as a trigger for the dioxin receptor-mediated signaling pathway

Dioxins and dioxin-like chemicals cause a wide range of pathologies including carcinogenesis, immune dysfunction, and developmental/reproductive abnormalities. Most of these toxic effects are mediated by aryl hydrocarbon receptor (AhR; also called the dioxin receptor), a ligand-activated transcription factor. Constitutive activation of AhR via genetic manipulation causes development of cancers, inflammation and immune abnormality in mice even without exposure to xenobiotic ligands. Recent investigation disclosed that cigarette smoke contains high levels of agonists for AhR and strongly activates the dioxin signaling pathway. In this review, we describe and discuss possible roles of AhR activation in cigarette smoke-related pathologies, especially focusing on carcinogenesis, inflammation, atherosclerosis, immune dysfunction and teratogenesis.

Changes in markers of epithelial permeability and inflammation in chronic smokers switching to a nonburning tobacco device (Eclipse)

Eclipse, produced by R. J. Reynolds Tobacco Company, is a potential reduced exposure product (PREP) that heats rather than burns tobacco. We hypothesized that switching to Eclipse would result in relative normalization of pulmonary epithelial permeability, airway inflammation, and blood leukocyte activation in current smokers. We assessed 10 healthy smokers (aged 21-50 years, 19+/-8 pack-years) at baseline and after 2 and 4 weeks of switching to Eclipse, for symptoms, pulmonary function, airway inflammation, lung clearance of (99m)technicium-diethylenetriaminepentaacetic acid, and blood leukocyte activation and production of reactive oxygen species. Values were compared before and after Eclipse use and with those of healthy, lifetime nonsmokers (aged 18-53 years). Compared with baseline values before switching to Eclipse, lung permeability half-time increased from 33+/-3 to 43+/-6 min (p = .017) after 2 weeks and to 44+/-7 min (p = .10) after 4 weeks of Eclipse use. Carboxyhemoglobin levels increased from 5%+/-2% to 7%+/-2% (p<.01) at 4 weeks. Compared with smoking the usual brand of cigarettes, after smoking Eclipse the percentage of natural killer cells, the expression of intercellular adhesion molecule-1 on monocytes, and the expression of CD45RO on T cells showed significant improvement. However, expression of other surface markers, notably CD23 on monocytes, became more abnormal. Production of reactive oxygen species by smokers' neutrophils and monocytes increased further with Eclipse use. We found no significant effects on pulmonary function, cells in induced sputum, or exhaled nitric oxide. Switching to Eclipse reduces alveolar epithelial injury in some smokers but may increase carboxyhemoglobin levels and oxidative stress.

Smoking and Aortic Diseases

Cigarette smoking is a major vascular risk factor and in this context, it is an independent risk factor for the development of aortic disease, especially the formation and growth of abdominal aortic aneurysms (AAA). Medline was searched up to January 31, 2007 for the relevant literature for this review of the mechanisms by which smoking causes aortic wall damage and its subsequent impact on the clinical manifestation of this process. Idiopathic AAAs and aortic dissection are considered, as well as other aortic diseases (eg, Takayasu, Kawasaki, Behcet and Buerger). There is evidence suggesting an abnormal homeostasis between proteolytic and antiproteolytic activity in the vascular wall during the development of AAAs, and these mechanisms can be influenced by smoking. Smoking cessation plays an important role in the management of aortic disease.

Biomarkers to assess the utility of potential reduced exposure tobacco products

To date, we have no valid biomarkers that serve as proxies for tobacco-related disease to test potential reduced exposure products. This paper represents the deliberations of four workgroups that focused on four tobacco-related heath outcomes: Cancer, nonmalignant pulmonary disease, cardiovascular disease, and fetal toxicity. The goal of these workgroups was to identify biomarkers that offer some promise as measures of exposure or toxicity and ultimately may serve as indicators for future disease risk. Recommendations were based on the relationship of the biomarker to what is known about mechanisms of tobacco-related pathogenesis, the extent to which the biomarker differs among smokers and nonsmokers, and the sensitivity of the biomarker to changes in smoking status. Other promising biomarkers were discussed. No existing biomarkers have been demonstrated to be predictive of tobacco-related disease, which highlights the importance and urgency of conducting research in this area.

