The Impacts of Dispositional Optimism and Psychological Resilience on the Subjective Well-Being of Burn Patients: A Structural Equation Modelling Analysis

Burn wounds are severely stressful events that can have a significant impact on the mental health of patients. However, the impact of burns on individuals with different personality traits can be different. The present study aimed to investigate the impact of dispositional optimism on the subjective well-being of burn patients, and mainly focused on the confirmation of the mediator role of psychological resilience. 410 burn patients from five general hospitals in Xi''an accomplished the revised Life Orientation Test, Connor-Davidson Resilience Scale, and Subjective Well-Being (SWB) scale. The results revealed that both dispositional optimism and psychological resilience were significantly correlated with SWB. Structural equation modelling indicated that psychological resilience partially mediated the relationship between dispositional optimism and SWB. The current findings extended prior reports and shed some light on how dispositional optimism influenced SWB. Limitations of the study were considered and suggestions for future studies were also discussed.     

Smoking Habits of Men Employed in Industry,and Mortality

A study of the relation between smoking habits and lung cancer in male industrial workers over a period of three years has confirmed the earlier findings in doctors that the death-rate from lung cancer correlates closely with the number of cigarettes smoked. Of 54,460 men studied 68.7% were current cigarette smokers. The annual mortality rate from lung cancer was 0.33 per thousand in non-smokers and ex-smokers, and 1.2 per thousand for all cigarette smokers, and higher in heavy smokers.Heavy cigarette smokers who retained the cigarette in the mouth between puffs (“drooping” cigarette habit) had an annual mortality rate of 4.1 per thousand.The mortality from coronary thrombosis in smokers was nearly three times that in non-smokers. A mortality gradient with rising consumption of cigarettes was observed.Some correlation between smoking and cancer of other sites and from non-neoplastic lung disease was observed in older men, but no correlation was found with other cardiovascular diseases and cerebrovascular diseases.     

Smoking in pregnancy: associations with skinfold thickness,maternal weight gain,and fetal size at birth.

Skinfold thickness is an index of subcutaneous fat, and certain maternal conditions during pregnancy affect the skinfold thicknesses of the baby. A study was performed to investigate the effect of smoking on skinfold thickness, maternal weight gain, and fetal size at birth. A total of 452 mothers with normal singleton pregnancies were groups as: non-smokers, light-to-moderate smokers, or heavy smokers. Maternal age, height, parity, and duration of pregnancy were similar in the three groups. Heavy smokers gained significantly less weight than non-smokers, but there was no significant difference in skinfold thickness. Babies born to smokers had lower birth weights and smaller head circumferences and were shorter than those born to non-smokers, but skinfold thicknesses were similar. The presence of a normal layer of subcutaneous fat in babies whose mothers smoked suggests that fetal growth retardation is not caused by nutritional deficiencies.     

Effect of Vegetarianism and Smoking on Vitamin B12, Thiocyanate,and Folate Levels in the Blood of Normal Subjects

Vitamin B₁₂, thiocyanate, and folate levels in the blood were estimated in 69 apparently normal subjects, of whom 26 were non-vegetarian non-smokers, 19 non-vegetarian smokers, 15 vegetarian non-smokers, and nine vegetarian smokers. The serum total (cyanide-extracted) B₁₂ level (value A) ranged from 105 to 728 pg/ml, with a mean of 292 pg/ml. The highest values were found in non-vegetarian non-smokers and the lowest in vegetarian smokers. There was no significant difference in value A between smokers as a group and non-smokers as a group. On the other hand, in vegetarians value A was very significantly lower than in non-vegetarians regardless of their smoking habits.It is suggested that A may represent both the protein-bound and free forms of vitamin B₁₂ in the blood, and B mainly the free B₁₂, which may be the physiologically active form. The plasma thiocyanate level varied from 1·0 to 15 μmol/100 ml, being, as expected, much higher in smokers (mean 8·20 μmol/100 ml) than in non-smokers (mean 2·02 μmol/100 ml). There was a rough correlation between falling B₁₂ levels and rising thiocyanate levels. The serum folate level ranged from 2·75 to 15·75 ng/ml, and was slightly but significantly higher in vegetarians (mean 6·60 ng/ml) than in non-vegetarians (mean 4·79 ng/ml), reflecting the greater content of folate in a vegetarian diet.     

