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G A Colditz

Publications and source records attributed to G A Colditz.

At least 55 records · Page 3Linked to original sources

Being breastfed in infancy and breast cancer incidence in adult life: results from the two nurses' health studies.

Events during perinatal and early life may influence the incidence of breast cancer in adult life, and some case-control studies suggest that having been breastfed may reduce breast cancer risk. The authors studied this association among premenopausal and postmenopausal women by using data from the two Nurses' Health Studies, the Nurses' Health Study (using data from 1992 to 1996) and the Nurses' Health Study II (using data from 1991 to 1997). A history of being breastfed was self-reported by the study participants. During a total of 695,655 person-years, 1,073 cases of invasive breast cancer were diagnosed. The authors did not observe any important overall association between having been breastfed and the development of breast cancer later in life among premenopausal women (covariate-adjusted relative risk = 0.97, 95% confidence interval (CI): 0.78, 1.20) or postmenopausal women (covariate-adjusted relative risk = 1.12, 95% CI: 0.92, 1.37). No significant trend was observed with increasing duration of breastfeeding. The authors also used data on breastfeeding retrospectively collected from 2,103 mothers of participants of the two Nurses' Health Studies. With the mothers' reports, the covariate-adjusted odds ratio of breast cancer was 1.11 (95% CI: 0.88, 1.39) for women who were breastfed compared with those who were not. Data from these two large cohorts do not support the hypothesis that being breastfed confers protection against subsequent breast cancer.

Adult↗

Intake of fish and omega-3 fatty acids and risk of stroke in women.

CONTEXT: Some prospective studies have shown an inverse association between fish intake and risk of stroke, but none has examined the relationship of fish and omega-3 polyunsaturated fatty acid intake with risk of specific stroke subtypes. OBJECTIVE: To examine the association between fish and omega-3 polyunsaturated fatty acid intake and risk of stroke subtypes in women. DESIGN, SETTING, AND SUBJECTS: Prospective cohort study of women in the Nurses' Health Study cohort, aged 34 to 59 years in 1980, who were free from prior diagnosed cardiovascular disease, cancer, and history of diabetes and hypercholesterolemia and who completed a food frequency questionnaire including consumption of fish and other frequently eaten foods. The 79 839 women who met our eligibility criteria were followed up for 14 years. MAIN OUTCOME MEASURE: Relative risk of stroke in 1980-1994 compared by category of fish intake and quintile of omega-3 polyunsaturated fatty acid intake. RESULTS: After 1 086 261 person-years of follow-up, 574 incident strokes were documented, including 119 subarachnoid hemorrhages, 62 intraparenchymal hemorrhages, 303 ischemic strokes (264 thrombotic and 39 embolic infarctions), and 90 strokes of undetermined type. Among thrombotic infarctions, 90 large-artery occlusive infarctions and 142 lacunar infarctions were identified. Compared with women who ate fish less than once per month, those with higher intake of fish had a lower risk of total stroke: the multivariate relative risks (RRs), adjusted for age, smoking, and other cardiovascular risk factors, were 0.93 (95% confidence interval [CI], 0.65-1.34) for fish consumption 1 to 3 times per month, 0.78 (95% CI, 0.55-1.12) for once per week, 0.73 (95% CI, 0.47-1.14) for 2 to 4 times per week, and 0.48 (95% CI, 0.21-1.06) for 5 or more times per week (P for trend =.06). Among stroke subtypes, a significantly reduced risk of thrombotic infarction was found among women who ate fish 2 or more times per week (multivariate RR, 0.49; 95% CI, 0.26-0.93). Women in the highest quintile of intake of long-chain omega-3 polyunsaturated fatty acids had reduced risk of total stroke and thrombotic infarction, with multivariate RRs of 0.72 (95% CI, 0.53-0.99) and 0.67 (95% CI, 0.42-1.07), respectively. When stratified by aspirin use, fish and omega-3 polyunsaturated fatty acid intakes were inversely associated with risk of thrombotic infarction, primarily among women who did not regularly take aspirin. There was no association between fish or omega-3 polyunsaturated fatty acid intake and risk of hemorrhagic stroke. CONCLUSIONS: Our data indicate that higher consumption of fish and omega-3 polyunsaturated fatty acids is associated with a reduced risk of thrombotic infarction, primarily among women who do not take aspirin regularly, but is not related to risk of hemorrhagic stroke.