Biomarkers to assess the utility of potential reduced exposure tobacco products

To date, we have no valid biomarkers that serve as proxies for tobacco-related disease to test potential reduced exposure products. This paper represents the deliberations of four workgroups that focused on four tobacco-related heath outcomes: Cancer, nonmalignant pulmonary disease, cardiovascular disease, and fetal toxicity. The goal of these workgroups was to identify biomarkers that offer some promise as measures of exposure or toxicity and ultimately may serve as indicators for future disease risk. Recommendations were based on the relationship of the biomarker to what is known about mechanisms of tobacco-related pathogenesis, the extent to which the biomarker differs among smokers and nonsmokers, and the sensitivity of the biomarker to changes in smoking status. Other promising biomarkers were discussed. No existing biomarkers have been demonstrated to be predictive of tobacco-related disease, which highlights the importance and urgency of conducting research in this area.

Effects of biochemically confirmed smoking cessation on white blood cell count

OBJECTIVES

To determine the relationship between white blood cell (WBC) Indices and several baseline variables In a large cohort of healthy smokers and to assess whether these changed after biochemically confirmed smoking cessation.

SUBJECTS AND METHODS

The study consisted of 784 healthy smokers enrolled in a trial of sustained-release bupropion, 300 mg/d, for relapse prevention after smoking cessation from 1995 to 1998. Both WBC counts and absolute neutrophil counts (ANCs) were measured at baseline, week 7, and week 52. Smoking status was assessed at weeks 7 and 52 by self-report and biochemically confirmed with expired air carbon monoxide levels. Multivariate analyses compared changes in WBC count and ANC between smokers who did and did not stop smoking, adjusting for treatment group, age, sex, and body mass index.

RESULTS

Of 784 smokers enrolled, 461 had biochemically confirmed tobacco abstinence after 7 weeks of bupropion; 429 were randomly assigned to receive continued bupropion therapy or placebo until week 52. Between baseline and week 7, there was a significantly larger decrease in WBC count in continuously abstinent subjects compared with continuing smokers (adjusted P = .03). At 52 weeks, continuously abstinent subjects, compared with continuing smokers, had a greater decline from baseline in WBC count (1.2 +/- 1.9 x 10(9)/L vs 0.1 +/- 1.9 x 10(9)/L; P < .001) and ANC (1.0 +/- 1.6 x 10(9)/L vs 0.2 +/- 1.5 x 10(9)/L; P < .001).

CONCLUSION

Biochemically confirmed tobacco abstinence leads to a rapid and sustained decrease in WBC and ANC, possibly reflecting a decrease In an underlying state of tobacco-induced inflammation.

The smoker's paradox and the real risk of smoking

No satisfactory explanations have been offered for the smoker's paradox, the greater short-term survival of smokers after a myocardial infarction nor for the large variations in the coronary risk rate for smoking ranging between 1 and 5.9. These discrepancies as well as the smoker's paradox may be caused by different baseline characteristics of smokers and nonsmokers, whereas the usually quoted coronary risk of 2 is derived from studies based on the assumption of equal baseline characteristics. As neither this assumption nor the possibility of unequal starting conditions have been tested, we examined the main cardiovascular risk factors in smoking and nonsmoking boys as near as possible to baseline, at the age of fourteen. This age appeared to be best suited, because boys starting to smoke early are most likely to become regular and heavy smokers. Of 336 boys, 39 had smoked 8.3+/-6.0 cigarettes/day for 15.5+/-11.2 months. Compared to nonsmokers, boys who started to smoke early had lower LDL cholesterol and alpha2-antiplasmin, greater handgrip strength, vital capacity and forced expiratory volume, better perfomance on bicycle ergometry and higher testosterone. The differences in total cholesterol, LDL cholesterol, vital capacity, handgrip strength, testosterone and alpha2-antiplasmin persisted after adjustment for age, body mass, and testosterone. In addition, the differences in perfomance on bicycle ergometry and forced expiratory volume persisted after adjustment for age. These favourable baseline characteristics of those starting to smoke early can explain the smoker's paradox. In addition, they suggest that the individual coronary risk in smokers is considerably higher than 2, because the assumption of equal baseline characteristics of smokers and nonsmokers cannot be upheld.

