High Prevalence Of Cigarette Smoking Research Articles

Airway Inflammation Among Hairdressing, Bakery and Pastry Cooking Apprentices: Occupational Exposure or Cigarette Smoking?

P-118 Background: The “Markers of Bronchial Inflammation in Occupational Asthma” project aims at investigating the early development of airway inflammation (AI) in hairdressing, bakery and pastry cooking apprentices. In a preliminary study we evaluated the influence of occupational exposure and cigarette smoking in the development of AI in young apprentices examined on two occasions prior to occupational exposure and one year after the beginning of their apprenticeship. Methodology: Youngsters enrolled as apprentices at 6 professional schools in Lorraine participated. Previous occupational exposure and smoking history were evaluated using a questionnaire and, for smoking, by measuring expired carbon monoxide (CO). Baseline pulmonary function was evaluated by spirometry and by measuring airway resistance by the forced oscillations technique (FOT). AI was evaluated using an abbreviated version of the methacholine challenge test (MCT) and by measuring exhaled nitric oxide (ENO). Results: 70 apprentices aged 16.9 ± 1.2 years were examined on two occasions at one year interval. There were 40 boys and 31 girls. Overall, 44 were bakery/pastry cooking apprentices and 27 hairdressing apprentices. 43.4% were non-smokers and 56.6% smokers. Spirometry at visit one was as follows: forced vital capacity (FVC) = 4.16 ± 0.9L (88.9 ± 11.3% of predicted); forced expiratory volume in one second (FEV1) = 3.63 ± 0.7L (89.7 ± 10.3% of predicted); FEV1/FVC = 87.9 ± 6.9% of observed. At visit one MCT was negative in all subjects while ENO measurements were within the range observed for unexposed smokers and non-smokers. At visit two, while spirometry remained unchanged, 11 subjects had a positive MCT, corresponding to an incidence of AI of 15.7%. Among these, only 4 were found to smokers (versus 7 non-smokers). Comments: This preliminary study shows (a) a high prevalence of cigarette smoking among young apprentices in occupations at risk of occupational asthma and (b) an high incidence of AI after a relatively modest (one year) occupational exposure. Moreover, it suggests that the observed AI is likely to be related to the exposure itself rather than cigarette smoking. However, due to the small sample size, these data should be considered cautiously. More consistent data are expected to be available at the end of the study (500 apprentices were expected to be enrolled).

Effect of American acculturation on cigarette smoking behavior among six major Asian American subpopulations in California

To investigate the moderating effect of acculturation and other individual characteristics on smoking behavior and examine the gender-specific prevalence of cigarette smoking among six major Asian American subpopulations in California. Using data from the 2001 California Health Interview Survey, we examined smoking prevalence among 5,265 Asian American adults, age 18 to 85 years, who reported being from 1 of the 6 major Asian American subpopulations in the California region. Level of U.S. acculturation was measured by five index variables: country of birth, parents' country of birth, languages spoken at home, years lived in the U.S., and frequency of eating tomatoes prepared in a quintessential American fashion. Multinomial logistic regression methods were used to estimate gender-specific rates of current and past cigarette smoking and its determinants. After adjusting for possible confounding due to age, education level, marital status, alcohol consumption, health care access, and health insurance status, we found that American acculturation level was negatively correlated with men's current smoking rates but positively correlated with women's current smoking rates. Overall, highly acculturated men and least acculturated women had the lowest current smoking rates. Current cigarette smoking prevalence rates were higher among men of Korean, Vietnamese, and Filipino background as compared to California men in general. Rates for men of Japanese, Chinese, and South Asian background were, in contrast, lower. As expected, smoking rates for women in all six subpopulations were lower than that seen among men. Tobacco use among Asian Americans is not uniformly low. Some subpopulations have relatively higher rates of use. Most troubling, the process of acculturation to living in the U.S. appears to disadvantage Asian American women. Comprehensive, community-based, culturally-tailored, and language-specific smoking control programs are urgently needed to reduce the high prevalence of cigarette smoking among some subpopulations of Asian American men and reverse the increasing trend of cigarette smoking among Asian American women.

