Showing papers by "Frank E. Speizer published in 1993"

An Association between Air Pollution and Mortality in Six U.S. Cities

Abstract: Background Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks. Methods In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities. Results Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most po...

Intake of trans fatty acids and risk of coronary heart disease arnong wornen

Abstract: Trans isomers of fatty acids, formed by the partial hydrogenation of vegetable oils to produce margarine and vegetable shortening, increase the ratio of plasma low-density-lipopratein to highdensity-lipoprotein cholesterol, so it is possible that they adversely influence risk of coronary heart disease (CHD). To investigate this possibility, we studied dietary data from participants in the Nurses' Health Study. We calculated intake of trans fatty acids fram dietary questionnaires completed by 85 095 women without diagnosed CHD, strake, diabetes, or hypercholesteralaemia in 1980. During 8 years of follow-up, there were 431 cases of new CHD (non-fatal myocardial infarction or death from CHD). After adjustment for age and total energy intake, intake of trans isomers was directly related to risk of CHD (relative risk for highest vs lowest quintile 1·50 [95% CI 1'12-2'00]. p for trend =:= 0·001). Additional control for established CH 0 risk factors, multivitamin use, and intakes of saturated fat, monounsaturated fat, and linoleic acid, dietary cholesterol. vitamins Eor C, carotene, or fibre did not change the relative risk substantially. The association was stronger for the 69 181 women whose margarine consumption over the previous 10 years had been stable (1'67 [1'05-2'66], p for trend =0'002). Intakes of foods that are major sources of trans isomers (margarine, cookies [biscuits], cake, and white bread) were each significantly associated with higher risks of CHD. These findings support the hypothesis that consumption of partially hydrogenated vegetable oils may contribute to occurrence of CHD.

Folate, Methionine, and Alcohol Intake and Risk of Colorectal Adenoma

Abstract: Background Reduced methylation of DNA may contribute to loss of the normal controls on proto-oncogene expression. In humans, hypomethylation of DNA has been observed in colorectal cancers and in their adenomatous polyp precursors. Accumulation of DNA methylation abnormalities, observed during progression of human colorectal neoplasia, may be influenced by certain dietary factors. The apparent protective effect of fresh fruits and vegetables, the major folate sources, on colorectal cancer incidence suggests that a methyl-deficient diet contributes to occurrence of this malignancy. Low dietary folate and methionine and high intake of alcohol may reduce levels of S-adenosylmethionine, which is required for DNA methylation. Purpose To determine if dietary factors that may influence methyl availability are related to colorectal adenomas, we prospectively examined the association of folate, methionine, and alcohol intakes and risk of colorectal adenoma. Methods We assessed dietary intake for a 1-year period for women of the Nurses' Health Study, started in 1976, and for men of the Health Professionals Follow-up Study, started in 1986--using a semiquantitative food frequency questionnaire. Adenomatous polyps of the left colon or rectum were diagnosed in 564 of 15,984 women who had had an endoscopy between 1980 and 1990 and in 331 of 9490 men who had undergone an endoscopy between 1986 and 1990. Results High dietary folate was inversely associated with risk of colorectal adenoma in women (multivariate relative risk [RR] = 0.66; 95% confidence interval [CI] = 0.46-0.95 between high and low quintiles of intake) and in men (RR = 0.63; 95% CI = 0.41-0.98) after adjusting for age, family history, indications for endoscopy, history of previous endoscopy, total energy intake, saturated fat intake, dietary fiber, and body mass index. Relative to nondrinkers, drinkers of more than 30 g of alcohol daily (about two drinks) had an elevated risk of adenoma (in women, RR = 1.84, 95% CI = 1.19-2.86; in men, RR = 1.64, 95% CI = 0.92-2.93). Methionine intake was inversely associated with risk of adenomas 1 cm or larger (RR = 0.62; 95% CI = 0.46-0.85, combining men and women). Conclusions Folate, alcohol, and methionine could influence methyl group availability, and a methyl-deficient diet may be linked to early stages of colorectal neoplasia. A dietary pattern that increases methyl availability could reduce incidence of colorectal cancer. Implications These data support efforts to increase dietary folate in segments of the population having diets with low intakes of this nutrient.

Smoking cessation and decreased risk of stroke in women.

Abstract: Objective. —To prospectively examine the relationship of time since stopping smoking with risk of stroke in middle-aged women. Design. —An ongoing prospective cohort of women with 12 years' follow-up data (1976 to 1988), in which information on smoking habits was updated every 2 years by postal questionnaire. Population Studied. —A total of 117 006 female registered nurses aged 30 to 55 years in 1976 and free of coronary heart disease, stroke, and cancer at baseline. Main Outcome Measures. —Incident strokes (fatal and nonfatal), further subdivided into ischemic stroke, subarachnoid hemorrhage, and cerebral hemorrhage. Results. —The age-adjusted relative risk of total stroke among current smokers compared with never smokers was 2.58 (95% confidence interval, 2.08 to 3.19). The corresponding relative risk among former smokers was 1.34 (95% confidence interval, 1.04 to 1.73). For total and ischemic stroke, the excess risks among former smokers largely disappeared from 2 to 4 years after cessation. The same patterns of decline were observed regardless of number of cigarettes smoked, the age at starting, or the presence of other risk factors for stroke. Conclusions. —The risk of suffering a stroke among cigarette smokers declines soon after cessation and the benefits are independent of the age at starting and the number of cigarettes smoked per day. ( JAMA . 1993;269:232-236)