Serum total sialic acid levels in smokers and users of smokeless tobacco in form of oral powder (Maraş powder)

Smokeless tobacco (ST) is widely used as chewing tobacco and as oral snuff in the world. Also, in Kahramanmaraş, a city in Southern Turkey, ST used as 'oral powder' or 'Maraş Powder' is consumed widely instead of cigarette smoking. The aim of this study was to search the effect of ST use on serum total sialic acid (TSA) and to compare the serum TSA levels in smokers and ST users. The study was performed at the Department of Chemistry-Biochemistry, University of Kahramamaraş Sutcu Imam, Turkey, in 2003. Serum samples obtained from smokers (Group I), Maraş powder users (Group II), and healthy control subjects (Group III) who were nonsmokers and nonusers ST. Individuals who were smokers and ST users were classified into subgroups with respect to amount of consumed cigarette or oral powder. Serum TSA was measured with the Denny's colorimetric method. The TSA concentrations were significantly higher in the sera of smokers (p < 0.001) and Maraş powder users (p < 0.001) than those of control subjects. The mean serum TSA level was found to be lowest in the control group and highest in the Maraş Powder users. But, there was no significant difference in serum TSA levels between smokers and Maraş powder users (p > 0.05). We can conclude from the results obtained that serum TSA was affected by ST use as seen in smokers. This finding may be an indication of harmful effects of ST use as Maraş powder as well as cigarette smoking.

Effect of smoking and abstention on oxidative burst and reactivity of neutrophils and monocytes

BACKGROUND

Smoking is associated with surgical wound infections, impaired wound healing, and tissue-destructive disorders. The mechanisms are largely unknown, but changes in the function and activity of inflammatory cells may be involved.

METHODS

Seventy healthy volunteers (54 smokers and 16 never smokers) were included. The smokers were studied while they smoked and after 20 days of abstinence. After the first 10 days of abstinence, they were randomized to double-blind treatment with transdermal nicotine patch 25 mg per day or placebo. Venous blood neutrophils and monocytes were sampled and isolated. In 22 randomly selected smokers and in all never smokers, the oxidative burst and chemotaxis were determined by a chemiluminescence response assay and a modified Boyden chamber technique, respectively. Stimulants were opsonized zymosan, formyl-Met-Leu-Phe, and zymosan-activated serum.

RESULTS

The neutrophil and monocyte oxidative burst was 50% and 68% lower, respectively, in smokers compared to never smokers (P < .05). Neutrophil chemotaxis was 93% higher in smokers (P < .05). Monocyte chemotaxis was lower in smokers compared to never smokers (P < .05). After 20 days of abstinence, neutrophil oxidative burst increased to the level of never smokers (P < .05); monocyte oxidative burst increased by 50% (P < .05). Chemotaxis was only marginally affected. The changes induced by abstinence were less pronounced in the transdermal nicotine patch group compared to the placebo group.

CONCLUSIONS

Smoking attenuates the oxidative burst of inflammatory cells and increases chemotaxis. Three weeks of abstinence normalize the oxidative burst, but affect chemotaxis only marginally.

Signatures of Environmental Exposures Using Peripheral Leukocyte Gene Expression: Tobacco Smoke

Functional biological markers of environmental exposures are important in epidemiological studies of disease risk. Such markers not only provide a measure of the exposure, they also reflect the degree of physiological and biochemical response to the exposure. In an observational study, using DNA microarrays, we show that it is possible to distinguish between 85 individuals exposed and unexposed to tobacco smoke on the basis of mRNA expression in peripheral leukocytes. Furthermore, we show that active exposure to tobacco smoke is associated with a biologically relevant mRNA expression signature. These findings suggest that expression patterns can be used to identify a complex environmental exposure in humans.

