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Aims: Low socioeconomic status is associated with all-cause mortality and cardiac risk factors. Furthermore, sudden cardiac death (SCD) is among the leading causes of death in the general population, and an identification of high-risk subgroups is needed. The aim of this study was to investigate the association between income and education level and incidence of SCD and to calculate the impact of modifiable mediating risk factors., Methods and Results: Participants in the Copenhagen City Heart Study were followed up from 1993 to 2016. Sudden cardiac death was identified using high-quality death certificates, autopsy reports, discharge summaries, and national registry data. Hazard ratios were calculated using Cox proportional hazards regression, and adjusted cumulative incidences were predicted using cause-specific Cox models. Mediation analyses were performed using a marginal structural model approach. During 24 years of follow-up, 10 006 people participated, whereof 5514 died during the study period with 822 SCDs. Compared with long education, persons with elementary school level education had an SCD incidence rate ratio (IRR) of 2.48 [95% confidence interval (CI) 1.86-3.31], and low income was likewise associated with an SCD IRR of 2.34 (95% CI 1.85-2.96) compared with high income. In the association between education and SCD, the combined mediating effect of smoking, physical activity, and body mass index accounted for ∼20% of the risk differences., Conclusion: We observed an inverse association between both income and education and the risk of SCD, which was only in part explained by common cardiac risk factors, implying that further research into the competing causes of SCD is needed and stressing the importance of targeted preventive measures., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: The objective of the study was to investigate the mediated proportion of smoking and alcohol consumption in the association between education and tooth loss. Further, the objective was, on the additive scale, to decompose the total effect of education on tooth loss into the direct effect of education, the natural indirect effect through smoking and alcohol consumption (differential exposure) and the mediated interaction between education, smoking and alcohol consumption on tooth loss (differential susceptibility)., Methods: The study was based on data from the Social Inequality in Cancer Cohort (SIC); a cohort constructed by seven pooled cohorts. The total study population comprised of 34 975 participants. With the use of natural effects models, we regarded smoking and alcohol consumption as intermediates; we investigated the role of smoking and alcohol consumption in mediating the effect of education on tooth loss., Results: In total, 4924 participants had tooth loss defined as <15 teeth present. The results of the analyses, on the additive scale, showed 1202 (95% CI: 623-1781) additional persons with tooth loss per 10 000 persons among low compared to highly educated men. Among women, the analyses showed 1159 (95% CI: 959-1359) additional persons with tooth loss per 10 000 persons. The results, on the relative scale, showed that 11% (95% CI: 8%-15%) of the social inequality in tooth loss was jointly mediated by smoking and alcohol consumption among low-educated men. Among women with low education, the mediated proportion was 26% (95% CI: 19%-36%)., Conclusion: Social inequality in tooth loss seems partly explained by differential exposure and differential susceptibility to smoking and alcohol consumption., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background and Purpose: Combined effects of socioeconomic position and well-established risk factors on stroke incidence have not been formally investigated., Methods: In a pooled cohort study of 68 643 men and women aged 30 to 70 years in Denmark, we examined the combined effect and interaction between socioeconomic position (ie, education), smoking, and hypertension on ischemic and hemorrhagic stroke incidence by the use of the additive hazards model., Results: During 14 years of follow-up, 3613 ischemic strokes and 776 hemorrhagic strokes were observed. Current smoking and hypertension were more prevalent among those with low education. Low versus high education was associated with greater ischemic, but not hemorrhagic, stroke incidence. The combined effect of low education and current smoking was more than expected by the sum of their separate effects on ischemic stroke incidence, particularly among men: 134 (95% confidence interval, 49-219) extra cases per 100 000 person-years because of interaction, adjusted for age, cohort study, and birth cohort. There was no clear evidence of interaction between low education and hypertension. The combined effect of current smoking and hypertension was more than expected by the sum of their separate effects on ischemic and hemorrhagic stroke incidence. This effect was most pronounced for ischemic stroke among women: 178 (95% confidence interval, 103-253) extra cases per 100 000 person-years because of interaction, adjusted for age, cohort study, and birth cohort., Conclusions: Reducing smoking in those with low socioeconomic position and in those with hypertension could potentially reduce social inequality stroke incidence., (© 2014 American Heart Association, Inc.)

Smoking cessation is crucial in preventing premature morbidity, disability and mortality worldwide. The effectiveness of quitting tobacco use surpasses any other intervention to minimise the risk for chronic cardiac and respiratory conditions. The overall health benefits of smoking cessation have been recognised for decades but as tobacco legislation has been changing in recent years, new evidence particularly concerning the effect of less smoke exposure on the vascular system has emerged. Recently, much research in chronic obstructive pulmonary disease (COPD) has concerned the ongoing inflammation - also in former smokers - and disease heterogeneity, which provides new knowledge regarding current and ex-smokers with COPD. Many other cardiovascular and respiratory diseases are associated with smoking, and the course of these diseases is not always studied in the context of smoking cessation versus continued smoking. This review summarises the latest available data on health benefits of smoking cessation with focus on both common and infrequent cardiovascular and respiratory diseases., (© 2011 Blackwell Publishing Ltd.)