DNA damage and integrity of UV-induced DNA repair in lymphocytes of smokers analysed by the comet assay

DNA damage was assessed in smoker lymphocytes by subjecting them to the single cell gel electrophoresis (SCGE) assay. In addition to the appearance of comet tails, smoker cells exhibited enlarged nuclei when analysed by the comet assay. On comparing basal DNA damage among smokers and a non-smoking control group, smoker lymphocytes showed higher basal DNA damage (smokers, 36.25±8.45 μm; non-smokers, 21.6±2.06 μm). A significant difference in DNA migration lengths was observed between the two groups at 10 min after UV exposure (smokers, 65.5±20.34 μm; non-smokers, 79.2±11.59 μm), but no significant differences were seen at 30 min after UV exposure (smokers, 21.13±10.73 μm; non-smokers, (27.2±4.13 μm). The study thus implies that cigarette smoking perhaps interferes with the incision steps of the nucleotide excision repair (NER) process. There appeared be no correlation between the frequency of smoking and DNA damage or the capacity of the cells to repair UV-induced DNA damage that suggests inherited host factors may be responsible for the inter-individual differences in DNA repair capacities. The study also suggests monitoring NER following UV insult using the SCGE assay is a sensitive and simple method to assess DNA damage and integrity of DNA repair in human cells exposed to chemical mutagens.     

Effects of lifestyle and genetic polymorphisms on consumption of coffee or black tea and urinary caffeine levels

To find the cause of individual differences in caffeine intake and its metabolism, we investigated the effects of lifestyle and genetic polymorphisms of caffeine metabolic enzymes on coffee or black tea and urinary caffeine levels among 259 male Japanese. It was seen that cigarette smokers drank more coffee or black tea than non-smokers (p < 0.001). There was an inverse correlation between the amount of coffee or black tea consumed and age or the frequency of alcohol drinking (p < 0.05). Genetic polymorphisms of N -acetyltransferase 2 (NAT2), cytochrome P450 (CYP)1A1 and 2E1 did not significantly affect the habit of drinking coffee or black tea. The frequency of allele 1, the NAT2 allele of rapid acetylators, increased according to coffee or black tea consumption (0.05 < p < 0.1). Among lifestyle factors, two factors, i.e. smoking and the amount of coffee or black tea consumed, were related to urinary caffeine levels (p < 0.05). Geometric means of urinary caffeine levels were higher in the group who consumed higher amounts of coffee or black tea (p < 0.05) and those of smokers were lower than non-smokers- approximately 70% of non-smokers (p < 0.05). The genetic polymorphisms of NAT2, CYP1A1 and CYP2E1 were not significantly associated with the urinary caffeine levels according to each consumption level of coffee or black tea. This study suggests that smoking should be considered for the proper appreciation of individual differences in caffeine intake and urinary caffeine levels.     

Emotional and Affective Temperaments in Smoking Candidates for Bariatric Surgery

Introduction

The prevalence of smoking habits in severe obesity is higher than in the general population. There is some evidence that smokers have different temperaments compared to non-smokers. The aim of this study is to evaluate the associations between smoking status (smokers, ex-smokers and non-smokers) and temperament characteristics in bariatric surgery candidates.

Methods

We analyzed data on temperament of 420 bariatric surgery candidates, as assessed by the AFECTS scale, in an exploratory cross-sectional survey of bariatric surgery candidates who have been grouped into smokers, ex-smokers and non-smokers.

Results

We detected significant statistical differences in temperament related to the smoking status in this population after controlling the current use of psychiatric medication. Smokers had higher anxiety and lower control than non-smokers. Ex-smokers with BMI >50 kg/m² presented higher coping and control characteristics than smokers.

Conclusions

Smoking in bariatric surgery candidates was associated with lower control and higher anxious temperament, when controlled by current use of psychiatric medication. Smokers with BMI >50 kg/m² presented lower coping and control than ex-smokers. Assessment of temperament in bariatric surgery candidates may help in decisions about smoking cessation treatment and prevention of smoking relapse after surgery.     

