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.     

Self-titration by cigarette smokers

An 11-week crossover study was carried out in which 12 subjects smoked high-nicotine (1·84 mg standard yield) and low-nicotine (0·6 mg) cigarettes after an initial period of smoking their usual brands with a medium-nicotine yield (mean 1·4 mg). Plasma and urine nicotine concentrations, carboxyhaemoglobin (COHb) concentration, puffing behaviour, 24-hour cigarette consumption, and butt nicotine content were measured. The changes in plasma nicotine and blood COHb concentrations showed that the smokers compensated for about two-thirds of the difference in standard yields when switched to either high- or low-nicotine cigarettes. Thus, compared with the medium-nicotine brand, the intake of nicotine and carbon monoxide was only about 10% higher when subjects smoked the high-nicotine cigarettes, which had a standard yield 30-40% higher than the medium brands; and only about 15% lower when they smoked the low-nicotine cigarettes, which had a standard yield about 50% lower than the medium brands. But nicotine content and urine nicotine concentrations followed a similar pattern. Changes in puffing behaviour and in 24-hour cigarette consumption were only slight.The results show clear evidence of both upward and downward self-titration of nicotine and carbon monoxide (and tar) intakes when smokers change to cigarettes with standard yields that differ over the range studied.     

Comparison of Effect on Tobacco Consumption and Carbon Monoxide Absorption of Changing to High and Low Nicotine Cigarettes

In 10 sedentary workers, smoking as they felt inclined over a five-hour period in the middle of a typical working day, changing to low nicotine cigarettes (<0·3 mg) caused an increase in the number and weight of cigarettes smoked, while changing to high nicotine cigarettes (3·2 mg) caused a decrease (P < 0·01). The average number and weight smoked in five hours for usual, low, and high nicotine brands were respectively 10·6 (6·00 g), 12·5 (6·52 g), and 6·7 (4·19 g). When smoking the usual brand the average blood carboxyhaemoglobin (COHb) increased 1·78% (from 6·38% to 8·16%). But on changing to either high or low nicotine cigarettes the COHb levels instead of increasing, tended to fall (P < 0·01). The average fall of 0·34% while smoking low nicotine cigarettes was due to the low carbon monoxide (CO) yield of these cigarettes, while the fall of 1·04% when smoking high nicotine cigarettes was attributable to reduced consumption. The findings support the view that smoking behaviour is modified to regulate nicotine intake. Besides having low tar and CO yields, the least harmful cigarettes for heavy smokers may be those with a high, rather than low, nicotine yield.     

Cigarette tar yields in relation to mortality from lung cancer in the cancer prevention study II prospective cohort, 1982-8

Objective To assess the risk of lung cancer in smokers of medium tar filter cigarettes compared with smokers of low tar and very low tar filter cigarettes.Design Analysis of the association between the tar rating of the brand of cigarette smoked in 1982 and mortality from lung cancer over the next six years. Multivariate proportional hazards analyses used to assess hazard ratios, with adjustment for age at enrolment, race, educational level, marital status, blue collar employment, occupational exposure to asbestos, intake of vegetables, citrus fruits, and vitamins, and, in analyses of current and former smokers, for age when they started to smoke and number of cigarettes smoked per day.Setting Cancer prevention study II (CPS-II).Participants 364 239 men and 576 535 women, aged ≥ 30 years, who had either never smoked, were former smokers, or were currently smoking a specific brand of cigarette when they were enrolled in the cancer prevention study.Main outcome measure Death from primary cancer of the lung among participants who had never smoked, former smokers, smokers of very low tar (≤ 7 mg tar/cigarette) filter, low tar (8-14 mg) filter, high tar (≥ 22 mg) non-filter brands and medium tar conventional filter brands (15-21 mg).Results Irrespective of the tar level of their current brand, all current smokers had a far greater risk of lung cancer than people who had stopped smoking or had never smoked. Compared with smokers of medium tar (15-21 mg) filter cigarettes, risk was higher among men and women who smoked high tar (≥ 22 mg) non-filter brands (hazard ratio 1.44, 95% confidence interval 1.20 to 1.73, and 1.64, 1.26 to 2.15, respectively). There was no difference in risk among men who smoked brands rated as very low tar (1.17, 0.95 to 1.45) or low tar (1.02, 0.90 to 1.16) compared with those who smoked medium tar brands. The same was seen for women (0.98, 0.80 to 1.21, and 0.95, 0.82 to 1.11, respectively).Conclusion The increase in lung cancer risk is similar in people who smoke medium tar cigarettes (15-21 mg), low tar cigarettes (8-14 mg), or very low tar cigarettes (≤ 7 mg). Men and women who smoke non-filtered cigarettes with tar ratings ≥ 22 mg have an even higher risk of lung cancer.     