Background: A key question regarding the documented association between smoking and depression is whether it reflects a causal influence of smoking on depression; however, only a limited number of longitudinal studies exist in the literature, all of which have relatively short time frames. The purpose was to prospectively assess the risk of depression according to daily tobacco consumption in a Danish longitudinal study., Methods: A prospective cohort study, the Copenhagen City Heart Study (n = 18,146), was analyzed with up to 26 years of follow-up. It contains three updated data sets on tobacco consumption and potential confounding factors. The study population was linked to Danish hospital registers to detect registrations with depression. Individuals with depression before baseline were excluded., Results: Women smoking more than 10 g of tobacco per day were at significantly increased risk of depression compared to women who did not smoke. The adjusted risk of depression among women smoking 11-20 g per day was 1.74 (CI:1.33-2.27) and 2.17 (CI:1.45-3.26) among women smoking more than 20 g per day. For men, there was an increased risk of depression for those smoking more than 20 g per day (HR = 1.90; CI:1.05-3.44). All tests for linear trend were significant (all p < 0.01). The estimates remained significant in sensitivity analyses aiming to eliminate reverse causation, and in analyses based on a reduced sample without individuals with chronic diseases or psychiatric disorders other than depression., Conclusion: The study suggests that smoking is associated with increased risk of developing depression. This underlines the potentially harmful consequences of smoking for mental health and supports efforts to prevent and stop smoking., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The purpose of this cohort study with up to 31 years of follow-up of 19,714 persons from three Danish population-based studies was to analyse the association between smoking reduction and lung cancer risk. Information on smoking habits and changes in these were linked to the Danish Cancer Registry for incident lung cancers and analysed with Cox regression. Results showed that compared to sustained heavy smokers, smoking reduction by at least 50% reduced lung cancer incidence by 27%. We conclude that smoking reduction is associated with a significantly reduced risk of lung cancer.

Context: Many smokers are unable or unwilling to completely quit smoking. A proposed means of harm reduction is to reduce the number of cigarettes smoked per day. However, it is not clear whether this strategy decreases the risk for tobacco-related diseases., Objective: To assess the effects of smoking reduction on lung cancer incidence., Design, Setting, and Participants: Observational population-based cohort study with up to 31 years of follow-up from the Copenhagen Centre for Prospective Population Studies, which administrates data from 3 longitudinal studies conducted in Copenhagen and suburbs, the Copenhagen City Heart Study, the Copenhagen Male Study, and the Glostrup Population Studies, Denmark. Participants were 11,151 men and 8563 women (N = 19,714) aged 20 to 93 years, who attended 2 consecutive examinations with a 5- to 10-year interval between 1964 and 1988. Participants underwent a physical examination and completed self-filled questionnaires about lifestyle habits. The study population was divided into 6 groups according to smoking habits: continued heavy smokers (> or =15 cigarettes/d), reducers (reduced from > or =15 cigarettes/d by minimum of 50% without quitting), continued light smokers (1-14 cigarettes/d), quitters (stopped between first and second examination), stable ex-smokers, and never smokers., Main Outcome Measure: Incident primary lung cancer cases assessed by record linkage with the National Cancer Registry until December 31, 2003., Results: There were 864 incident lung cancers during follow-up. Using Cox regression, the adjusted hazard ratio (HR) for lung cancer in reducers was 0.73 (95% confidence interval [CI], 0.54-0.98) compared with persistent heavy smokers. The HR for light smokers was 0.44 (95% CI, 0.35-0.56); for quitters, HR 0.50 (95% CI, 0.36-0.69), for stable ex-smokers, HR 0.17 (95% CI, 0.13-0.23), and for never smokers, HR 0.09 (95% CI, 0.06-0.13)., Conclusion: Among individuals who smoke 15 or more cigarettes per day, smoking reduction by 50% significantly reduces the risk of lung cancer.

Objective: To address the role of alcohol intake and tobacco smoking and the combination of the two on subsequent risk of Dupuytren's disease., Study Design and Setting: Cohort study of 7,254 subjects enrolled in the Copenhagen City Heart Study (1981-1983). Both self-reported information on lifestyle and objective measures at the baseline examination were linked to presence of Dupuytren's disease at a subsequent examination (1991-1994) using multivariate logistic regression analysis., Results: A total of 772 subjects had signs of Dupuytren's disease at follow-up. After adjustment for age, sex, educational level, diabetes, and either alcohol or tobacco consumption, respectively, odds ratios for having the disease increased in a dose-dependent manner with increasing levels of alcohol or tobacco intake; however, there was no statistical interaction between heavy smoking and heavy drinking., Conclusion: Alcohol intake and tobacco smoking are independently associated with increased risk of Dupuytren's disease, and the combination of the two conveys a very large risk.