The influence of smoking on plasma folate and lipoproteins in Alzheimer disease, mild cognitive impairment and depression

The risk for Alzheimer's disease (AD) is associated with lifestyle factors, especially cigarette smoking. In this study we investigated the influence of smoking on the serum levels of folic acid, LDL and HDL in AD patients, patients with minimal cognitive impairment (MCI) and patients with major depression. We investigated a total of n = 374 patients in the diagnostic categories:, AD: n = 272, MCI: n = 60, Major depression: n = 42. We found significantly lower HDL levels in smokers and previous smokers in comparison to non-smokers, p<0,05. The LDL: HDL ratio in smokers was significant higher (+20%) compared to previous smokers and non-smokers, p < 0.05. The mean levels of folic acid were statistically significant (p<0.05) lower (-24%) in smokers compared to non-smokers. Patients with MCI and Alzheimer;s disease (and also major depression) who are "smokers" show serum levels of HDL and folic acid that are known to be strong risk factors for vascular damage and increased risk for vascular brain damage and impaired cognitive function. Therefore cessation of smoking, substitution with folate or statin therapy of smoking patients with MCI or AD might be beneficial to slow down further cognitive decline.     

Humans Have Antibodies against a Plant Virus: Evidence from Tobacco Mosaic Virus

Tobacco mosaic virus (TMV), a widespread plant pathogen, is found in tobacco (including cigarettes and smokeless tobacco) as well as in many other plants. Plant viruses do not replicate or cause infection in humans or other mammals. This study was done to determine whether exposure to tobacco products induces an immune response to TMV in humans. Using a sandwich ELISA assay, we detected serum anti-TMV antibodies (IgG, IgG1, IgG3, IgG4, IgA, and IgM) in all subjects enrolled in the study (20 healthy smokers, 20 smokeless-tobacco users, and 20 non-smokers). Smokers had a higher level of serum anti-TMV IgG antibodies than non-smokers, while the serum level of anti-TMV IgA from smokeless tobacco users was lower than smokers and non-smokers. Using bioinformatics, we also found that the human protein TOMM40L (an outer mitochondrial membrane 40 homolog – like translocase) contains a strong homology of six contiguous amino acids to the TMV coat protein, and TOMM40L peptide exhibited cross-reactivity with anti-TMV antibodies. People who smoke cigarettes or other tobacco products experience a lower risk of developing Parkinson’s disease, but the mechanism by which this occurs is unclear. Our results showing molecular mimicry between TMV and human TOMM40L raise the question as to whether TMV has a potential role in smokers against Parkinson’s disease development. The potential mechanisms of molecular mimicry between plant viruses and human disease should be further explored.     

Measurement of 7 methyl and 7 2 hydroxyethyl guanine DNA adducts in white blood cells of smokers and non smokers

The goal of the present study was to measure the levels of 7-methylguanine and 7-(2- hydroxyethyl)guanine DNA adducts in human white blood cells in relation to smoking. DNA was isolated from samples of 11 smokers and eight non-smokers. The 32P-postlabelled 7-methylguanine and 7-(2-hydroxyethyl)guanine adducts were analysed by thin-layer chromatography (TLC) combined with a high pressure liquid chromatography (HPLC) assay. In smokers the mean 7-methylguanine and 7-(2-hydroxyethyl)guanine levels were 32.3 +/- 7.1 and 6.6 +/- 2.3 adducts per 108 nucleotides respectively. The corresponding values in non-smokers were 25.0 +/- 7.0 and 3.7 +/- 2.4 adducts per 108 nucleotides. There were significantly higher levels of 7-methylguanine and 7-(2-hydroxyethyl)guanine adducts in WBC in smokers than in non-smokers ( p = 0.041; p = 0.018), respectively. A positive correlation between 7-methylguanine and 7-(2-hydroxyethyl)guanine levels was observed.     

Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption

Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile.     