Report from the CDC. Changes in Selected Chronic Disease-Related Risks and Health Conditions for Nonpregnant Women 18–44 Years Old BRFSS

We examined changes in the prevalence of selected chronic disease-related indicators among women aged 18-44 years using the Behavioral Risk Factor Surveillance System (BRFSS) data for two time periods, 1991-1992 and 2000-2001. We examined alcohol use, cigarette smoking, leisure time physical activity, body mass index (BMI), having had Pap smear screening, and having been diagnosed with hypertension, diabetes, high cholesterol, and asthma. We created a multicondition index by combining multiple chronic disease-related conditions. Younger women, <25 years of age, reported a higher prevalence of cigarette smoking and binge drinking. Black women and women with lower educational levels had a higher prevalence of obesity, and higher proportions were diagnosed with hypertension and diabetes. About 35% of the women had been diagnosed with at least one chronic disease-related condition. More than 10% of black women reported being diagnosed with two chronic disease-related conditions, compared with 7% in white women and 8% in Hispanic women. The BRFSS data can be used for monitoring the prevalence of multiple chronic disease-related behaviors and conditions.

Confounding by dietary factors in case?control studies on the efficacy of cancer screening in Japan

Evaluation of cancer screening using case-control studies is less valid in comparison to randomized controlled trails, due to the intrusion of a possible self-selection bias in the former. The randomized controlled trial approach, however, may be difficult in developed countries where mass cancer screening programs are already being performed nationally. Accordingly, case-control studies are often performed instead of randomized controlled trials. In case-control studies, no reports could be found in the literature using dietary habit, an important influencing factor in carcinogenesis, as an adjusting item. We surveyed nutrition and food intake status through a nutrition survey using the weighing method, and smoking prevalence and alcohol consumption with questionnaires in the general population in northern Japan, in subjects over 30 years of age. We then compared these results among non-participants and participants in cancer screening programs, and evaluated how any differences between the two groups might affect the results of case-control studies. Non-participants had a significantly lower intake of vegetables, carotene, vitamin C, and dietary fiber, which are thought to be beneficial factors in the prevention of carcinogenesis. Non-participants had a significantly higher cigarette smoking prevalence than participants. In relation to the intake of vegetables, a difference between participants and non-participants was evident, as proper adjustment for vegetable intake led to an odds ratio closer to the null value. The value of the odds ratio will probably not decrease, but it might increase when other dietary factors or smoking are taken into consideration.

Self-rated health in a population of expatriate workers and partners in Riyadh, Saudi Arabia

Anthropological theory suggests that expatriate workers progress through a sequence of adaptive stages during their adjustment to a new environment. The psychological and physiological effects of this adaptation process may be reflected in changes in self-rated general health. To explore the relationship between self-rated general health, duration of expatriate assignment and two health-related behaviours: physical exercise and cigarette smoking. A self-administered questionnaire recorded the demographics, self-rated general health, exercise and smoking behaviours of the adult non-Saudi residents of an expatriate compound in Riyadh, Saudi Arabia. The mean self-rated general health of the study group was better than comparable UK and New Zealand population norms. Self-rated general health was not associated with duration of assignment, but was associated with physical exercise, including a dose-response effect. Middle Eastern expatriates had lower self-rated health scores and a higher prevalence of cigarette smoking than other expatriates. While the sampling frame limits generalization, physical exercise may promote expatriates' general health. Middle Eastern expatriates may be a target group for smoking health education.

Cigarette smoking and exposure to environmental tobacco smoke in China: the international collaborative study of cardiovascular disease in Asia.