Adult↗

Physical activity and risk for cardiovascular events in diabetic women.

BACKGROUND: Increased physical activity has been associated with reduced risk for cardiovascular disease in the general population, but data are limited on its role among persons with type 2 diabetes mellitus. OBJECTIVE: To determine whether physical activity decreases risk for cardiovascular disease among diabetic women. DESIGN: Prospective cohort study. SETTING: The Nurses' Health Study. PATIENTS: 5125 female nurses with diabetes. MEASUREMENTS: Physical activity was first assessed in 1980 and was updated in 1982, 1986, 1988, and 1992 through validated questionnaires. Average hours of moderate or vigorous exercise and a metabolic equivalent of task (MET) score were computed. RESULTS: During 14 years of follow-up (31 432 person-years), 323 new cases of cardiovascular disease were documented (225 cases of coronary heart disease and 98 cases of stroke). The age-adjusted relative risks according to average hours of moderate or vigorous activity per week (<1, 1 to 1.9, 2 to 3.9, 4 to 6.9, >/=7) were 1.0, 0.93 (95% CI, 0.69 to 1.26), 0.82 (CI, 0.61 to 1.10), 0.54 (CI, 0.39 to 0.76), and 0.52 (CI, 0.25 to 1.09) (P < 0.001 for trend). These figures did not change materially after adjustment for smoking, body mass index, and other cardiovascular risk factors (1.0, 1.02, 0.87, 0.61, and 0.55, respectively; P = 0.001 for trend). In separate analyses, levels of physical activity were inversely associated with coronary heart disease and ischemic stroke. Among women who did not exercise vigorously, the multivariate relative risks for cardiovascular disease across quartiles of MET score for walking were 1.0, 0.85, 0.63, and 0.56 (P = 0.03 for trend). Faster usual walking pace was independently associated with lower risk. CONCLUSION: Among diabetic women, increased physical activity, including regular walking, is associated with substantially reduced risk for cardiovascular events.

Adult↗

Living arrangements, social integration, and change in functional health status.

Limited prospective data have examined the association between living arrangements and emotional wellbeing. The authors assessed whether older women living with a spouse were less likely to experience a decline in mental health, vitality, or physical function compared with women living alone or with nonspouse others. The association between living arrangement and 4-year change in functional health status was examined prospectively among 28,324 women aged 60-72 years in the Nurses' Health Study. After adjustment for age, baseline function, comorbid conditions, and health behaviors, women living alone had lower risk of decline in mental health (relative risk (RR) = 0.73, 95 percent confidence interval (CI): 0.65, 0.81) and vitality (RR = 0.72, 95 percent CI: 0.65, 0.80) compared with those living with a spouse. Contact with friends and relatives and level of social engagement were significantly protective against a decline in mental health among women living alone but not among women living with a spouse. These results suggest that women living independently are neither socially isolated nor at increased risk for decline in functional health status. In fact, these women actually fare better on measures of psychologic function than do women living with a spouse.

Activities of Daily Living↗

Cigarette smoking and the incidence of Parkinson's disease in two prospective studies.

An inverse association between cigarette smoking and idiopathic Parkinson's disease has been reported in several retrospective studies, but prospective evidence is available only for men. We assessed the association between the incidence of Parkinson's disease and smoking in two large prospective cohort studies comprising men and women. New cases of Parkinson's disease were identified in the Nurses' Health Study for 1976-1996, and in the Health Professionals Follow-up Study for 1986-1996. Smoking history was assessed at baseline and updated on subsequent biennial questionnaires. In women, the age-adjusted rate ratios (95% confidence intervals) for Parkinson's disease relative to never-smokers were 0.7 (0.5, 1.0) for past smokers, and 0.4 (0.2, 0.7) for current smokers. In men, the age-adjusted rate ratios for Parkinson's disease relative to never-smokers were 0.5 (0.4, 0.7) for past smokers, and 0.3 (0.1, 0.8) for current smokers. In both cohorts, the strength of the association decreased with time since quitting (among past smokers), increased with number of cigarettes per day (among current smokers), and increased with pack-years of smoking. These prospective findings confirm that an inverse association between smoking and the incidence of Parkinson's disease exists in both men and women.