Background: Smoking is the most important single preventable cause of a variety of common diseases, and a considerable share of premature death is attributable to smoking. Although the effects of smoking on morbidity and mortality are widely recognized, little is known about the impact of smoking on early retirement due to chronic disease. The objective of the study is to determine the effects of smoking behaviour on early retirement due to permanent disability in a large sample of the general population., Methods: Follow-up study based on data from three longitudinal population studies conducted in the Copenhagen area. The final study population comprised 9,053 persons, 5,623 men and 3,430 women. Endpoint was grant of disability pension in the period 1980-1985. Baseline information was obtained from a self-administered questionnaire. Information about disability pensions was obtained from Statistics Denmark. Data analysis was performed by univariate and multiple logistic regression analyses., Results: Smoking was found to be strongly associated with the risk of being granted a disability pension after adjustment for various confounders. The risk increased with daily consumption reaching a maximum odds ratio of 5.66 (1.88-17.00) and 5.61 (2.11-14.92) in heavily smoking men and women, respectively, who were below age 60., Conclusions: Smokers are at considerably higher risk of early retirement due to chronic disease. In addition to the burden of disease, this leads to social and economic problems for the individual and has a significant economic impact on society.

Background: Net costs of smoking in a lifetime perspective and, hence, the economic interests in antismoking policies have been questioned. It has been proposed that the health-related costs of smoking are balanced by smaller expenditure due to shorter life expectancy., Method: A dynamic (life cycle) method taking differences in life expectancy into account. Main outcome measures were direct and indirect lifetime health costs for ever-smokers and never-smokers, and cost ratios (ever-smokers to never-smokers). The estimations were based on annual disease rates of use of the healthcare services, smoking relative risks, smoking prevalences, and costs., Results: Annual direct and indirect costs of ever-smokers were higher than for never-smokers in all age groups of both genders. The direct and indirect cost ratios were highest at age 45 for women, and at age 35 and 40 for men, respectively. Taking life expectancy differences into account, direct and indirect lifetime health costs for men aged 35, discounted by 5% per year were 66% and 83% higher in ever-smokers than in never-smokers. Corresponding results for women were 74% and 79%, respectively. The results are insensitive to a broad range of relative risk-estimates and discount rates including no discounting. Excess costs of ever-smokers disappear if the inclusion of smoking-related diseases is narrowed to that of previous studies., Conclusion: Smoking imposes costs to society even when taking life expectancy into consideration--both in direct and indirect costs.

Objectives: This study aims at examining whether the relation between established risk factors and mortality differs with socioeconomic status as measured by level of education., Methods: A population-based sample of 14,399 women and 16,236 men aged 20-93 years from Copenhagen was stratified into three educational levels measured as basic schooling, and the effect of smoking habits, alcohol consumption, physical activity, and body mass index, respectively, on mortality was assessed., Results: Those with the lowest level of education were most frequently heavy smokers, heavy drinkers, physically inactive, and obese. During a mean follow up of 16 years 10,952 subjects died. Compared with subjects with the lowest educational level, women with the highest educational level had a relative risk of 0.80 (95% CI; 0.70-0.91), and men of 0.71 (0.65-0.78). Heavy smoking compared with never smoking implied a more than twofold increased risk at all three educational levels among both men and women. The relation between alcohol intake and mortality was J-shaped on all three educational levels. There were decreasing risk functions describing the relations between physical activity and mortality on all three strata. Further, subjects who were either very lean or obese had increased risks of death compared with those of normal weight at all educational levels in both genders., Conclusions: The difference in distribution of the main known risk factors may be part of the explanation for the differences in mortality risk. However, these risk factors seem to influence mortality equally at different educational levels. Therefore, social inequalities in mortality do not seem to be explained only by differences in effect of lifestyle risk factors, but are also related to the social rank or unexamined factors within., (Copyright 2004 Taylor & Francis)

Patients suffering from atherosclerotic diseases are prone to repeated episodes of ischemia/reperfusion that has been demonstrated to induce oxidative stress by formation of oxygen free radicals. It might therefore be expected that such endogenously exposure to free radicals increases the individual cancer risk in patients with atherosclerotic diseases. We therefore studied the sex-specific risk of lung cancer and other cancers in atherosclerotic patients in a prospective study conducted in the Copenhagen area. The study cohort was linked to the Danish Hospital Discharge Register and we identified 2261 1-year survivors of atherosclerotic diseases through 1977 and 1993, while 26150 of the study subjects had no record of an atherosclerotic diagnosis. After linkage to the Danish Cancer Registry associations between atherosclerosis and cancer were analysed for each sex separately by means of Cox proportional hazard regression models. Atherosclerotic women had a significant RR of lung cancer of 3.26 (95% CI: 1.95-5.46) compared to non-atherosclerotic women after adjustment for age, calendar period, study population, smoking habits, school education and alcohol consumption. No significant risk of male lung cancer, RR=1.12 (95% CI: 0.77-1.64), or other smoking-related cancers in either sex was observed after multivariate adjustment. Atherosclerosis did not predict non-smoking-related cancers in general in either men, RR=0.91 (95% CI 0.69-1.20), or women, RR=0.93 (95% CI: 0.64-1.35). We hypothesize that oxidative stress due to episodes of ischemia/reperfusion increases the risk of lung cancer in atherosclerotic females because of a gender specific susceptibility to oxidative DNA damage.