Association between Self-Reported Smoking and Hemoglobin A1c in a Korean Population without Diabetes: The 2011–2012 Korean National Health and Nutrition Examination Survey

BackgroundSeveral Western studies have revealed that among non-diabetics, glycosylated hemoglobin A1c (HbA1c) levels are higher in smokers than non-smokers. While studies conducted in Western populations consistently support this association, a recent meta-analysis reported that studies carried out in non-Western populations, including studies of Chinese, Egyptian, and Japanese-Americans, did not detect any significant differences in HbA1c levels between smokers and non-smokers.ObjectivesWe assessed the association between smoking habits and HbA1c levels in the general Korean adult population using data from the Korean National Health and Nutrition Examination Survey (KNHANES) performed in 2011–2012.MethodsA total of 10,241 participants (weighted n=33,946,561 including 16,769,320 men and 17,177,241 women) without diabetes were divided into four categories according to their smoking habits: never smokers (unweighted n/ weighted n= 6,349/19,105,564), ex-smokers (unweighted n/ weighted n= 1,912/6,207,144), current light smokers (<15 cigarettes per day, unweighted n/ weighted n=1,205/5,130,073), and current heavy smokers (≥15 cigarettes per day, unweighted n/ weighted n=775/3,503,781).ResultsIn age- and gender-adjusted comparisons, the HbA1c levels of each group were 5.52 ± 0.01% in non-smokers, 5.49 ± 0.01% in ex-smokers, 5.53 ± 0.01% in light smokers, and 5.61 ± 0.02% in heavy smokers. HbA1c levels were significantly higher in light smokers than in ex-smokers (p = 0.033), and in heavy smokers compared with light smokers (p < 0.001). The significant differences remained after adjusting for age, gender, fasting plasma glucose, heavy alcohol drinking, hematocrit, college graduation, and waist circumference. Linear regression analyses for HbA1c using the above-mentioned variables as covariates revealed that a significant association between current smoking and HbA1c (coefficient 0.021, 95% CI 0.003–0.039, p = 0.019).ConclusionsCurrent smoking was independently associated with higher HbA1c levels in a cigarette exposure-dependent manner in a representative population of Korean non-diabetic adults. In this study, we have observed an association between smoking status and HbA1c levels in non-diabetics drawn from a non-Western population, consistent with previous findings in Western populations.     

Expression of citrulline and homocitrulline residues in the lungs of non-smokers and smokers: implications for autoimmunity in rheumatoid arthritis

IntroductionSmoking is a well-established risk factor for rheumatoid arthritis (RA), and it has been proposed that smoking-induced citrullination renders autoantigens immunogenic. To investigate this mechanism, we examined human lung tissue from 40 subjects with defined smoking status, with or without chronic obstructive pulmonary disease (COPD), and control tissues from other organs for citrullinated proteins and the deiminating enzymes peptidylarginine deiminase type-2 (PAD2) and -4 (PAD4).MethodsLung tissue samples, dissected from lobectomy specimens from 10 never smokers, 10 smokers without airflow limitation, 13 COPD smokers and eight COPD ex-smokers, and control tissue samples (spleen, skeletal muscle, liver, ovary, lymph node, kidney and heart), were analysed for citrullinated proteins, PAD2 and PAD4 by immunoblotting. Citrulline and homocitrulline residues in enolase and vimentin were analysed by partial purification by gel electrophoresis followed by mass spectrometry in 12 of the lung samples and one from each control tissues. Band intensities were scored semi-quantitatively and analysed by two-tailed Mann-Whitney T-test.ResultsWithin the lung tissue samples, citrullinated proteins, PAD2 and PAD4 were found in all samples, with an increase in citrullination in COPD (P = 0.039), but minimal difference between smokers and non-smokers (P = 0.77). Citrullination was also detected at lower levels in the tissues from other organs, principally in lymph node, kidney and skeletal muscle. Mass spectrometry of the lung samples showed that vimentin was citrullinated at positions 71, 304, 346, 410 and 450 in non-smokers and smokers both with and without COPD. A homocitrulline at position 104 was found in four out of six COPD samples and one out of six non-COPD. Citrulline-450 was also found in three of the control tissues. There were no citrulline or homocitrulline residues demonstrated in α-enolase.ConclusionsWe have shown evidence of citrullination of vimentin, a major autoantigen in RA, in both non-smokers and smokers. The increase in citrullinated proteins in COPD suggests that citrullination in the lungs of smokers is mainly due to inflammation. The ubiquity of citrullination of vimentin in the lungs and other tissues suggests that the relationship between smoking and autoimmunity in RA may be more complex than previously thought.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0520-x) contains supplementary material, which is available to authorized users.     