Adult↗

Prospective study of caffeine consumption and risk of Parkinson's disease in men and women.

Results of case-control studies and of a prospective investigation in men suggest that consumption of coffee could protect against the risk of Parkinson's disease, but the active constituent is not clear. To address the hypothesis that caffeine is protective against Parkinson's disease, we examined the relationship of coffee and caffeine consumption to the risk of this disease among participants in two ongoing cohorts, the Health Professionals' Follow-Up Study (HPFS) and the Nurses' Health Study (NHS). The study population comprised 47,351 men and 88,565 women who were free of Parkinson's disease, stroke, or cancer at baseline. A comprehensive life style and dietary questionnaire was completed by the participants at baseline and updated every two to four years. During the follow-up (10 years in men, 16 years in women), we documented a total of 288 incident cases of Parkinson's disease. Among men, after adjustment for age and smoking, the relative risk of Parkinson's disease was 0.42 (95% CI: 0.23-0.78; p for trend < 0.001) for men in the top one-fifth of caffeine intake compared to those in the bottom one-fifth. An inverse association was also observed with consumption of coffee (p for trend = 0.004), caffeine from noncoffee sources (p for trend < 0.001), and tea (p for trend = 0.02) but not decaffeinated coffee. Among women, the relationship between caffeine or coffee intake and risk of Parkinson's disease was U-shaped, with the lowest risk observed at moderate intakes (1-3 cups of coffee/day, or the third quintile of caffeine consumption). These results support a possible protective effect of moderate doses of caffeine on risk of Parkinson's disease.

Adult↗

Cross-sectional measurement of nutrient intake among adolescents in 1996.

BACKGROUND: Many components are involved in an assessment of diet and health among youth. To address these issues and document the major contributions of fat, fiber, vitamins, and minerals to the diet, we analyzed baseline cross-sectional data from a cohort of 16,882 youth. METHODS: Cross-sectional analyses were conducted on the Growing Up Today Study dietary data reported by 16,882 9- to 14-year-olds in 1996. The adolescent food frequency questionnaire was used to assess this age group's eating habits. Arithmetic means and standard deviations were calculated on energy-adjusted and unadjusted data. RESULTS: Mean intake (including vitamin/mineral supplementation) for all nutrients met 100% of the RDAs, except calcium for girls. Comparing the servings of foods with the USDA Food Pyramid, neither boys nor girls met recommended number of servings except for dairy. Overweight participants consumed fewer kilocalories and lower levels of nutrients than their nonoverweight peers. CONCLUSION: These cross-sectional data from 1996 indicate that this cohort is consuming foods and nutrients comparable with national data of less fat and more carbohydrates in their diet. Overweight participants have similar dietary patterns except for total energy. The cohort's diet (with vitamin/mineral supplementation) is meeting the RDAs, but actual foods consumed suggest a lack of balance in the diet.

Adolescent↗

Comparing physical activity questionnaires for youth: seasonal vs annual format.

BACKGROUND: In large cohort studies of older children, self-report is the only practical way to assess physical activity. Assessing usual activity over the entire year is desirable, but children and adolescents may overestimate activities with high seasonal variability. Use of questionnaires in which individuals report each activity by season may improve accuracy. METHODS: A total of 6782 girls and 5110 boys, aged 9-14 years in 1996, completed self-administered activity questionnaires in 1996 and in 1997. In 1996, participants reported the average time spent in each of 17 activities during the previous 12 months; in 1997, we also asked for the average time spent in the previous year, but within each of the four seasons. RESULTS: Girls reported a median of 12.8 hours/week total activity in 1996 and 10.4 hours/week in 1997. For boys, the estimates were 15.5 hours/week and 13.4 hours/week, respectively. Girls and boys within 1-year age strata (e.g., comparison of 10-year olds in 1996 with 10-year olds in 1997) reported an average of 3.7 and 3.1 fewer hours per week, respectively, on the 1997 seasonal format versus the 1996 annual format questionnaire. In longitudinal analyses, the difference between the annual and the seasonal estimates was greater if participants did the activity in fewer seasons in 1997. CONCLUSIONS: In comparison to an annual format questionnaire, a seasonal format questionnaire may improve accuracy of self-report of physical activity by reducing over-reporting of activities in which pre-adolescents and adolescents engage in fewer seasons.

