Use of wood stoves and risk of cancers of the upper aero-digestive tract: a case-control study.
BACKGROUND: Incidence rates for cancers of the upper aero-digestive tract in Southern Brazil are among the highest in the world. A case-control study was designed to identify the main risk factors for carcinomas of mouth, pharynx, and larynx in the region. We tested the hypothesis of whether use of wood stoves is associated with these cancers. METHODS: Information on known and potential risk factors was obtained from interviews with 784 cases and 1568 non-cancer controls. We estimated the effect of use of wood stove by conditional logistic regression, with adjustment for smoking, alcohol consumption and for other sociodemographic and dietary variables chosen as empirical confounders based on a change-in-estimate criterion. RESULTS: After extensive adjustment for all the empirical confounders the odds ratio (OR) for all upper aero-digestive tract cancers was 2.68 (95% confidence interval [CI] : 2.2-3.3). Increased risks were also seen in site-specific analyses for mouth (OR = 2.73; 95% CI: 1.8-4.2), pharyngeal (OR = 3.82; 95% CI: 2.0-7.4), and laryngeal carcinomas (OR = 2.34; 95% CI: 1.2-4.7). Significant risk elevations remained for each of the three anatomic sites and for all sites combined even after we purposefully biased the analyses towards the null hypothesis by adjusting the effect of wood stove use only for positive empirical confounders. CONCLUSIONS: The association of use of wood stoves with cancers of the upper aero-digestive tract is genuine and unlikely to result from insufficient control of confounding. Due to its high prevalence, use of wood stoves may be linked to as many as 30% of all cancers occurring in the region. (+info)
Body mass decrease after initial gain following smoking cessation.
BACKGROUND: Although smoking cessation is strongly associated with subsequent weight gain, it is not clear whether the initial gain in weight after smoking cessation remains over time. METHOD: Cross-sectional analyses were made, using data from periodic health examinations for workers, on the relationship between body mass index (BMI) and the length of smoking cessation. In addition, linear regression coefficients of BMI on the length of cessation were estimated according to alcohol intake and sport activity, to examine the modifying effect of these factors on the weight of former smokers. RESULTS: Means of BMI were 23.1 kg/m2, 23.3 kg/m2, 23.6 kg/m2 for light/medium smokers, heavy smokers and never smokers, respectively. Among former smokers who had smoked > or = 25 cigarettes a day, odds ratio (OR) of BMI >25 kg/m2 were 1.88 (95% confidence interval [CI] : 1.05-3.35), 1.32 (95% CI : 0.74-2.34), 0.66 (95% CI: 0.33-1.31) for those with 2-4 years, 5-7 years, and 8-10 years of smoking cessation, respectively. The corresponding OR among those who previously consumed <25 cigarettes a day were 1.06 (95% CI: 0.58-1.94), 1.00 (95% CI: 0.58-1.71), and 1.49 (95% CI: 0.95-2.32). CONCLUSIONS: The results suggest that although heavy smokers may experience large weight gain and weigh more than never smokers in the few years after smoking cessation, they thereafter lose weight to the never smoker level, while light and moderate smokers gain weight up to the never smoker level without any excess after smoking cessation. (+info)
Socioeconomic inequalities in health in the working population: the contribution of working conditions.
BACKGROUND: The aim was to study the impact of different categories of working conditions on the association between occupational class and self-reported health in the working population. METHODS: Data were collected through a postal survey conducted in 1991 among inhabitants of 18 municipalities in the southeastern Netherlands. Data concerned 4521 working men and 2411 working women and included current occupational class (seven classes), working conditions (physical working conditions, job control, job demands, social support at work), perceived general health (very good or good versus less than good) and demographic confounders. Data were analysed with logistic regression techniques. RESULTS: For both men and women we observed a higher odds ratio for a less than good perceived general health in the lower occupational classes (adjusted for confounders). The odds of a less than good perceived general health was larger among people reporting more hazardous physical working conditions, lower job control, lower social support at work and among those in the highest category of job demands. Results were similar for men and women. Men and women in the lower occupational classes reported more hazardous physical working conditions and lower job control as compared to those in higher occupational classes. High job demands were more often reported in the higher occupational classes, while social support at work was not clearly related to occupational class. When physical working conditions and job control were added simultaneously to a model with occupational class and confounders, the odds ratios for occupational classes were reduced substantially. For men, the per cent change in the odds ratios for the occupational classes ranged between 35% and 83%, and for women between 35% and 46%. CONCLUSIONS: A substantial part of the association between occupational class and a less than good perceived general health in the working population could be attributed to a differential distribution of hazardous physical working conditions and a low job control across occupational classes. This suggests that interventions aimed at improving these working conditions might result in a reduction of socioeconomic inequalities in health in the working population. (+info)
Relation between obesity and breast cancer in young women.