Objective: To analyse the effects of smoking reduction and smoking cessation on incidence of myocardial infarction after adjustment for established cardiovascular risk factors., Design: Prospective cohort study with record linkage to mortality and hospital registers. The association of individual change in smoking with myocardial infarction was examined in Cox proportional hazard analyses with continuous heavy smokers (> or =5 cigarettes/day) as reference., Setting: Pooled data from three population studies conducted in Copenhagen, Denmark., Participants: 10 956 men and 8467 women with complete information on smoking habits at two examinations five to ten years apart were followed up from the second examination for a first hospital admission or death from myocardial infarction. Mean duration of follow up was 13.8 years., Main Results: A total of 643 participants who were heavy smokers at baseline reduced their daily tobacco consumption by at least 50% without quitting between first and second examination, and 1379 participants stopped smoking. During follow up 1658 men and 521 women experienced a fatal or non-fatal myocardial infarction. After adjustment for cardiovascular risk factors, people who stopped smoking had a decreased risk of myocardial infarction, hazard ratio 0.71 (95% confidence intervals 0.59 to 0.85). Smoking reduction was not associated with reduced risk of myocardial infarction, hazard ratio 1.15 (95% confidence intervals 0.94 to 1.40). These associations remained unchanged after controlling for baseline illness in different ways., Conclusions: Smoking cessation in healthy people reduces the risk of a subsequent myocardial infarction, whereas this study provides no evidence of benefit from reduction in the amount smoked.

The authors investigated the association between changes in smoking habits and mortality by pooling data from three large cohort studies conducted in Copenhagen, Denmark. The study included a total of 19,732 persons who had been examined between 1967 and 1988, with reexaminations at 5- to 10-year intervals and a mean follow-up of 15.5 years. Date of death and cause of death were obtained by record linkage with nationwide registers. By means of Cox proportional hazards models, heavy smokers (>or=15 cigarettes/day) who reduced their daily tobacco intake by at least 50% without quitting between the first two examinations and participants who quit smoking were compared with persons who continued to smoke heavily. After exclusion of deaths occurring in the first 2 years of follow-up, the authors found the following adjusted hazard ratios for subjects who reduced their smoking: for cardiovascular diseases, hazard ratio (HR) = 1.01 (95% confidence interval (CI): 0.76, 1.35); for respiratory diseases, HR = 1.20 (95% CI: 0.70, 2.07); for tobacco-related cancers, HR = 0.91 (95% CI: 0.63, 1.31); and for all-cause mortality, HR = 1.02 (95% CI: 0.89, 1.17). In subjects who stopped smoking, most estimates were significantly lower than the heavy smokers'. These results suggest that smoking reduction is not associated with a decrease in mortality from tobacco-related diseases. The data confirm that smoking cessation reduces mortality risk.

Study Objective: To determine risk of myocardial infarction (MI) and all cause mortality associated with light smoking and inhalation habits in men and women., Design: Prospective cohort study with follow up of MI and all cause mortality through record linkage., Setting: The Copenhagen City Heart Study, a cardiovascular study based on a sample of the general population established in 1976., Participants: 6505 women and 5644 men followed up until 1998 for first MI and for death from all causes., Main Results: During follow up 476 women and 872 men suffered a MI whereas 2305 women and 2883 men died. After adjusting for major cardiovascular risk factors there was a dose-response relation between smoking with and without inhaling and both MI and all cause mortality. Among inhaling smokers significantly increased risks were found in women at a consumption of only 3-5 grams of tobacco per day with relative risks (RR) of MI and all cause mortality of 2.14 (95% CI 1.11 to 4.13) and 1.86 (95% CI 1.37 to 2.51), respectively. In men increased risks were seen when smoking 6-9 grams per day with RR of MI and all cause mortality of 2.10 (95% CI 1.40 to 3.14) and 1.76 (95% CI 1.39 to 2.23), respectively. Risks were also increased in non-inhaling smokers, although in men only significantly so for all cause mortality. After adjusting for inhalation and quantity smoked, cigarette smokers had a higher risk of all cause mortality (RR 1.16 (95% CI 1.07 to 1.26)) but not of MI (RR 1.11 (95% CI 0.95 to 1.30)). The RR associated with smoking were significantly higher in women than in men for both MI and all cause mortality., Conclusions: Smoking as little as 3-5 grams of tobacco per day or not inhaling the smoke was shown to carry a significantly increased risk of developing MI and of all cause mortality with higher RR found in women than in men. The study emphasises the importance of recognising that even very limited tobacco consumption has detrimental health effects.