Association of Leisure-Time Physical Activity to Cardiovascular Disease Prevalence in Relation to Smoking among Adult Nevadans

It is well known that cigarette smoking and physical activity have significant impacts on cardiovascular disease (CVD) mortality and morbidity. Meanwhile, it is of interest to understand whether physical activity protects against CVD for smokers in a similar manner as it does for non-smokers. The present study examined how leisure-time physical activity (LTPA) is associated with the prevalence of CVD in relation to smoking status among adult Nevadans, using data from the 2010 Nevada Behavioral Risk Factor Surveillance System. Of the 3,913 survey respondents, 8.5% self-reported that they had ever been diagnosed with CVD. People with a history of CVD were significantly less likely to engage in LTPA than those with no history of CVD (p < 0.05). After adjusting for common sociodemographic variables, it was revealed that people with CVD were twice more likely to not engage in LTPA than their counterparts independent of smoking status. Without taking LTPA into account, the odds of having CVD for current and former smokers was 1.87–2.25 times higher than the odds for non-smokers. Interestingly, however, if LTPA was accounted for, there was no significant difference in the odds of having CVD between current and non-smokers. These results indicate that LTPA is inversely associated with the prevalence of CVD independent of smoking status, and that regular physical activity may protect against CVD for smokers as well as for non-smokers. Physical activity, along with smoking cessation, should be promoted to better prevent and control CVD among smokers.     

Chronic Bronchitis: Method of Cigarette Smoking

Male volunteers for mass radiography examination, aged 40 or more, were questioned about their sputum production, smoking habits, and, when applicable, their method of smoking cigarettes.Of 5,438 cigarette smokers 460 (8·4%) smoked their cigarettes without removing the cigarette from the mouth between puffs (“drooping” cigarette smokers) whereas the rest smoked in the normal manner.Persons who admitted to producing sputum from their chests on most days of the year or on most days for at least three months of the year for a minimum of two years were classified as chronic bronchitics in the absence of other causative disease.The rate of chronic bronchitis among the “drooping” cigarette smokers (41·5%) was considerably greater than that among those smoking cigarettes in the normal manner (33·6%). The same pattern was maintained when age and cigarette consumption were standardized, though “drooping” cigarette smokers had a slight bias towards plain as distinct from filter cigarettes and towards a lower social class this was not sufficient to account for the excess of chronic bronchitis among those using this method of smoking.     

Comprehensive characterisation of pulmonary and serum surfactant protein D in COPD

Background

Pulmonary surfactant protein D (SP-D) is considered as a candidate biomarker for the functional integrity of the lung and for disease progression, which can be detected in serum. The origin of SP-D in serum and how serum concentrations are related to pulmonary concentrations under inflammatory conditions is still unclear.

Methods

In a cross-sectional study comprising non-smokers (n = 10), young - (n = 10), elderly smokers (n = 20), and smokers with COPD (n = 20) we simultaneously analysed pulmonary and serum SP-D levels with regard to pulmonary function, exercise, repeatability and its quaternary structure by native gel electrophoresis. Statistical comparisons were conducted by ANOVA and post-hoc testing for multiple comparisons; repeatability was assessed by Bland-Altman analysis.

Results

In COPD, median (IQR) pulmonary SP-D levels were lower (129(68) ng/ml) compared to smokers (young: 299(190), elderly: 296(158) ng/ml; p < 0.01) and non-smokers (967(708) ng/ml; p < 0.001). The opposite was observed in serum, with higher concentrations in COPD (140(89) ng/ml) as compared to non-smokers (76(47) ng/ml; p < 0.01). SP-D levels were reproducible and correlated with the degree of airway obstruction in all smokers. In addition, smoking lead to disruption of the quaternary structure.

Conclusions

Pulmonary and serum SP-D levels are stable markers influenced by smoking and related to airflow obstruction and disease state. Smaller subunits of pulmonary SP-D and the rapid increase of serum SP-D levels in COPD due to exercise support the translocation hypothesis and its use as a COPD biomarker.

Trial registration

no interventional trial     

Adhesion molecules in subjects with COPD and healthy non-smokers: a cross sectional parallel group study

Background

The aim of the study was to investigate how the expression of adhesion molecules changes as neutrophils migrate from the circulation to the lung and if these changes differ between non-smoking subjects and smokers with and without COPD.