This study was conducted to assess the relation between body size and risk of breast cancer among young women. A case-control study was conducted among women aged 21-45 years living in three counties in Washington State. Cases were women born after 1944 with invasive or in situ breast cancer that was diagnosed between January 1, 1983, and April 30, 1990. Controls were selected using random digit dialing and were frequency-matched to cases on the basis of age and county of residence. Interviews took place between 1986 and 1992. Body size was evaluated using indices from several different time periods. After adjustment for confounders, a decreased risk of breast cancer was found for women in the highest quintile of body mass index (weight (kg)/height (m)2) as compared with the lowest quintile (for maximum lifetime body mass index, odds ratio = 0.69, 95% confidence interval (CI) 0.51-0.94). Age modified the relation between body size and risk of breast cancer. The odds ratio for women in the highest quintile of maximum body mass index who were aged 21-35 years was 0.29 (95% CI 0.16-0.55), as compared with an odds ratio of 1.5 for women aged 36-45 years (95% CI 0.9-2.5) (p for interaction = 0.003). This study supports prior research showing a decreased risk of breast cancer associated with increased body size among premenopausal or young women. More detailed analysis in this study found a strong effect that was limited to the youngest age group (< or = 35 years). (+info)
Different factors influencing the expression of Raynaud's phenomenon in men and women.
OBJECTIVE: To determine whether the risk profile for Raynaud's phenomenon (RP) is different between men and women. METHODS: In this cross-sectional study of 800 women and 725 men participating in the Framingham Offspring Study, the association of age, marital status, smoking, alcohol use, diabetes, hypertension, and hypercholesterolemia with prevalent RP was examined in men and women separately, after adjusting for relevant confounders. RESULTS: The prevalence of RP was 9.6% (n = 77) in women and 5.8% (n = 42) in men. In women, marital status and alcohol use were each associated with prevalent RP (for marital status adjusted odds ratio [OR] 2.3, 95% confidence interval [95% CI] 1.4-3.9; for alcohol use OR 2.2, 95% CI 1.0-5.2), whereas these factors were not associated with RP in men (marital status OR 1.4, 95% CI 0.6-3.5; alcohol use OR 1.0, 95% CI 0.2-4.4). In men, older age (OR 2.3, 95% CI 1.0-5.2) and smoking (OR 2.6, 95% CI 1.1-6.3) were associated with prevalent RP; these factors were not associated with RP in women (older age OR 0.8, 95% CI 0.4-1.6; smoking OR 0.7, 95% CI 0.4-1.1). Diabetes, hypertension, and hypercholesterolemia were not associated with RP in either sex. CONCLUSION: The results indicate that risk factors for RP differ between men and women. Age and smoking were associated with RP in men only, while the associations of marital status and alcohol use with RP were observed in women only. These findings suggest that different mechanisms influence the expression of RP in men and women. (+info)
Premature morbidity from cardiovascular and cerebrovascular diseases in women with systemic lupus erythematosus.