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.     

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.     

Cigarette Smoking Causes Hearing Impairment among Bangladeshi Population

Lifestyle including smoking, noise exposure with MP3 player and drinking alcohol are considered as risk factors for affecting hearing synergistically. However, little is known about the association of cigarette smoking with hearing impairment among subjects who carry a lifestyle without using MP3 player and drinking alcohol. We showed here the influence of smoking on hearing among Bangladeshi subjects who maintain a lifestyle devoid of using MP3 player and drinking alcohol. A total of 184 subjects (smokers: 90; non-smokers: 94) were included considering their duration and frequency of smoking for conducting this study. The mean hearing thresholds of non-smoker subjects at 1, 4, 8 and 12 kHz frequencies were 5.63±2.10, 8.56±5.75, 21.06±11.06, 40.79±20.36 decibel (dB), respectively and that of the smokers were 7±3.8, 13.27±8.4, 30.66±12.50 and 56.88±21.58 dB, respectively. The hearing thresholds of the smokers at 4, 8 and 12 kHz frequencies were significantly (p<0.05) higher than those of the non-smokers, while no significant differences were observed at 1 kHz frequency. We also observed no significant difference in auditory thresholds among smoker subgroups based on smoking frequency. In contrast, subjects smoked for longer duration (>5 years) showed higher level of auditory threshold (62.16±19.87 dB) at 12 kHz frequency compared with that (41.52±19.21 dB) of the subjects smoked for 1-5 years and the difference in auditory thresholds was statistically significant (p<0.0002). In this study, the Brinkman Index (BI) of smokers was from 6 to 440 and the adjusted odds ratio showed a positive correlation between hearing loss and smoking when adjusted for age and body mass index (BMI). In addition, age, but not BMI, also played positive role on hearing impairment at all frequencies. Thus, these findings suggested that cigarette smoking affects hearing level at all the frequencies tested but most significantly at extra higher frequencies.     

Blood carboxyhaemoglobin,plasma thiocyanate,and cigarette consumption: implications for epidemiological studies in smokers.

Carboxyhaemoglobin and plasma thiocyanate concentrations were found to be significantly correlated with self-reported daily cigarette consumption in 360 smokers (r = 0.416 and 0.412 respectively; p less than 0.001). The extent to which inhalation patterns affected the intake of cigarette smoke constituents was determined from the partial correlation between carboxyhaemoglobin and plasma thiocyanate concentrations after the number of cigarettes smoke per day had been allowed for (r = 0.48). Thus 23% of the variation in carboxyhaemoglobin and thiocyanate concentrations was accounted for by the was a cigarette was smoked and a further 21% by the number smoked a day. Furthermore, the relation between carboxyhaemoglobin or plasma thiocyanate and daily cigarette consumption was not linear but reached an asymptote at consumption rates above 25 cigarettes a day. These results suggest that by itself daily cigarette consumption will not identify those smokers most at risk and will also underestimate and dose-response relationship between smoking and selected diseases.     

Prevalence and patterns of smoking in Delhi: cross sectional study.

OBJECTIVE--To determine the prevalence and predictors of smoking in urban India. DESIGN--Cross sectional. SETTING--Delhi, urban India, 1985-6. SUBJECTS--Random sample of 13,558 men and women aged 25-64 years. MAIN OUTCOME MEASURES--Smoking prevalence; subjects who were currently smoking and who had smoked > or = 100 cigarettes or beedis or chuttas in their lifetime were defined as smokers. RESULTS--45% (95% confidence interval 43.8 to 46.2) of men and 7% (6.4 to 7.6) of women were smokers. Education was the strongest predictor of smoking, and men with no education were 1.8 (1.5 to 2.0) times more likely to be smokers than those with college education, and women with no education were 3.7 (2.9 to 4.8) times more likely. Among smokers, 52.6% of men and 4.9% of women smoked only cigarettes while the others also smoked beedi or chutta. Compared with cigarette smokers, people smoking beedi or chutta were more likely to be older and married; have lower education, manual occupations, incomes, and body mass index; and not drink alcohol or take part in leisure exercise. CONCLUSION--There are two subpopulations of smokers in urban India, and the prevention strategy required for each may be different. The educated, white collar cigarette smoker in India might respond to measures that make non-smoking fashionable, while the less educated, low income people who smoke beedi or chutta may need strategies aimed at socioeconomic improvement.     

