Body mass index and mortality in women: follow-up of the Canadian National Breast Screening Study cohort.

OBJECTIVE: The present study was conducted to examine the relationship between obesity and all-cause mortality in women. STUDY DESIGN AND SETTINGS: The subjects were women enrolled from 1980 to 1985 in a Canadian randomized trial, the National Breast Screening Study (NBSS) to evaluate the efficacy of mammographic screening. Mortality was ascertained by record linkage to the Canadian Mortality Data Base. Hazard ratios (HR) for the association between body mass index (BMI) and all-cause mortality were obtained from Cox proportional hazard regression models. RESULTS: During an average follow-up period of 16.5 years, 2566 deaths were identified among the 49 165 women, age 40-59 y at enrollment. The risk of all-cause death increased linearly above a BMI of 22 kg/m(2) and the trend was statistically significant. The HR (and 95% confidence intervals) in the various categories of BMI (kg/m(2)) were: BMI<18.5: 1.12 (0.99-1.25); BMI 18.5-21.9: 1.00 (reference); BMI 22-24.9: 1.15 (1.11-1.18); BMI 25.0-27.9: 1.28 (1.24-1.32); BMI 28.0 -29.9: 1.34 (1.29-1.39); BMI 30.0-34.9: 1.30 (1.25,1.35); and BMI > or =35.0: 1.40 (1.33-1.47). CONCLUSION: This study confirms the association of high BMI with increased all-cause mortality in women.

Alcohol and breast cancer mortality in a cohort study.

Available epidemiological evidence indicates that alcohol intake is associated with a higher risk of developing breast cancer. Plausible biological pathways include its effect on levels of estrogens, cell membrane integrity and cell-to-cell communication, inhibition of DNA repair, and congener effect. The present study evaluated the impact of alcohol on mortality from breast cancer, an area with relatively few studies in the literature. The subjects were participants in a Canadian prospective cohort study, the National Breast Screening Study (NBSS). Women were enrolled in the cohort from 1980 to 1985 to evaluate the efficacy of mammographic screening. Information on usual diet and alcohol intake at enrolment and other epidemiological variables was collected by means of a mailed, self-administered questionnaire. Mortality from breast cancer during follow- up to 31 December, 1993 was ascertained by record linkage to the Canadian Mortality Data Base maintained by Statistics Canada. During the follow-up period of 1980-1993 (average 10.3 years), 223 deaths from breast cancer were identified for this analysis. The hazard ratios for the risk of death from breast cancer increased with intakes of total alcohol of 10-20 g/day (1.039, 1.009-1.071) and > 20 g/day ( 1.063, 1.029-1.098). This increase was contributed largely by the intake of wine, a 15% increase in risk at intakes higher than 10 g/day of alcohol from wine. Alcohol from spirits was associated with a small decrease in risk of death (hazard ratio at 10g/day, 0.945, 0.915-0.976). The effect of alcohol from beer was not significant in the two categories studied. Although our results were statistically significant, the magnitude of the change in risk was small.

Do Ontarians drink in moderation? a baseline assessment against Canadian low risk drinking guidelines.

We used the 1997 Ontario Drug Monitor, a population-based, random-digit dialing survey of 2,776 adults, to obtain a baseline assessment of alcohol drinking by Ontarians against the 1997 low-risk drinking guidelines of the Addiction Research Foundation and the Canadian Centre on Substance Abuse. Average weekly alcohol consumption and the frequency of exceeding the daily limit, estimated using the graduated frequency scale, were determined for the population overall, and by sex and age group (18-44 and 45+ years). Most Ontarians drank alcohol in a pattern associated with a low risk of health consequences. About 10% of women and 25% of men drank in a style associated with some increase in acute or long-term risk. Younger men were most likely to drink in a risky pattern. Most drinkers of middle age or older, for whom cardiovascular disease is a significant health risk, consumed alcohol in a pattern associated with cardiovascular benefit.

Alcohol consumption and coronary heart disease morbidity and mortality.

Alcohol consumption is associated with a reduced risk of coronary heart disease (CHD) but an increased risk of other causes of morbidity and mortality. It remains unclear whether there is an upper limit to a protective effect of alcohol intake on CHD risk. Whether there is a U- or an L-shaped relation between alcohol consumption and CHD incidence (hospitalization and mortality due to ischemic heart disease: International Classification of Diseases codes 410-414) is examined using the National Health and Nutrition Examination Survey I. Baseline data were collected in 1971-1975. Follow-up data through 1987 (14.6 years mean follow-up) were analyzed for 6,788 European-American males (n = 2,960) and females (n = 3,828) aged 40-75 years at baseline. Cox regression was used to assess the association between alcohol consumption and incidence of CHD. For females, an increased risk was found above 28 drinks per week relative to abstainers (relative risk = 2.6, 95% confidence interval 1.2-5.5), which was significant, but was based on small numbers. For males, no upturn in risk was found at higher intake. Mortality data supported these results. Sex differences should be explored further, since they are relevant to understanding causal mechanisms and public policy and prevention.