OBJECTIVE: To determine rates of morbidity due to cardiovascular and cerebrovascular diseases among women with systemic lupus erythematosus (SLE). METHODS: I used the California Hospital Discharge Database, which contains information on all discharges from acute care hospitals in California, to identify women with SLE who had been hospitalized for treatment of either acute myocardial infarction (AMI), congestive heart failure (CHF), or cerebrovascular accident (CVA) from 1991 to 1994. I compared the proportions of hospitalizations for each cause among women with SLE with those in a group of women without SLE, for 3 age strata (18-44 years, 45-64 years, and > or =65 years). RESULTS: Compared with young women without SLE, young women with SLE were 2.27 times more likely to be hospitalized because of AMI (95% confidence interval [95% CI] 1.08-3.46), 3.80 times more likely to be hospitalized because of CHF (95% CI 2.41-5.19), and 2.05 times more likely to be hospitalized because of CVA (95% CI 1.17-2.93). Among middle-aged women with SLE, the frequencies of hospitalization for AMI and CVA did not differ from those of the comparison group, but the risk of hospitalization for CHF was higher (odds ratio [OR] 1.39, 95% CI 1.05-1.73). Among elderly women with SLE, the risk of hospitalization for AMI was significantly lower (OR 0.70, 95% CI 0.51-0.89), the risk of hospitalization for CHF was higher (OR 1.25, 95% CI 1.01-1.49), and the risk of hospitalization for CVA was not significantly different from those in the comparison group. CONCLUSION: Young women with SLE are at substantially increased risk of AMI, CHF, and CVA. The relative odds of these conditions decrease with age among women with SLE. (+info)
Chronic infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus: population based study of coronary heart disease.
OBJECTIVE: To study possible associations between coronary heart disease and serological evidence of persistent infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus. DESIGN: Population based, case-control study, nested within a randomised trial. SETTING: Five general practices in Bedfordshire, UK. INDIVIDUALS: 288 patients with incident or prevalent coronary heart disease and 704 age and sex matched controls. RESULTS: High concentrations of serum IgG antibodies to H pylori were present in 54% of cases v 46% of controls, with corresponding results for C pneumoniae seropositivity (33% v 33%), and cytomegalovirus seropositivity (40% v 31%). After adjustments for age, sex, smoking, indicators of socioeconomic status, and standard risk factors, the odds ratios (95% confidence intervals) for coronary heart disease of seropositivity to these agents were: 1.28 (0.93 to 1.75) for H pylori, 0.95 (0.66 to 1.36) for C pneumoniae, and 1.40 (0.96 to 2. 05) for cytomegalovirus. CONCLUSIONS: There is no good evidence of strong associations between coronary heart disease and serological markers of persistent infection with H pylori, C pneumoniae, or cytomegalovirus. To determine the existence of moderate associations between these agents and disease, however, larger scale studies will be needed that can keep residual confounders to a minimum. (+info)
Cytomegalovirus seropositivity and incident ischaemic heart disease in the Caerphilly prospective heart disease study.
OBJECTIVE: To assess the role of cytomegalovirus (CMV) infection in primary ischaemic heart disease. METHODS: Plasma specimens collected during 1979-83 from men in Caerphilly, south Wales, were analysed for IgG antibodies to CMV by enzyme linked immunosorbent assay and latex tests. Incident ischaemic heart disease events were ascertained after five and 10 years from death certificates, hospital records, and ECG changes; 195 incident ischaemic heart disease cases were compared with 216 controls of a similar age drawn from the rest of the cohort. RESULTS: 164 cases (84%) and 180 controls (83%) were seropositive for CMV. Optical density, an indicator of CMV antibody titre, was similar for cases and controls. Among controls, seropositivity was not associated with age, socioeconomic status currently or in childhood, smoking, height, body mass index, blood pressure, total cholesterol, fibrinogen, plasma viscosity, or leucocyte count. The unadjusted odds ratio relating CMV seropositivity to incident ischaemic heart disease was 1.06 (95% confidence interval 0.63 to 1.79) and was little changed (1.11, 0.63 to 1.97) after adjustment for age, smoking, body mass index, systolic blood pressure, total cholesterol, and socioeconomic status currently and in childhood. CONCLUSIONS: CMV infection is unlikely to be a strong risk factor for development of myocardial infarction in middle aged men. (+info)