Twin studies suggest that genetic factors influence smoking behavior. However, in these studies, genetic and environmental influences may be confounded. We examined whether smoking behavior of adoptees is associated with smoking behavior in adoptive and biological relatives in a design in which this confounding is minimized. Data on smoking status were collected using a mailed questionnaire in a sample of 840 adoptive families from the Danish Adoption Register including all non-familial adoptions from 1924 through 1947. Smoking data were available for 706 adoptees, 451 biological fathers, 580 biological mothers, 641 adoptive fathers, 693 adoptive mothers, 199 biological full-siblings, 684 maternal half-siblings, and 576 paternal half-siblings. Adoptees' status as ever, current, heavy, or former (ex-)smokers was related to their relatives' smoking status. Adoptees ever smoking was associated with their full-siblings' status as ever smokers (OR = 3.6 [1.5-8.7]). Adoptees' current smoking was also associated with their full-siblings' ever (OR = 3.2 [1.5-7.7]) and current (OR = 2.6 [1.3-5.0]) smoking, whereas adoptees' heavy smoking was associated with their full-siblings ever (OR = 5.5 [2.1-14.3]), current (OR = 4.0[1.9-8.6]) and heavy (OR = 2.0[1.0-4.2]) smoking. Compared with current smokers, adoptee ex-smokers had full-siblings who were ex-smokers more often (OR = 3.5 [1.0-11.6]), current (OR = 0.4 [0.2-0.8]), and heavy (OR = 0.3 [0.1-0.9]) smokers less often. Adoptees' smoking behavior was not associated with adoptive or biological parents' status as current smokers. This study of smoking behavior in adult adoptees and their biological and adoptee family supports the finding in twin studies of a genetic influence on smoking within the same generation., (Copyright 2001 Wiley-Liss, Inc.)

Introduction: In the present population-based cohort study, we prospectively determined the influence of current, previous, and cumulative smoking history on the risk of hip fracture in men and women and addressed the issue of possible gender difference in susceptibility to tobacco smoking., Material: A total of 13,393 women and 17,379 men, initially examined between 1964 and 1992, were followed up until 1997 for their first admission because of hip fracture., Results: During follow-up, a total of 1169 hip fractures were identified. After adjustment for potential confounders, female current smokers had a relative risk of hip fracture of 1.36 (1.12-1.65) and male smoked 1.59 (1.04-2.43) relative to those who have never smoked. In both sexes, the relative risk of hip fracture gradually increased with current and accumulated tobacco consumption. A test for interaction between gender and smoking habits was insignificant. Men who stopped smoking for more than five years had a lower risk of hip fracture than men who currently smoked, whereas no such risk reduction was seen in female ex-smokers., Conclusion: Tobacco smoking is an independent risk factor for hip fracture in men and women, and there appears to be no gender differences in the smoking-related risk. Men who stopped smoking for more than five years had lower risk of hip fracture than men who currently smoked, whereas no such risk reduction was seen in female ex-smokers.

Background: The aim of this study was to examine the extent and gender distribution of unassisted tobacco reduction and cessation in a cohort of moderate and heavy smokers and to identify possible predictor variables associated with these changes in smoking behavior., Methods: This was a prospective population study of 3,791 moderate and heavy smokers, 15 g tobacco/day or more, who were enrolled in the Copenhagen City Heart Study in 1976-1978 and attended a reexamination 5 years later. Data on smoking behavior were collected at baseline and follow-up. Smoking reduction was defined as a decrease in mean daily tobacco consumption of 10 g or more. Using multivariate logistic regression, subjects who reported reduced smoking or who reported smoking cessation were compared with subjects who continued the habit unchanged., Results: After 5 years 13% of the men and 9% of the women had reduced their tobacco consumption, and 9 and 7%, respectively, had quit altogether. Smoking reduction was strongly associated with high tobacco consumption (25+ g/day) at baseline and also with severely impaired lung function (FEV(1) <50% predicted) and overweight (BMI >25). Predictors of smoking cessation included impaired lung function and a tobacco consumption of 15-24 g/day. Additional determinants of smoking reduction and cessation such as inhalation habits and sociodemographic variables differed by gender., Conclusions: Several predictors of smoking reduction and cessation were identified, indicating that these subgroups of smokers differ substantially from continuing smokers. This should be taken into account when assessing potential health benefits from these changes in smoking behavior., (Copyright 2001 American Health Foundation and Academic Press.)