Smoking habits of men and women.

The smoking habits of 1501 cigarette smokers attending 28 general practitioners in five group practices in London were assessed. Prevalence of smoking, daily cigarette consumption, and the use of cigars, untipped cigarettes, and hand-rolled cigarettes were lower in the women. After controlling for consumption the proportions of men and women who smoked every day were similar. Women who smoked 20 or more a day were similar to men in their self-reported inhaling habits and use of low-nicotine cigarettes. The results suggest that women differ from men in those aspects of smoking that are determined predominantly by social factors but that their smoking habits become similar when pharmacological motivation takes over. This apparently occurs when consumption reaches about 20 cigarettes a day, when smoking almost inevitably becomes a regular event and the sex differences disappear.     

Effect of smoke-free workplaces on smoking behaviour: systematic review

ObjectiveTo quantify the effects of smoke-free workplaces on smoking in employees and compare these effects to those achieved through tax increases.DesignSystematic review with a random effects meta-analysis.SettingWorkplaces in the United States, Australia, Canada, and Germany.ParticipantsEmployees in unrestricted and totally smoke-free workplaces.ResultsTotally smoke-free workplaces are associated with reductions in prevalence of smoking of 3.8% (95% confidence interval 2.8% to 4.7%) and 3.1 (2.4 to 3.8) fewer cigarettes smoked per day per continuing smoker. Combination of the effects of reduced prevalence and lower consumption per continuing smoker yields a mean reduction of 1.3 cigarettes per day per employee, which corresponds to a relative reduction of 29%. To achieve similar reductions the tax on a pack of cigarettes would have to increase from $0.76 to $3.05 (€0.78 to €3.14) in the United States and from £3.44 to £6.59 (€5.32 to €10.20) in the United Kingdom. If all workplaces became smoke-free, consumption per capita in the entire population would drop by 4.5% in the United States and 7.6% in the United Kingdom, costing the tobacco industry $1.7 billion and £310 million annually in lost sales. To achieve similar reductions tax per pack would have to increase to $1.11 and £4.26.ConclusionsSmoke-free workplaces not only protect non-smokers from the dangers of passive smoking, they also encourage smokers to quit or to reduce consumption.

What is already known on this topic

Smoke-free workplaces are associated with lower cigarette consumption per continuing smoker

What this study adds

Smoke-free workplaces reduce prevalence of smoking as well as consumptionThe combined effects of people stopping smoking and reducing consumption reduces total cigarette consumption by 29%To achieve similar results through taxation would require cigarette taxes per pack to increase from $0.76 to $3.05 in the United States and from £3.44 to £6.59 in the United Kingdom     

γH2AX: A potential DNA damage response biomarker for assessing toxicological risk of tobacco products

Differentiation among American cigarettes relies primarily on the use of proprietary tobacco blends, menthol, tobacco substitutes, paper porosity, paper additives, and filter ventilation. These characteristics substantially alter per cigarette yields of tar and nicotine in standardized protocols promulgated by government agencies. However, due to compensatory alterations in smoking behavior to sustain a preferred nicotine dose (e.g., by increasing puff frequency, inhaling more deeply, smoking more cigarettes per day, or blocking filter ventilation holes), smokers actually inhale similar amounts of tar and nicotine regardless of any cigarette variable, supporting epidemiological evidence that all brands have comparable disease risk. Consequently, it would be advantageous to develop assays that realistically compare cigarette smoke (CS)-induced genotoxicity regardless of differences in cigarette construction or smoking behavior. One significant indicator of potentially carcinogenic DNA damage is double strand breaks (DSBs), which can be monitored by measuring Ser 139 phosphorylation on histone H2AX. Previously we showed that phosphorylation of H2AX (defined as γH2AX) in exposed lung cells is proportional to CS dose. Thus, we proposed that γH2AX may be a viable biomarker for evaluating genotoxic risk of cigarettes in relation to actual nicotine/tar delivery. Here we tested this hypothesis by measuring γH2AX levels in A549 human lung cells exposed to CS from a range of commercial cigarettes using various smoking regimens. Results show that γH2AX induction, a critical event of the mammalian DNA damage response, provides an assessment of CS-induced DNA damage independent of smoking topography or cigarette type. We conclude that γH2AX induction shows promise as a genotoxic bioassay offering specific advantages over the traditional assays for the evaluation of conventional and nonconventional tobacco products.     

