Pulmonary dysfunction, smoking, socioeconomic status and the risk of developing rheumatoid arthritis.

OBJECTIVES: Environmental risk factors are of potential interest for both prevention and treatment of RA. The purpose of this study was to examine the effect of pulmonary function, smoking and socio-economic status on the future risk of RA. METHODS: Between 1974 and 1992, 22 444 men and 10 902 women were included in the Malmö Preventive Medicine Program (MPMP). Pulmonary function was assessed by a standard screening spirometry. Chronic obstructive pulmonary disease (COPD) and restrictive pulmonary dysfunction were defined based on pulmonary function tests. Individuals who developed RA were identified by linking the MPMP database to national and local RA registers. The patients were classified according to the 1987 ACR criteria for RA. Four matched controls for every case were selected. RESULTS: We identified 290 cases of incident RA (151 men/139 women; mean age at diagnosis 60 years). The median time from inclusion to diagnosis was 12 years. Forced vital capacity and forced expiratory volume within 1 s values were similar in cases and controls, overall and also in separate analysis of those screened ≤8 years before diagnosis. There was no association between COPD or restrictive pulmonary dysfunction and subsequent development of RA. Current smoking was a strong predictor for RA [odds ratio (OR) 1.79; 95% CI 1.32, 2.42]. Blue-collar workers had an increased risk of RA (OR 1.54; 95% CI 1.12, 2.10), independent of smoking. CONCLUSION: Pulmonary dysfunction did not predict RA, but smoking and low socio-economic status were independent risk factors for RA. Other effects of smoking may be important for RA susceptibility.

C-reactive protein, established risk factors and social inequalities in cardiovascular disease - the significance of absolute versus relative measures of disease.

BACKGROUND: The widespread use of relative scales in socioepidemiological studies has recently been criticized. The criticism is based mainly on the fact that the importance of different risk factors in explaining social inequalities in cardiovascular disease (CVD) varies, depending on which scale is used to measure social inequalities. The present study examines the importance of established risk factors, as opposed to low-grade inflammation, in explaining socioeconomic differences in the incidence of CVD, using both relative and absolute scales. METHODS: We obtained information on socioeconomic position (SEP), established risk factors (smoking, hypertension, and hyperlipidemia), and low-grade inflammation as measured by high-sensitive (hs) C-reactive protein (CRP) levels, in 4,268 Swedish men and women who participated in the Malmö Diet and Cancer Study (MDCS). Data on first cardiovascular events, i.e., stroke or coronary event (CE), was collected from regional and national registers. Social inequalities were measured in relative terms, i.e., as ratios between incidence rates in groups with lower and higher SEP, and also in absolute terms, i.e., as the absolute difference in incidence rates in groups with lower and higher SEP. RESULTS: Those with low SEP had a higher risk of future CVD. Adjustment for risk factors resulted in a rather small reduction in the relative socioeconomic gradient, namely 8% for CRP (>/= 3 mg/L) and 21% for established risk factors taken together. However, there was a reduction of 18% in the absolute socioeconomic gradient when looking at subjects with CRP-levels < 3 mg/L, and of 69% when looking at a low-risk population with no smoking, hypertension, or hyperlipidemia. CONCLUSION: C-reactive protein and established risk factors all contribute to socioeconomic differences in CVD. However, conclusions on the importance of "modern" risk factors (here, CRP), as opposed to established risk factors, in the association between SEP and CVD depend on the scale on which social inequalities are measured. The one-sided use of the relative scale, without including a background of absolute levels of disease, and of what causes disease, can consequently prevent efforts to reduce established risk factors by giving priority to research and preventive programs looking in new directions.

Lung cancers attributable to environmental tobacco smoke and air pollution in non-smokers in different European countries: a prospective study.