Background: Previous findings suggest that tobacco smoking increases the risk of hip fracture in women. A similar adverse effect of smoking is suspected to be present in men, but bone mineral density studies have raised the concern that men may be more sensitive to the deleterious effect of smoking on bone than women. In this study we prospectively determined the influence of current, previous, and cumulative smoking history on risk of hip fracture in men and women and addressed the issue of possible gender difference in the susceptibility to tobacco smoking., Methods: Pooled data from three population studies conducted in Copenhagen with detailed information on smoking habit. A total of 13,393 women and 17,379 men, initially examined between 1964 and 1992, were followed until 1997 for first admission due to hip fracture. The relative risks (RR) of hip fracture associated with smoking were estimated by means of multiplicative Poisson regression models., Results: During follow-up, 722 hip fractures were identified in women, and 447 in men. After adjustment for potential confounders, including body mass index, female current smokers had an RR of hip fracture of 1.36 (95% CI: 1.12-1.65) and male smokers 1.59 (95% CI: 1.04-2.43) relative to never smokers. In both sexes, the RR of hip fracture gradually increased by current and accumulated tobacco consumption. The RR were consistently higher in men than in women, but the test for interaction between sex and tobacco smoking was insignificant. After 5 years, male ex-smokers had an adjusted RR of 0.73 (95% CI: 0.55-0.98) relative to current smokers, while no significant decrease in risk was observed in female ex-smokers (RR = 0.91; 95% CI: 0.72-1.17)). Approximately 19% of all hip fractures in the present study population were attributable to tobacco smoking., Conclusion: Tobacco smoking is an independent risk factor for hip fracture in men and women, and there appears to be no gender differences in smoking related risk. Smoking cessation reduces the risk of hip fracture in men after 5 years, while the deleterious effect of smoking seems to be more long-lasting in female ex-smokers.

Because of a "healthy responder effect," secular trends in mortality based on cohort studies may be biased if based on responders only. Because responders are selected on the basis of their health at study entry, subjects just entering a study are not comparable with subjects who have been in the study for several years. The result may be an artificial increase in mortality, which impedes analyzing the effect of secular trends in risk factors on mortality. The objective of this paper is to suggest a solution by using data on nonresponders and applying a sensitivity analysis. We illustrate this solution with data on trends in smoking prevalence and all-cause mortality based on a large Danish cohort study with 19 years of complete follow-up on responders and nonresponders. Secular trends in mortality based on the whole sample vs responders only illustrated that results based on responders were biased. In a sensitivity analysis, the observed person-years of nonresponders were distributed among six categories of persons with respect to smoking behavior (never-smokers; ex-smokers; noninhaling current smokers; and current smokers of 1-14, 15-24, and > or =25 gm tobacco per day) according to preset assumptions regarding smoking habits. The observed deaths among nonresponders were then distributed on the six smoking categories according to relative risks derived from a Poisson regression analysis among responders. This procedure allowed us to study the effect of adjustment for smoking on the unbiased secular trend in mortality. By applying different assumptions regarding smoking habits among nonresponders, we explored the effect of the assumptions on the adjusted secular trend in mortality. We conclude that secular trends in mortality based on responders in a cohort study are likely to be biased. If complete follow-up on nonresponders is available, this method could prove useful in other cohort studies.

Studies reporting increased mortality in smokers are abundant, but only few have included large numbers of heavily smoking women. Based on three large Danish population studies we calculated median survival in smokers and never-smokers and compared the impact of smoking in men and women. Seventeen thousand six hundred and sixty-nine men and 13,525 women were followed for up to 30 years for all-cause mortality. During follow-up there were 8644 deaths. Large differences in tobacco-exposure between men and women were found, in particular in older birth-cohorts. Despite a smaller accumulated exposure, the impact smoking had on median survival was similar in men and women. Female inhaling heavy smokers (> or = 15 cig./day) lost 9.4 and inhaling light smokers 7.4 years in comparison with female never-smokers. Corresponding loss of life-expectancy in males was 9.2 years and 6.0 years, respectively. In conclusion, this study shows survival prospects in relation to smoking in both men and women in a way that is easily communicated. The results indicate that women who smoke as much as men run a relatively higher risk in terms of reduced life expectancy.

Background: Studies of time trends in smoking prevalence provide a better understanding of the determinants of smoking. The present study analyses changes over time in the prevalence of smoking and heavy smoking in relation to sex, age, and education., Methods: Data on smoking behaviour were collected by questionnaire in random samples of the general population in the area of Copenhagen. The database used included 71,842 measurements of smoking behaviour for 32,156 subjects aged 30 years or more, who had been examined at intervals between 1964 and 1994. In bi- and multivariate analyses the effects of sex, age, education, time period, and study group on the prevalence of smoking and of heavy smoking were assessed., Results: Smoking was least prevalent in women, in the oldest age group (more than 70 years), and among those with 8 years or more of school education. During the study period (from 1964/74 to 1990/94), the prevalence of smoking decreased from 72% to 54% in men and from 52% to 46% in women. In both men and women this decrease was smallest in the least educated (less than 8 years of school education). Heavy smoking was also least prevalent in women, in the oldest age group, and among the well educated. During the study period, the unadjusted prevalence of heavy smoking decreased from 52% to 38% in men, while it increased from 17% to 21% in women. The multivariate analysis showed that the time trend for heavy smoking only depended on sex, while educational attainment and age had no impact on the trend., Conclusion: During the last 30 years the prevalence of smoking has decreased in Denmark. The decrease has been smallest in women, and among the least educated, and the increasing trend in the prevalence of heavy smoking in women is a cause for concern.