Obesity and Smoking Habits

A large-scale survey of steel workers in South Wales has shown a considerable difference between the body weights of smokers and of non-smokers. The difference increases with age so that men over 40 years who have never smoked are on average 13 lb (5·9 kg) heavier than smokers. Even so, smokers are about 15 lb (6·8 kg) heavier than the weight standard considered desirable by the Metropolitan Life Insurance Company, while non-smokers are nearly 30 lb (13·6 kg) heavier.About 20% of the men are attempting to give up the smoking habit. Ex-smokers who have given up smoking for more than eight years approach the body weight of men of the same age who have never smoked.Many reports have been published on the health consequences of smoking and of obesity. Because smoking and obesity are inversely related studies of the interrelation of these two health hazards and of their relative importance are needed.     

Bronchial Reactivity to Cigarette and Cigar Smoke

The change in specific airway conductance produced by smoking a cigarette under standard conditions was measured in 91 heavy smokers. Subsequently 19 of the most reactive subjects smoked two cigarettes with different filters and another containing cigar tobacco. The results indicated that reactivity to cigarette smoke was reduced significantly by increasing the retention efficiency of the filter and that reactivity to inhaled cigar-tobacco smoke was no less than that to cigarette smoke.     

Asthma from childhood at age 21: the patient and his disease.

Information was obtained from 336 21-year-olds who had begun wheezing before the age of 7 about their knowledge of asthma and its effect on their current life style. Two-thirds of the subjects were still symptomatic. A control group of 62 subjects was available for comparison. Knowledge about asthma was poor, particularly among those with less troublesome symptoms. Half of those with frequent episodic asthma and one-third with persistent asthma did not regard excess use of bronchodilator aerosols as potentially dangerous. Over three-quarters of those with persistent asthma were not receiving adequate treatment. One-third of third of those with persistent asthma were missing substantial time from work because of respiratory illness, and a similar proportion were restricting sporting activities. The incidence of smoking was disturbingly high in all asthma groups. The higher the number of cigarettes ever smoked and the higher the current tobacco consumption the less satisfactory was the progress of asthma. Both cigarette smoking and severity of asthma contributed to chronic production of sputum. Children and teenagers with asthma should be educated to seek more appropriate medical help and thereby reduce morbidity.     

Modifying risk of developing lung cancer by changing habits of cigarette smoking.

Data from a hospital based case-control study of lung cancer in Western Europe were used to examine changes in the risk of developing lung cancer after changes in habits of cigarette smoking. Only data for subjects who had smoked regularly at some time in their lives were included. The large size of the study population (7181 patients and 11 006 controls) permitted precise estimates of the effect of giving up smoking. Risks of developing lung cancer for people who had given up smoking 10 or more years before interview were less than half of those for people who continued to smoke. The reduction in risk was seen in men and women and in former smokers of both filter and non-filter cigarettes but varied by duration of smoking habit before giving up. The protective effect of giving up became progressively greater with shorter duration of smoking habit. The risks after not smoking for 10 years for both men and women who had previously smoked for less than 20 years were roughly the same as those for lifelong non-smokers. Reducing the number of cigarettes smoked a day or switching from non-filter to filter cigarettes also lowered the risk of developing lung cancer but not to the extent associated with giving up smoking.     

Delay and probability discounting as related to different stages of adolescent smoking and non-smoking

This study examined relations between different patterns of adolescent cigarette smoking and discounting of monetary rewards due to delay (delay discounting) and probabilistic uncertainty (probability discounting). The study also examined the relation between smoking and the number of peer friends who smoke and level of parent education. Participants were 55 adolescents (28 females) between 14 and 16 years of age who were categorized according to the following patterns of smoking behavior: "never smokers" (n=19; 10 females) who had not tried even one cigarette; "triers" (n=17; 9 females) who had recently tried cigarettes for the first time; and "current smokers" (n=19; 9 females) who smoked a minimum of one cigarette every week for at least 6 months prior to data collection. It was hypothesized that current smokers would discount more than those who had never smoked. No specific hypotheses were made for participants only trying cigarettes. Unexpectedly, results indicated no differences in discounting between the current smokers and never smokers. However, the trier group discounted probabilistic rewards significantly more than the never- and current-smoker groups. Also, triers and current smokers both reported having more friends who smoked than never smokers, and fathers of never smokers had significantly more education than fathers of either triers or current smokers. These results suggest that impulsive discounting may be more related to adolescents trying cigarettes than to their becoming regular smokers, whereas number of peer friends who smoke and parent level of education seem to differentiate between those who have smoked to some extent (triers and current smokers) and those who have not even tried cigarettes (never smokers).     