We estimated the prevalence of cigarette smoking and the extent of environmental tobacco smoke exposure (ETS) in the general population in China. A cross-sectional survey was conducted on a nationally representative sample of 15540 Chinese adults aged 35-74 years in 2000-2001. Information on cigarette smoking was obtained by trained interviewers using a standard questionnaire. The prevalence of current cigarette smoking was much higher among men (60.2%) than among women (6.9%). Among nonsmokers, 12.1% of men and 51.3% of women reported exposure to ETS at home, and 26.7% of men and 26.2% of women reported exposure to ETS in their workplaces. On the basis of our findings, 147358000 Chinese men and 15895000 Chinese women aged 35-74 years were current cigarette smokers, 8658000 men and 108402000 women were exposed to ETS at home, and 19072000 men and 55372000 women were exposed to ETS in their workplaces. The high prevalence of cigarette smoking and environmental tobacco smoke exposure in the Chinese population indicates an urgent need for smoking prevention and cessation efforts.

Prevalence of Cigarette Use Among 14 Racial/Ethnic Populations

Prevalence of Cigarette Use Among 14 Racial/Ethnic Populations

Obstructive Lung Disease Among the Urban Homeless

Homelessness is a growing problem in the United States that may significantly impair physical health. The homeless have a high prevalence of cigarette smoking, poor nutrition, and adverse environmental exposures, which could contribute to obstructive lung disease (OLD). Despite this risk, the prevalence of OLD among the homeless remains unknown. We aimed to systematically assess the prevalence of OLD among the urban homeless. We conducted a cross-sectional study of the prevalence of OLD among homeless individuals in San Francisco. By random sampling, we recruited 68 adults living in one homeless shelter to participate in a structured interview survey and spirometry assessment. We used a multifaceted approach to assess OLD, including respiratory symptoms, self-reported physician diagnosis of asthma, chronic bronchitis, emphysema, or COPD, and spirometry (defined as FEV1 < 80% predicted and FEV1/FVC ratio < 0.70). Sixty-eight adults completed the survey, and 67 adults completed the spirometry. Homeless adults were likely to be homeless < 1 year and homeless for the first time. There was a high prevalence of cigarette smoking (75% ever smokers, 68% current smokers). The prevalence of symptoms suggestive of OLD was high, including cough (29%), wheezing (40%), chronic bronchitis symptoms (21%), and dyspnea on exertion (29%). A substantial proportion of homeless subjects indicated a prior diagnosis of asthma (24%), chronic bronchitis (19%), and COPD (4%). Based on spirometry, the prevalence of OLD was 15% (95% confidence interval, 8 to 26%), which was more than double the expected prevalence in the general US population. As OLD is a leading cause of death in the United States, it is important to identify it early for treatment. Homeless individuals have a higher-than-expected prevalence of OLD. Public health interventions should target the homeless population for prevention and treatment of OLD.

Specifying cigarette smoking and quitting among people with serious mental illness.

People with serious mental illnesses (SMI) have a high prevalence of cigarette smoking. Details of their smoking and quitting behaviors are needed to create effective interventions. This study aims to describe the smoking and quitting histories, current behaviors, and motivations of an outpatient sample of smokers with SMI. A structured interview and Breathalyzer assessment were administered to 120 smokers from four diverse mental health settings. Participants' smoking and quitting self-report data are presented in combination with demographic and clinical variables; the results provide implications for smoking cessation, amelioration, and prevention interventions and for future research.

The Influence of Tobacco Smoking on the Onset of Periodontitis in Young Persons

This paper reviews the evidence for cigarette smoking as a risk factor for the development of severe destructive periodontal disease in young adults. A high prevalence of cigarette smoking has been identified among young individuals with aggressive periodontitis and tobacco usage increases the risk of periodontal destruction most significantly in young populations. The effect appears to be dose related and is independent of levels of plaque accumulation. Young smokers have more alveolar bone loss and attachment loss than non smoking equivalents. Prolonged and heavy smoking can reduce gingival bleeding and therefore mask the clinical marker of bleeding on probing often used by dentists to monitor periodontal health. This has implications for potential misdiagnosis and failure to detect periodontitis at an early stage. Nicotine metabolites concentrate in the periodontal tissues and can have local effects as well as the potential to affect the systemic host response. Dentists are well placed to assess the smoking status of their young patients and have a role to play in the delivery of smoking cessation advice especially as it pertains to periodontal health. In this way the dental profession can also make a significant contribution to the general health and well being of our youth and future generations.