Objective: To examine the factors that determine whether or not smokers become long-term quitters, and to study whether determinants of successful cessation differ with levels of motivation to stop., Design: In a cohort of men and women, aged 30-60 years at first examination in 1982/1984, smoking behaviour was evaluated from questionnaires at baseline and at follow up 10 years later., Setting: County of Copenhagen, Denmark., Participants: 2554 subjects from the original sample of 4581 were successfully followed. This study deals with the 1365 subjects who were smokers at the first examination., Main Outcome Measure: Smoking status (abstinent for one year or more) at follow up., Results: At follow up 15% of the baseline smokers had been abstinent for one year or more. In multivariate analysis, successful smoking cessation was associated with older age, high social status, low prior tobacco consumption, baseline motivation to stop smoking, and having a non-smoking spouse/cohabitant. The same result was obtained when the analyses were repeated separately for smokers with and without motivation to stop., Conclusions: Smokers motivated to stop are more likely to quit and remain abstinent than smokers with no such motivation. Age, social status, spouse/cohabitant's smoking behaviour, and the daily consumption of tobacco predict success in smoking cessation, irrespective of smokers' former motivation to stop.

Objective: To compare risk of myocardial infarction associated with smoking in men and women, taking into consideration differences in smoking behaviour and a number of potential confounding variables., Design: Prospective cohort study with follow up of myocardial infarction., Setting: Pooled data from three population studies conducted in Copenhagen., Subjects: 11,472 women and 13,191 men followed for a mean of 12.3 years., Main Outcome Measures: First admission to hospital or death caused by myocardial infarction., Results: 1251 men and 512 women had a myocardial infarction during follow up. Compared with non-smokers, female current smokers had a relative risk of myocardial infarction of 2.24 (range 1.85-2.71) and male smokers 1.43 (1.26-1.62); ratio 1.57 (1.25-1.97). Relative risk of myocardial infarction increased with tobacco consumption in both men and women and was higher in inhalers than in non-inhalers. The risks associated with smoking, measured by both current and accumulated tobacco exposure, were consistently higher in women than in men and did not depend on age. This sex difference was not affected by adjustment for arterial blood pressure, total and high density lipoprotein cholesterol concentrations, triglyceride concentrations, diabetes, body mass index, height, alcohol intake, physical activity, and level of education., Conclusion: Women may be more sensitive than men to some of the harmful effects of smoking. Interactions between components of smoke and hormonal factors that may be involved in development of ischaemic heart disease should be examined further.

Background: Mortality from smoking-related diseases in women is increasing worldwide. Studies comparing hazards associated with smoking in women and men based on a sufficient number of heavy smokers of both genders are lacking., Methods: We used pooled data from three prospective population studies conducted in Copenhagen to compare total and cause-specific mortality in relation to smoking habits. A total of 30917 subjects, 44% women, with initial examinations between 1964 and 1992 were followed until 1994 for date and cause of death., Results: During follow up, 2900 women and 5744 men died. Smoking characteristics differed considerably with gender, particularly in the older subjects. Overall mortality rates in smokers were approximately twice those in people who never smoked. Positive associations with smoking in both men and women were confirmed for all-cause mortality as well as mortality from respiratory disease, vascular disease, lung cancer, and other tobacco-related cancers. Despite large gender differences in age at smoking debut, total and cause-specific relative mortality in smokers was similar in men and women. After excluding non-inhalers, relative risks associated with smoking for respiratory and vascular disease were higher for women than men whereas there were no gender differences in smoking related risk of cancers., Conclusions: The relative risks suggest that women may be more sensitive than men to some of the deleterious effects of smoking. However, because of lower baseline mortality rates in women, rate differences may be similar and results should be interpreted with caution.

Our aim was to compare risk of lung cancer associated with smoking by gender and histologic type. A total of 30,874 subjects, 44% women, from three prospective population-based studies with initial examinations between 1964 and 1992 were followed until 1994 through the National Cancer Registry. There were 867 cases of lung cancer, 203 among women and 664 among men. Rates among female and male never-smokers were similar, although confidence intervals around rates were wide. Rate ratios (RRs) increased with number of pack-years for both men and women to a maximum of approximately 20 in inhaling smokers with more than 60 pack-years of tobacco exposure. RRs did not differ much between men and women: adjusted for pack-years, age, and study population, the ratio between female and male smokers' RRs of developing lung cancer was 0.8 (95% confidence interval = 0.3-2.1). All histologic types were associated with smoking, with the largest RR seen for squamous cell carcinoma and anaplastic carcinoma. This prospective population-based study does not confirm previous reports from case-control studies of a higher relative risk in women than in men for lung cancer associated with smoking.