BACKGROUND: Several countries are discussing new legislation on the ban of smoking in public places, and on the acceptable levels of traffic-related air pollutants. It is therefore useful to estimate the burden of disease associated with indoor and outdoor air pollution. METHODS: We have estimated exposure to Environmental Tobacco Smoke (ETS) and to air pollution in never smokers and ex-smokers in a large prospective study in 10 European countries (European Prospective Investigation into Cancer and Nutrition)(N = 520,000). We report estimates of the proportion of lung cancers attributable to ETS and air pollution in this population. RESULTS: The proportion of lung cancers in never- and ex-smokers attributable to ETS was estimated as between 16 and 24%, mainly due to the contribution of work-related exposure. We have also estimated that 5-7% of lung cancers in European never smokers and ex-smokers are attributable to high levels of air pollution, as expressed by NO2 or proximity to heavy traffic roads. NO2 is the expression of a mixture of combustion (traffic-related) particles and gases, and is also related to power plants and waste incinerator emissions. DISCUSSION: We have estimated risks of lung cancer attributable to ETS and traffic-related air pollution in a large prospective study in Europe. Information bias can be ruled out due to the prospective design, and we have thoroughly controlled for potential confounders, including restriction to never smokers and long-term ex-smokers. Concerning traffic-related air pollution, the thresholds for indicators of exposure we have used are rather strict, i.e. they correspond to the high levels of exposure that characterize mainly Southern European countries (levels of NO2 in Denmark and Sweden are closer to 10-20 ug/m3, whereas levels in Italy are around 30 or 40, or higher).Therefore, further reduction in exposure levels below 30 ug/m3 would correspond to additional lung cancer cases prevented, and our estimate of 5-7% is likely to be an underestimate. Overall, our prospective study draws attention to the need for strict legislation concerning the quality of air in Europe.

Social mobility, marital status, and mortality risk in an adult life course perspective: the Malmö Preventive Project.

AIMS: Adverse social factors predict increased mortality. This study aimed to assess the influence of social class and marital status on mortality, adding an adult life course perspective. METHODS: In total, 32,907 males and 20,204 females were evaluated based on census data in Malmö, Sweden. Of these subjects, 22,444 males and 10,902 females also took part in health screening. The main outcomes were all-cause and cause-specific mortality rates in subgroups based on social class and marital status, either measured once or repeatedly in adult life. Results were based on a total of 522,807 years of follow-up in men (5,761 deaths) and 239,815 in women (1,354 deaths). RESULTS: Total and cardiovascular mortality were significantly higher in manual male employees with age-adjusted risk ratios (RR) of 1.7 (95% CI 1.5-1.9) and 1.6 (1.3-2.0) in skilled manual workers, and 2.0 (1.7-2.2) and 1.9 (1.6-2.3) in unskilled manual workers, compared with high-level non-manual employees. The differences remained after adjustment for baseline risk factors and prevalent cardiovascular disease, and were similar for women. Increased mortality risk was also documented for subjects who were divorced or unmarried (adjusted for social class), as well as being downward socially mobile or in a permanent low social class (manual) position. CONCLUSIONS: Social class based on occupation, either measured once or repeatedly in adult life, is associated with marked differences in mortality risk in middle-aged subjects. People who remain married/cohabiting or remarry are at lower risk of early death than people who remain unmarried or divorced.

Past food habit change is related to obesity, lifestyle and socio-economic factors in the Malmo Diet and Cancer Cohort.

OBJECTIVES: To examine if obesity status and socio-economic and lifestyle factors are associated with self-reported past food habit change, and also whether the level of obesity depends on the reason for change. DESIGN: Cross-sectional analysis within the Malmo Diet and Cancer (MDC) study using data from the baseline examination and the extensive socio-economic and lifestyle questionnaire including questions of past food habit change. The risk of having changed food habits in the past was examined using logistic regression. Mean differences in obesity status across categories of reasons for past food habit change were examined using analysis of variance. SETTING: Malmö, the third largest city in Sweden. SUBJECTS: A sub-sample (15 282 women and 9867 men) from the MDC cohort recruited from 1992 to 1996. RESULTS: Individuals with body mass index (BMI) >30 kg m(-2) had an increased risk of having reported past food habit change compared with individuals with BMI <25 kg m(-2) (odds ratio (OR) = 1.63, 95% confidence interval (CI) = 1.48-1.83 for women; OR = 1.53, 95% CI = 1.32-1.76 for men). The highest level of obesity was observed among individuals who had changed their diet due to reasons related to the metabolic syndrome. Changers were more likely to be highly educated and to live alone, be retired, ex-smokers and non-drinkers at baseline. CONCLUSIONS: Because past food habit change is related to obesity and other lifestyle and socio-economic factors, a complex confounding situation may exist that could seriously influence observed relationships between diet and disease. Studies need to collect information on past food habit change and take this information into account in the analysis and when interpreting study outcomes.