Adolescent↗

Prospective study of dietary fat and the risk of age-related macular degeneration.

BACKGROUND: The relation between intakes of total fat and specific types of fat and age-related macular degeneration (AMD) remains unclear. OBJECTIVE: Our objective was to examine prospectively the association between fat intake and AMD. DESIGN: We conducted a prospective follow-up study of participants in the Nurses' Health Study and the Health Professionals Follow-up Study. At baseline (1984 for women and 1986 for men), the study included 42743 women and 29746 men aged > or = 50 y with no diagnosis of AMD who were followed until 1996. Fat intake was assessed with a food-frequency questionnaire. RESULTS: We accrued 567 patients with AMD with a visual loss of 20/30 or worse. The pooled multivariate relative risk (RR) for the highest compared with the lowest quintile of total fat intake was 1.54 (95% CI: 1.17, 2.01; P for trend = 0.008). Linolenic acid was positively associated with risk of AMD (top versus bottom quintile of RR: 1.49; 95% CI: 1.15, 1.94; P for trend = 0.0009). Docosahexaenoic acid had a modest inverse relation with AMD (top versus bottom quintile of RR: 0.70; 95% CI: 0.52, 0.93; P for trend = 0.05), and >4 servings of fish/wk was associated with a 35% lower risk of AMD compared with < or = 3 servings/mo (RR: 0.65; 95% CI: 0.46, 0.91; P for trend = 0.009). CONCLUSIONS: Total fat intake was positively associated with risk of AMD, which may have been due to intakes of individual fatty acids, such as linolenic acid, rather than to total fat intakes per se. A high intake of fish may reduce the risk of AMD.

Age Factors↗

Dietary fat intake and risk of type 2 diabetes in women.

BACKGROUND: The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear. OBJECTIVE: Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes. DESIGN: We prospectively followed 84204 women aged 34-59 y with no diabetes, cardiovascular disease, or cancer in 1980. Detailed dietary information was assessed at baseline and updated in 1984, 1986, and 1990 by using validated questionnaires. Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates. RESULTS: During 14 y of follow-up, 2507 incident cases of type 2 diabetes were documented. Total fat intake, compared with equivalent energy intake from carbohydrates, was not associated with risk of type 2 diabetes; for a 5% increase in total energy from fat, the relative risk (RR) was 0.98 (95% CI: 0.94, 1.02). Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes. However, for a 5% increase in energy from polyunsaturated fat, the RR was 0.63 (0.53, 0.76; P < 0.0001) and for a 2% increase in energy from trans fatty acids the RR was 1.39 (1.15, 1.67; P = 0.0006). We estimated that replacing 2% of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40% lower risk (RR: 0.60; 95% CI: 0.48, 0.75). CONCLUSIONS: These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of type 2 diabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially.

Adult↗

Postmenopausal hormone use, screening, and breast cancer: characterization and control of a bias.

Previous investigators have suggested that screening-related biases may explain associations between postmenopausal hormone use and breast cancer. To investigate these biases, we studied postmenopausal women in the Nurses' Health Study from 1988 to 1994. Hormone use is associated with increased subsequent screening. Among women not screened in the previous 2 years, the probability difference, comparing current hormone users with others, for having mammography in the following 2 years is 19.5%; among women previously screened, the difference is 4.9%. These differences persist after control for other factors. If the increase in screening is causal, screening by mammogram could be intermediate in the causal pathway to breast cancer diagnosis. To deal with this problem, we restrict attention to a subset of the cohort in which the effect of postmenopausal hormone use on screening is small (women previously screened). In this subset, the rate ratio comparing breast cancer rates among current postmenopausal hormone users with others is 1.28. In a sensitivity analysis, the bias could not by itself plausibly account for the associations in our data. Our data provide evidence of an association between postmenopausal hormone use and breast cancer that is not solely the product of a detection bias.