The influence of tobacco smoking on the onset of periodontitis in young persons.

This paper reviews the evidence for cigarette smoking as a risk factor for the development of severe destructive periodontal disease in young adults. A high prevalence of cigarette smoking has been identified among young individuals with aggressive periodontitis and tobacco usage increases the risk of periodontal destruction most significantly in young populations. The effect appears to be dose related and is independent of levels of plaque accumulation. Young smokers have more alveolar bone loss and attachment loss than non smoking equivalents. Prolonged and heavy smoking can reduce gingival bleeding and therefore mask the clinical marker of bleeding on probing often used by dentists to monitor periodontal health. This has implications for potential misdiagnosis and failure to detect periodontitis at an early stage. Nicotine metabolites concentrate in the periodontal tissues and can have local effects as well as the potential to affect the systemic host response. Dentists are well placed to assess the smoking status of their young patients and have a role to play in the delivery of smoking cessation advice especially as it pertains to periodontal health. In this way the dental profession can also make a significant contribution to the general health and well being of our youth and future generations.

Associations between smoking prevalence, stages of change, cigarette consumption, and quit attempts across the United States

Background. We tested whether across the 50 U.S. States, smoking prevalence was associated with smoking behavior among smokers. Methods. We used published data on smoking prevalence, cigarette consumption, and quit attempts by State from the Behavioral Risk Factor Surveillance System (BRFSS) for 1993, 1996, and 1999, and published data on the distribution of smokers by stage of change in each State from the Current Population Survey (CPS). Data were weighted for the population size in each State. Results. For 1993, we found no statistically significant association between smoking prevalence and stages of change. For 1996 and 1999, across the 50 States, each additional percentage point in smoking prevalence was associated with, respectively, 0.62% and 1.19% more smokers in the “precontemplation” stage, that is, smokers not intending to quit smoking (both P < 0.01), with, respectively, 0.82% and 1.21% more “heavy” smokers who smoked 21–40 cigarettes per day (both P ≤ 0.001), and with, respectively, 1.12% and 0.81% fewer daily smokers who quit smoking for 1+ days in the previous year (both P ≤ 0.04). Conclusions. Across the 50 States, a higher prevalence of cigarette smoking was associated with a lower motivation to quit smoking, fewer quit attempts, and higher cigarette consumption among smokers.

Risk factors for aneurysmal subarachnoid hemorrhage in Aomori, Japan.

Japan is known to have an incidence of aneurysmal subarachnoid hemorrhage (SAH) as high as that in Finland, where SAH is especially common. However, the risk factors for SAH in Japan are unknown. The purpose of this study was to identify the risk factors and then examine their possible roles in cases of SAH in Japan. Case-control data were collected in the Aomori prefecture between June 2000 and May 2001 and in the Shimokita area between 1989 and 1998. A history of hypertension, cigarette smoking, alcohol consumption, hypercholesterolemia, and diabetes mellitus were examined as possible risk factors for SAH by using stepwise logistic regression analysis. Stepwise logistic regression analysis showed that a history of hypertension and current smoking increased the risk of SAH and that a history of hypercholesterolemia decreased the risk of SAH. Alcohol consumption and a history of diabetes mellitus were excluded from the model, because their log-likelihood ratios were not significant. The adjusted odds ratios, obtained by forcing matching factors, were 2.29 for a history of hypertension (95% CI, 1.66 to 3.16), 3.12 for current smoking (95% CI, 2.05 to 4.77), and 0.41 for a history of hypercholesterolemia (95% CI, 0.24 to 0.71). The prevalence of hypertension in control subjects was 27% in men and 31% in women, whereas the prevalence of cigarette smoking in control subjects was 46% in men and 9% in women. Hypertension and cigarette smoking seem to be independent risk factors for SAH in Japan. The high prevalence of hypertension in both sexes and the high prevalence of cigarette smoking in men in the general population might contribute to the high incidence of SAH in Japan.