Family History, Age, and Risk of Breast Cancer: Prospective Data From the Nurses' Health Study

Abstract: Objective. —To examine prospectively the risk of breast cancer as influenced by a maternal history of breast cancer, the mother's age at diagnosis, or a sister's history of breast cancer. Design. —Prospective cohort study with biennial follow-up. Setting/Participants. —117988 women in the Nurses' Health Study aged 30 to 55 years in 1976, followed up through 1988 (1.3 million person-years of follow-up). Results. —We identified 2389 incident cases of invasive breast cancer. Compared with women without a maternal history of breast cancer, the age-adjusted relative risk (RR) of breast cancer was highest among women whose mother was diagnosed before the age of 40 years (RR, 2.1 [95% confidence interval, 1.6 to 2.8]). The RR decreased with advancing maternal age at time of diagnosis to 1.5 (95% confidence interval, 1.1 to 2.2) for maternal diagnosis after the age of 70 years. Having a sister with a history of breast cancer also was related to increased risk; for women with one sister with breast cancer compared with those with one sister without such a history, the age-adjusted RR was 2.3 (95% confidence interval, 1.6 to 3.4). Women whose mother and sister both had a history of breast cancer had an RR of 2.5 (95% confidence interval, 1.5 to 4.2) compared with those without a family history. These associations did not differ appreciably when stratified by age; menopausal status; history of benign breast disease; body mass index; age at menarche; or parity or age at first birth of the women at risk. The results remained unchanged when we controlled for these risk factors in multivariate models. Despite slightly greater mammography surveillance and earlier detection of tumors among women with a family history of breast cancer, detection bias is unlikely to account for more than a small part of the observed association. Conclusions. —Risk of breast cancer is approximately doubled among women whose mother had breast cancer diagnosed before the age of 40 years or who have a sister with breast cancer, and remains elevated even for those whose mothers were diagnosed with breast cancer at the age of 70 years or older. However, the risk associated with a mother or sister history of breast cancer is smaller than suggested by earlier retrospective studies. Overall, within this population of middle-aged women, only 2.5% of breast cancer cases are attributable to a positive family history. ( JAMA . 1993;270:338-343)

Tubal ligation, hysterectomy, and risk of ovarian cancer. A prospective study

Abstract: Objective. —To assess whether tubal ligation and hysterectomy affect subsequent risk of ovarian cancer. Design. —Prospective cohort study with 12 years of follow-up. Setting. —United States, multistate. Participants. —A total of 121 700 female registered nurses who were 30 to 55 years of age in 1976; the follow-up rate was 90% as of 1988. Main Outcome Measure. —Ovarian cancer of epithelial origin confirmed by medical record review. Results. —We observed a strong inverse association between tubal ligation and ovarian cancer, which persisted after adjustment for age, oral contraceptive use, parity, and other ovarian cancer risk factors (multivariate relative risk [RR] 0.33; 95% confidence interval [CI], 0.16 to 0.64). The association was similar when we assessed tubal ligation status at the baseline questionnaire and excluded cases in the first 4 years to eliminate any possible short-term decrease in risk due to screening of the ovaries during ligation surgery. We noted a weaker inverse association between simple hysterectomy and ovarian cancer (RR, 0.67; 95% CI, 0.45 to 1.00). Neither vasectomy nor condom use by a partner was associated with risk of ovarian cancer. Conclusions. —These data indicate that tubal ligation, and perhaps hysterectomy, may substantially reduce risk of epithelial ovarian cancer. ( JAMA . 1993;270:2813-2818)

Lung Function, Pre- and Post-natal Smoke Exposure, and Wheezing in the First Year of Life

Abstract: The relationship between initial level of lung function and subsequent wheezing, lower respiratory illness (LRI) was studied in 97 infants in whom the first measurement of pulmonary function (PFT) was made before 6 months of age. Occurrence of LRI was evaluated by standardized questionnaires at each well-baby visit, biweekly telephone calls to mothers, and review of all visits to physicians. Infant PFT was assessed by partial expiratory flow-volume curves and helium-dilution measurement of functional residual capacity (FRC). Maternal, prenatal smoking was assessed by urine cotinine and standard questionnaires. Infants who developed an LRI during the first year of life had lower preillness length-corrected forced expiratory flow at FRC (Vfrc) than those who did not experience an LRI (males, 2.06 ± 0.20 versus 2.32 ± 0.29 ml/s/cm; females, 2.38 ± 0.20 versus 2.91 ± 0.26 ml/s/cm). Similar results were observed with FRC-corrected Vfrc. No differences were observed for FRC. Differences in lung function were gr...