Obesity, survival, and hospital costs-findings from a screening project in Sweden.

OBJECTIVE: Our aims were to estimate 1) the costs of hospital treatment and 2) the value of lost production due to early death associated with overweight and obese patients, and then to extrapolate the findings to national costs. METHODS: We use regression models to analyze survival, expected number of days in hospital treatment for patients with different body mass index (BMI), and costs with data obtained from screening of 33,196 middle-aged subjects living in Malmö, Sweden, and collected during a 15-year follow-up period. We subsequently scale up costs to national aggregate level using the BMI prevalence data from the screening project to the national population. RESULTS: The total excess hospital (somatic, psychiatric) care cost (Swedish krona or SEK) for the national health-care budget, excess as compared to normal weight patients for obese (BMI > 30) and overweight (25 < or = BMI < 30) was estimated to SEK2155 million per annum (269 million dollars, assuming 1 dollar = SEK8), or about 2.3% of total hospital care costs in Sweden. The corresponding indirect costs due to early death were estimated to SEK2935 million (367 million dollars). For males at age 55, the potential hospital costs saving, excluding costs of the intervention that could be gained by an intervention that successfully and safely could alter the weight of an obese individual to become normal weight, was estimated on average to SEK4434 (554 dollars) per annum. CONCLUSION: Hospital treatment costs are found to be higher for obese and overweight patients than for normal weight patients indicating potential cost savings especially on indirect costs by effective, safe and low cost weight-loss intervention.

Who are the "quitters"? a cross-sectional study of circumstances associated with women giving up smoking.

BACKGROUND: Smoking is an important preventable risk factor for cardiovascular disease, cancer, and many other diseases. Even though tobacco consumption is declining in Sweden, it is not declining in all groups. This study explored socioeconomic and psychosocial circumstances hindering or facilitating smoking cessation in three birth cohorts of women from the general population. METHODS: Between 1991 and 1996 a comprehensive questionnaire was administered to 17,319 women, 45-73 years old, from the Malmö Diet and Cancer cohort. Smoking habits were compared in relation to socioeconomic and psychosocial circumstances in three birth cohorts. RESULTS: Of these women, 44% were never smokers, 28% were ex-smokers, and 28% were smokers (regular or occasional). When compared with smokers, ex-smokers were more often married, had a higher socioeconomic position, a longer education, more smoke-free surroundings, better emotional support, higher BMI, and better self-perceived health. Ex-smokers reported less work-related stress and less shift work. A history of cardiovascular disease was not associated with smoking cessation. The socioeconomic differences between current and former smokers were higher for young women as compared with older birth cohorts. CONCLUSIONS: Continuing smokers and quitters differ with regard to socioeconomic and psychosocial circumstances and factors related to working life and environmental tobacco exposure. By determining who the quitters are through continued follow-up, useful insights can be gained to develop strategies to achieve successful cessation of smoking.

Life-course perspective on socioeconomic differences in carotid atherosclerosis.

OBJECTIVE: Socioeconomic status (SES) in adulthood is known to be related to carotid atherosclerosis. However, few studies have tried to assess its association with SES from a life-course perspective. METHODS AND RESULTS: We examined the relationship between SES in childhood and in adulthood and carotid atherosclerosis in a general population of Swedish men and women. Carotid stenosis was determined by B-mode ultrasound. Results showed that women whose fathers' occupations involved unskilled manual labor had higher odds of carotid stenosis than did women whose fathers' occupations involved high- or medium-level nonmanual labor, even after adjustment for adult occupational status and risk factors (odds ratio 1.8, 95% CI 1.1 to 2.8). No such association appeared in men. Furthermore, the impact of life-course SES on atherosclerosis was examined by using an additive measure of one's combined SES during childhood and adulthood. Among women, the odds of carotid stenosis increased with a rise in exposure to low SES during the life-course (P for trend <0.001). In men, no such trend was found. CONCLUSIONS: The results indicate that the total life-course exposure to low SES, with contributions from childhood and adulthood, seems to play a role in atherogenesis in women. Such a pattern of association could not be shown in men.