Background: Two recent much cited publications have raised the concern that risk associated with cigarette smoking has so far been underestimated. In this study we wish to determine whether excess all-cause mortality associated with smoking has increased during the last 20-30 years in a study population representative of the general Danish population and whether any such changes relate to changes in smoking behaviour., Methods: Pooled data from three prospective population studies conducted in Copenhagen with detailed information on smoking habits. A total of 31,194 subjects, 17,669 males and 13,525 females, initially examined between 1964 and 1992 with examinations repeated at intervals from 1-10 years, were followed until 1995 for all-cause mortality. Relative mortality risk in smokers versus never-smokers was calculated within periods of five calendar years and compared throughout the study period., Results: Male smokers' exposure did not change during the study period whereas female smokers' exposure to tobacco increased in terms of age at smoking onset, quantity smoked and depth of inhalation. During follow-up 5744 males and 2900 females died. In males, death rate ratios (comparing continuous smokers with never-smokers) did not change in the study period. In females, ratios increased from 1964-1978 to 1979-1994 by a factor of 1.3 (95% confidence interval 1.0-1.8)., Conclusions: In agreement with the observed changes in smoking habits, excess mortality in male smokers did not increase whereas excess mortality in female smokers increased slightly.

Recent findings suggest that females may be more susceptible than males to the deleterious influence of tobacco smoking in developing chronic obstructive pulmonary disease (COPD). This paper studies the interaction of gender and smoking on development of COPD as assessed by lung function and hospital admission. A total of 13,897 subjects, born after 1920, from two population studies, 9,083 from the Copenhagen City Heart Study (CCHS) and 4,814 from the Glostrup Population Studies (GPS), were followed for 7-16 yrs. Data were linked with information on hospital admissions caused by COPD. Based on cross-sectional data, in the CCHS the estimated excess loss of forced expiratory volume in one second (FEV1) per pack-year of smoking was 7.4 mL in female smokers who inhaled and 6.3 mL in male smokers who inhaled. In the GPS, the corresponding excess loss of FEV1 was 10.5 and 8.4 mL in females and males, respectively. Two hundred and eighteen subjects in the CCHS and 23 in the GPS were hospitalized during follow-up. Risk associated with pack-years was higher in females than in males (relative risks (RRs) for 1-20, 20-40 and >40 pack-years were 7.0 (3.5-14.1), 9.8 (4.9-19.6) and 23.3 (10.7-50.9) in females, and 3.2 (1.1-9.1), 5.7 (2.2-14.3) and 8.4 (3.3-21.6) in males) but the interaction term gender x pack-years did not reach significance (p=0.08). Results were similar in the GPS. After adjusting for smoking in more detail, females in both cohorts had an increased risk of hospitalization for COPD compared to males with a RR of 1.5 (1.2-2.1) in the CCHS and 3.6 (1.4-9.0) in the GPS. This was not likely to be caused by a generally increased rate of hospital admission for females. Results were similar when including deaths from COPD as endpoint. In two independent population samples, smoking had greater impact on the lung function of females than males, and after adjusting for smoking females subsequently suffered a higher risk of being admitted to hospital for COPD. Results suggest that adverse effects of smoking on lung function may be greater in females than in males.

Background: Little is known about the effects of changes in smoking habits on the subsequent risk of chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate the relationship between smoking cessation and reduction and admission to hospital for COPD in a general population sample.Methods: A total of 19,709 participants from three prospective population studies in Copenhagen were followed with record linkage for date of first hospital admission for COPD until 1998 (mean follow up 14 years). Heavy smokers (>/=15 cigarettes/day) who reduced their tobacco consumption by at least 50% between the two initial examinations without quitting and smokers who stopped smoking during this time were compared with continuous heavy smokers using a Cox proportional hazards model.Results: During the follow up period 1,260 subjects (741 men and 519 women) were admitted to hospital for COPD. After multivariate adjustment, quitting smoking was associated with a significant reduction in the risk of hospital admission. The relative hazard (HR) was 0.57 (95% confidence interval (CI) 0.33 to 0.99). Those who reduced smoking did not show a significantly lower risk of hospitalisation than continuing heavy smokers (HR 0.93 (95% CI 0.73 to 1.18)). Exclusion of events during the first 5 study years, detailed adjustment for lung function, or restriction of analyses to participants with impaired pulmonary function did not reverse the observed trend.Conclusions: Self-reported smoking cessation is associated with a reduction in the risk of COPD morbidity of approximately 40%; the benefit of smoking reduction is questionable. [ABSTRACT FROM AUTHOR]