Puffing Frequency and Nicotine Intake in Cigarette Smokers

The smoking behaviour of 36 subjects smoking cigarettes with different filter retention efficiencies for nicotine was studied. Subjects were observed while performing various tasks on a driving simulator and also during a resting period after the tasks. Smokers of cigarettes with high-retention filters took more frequent puffs and obtained nearly the same amount of nicotine as smokers of cigarettes with low-retention filters, both while performing the tasks and during the resting period. Smokers of both types of cigarettes took significantly more puffs and obtained more nicotine per unit time during the resting period than during the tasks. The results are compatible with the possibility that smokers automatically adjust the nicotine dose obtained from a cigarette to some “optimum” level which may vary with different activities.     

Human urine mutagenicity study comparing cigarettes which burn or only heat tobacco

Cigarette smokers have been reported to void urine which is more mutagenic, as measured in the Ames bacterial mutation assay, than urine voided by non-smokers. Condensate from the mainstream smoke of a cigarette which heats, but does not burn tobacco (test cigarette) showed no evidence of mutagenicity in a battery of in vitro genotoxicity assays under conditions in which condensate from the mainstream smoke of cigarettes that burn tobacco was mutagenic. The objective of this study was to determine whether the absence of mutagenic activity observed in the in vitro assays would be reflected in the urine of smokers of the test cigarette. 72 subjects (31 smokers and 41 non-smokers) were enrolled in a 6-week study, with the smokers randomly divided into 2 groups. The study was designed as a double crossover, with each smoker smoking both test (tobacco-heating) and reference (tobacco-burning) cigarettes. This design allowed each smoker to serve as his or her own control while at the same time allowing comparisons between groups of non-smokers and smokers of both test and reference cigarettes. 24-h urine samples were collected twice a week and concentrated using XAD-2 resin. Urine concentrates were tested in Ames bacterial strains TA98 and TA100, with and without metabolic activation and with and without beta-glucuronidase/aryl sulfatase. Individuals who smoked the test cigarette voided urine which was significantly less mutagenic than that voided when they smoked reference cigarettes. The mutagenicity of urine from smokers who smoked the test cigarette and non-smokers did not differ under any of the assay conditions used in this study.     

Relation of nicotine yield of cigarettes to blood nicotine concentrations in smokers.

Blood nicotine and carboxyhaemoglobin (COHb) concentrations were studied in 330 smokers (206 women and 124 men). Blood nicotine concentrations in individual smokers varied from 25 to 444 nmol/l (4 to 72 ng/ml). The average concentration, 203 nmol/l (33 ng/ml), was the same in the men and the women, although cigarette consumption was higher in the men. Despite large differences in nicotine yield, there was no relation between blood nicotine concentration and the type of cigarette smoked: smokers of plain, untipped cigarettes (1.9 mg nicotine), cigarettes with unventilated filters (1.3 mg nicotine), and cigarettes with ventilated filters (0.8 mg nicotine) had similar blood nicotine concentrations. Cigarette consumption was also similar in these three groups. The correlation between blood nicotine concentration and nicotine yield of cigarette, though significant, was low (0.21, p < 0.001), showing that the nicotine yield of the cigarettes accounted for only 4.4% of the variation in blood nicotine concentrations. Similarly, the low correlation of 0.30 between COHb concentration and cigarette consumption suggests that cigarette consumption accounted for only 9% of the variation in the amount of smoke taken into the smokers'' lungs. These results suggest that the assumed health advantage of switching to lower-tar and lower-nicotine cigarettes may be largely offset by the tendency of smokers to compensate by increasing inhalation. The findings of epidemiological studies showing lower risks with filter-tipped cigarettes may be attributable to other factors such as biases in the samples and changes in the quality and carcinogenicity of tobacco tar, rather than to reduced tar intake.