Methods

Non-smoking healthy subjects (n=22), smokers without (n=21) and with COPD (n=18) were included. Neutrophils from peripheral blood, sputum and bronchial biopsies were analysed for cell surface expression of adhesion molecules (CD11b, CD62L, CD162). Serum, sputum supernatant and BAL-fluid were analysed for soluble adhesion molecules (ICAM-1, -3, E-selectin, P-selectin, VCAM-1, PECAM-1).

Results

Expression of CD11b was increased on circulating neutrophils from smokers with COPD. It was also increased on sputum neutrophils in both smokers groups, but not in non-smokers, as compared to circulating neutrophils.Serum ICAM-1 was higher in the COPD group compared to the other two groups (p<0.05) and PECAM-1 was lower in smokers without COPD than in non-smoking controls and the COPD group (p<0.05). In BAL-fluid ICAM-1 was lower in the COPD group than in the other groups (p<0.05).

Conclusions

Thus, our data strongly support the involvement of a systemic component in COPD and demonstrate that in smokers neutrophils are activated to a greater extent at the point of transition from the circulation into the lungs than in non-smokers.     

Measurement of 7 methyl and 7 2 hydroxyethyl guanine DNA adducts in white blood cells of smokers and non smokers

The goal of the present study was to measure the levels of 7-methylguanine and 7-(2- hydroxyethyl)guanine DNA adducts in human white blood cells in relation to smoking. DNA was isolated from samples of 11 smokers and eight non-smokers. The 32P-postlabelled 7-methylguanine and 7-(2-hydroxyethyl)guanine adducts were analysed by thin-layer chromatography (TLC) combined with a high pressure liquid chromatography (HPLC) assay. In smokers the mean 7-methylguanine and 7-(2-hydroxyethyl)guanine levels were 32.3 +/- 7.1 and 6.6 +/- 2.3 adducts per 108 nucleotides respectively. The corresponding values in non-smokers were 25.0 +/- 7.0 and 3.7 +/- 2.4 adducts per 108 nucleotides. There were significantly higher levels of 7-methylguanine and 7-(2-hydroxyethyl)guanine adducts in WBC in smokers than in non-smokers (p = 0.041; p = 0.018), respectively. A positive correlation between 7-methylguanine and 7-(2-hydroxyethyl)guanine levels was observed.     

Prospective study of effect of switching from cigarettes to pipes or cigars on mortality from three smoking related diseases.

OBJECTIVE: To estimate the extent to which cigarette smokers who switch to cigars or pipes alter their risk of dying of three-smoking related diseases-lung cancer, ischaemic heart disease, and chronic obstructive lung disease. DESIGN: A prospective study of 21520 men aged 35-64 years when recruited in 1975-82 with detailed history of smoking and measurement of carboxyhaemoglobin. MAIN OUTCOME MEASURES: Notification of deaths (to 1993) classified by cause. RESULTS: Pipe and cigar smokers who had switched from cigarettes over 20 years before entry to the study smoked less tobacco than cigarette smokers (8.1 g/day v 20 g/day), but they had the same consumption as pipe and cigar smokers who had never smoked cigarettes (8.1 g) and had higher carboxyhaemoglobin saturations (1.2% v 1.0%, P < 0.001), indicating that they inhaled tobacco smoke to a greater extent. They had a 51% higher risk of dying of the three smoking related diseases than pipe or cigar smokers who had never smoked cigarettes (relative risk 1.51; 95% confidence interval 0.96 to 2.38), a 68% higher risk than lifelong non-smokers (1.68; 1.16 to 2.45), a 57% higher risk than former cigarette smokers who gave up smoking over 20 years before entry (1.57; 1.04 to 2.38), and a 46% lower risk than continuing cigarette smokers (0.54; 0.38 to 0.77). CONCLUSION: Cigarette smokers who have difficulty in giving up smoking altogether are better off changing to cigars or pipes than continuing to smoke cigarettes. Much of the effect is due to the reduction in the quantity of tobacco smoked, and some is due to inhaling less. Men who switch do not, however, achieve the lower risk of pipe and cigar smokers who have never smoked cigarettes. All pipe and cigar smokers have a greater risk of lung cancer than lifelong non-smokers or former smokers.