Adult↗

Association of bowel movement frequency and use of laxatives with the occurrence of symptomatic gallstone disease in a prospective study of women.

OBJECTIVES: The authors prospectively examined the association between bowel movement frequency (used as a proxy for intestinal transit), laxative use, and the risk of symptomatic gallstone disease. METHODS: A total of 79,829 women, aged 36-61 yr, without a history of symptomatic gallstone disease and free of cancer, responded to a mailed questionnaire in 1982 that assessed bowel movement frequency and use of laxatives. Between 1984 and 1996, 4,443 incident cases of symptomatic gallstone disease were documented. Relative risks (RRs) of symptomatic gallstone disease and 95% confidence intervals (CIs) were calculated using logistic regression. RESULTS: After controlling for age and established risk factors, the multivariate RRs were, compared to women with daily bowel movements, 0.97 (95% CI 0.86-1.08) for women with bowel movements every third day or less, and 1.00 (95% CI 0.91-11.1) for women with bowel movement more than once daily. No trend was evident. As compared to women who never used laxatives in 1982, a significant modest inverse association was seen for monthly laxative use, with a multivariate RR of 0.84 (95% CI 0.72-0.98), and weekly to daily laxative use was associated with a RR of 0.88 (95% CI 0.78-1.02). CONCLUSIONS: These findings do not support an association between infrequent bowel movements and risk of symptomatic gallstone disease in women, and indicate that simple questions directed at bowel movement frequency are unlikely to enhance our ability to predict risk of symptomatic gallstone disease. The slightly inverse association between use of laxatives and risk of symptomatic gallstone disease may be due to a mechanism that is not related to bowel movement frequency.

Cathartics↗

Peer, parent, and media influences on the development of weight concerns and frequent dieting among preadolescent and adolescent girls and boys.

OBJECTIVE: To assess prospectively the influence of peers, parents, and the media on the development of weight concerns and frequent dieting. DESIGN: Prospective cohort study. SETTING: Questionnaires mailed annually to participants throughout the United States. PARTICIPANTS: One-year follow-up of 6770 girls and 5287 boys who completed questionnaires in 1996 and 1997 and were between 9 and 14 years of age in 1996. MAIN OUTCOME MEASURE: Onset of high levels of concern with weight and dieting frequently to control weight. RESULTS: During 1 year of follow-up, 6% of girls and 2% of boys became highly concerned with weight and 2% of girls and 1% of boys became constant dieters. Peer influence was negligible. Independent of age and body mass index, both girls (odds ratio [OR]): 1.9; 95% confidence interval [CI]: 1.1-3.1) and boys (OR: 2.7; 95% CI: 1.1-6. 4) who were making a lot of effort to look like same-sex figures in the media were more likely than their peers to become very concerned with their weight. Moreover, both girls (OR: 2.3; 95% CI: 1.1-5.0) and boys (OR: 2.6; 95% CI: 1.1-6.0) who reported that their thinness/lack of fat was important to their father were more likely than their peers to become constant dieters. CONCLUSIONS: Our results suggest that parents and the media influence the development of weight concerns and weight control practices among preadolescents and adolescents. However, there are gender differences in the relative importance of these influences.

Adolescent↗

Adolescents' perceptions of social status: development and evaluation of a new indicator.