The association between secondhand smoke and the risk of developing acute coronary syndromes, among non-smokers, under the presence of several cardiovascular risk factors: The CARDIO2000 case-control study.

BackgroundThe purpose of this study was to investigate the association between secondhand smoke and the risk of developing a first event of acute coronary syndromes (ACS), i.e. acute myocardial infarction or unstable angina, among non-smokers, in relation to the presence of several other cardiovascular risk factors.MethodsEight hundred and forty-eight patients with first event of ACS and 1078 cardiovascular disease-free matched controls completed a detailed questionnaire regarding their exposure to secondhand smoke, among other investigated parameters.ResultsTwo hundred and ninety–seven (35%) of the patients and 259 (24%) of the controls were defined as secondhand smokers. After controlling for several potential confounders, the results showed that non-smokers occasionally (< 3 time per week) exposed to cigarette smoke were associated with 26% higher risk of ACS (OR = 1.26, P-value < 0.01) compared to non-smokers not exposed to smoke, while regular exposure is associated with 99% higher risk of developing ACS (OR = 1.99, P-value < 0.001). Moreover, the previous risk increases progressively from 15% to 256% if one or more of the classical cardiovascular risk factors (i.e. hypertension, hypercholesterolemia, diabetes mellitus, sedentary life and family history of premature coronary heart disease) are present.ConclusionsConsequently, this study supports the hypothesis that even occasional secondhand smoke increases the risk of developing acute coronary syndromes, especially when other risk factors are present. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease are important.

Diabetes, Insulin Resistance and Vascular Disease Among Indian Asians and Europeans

Indian Asians account for one-fifth of all cardiovascular deaths worldwide. Cardiovascular mortality in Indian Asians overseas is higher than in indigenous populations. Diabetes, insulin resistance, and related metabolic disturbances are more common among Indian Asians than Europeans and may account for up to 70% of major Q wave ECG abnormalities in Asians. Previous studies provide evidence that genetic and environmental factors, the latter including intrauterine growth retardation, reduced physical activity, increased weight, and dietary intake, contribute to the high prevalence of diabetes and insulin resistance in Asians. The importance of conventional coronary risk factors is emphasized by studies showing higher prevalence of cigarette smoking, hypertension, and hypercholesterolemia in migrant and urban Indians compared with rural Indians. Recent studies suggest that new risk factors, including C-reactive protein, homocysteine, and lipoprotein(a), are increased among Indian Asians compared with Europeans and may contribute to part of the excess cardiovascular risk in Asians. Further work is needed to identify the precise genetic and environmental mechanisms underlying increased vascular risk in Indian Asians. Clinical strategies must be developed that identify Indian Asians at increased risk and assess the effectiveness of treatment for insulin resistance, and other cardiovascular risk factors, in this racial group.

Influence of cigarette smoking on prepulse inhibition of the acoustic startle response in schizophrenia.

The prevalence of tobacco smoking is known to be higher in patients with schizophrenia than other psychiatric disorders and general population. These patients also show reduced prepulse inhibition (PPI) of the startle response. PPI refers to a reduction in response to a strong startling stimulus if preceded shortly by a stimulus of sub-threshold intensity. PPI is thought of as an objective index of sensorimotor gating. Nicotine administered subcutaneously or via cigarette smoking enhances PPI in healthy human beings. It also enhances PPI at low, but not high, doses in the rat. We examined the influence of smoking on PPI of the acoustic startle response in 46 male patients with chronic schizophrenia. In a naturalistic design, patients (n = 9) who smoked a cigarette less than 10 min prior to being tested on PPI were compared with other smoking (n = 23) and non-smoking patients (n = 14). We found that the group of patients who smoked a cigarette prior to being tested had significantly greater PPI than other two groups. These observations suggest a PPI-enhancing effect of cigarette smoking on PPI in patents with schizophrenia. Higher prevalence of cigarette smoking in schizophrenic patients may reflect an attempt to improve sensorimotor gating deficits. Copyright 2001 John Wiley & Sons, Ltd.