Smoking status and differential white cell count in men and women in the EPIC-Norfolk population

The total white blood cell (WBC) count is reported to be an independent predictor of mortality in several prospective studies. We investigated the association between total and differential WBC counts and cigarette smoking habit in a cross-sectional population-based study of 6902 men and 8405 women 39-79 years of age participating between July 1994 and 1997 in the European Prospective Investigation of Cancer (EPIC-Norfolk) study. Main outcome measures included WBC, granulocyte, lymphocyte and monocyte counts measured at a baseline health check and self-reported cigarette smoking habit. The age- and body mass index-adjusted mean total WBC counts were 7.8, 6.4, and 6.2x10(3) per ul (P<0.0001) among male current, former and never smokers, respectively, and 7.4, 6.3 and 6.2x10(3) per ul (P<0.0001), respectively, in women. The greatest absolute and percentage differences between smoking groups were observed for the granulocyte count. Current smoking habit had a stronger effect on mean total WBC counts than cumulative exposure as measured by pack years. Among former smokers mean age- and body mass index-adjusted WBC, granulocyte and lymphocyte counts were inversely related to duration of smoking cessation (P< or =0.02). Smokers who had given up less than 12 months previously had WBC counts substantially lower (6.7 and 6.9x10(3) per ul, respectively, in men and women) than current smokers. In conclusion, the total WBC count and its components (particularly the granulocyte count) are strongly associated with cigarette smoking habit. Smoking cessation may have an almost immediate impact at least on pathophysiologic processes such as inflammation that may be indicated by the WBC count. The apparent almost immediate reversibility of effects of smoking on inflammation, as indicated by the WBC count, may help motivate efforts to stop smoking.

Abstinence from smoking reduces incisional wound infection: a randomized controlled trial

OBJECTIVE

Clinical studies show that the incidence of postoperative wound complications is higher in smokers than nonsmokers. In this study, we evaluated the effect of abstinence from smoking on incisional wound infection.

METHODS

Seventy-eight healthy subjects (48 smokers and 30 never-smokers) were included in the study and followed for 15 weeks. In the first week of the study, the smokers smoked 20 cigarettes per day. Subsequently, they were randomized to continuous smoking, abstinence with transdermal nicotine patch (25 mg per day), or abstinence with placebo patch. At the end of the first week and 4, 8, and 12 weeks after randomization, incisional wounds were made lateral to the sacrum to excise punch biopsy wounds. At the same time identical wounds were made in 6 never-smokers. In 24 never-smokers a wound was made once. All wounds were followed for 2 weeks for development of wound complications.

RESULTS

A total of 228 wounds were evaluated. In smokers the wound infection rate was 12% (11 of 93 wounds) compared with 2% (1 of 48 wounds) in never-smokers (P <0.05). Wound infections were significantly fewer in abstinent smokers compared with continuous smokers after 4, 8, and 12 weeks after randomization. No difference between transdermal nicotine patch and placebo was found.

CONCLUSIONS

Smokers have a higher wound infection rate than never-smokers and 4 weeks of abstinence from smoking reduces the incidence of wound infections.

Altered cannabinoid receptor mRNA expression in peripheral blood mononuclear cells from marijuana smokers

We studied, using RT-PCR, the relative expression of cannabinoid receptor (CBR) mRNA in peripheral blood mononuclear cells (PBMC) from different donor groups. Cells from normal donors expressed a CB2 mRNA level threefold higher than CB1 across all age, gender or ethnicity groups, and amplicons were of the same size in all donors. However, cells from marijuana users expressed higher levels of CBR mRNA, but with a preserved CB1/CB2 ratio of 1:3. CBR gene products were also studied following short-term mitogen activation in vitro. CB1 expression decreased following mitogen stimulation when compared to the time-matched medium only cells while the expression of CB2 mRNA remained unchanged. These studies suggest that marijuana smoking and immune activation can alter the basal levels of CB1 and CB2 in PBMCs.