OBJECTIVE: Eliminating health disparities, including those that are a result of socioeconomic status (SES), is one of the overarching goals of Healthy People 2010. This article reports on the development of a new, adolescent-specific measure of subjective social status (SSS) and on initial exploratory analyses of the relationship of SSS to adolescents' physical and psychological health. METHODS: A cross-sectional study of 10 843 adolescents and a subsample of 166 paired adolescent/mother dyads who participated in the Growing Up Today Study was conducted. The newly developed MacArthur Scale of Subjective Social Status (10-point scale) was used to measure SSS. Paternal education was the measure of SES. Indicators of psychological and physical health included depressive symptoms and obesity, respectively. Linear regression analyses determined the association of SSS to depressive symptoms, and logistic regression determined the association of SSS to overweight and obesity, controlling for sociodemographic factors and SES. RESULTS: Mean society ladder ranking, a subjective measure of SES, was 7.2 +/- 1.3. Mean community ladder ranking, a measure of perceived placement in the school community, was 7.6 +/- 1.7. Reliability of the instrument was excellent: the intraclass correlation coefficient was 0.73 for the society ladder and 0.79 for the community ladder. Adolescents had higher society ladder rankings than their mothers (micro(teen) = 7.2 +/- 1.3 vs micro(mom) = 6.8 +/- 1.2; P =.002). Older adolescents' perceptions of familial placement in society were more closely correlated with maternal subjective perceptions of placement than those of younger adolescents (Spearman's rho(teens <15 years) = 0.31 vs Spearman's rho(teens 15 years) = 0.45; P <.001 for both). SSS explained 9.9% of the variance in depressive symptoms and was independently associated with obesity (odds ratio(society) = 0.89, 95% confidence interval = 0.83, 0.95; odds ratio(community) = 0.91, 95% confidence interval = 0.87, 0.97). For both depressive symptoms and obesity, community ladder rankings were more strongly associated with health than were society ladder rankings in models that controlled for both domains of SSS. CONCLUSIONS: This new instrument can reliably measure SSS among adolescents. Social stratification as reflected by SSS is associated with adolescents' health. The findings suggest that as adolescents mature, SSS may undergo a developmental shift. Determining how these changes in SSS relate to health and how SSS functions prospectively with regard to health outcomes requires additional research.

Adolescent↗

Physical activity and mortality: a prospective study among women.

OBJECTIVES: This study examined the association between recreational physical activity and mortality in middle-aged and older women and the possibility that physical activity serves as an important marker of health. METHODS: Analyses were conducted among participants in the Nurses' Health Study. Levels of physical activity were assessed by questionnaire in 1980 and updated every 2 to 4 years. RESULTS: Levels of physical activity were inversely associated with mortality risk; however, each activity level above the reference level had approximately the same level of risk reduction (20%-30%). The inverse association was stronger for cardiovascular deaths than for cancer deaths and was strongest for respiratory deaths. Women who died of noncardiovascular, noncancer causes were more likely to have reported that poor health limited their physical activity than were women who died of other causes or who remained alive. CONCLUSIONS: Part of the link between physical activity and mortality risk is probably spurious and difficult to remove analytically; however, on the basis of epidemiologic evidence, much of the health benefit of activity is real.

Adult↗

Coffee and alcohol consumption and the risk of pancreatic cancer in two prospective United States cohorts.

Although most prospective cohort studies do not support an association between coffee consumption and pancreatic cancer, the findings for alcohol are inconsistent. Recently, a large prospective cohort study of women reported statistically significant elevations in risk of pancreatic cancer for both coffee and alcoholic beverage consumption. We obtained data on coffee, alcohol, and other dietary factors using semiquantitative food frequency questionnaires administered at baseline (1986 in the Health Professionals Follow-Up Study and 1980 in the Nurses' Health Study) and in subsequent follow-up questionnaires. Data on other risk factors for pancreatic cancer, including cigarette smoking, were also available. Individuals with a history of cancer at study initiation were excluded from all of the analyses. During the 1,907,222 person-years of follow-up, 288 incident cases of pancreatic cancer were diagnosed. The data were analyzed separately for each cohort, and results were pooled to compute overall relative risks (RR). Neither coffee nor alcohol intakes were associated with an increased risk of pancreatic cancer in either cohort or after pooling the results (pooled RR, 0.62; 95% confidence interval, 0.27-1.43, for >3 cups of coffee/day versus none; and pooled RR, 1.00; 95% confidence interval, 0.57-1.76, for > or = 30 grams of alcohol/day versus none). The associations did not change with analyses examining different latency periods for coffee and alcohol. Similarly, no statistically significant associations were observed for intakes of tea, decaffeinated coffee, total caffeine, or alcoholic beverages. Data from these two large cohorts do not support any overall association between coffee intake or alcohol intake and risk of pancreatic cancer.

Adult↗