Community-acquired Pneumonia in Hospitalized Urban Young Nigerian Children:Clinical and Haematological Correlates of Diagnosis and Outcome.

As part of a comprehensive hospital-based study of acute lower respiratory infections (ALRI) in under-five urban Nigerian children, we sought to identify the possible clinical and investigative correlates of lobar versus bronchopneumonia, and the possible determinants of mortality in community-acquired pneumonia. Over a 30-month period, 419 cases of ALRI were studied; pneumonia accounted for 323(77.1 per cent) of these. Of those with pneumonia, bronchopneumonia (BP) was diagnosed in 234 (72.4 per cent), lobar pneumonia (LP) in 66 (20.4 per cent), while 23(7.1 per cent) had features of both. BP alone (BPA) and LP alone (LPA) without concomitant respiratory syndromes were diagnosed in 127(39.4 per cent) and 39 (12.1 per cent) cases , respectively. Although there was an overall annual preponderance of BP admissions, the peak admissions for LP was recorded in the harmattan months of November through January. The overall mean age was 15.7 months, but compared with those with LPA, BPA cases were significantly younger (mean ages, 14.2 13.8mo. for BPA vs. 19.514.2mo. for LPA, p=0.021), had a significantly shorter mean duration of cough (p=0.044), and a higher prevalence of convulsion (p=0.02). Furthermore, concomitant measles, heart failure, and severe anaemia were significantly commoner among cases with a diagnosis of BP (p=0.018, 0.033, & 0.009 respectively). On the other hand, LPA cases were associated with a significantly higher prevalence of cigarette smoking in the household (p=0.038; RR=1.86; 95%CI=0.93-5.80), grunting respiration (p=0.01), and a higher mean admission temperature (p=0.03). Also, pleural effusion and sickle cell disease correlated more frequently with a final diagnosis of LP (p=0.00 & 0.01 respectively). Similarly, compared with BPA cases, significantly higher white blood cell (WBC) counts and polymorphs were recorded in LPA cases (p=0.002 & 0.01). A fatal outcome was recorded in 35(10.8 per cent) cases. Mortality was significantly higher in those with pre-admission antimicrobial use (p=0.04), a combination of diarrhoea and vomiting (p=0.025), domestic firewood burning (p=0.023), and malnutrition (p=0.0003). A fatal outcome was also significantly associated with longer symptom duration for cough (p=0.002), fever (p=0.002), poor feeding (p=0.016), higher mean WBC counts and polymorphs (p=0.013 & 0.023 respectively). Harmattan season, grunting respiration, longer symptom-duration, and pleural effusion correlated most frequently with a final diagnosis of LP, while a younger age, anaemia, heart failure and measles were more frequently associated with BP. The association of fatality with malnutrition, pre-admission antibiotic use, concomitant alimentary symptoms, longer symptom-duration, and high WBC/polymorph counts suggests the need for factoring these parameters into evolving a regional paediatric pneumonia severity index and therapeutic decision algorithms. Nigerian Journal of Paediatrics 2001:28:101 pp. 101-114

Starting smoking: girls' explanations of the influence of peers

A questionnaire survey of cigarette smoking completed in six secondary schools by 4773 pupils aged 11–16 years included five items concerning the circumstances of smoking initiation: (1) age at first cigarette; (2) source of supply; (3) location of first smoke; (4) persons present; and (5) perceived degree of coercion. Although there was a highly significant gender difference on the item concerning age at first cigarette, with the average for boys lower than that for girls, the remaining items showed no gender effects. In order to explore further the reasons for the observed higher prevalence of cigarette smoking among teenage girls compared to boys, 33 focus groups were undertaken with girls in Years 7 and 9. These qualitative data provide evidence of the social representations of different groups and of smoking and non-smoking identities. Any understanding of smoking among girls needs to take account the dynamics of girls' membership in groups of never, experimental and regular smokers in determining subsequent smoking behaviour.

Passive smoking and the risk of coronary heart disease--a meta-analysis of epidemiologic studies.

The effect of passive smoking on the risk of coronary heart disease is controversial. We conducted a meta-analysis of the risk of coronary heart disease associated with passive smoking among nonsmokers. We searched the Medline and Dissertation Abstracts Online data bases and reviewed citations in relevant articles to identify 18 epidemiologic (10 cohort and 8 case-control) studies that met prestated inclusion criteria. Information on the designs of the studies, the characteristics of the study subjects, exposure and outcome measures, control for potential confounding factors, and risk estimates was abstracted independently by three investigators using a standardized protocol. Overall, nonsmokers exposed to environmental smoke had a relative risk of coronary heart disease of 1.25 (95 percent confidence interval, 1.17 to 1.32) as compared with nonsmokers not exposed to smoke. Passive smoking was consistently associated with an increased relative risk of coronary heart disease in cohort studies (relative risk, 1.21; 95 percent confidence interval, 1.14 to 1.30), in case-control studies (relative risk, 1.51; 95 percent confidence interval, 1.26 to 1.81), in men (relative risk, 1.22; 95 percent confidence interval, 1.10 to 1.35), in women (relative risk, 1.24; 95 percent confidence interval, 1.15 to 1.34), and in those exposed to smoking at home (relative risk, 1.17; 95 percent confidence interval, 1.11 to 1.24) or in the workplace (relative risk, 1.11; 95 percent confidence interval, 1.00 to 1.23). A significant dose-response relation was identified, with respective relative risks of 1.23 and 1.31 for nonsmokers who were exposed to the smoke of 1 to 19 cigarettes per day and those who were exposed to the smoke of 20 or more cigarettes per day, as compared with nonsmokers not exposed to smoke (P=0.006 for linear trend). Passive smoking is associated with a small increase in the risk of coronary heart disease. Given the high prevalence of cigarette smoking, the public health consequences of passive smoking with regard to coronary heart disease may be important.

Dopamine and nicotinic receptor binding and the levels of dopamine and homovanillic acid in human brain related to tobacco use

Reports of a reduction in the risk of developing Parkinson's disease and Alzheimer's disease in tobacco smokers, together with the loss of high-affinity nicotine binding in these diseases, suggest that consequences of nicotinic cholinergic transmission may be neuroprotective. Changes in brain dopaminergic parameters and nicotinic receptors in response to tobacco smoking have been assessed in this study of autopsy samples from normal elderly individuals with known smoking histories and apolipoprotein E genotype. The ratio of homovanillic acid to dopamine, an index of dopamine turnover, was reduced in elderly smokers compared with age matched non-smokers ( P<0.05) in both the caudate and putamen. Dopamine levels were significantly elevated in the caudate of smokers compared with non-smokers ( P<0.05). However there was no significant change in the numbers of dopamine (D1, D2 and D3) receptors or the dopamine transporter in the striatum, or for dopamine D1 and D2 receptors in the hippocampus in smokers compared with non-smokers or ex-smokers. The density of high-affinity nicotine binding was higher in smokers than non-smokers in the hippocampus, entorhinal cortex and cerebellum (elevated by 51–221%) and to a lesser extent in the striatum (25–55%). The density of high-affinity nicotine binding in ex-smokers was similar to that of the non-smokers in all the areas investigated. The differences in high-affinity nicotine binding between smokers and the non- and ex-smokers could not be explained by variation in apolipoprotein E genotype. There were no differences in α-bungarotoxin binding, measured in hippocampus and cerebellum, between any of the groups. These findings suggest that chronic cigarette smoking is associated with a reduction of the firing of nigrostriatal dopaminergic neurons in the absence of changes in the numbers of dopamine receptors and the dopamine transporter. Reduced dopamine turnover associated with increased numbers of high-affinity nicotine receptors is consistent with attentuated efficacy of these receptors in smokers. A decrease in striatal dopamine turnover may be a mechanism of neuroprotection in tobacco smokers that could delay basal ganglia pathology. The current findings are also important in the interpretation of measurements of nicotinic receptors and dopaminergic parameters in psychiatric conditions such as schizophrenia, in which there is a high prevalence of cigarette smoking.