A Prospective Study of the Intake of Vitamins C, E, and A and the Risk of Breast Cancer

Abstract: Background Although it has been hypothesized that large intakes of the antioxidant vitamins C, E, and A reduce the risk of breast cancer, few prospective data are available. Methods We prospectively studied 89,494 women who were 34 to 59 years old in 1980 and who did not have diagnosed cancer. Their intakes of vitamins C, E, and A from foods and supplements were assessed at base line and in 1984 with the use of a validated semiquantitative food-frequency questionnaire. Results Breast cancer was diagnosed in 1439 women during eight years of follow-up. After multivariate adjustment for known risk factors, the relative risk among women in the highest quintile group for intake of vitamin C as compared with the risk among those in the lowest quintile group was 1.03 (95 percent confidence interval, 0.87 to 1.21); for vitamin E, after vitamin A intake had been controlled for, the relative risk was 0.99 (95 percent confidence interval, 0.83 to 1.19). In contrast, among women in the highest quintile group for inta...

Cigarette smoking and the risk of diabetes in women.

Abstract: OBJECTIVES. Noninsulin-dependent diabetes mellitus, a major risk factor for cardiovascular disease, is prevalent in more than 12 million Americans. A voluminous amount of data demonstrates that cigarette smoking is an important cause of cancer and coronary heart disease. However, the association between cigarette smoking and the risk of diabetes is virtually unexplored, especially in women. METHODS. We examined the association between smoking and the incidence of noninsulin-dependent diabetes mellitus among 114,247 female nurses who were free of diabetes, cardiovascular disease, and cancer in 1976. We collected exposure information and disease status prospectively for 12 years from biennially self-administered questionnaires. RESULTS. Current smokers had an increased risk of diabetes, and we observed a significant dose-response trend for higher risk among heavier smokers. During 1,277,589 person-years of follow-up, 2333 women were clinically diagnosed with diabetes. The relative risk of diabetes, adjusted...

Smoking cessation in relation to total mortality rates in women. A prospective cohort study.

Abstract: Objective: To examine the temporal relationship between stopping smoking and total mortality rates among middle-aged women. Design: Prospective cohort study with 12 years of follow-up. Setting: Reg...

A Comparison of Prospective and Retrospective Assessments of Diet in the Study of Breast Cancer

Abstract: Fat intake was examined in relation to risk of breast cancer using dietary questionnaires administered both before and after the diagnosis of breast cancer. Among the Nurses' Health Study cohort members who completed a food frequency questionnaire and were free of cancer in 1986, 398 were diagnosed with breast cancer during 2 years of follow-up. These cases and 798 age-matched controls (cohort members who also completed a dietary questionnaire in 1986 but did not develop breast cancer) were sent another food frequency questionnaire in 1989 inquiring about their diet in 1985. Three hundred cases and 602 controls responded to the second questionnaire. The age-adjusted analysis using the prospective (1986) questionnaire demonstrated no appreciable associations between breast cancer incidence and intakes of total fat (odds ratio (OR) between highest and lowest quintiles = 0.87; 95% confidence interval (CI) 0.54-1.40) and saturated fat (OR = 0.97; CI 0.64-1.46). The age-adjusted analysis using the retrospective (1989) questionnaire suggested positive associations between breast cancer incidence and intakes of total fat (OR = 1.43; 95% CI 0.90-2.27) and saturated fat (OR = 1.38; 95% CI 0.89-2.13). When nutrients were adjusted for total energy intake, the direction and magnitude of the differences between the prospective and retrospective analyses were similar to the analyses unadjusted for energy intake. These results suggest that case-control studies of diet and breast cancer may yield biased associations between fat intake and the risk of breast cancer.

A Retrospective Cohort Study of Vasectomy and Prostate Cancer in US Men

Abstract: Objective. —To examine the relationship between vasectomy and prostate cancer. Design. —Retrospective cohort study. Setting. —Husbands of nurses in 11 large states in the United States. Participants. —In questionnaires administered in 1976 and 1978, 14607 married female participants of the Nurses' Health Study reported vasectomy as the couple's form of contraception. In 1989, we contacted these 14607 women and 14 607 age-matched participants whose husbands had not had a vasectomy prior to 1978 to ascertain their husband's disease status between 1976 and 1989. Main Outcome Measure. —Diagnosis of prostate cancer. Results. —During the study period, from 1976 through 1989, 96 new cases of prostate cancer were diagnosed in the cohort. Vasectomy was associated with an increased risk of prostate cancer (age-adjusted relative risk, 1.56; 95% confidence interval, 1.03 to 2.37;P=.04). The relative risk of prostate cancer increased overtime since vasectomy. Among men who had their vasectomy 20 or more years in the past, the relative risk of prostate cancer was 1.89 (95% confidence interval, 1.14 to 3.14;P=.005), and after excluding stage A and B cases, the relative risk was 2.06 (95% confidence interval, 0.95 to 4.43;P=.07). This elevated risk of prostate cancer among vasectomized men persisted when we adjusted for smoking, alcohol consumption, educational level, body mass index, and geographical area of residence. Conclusions. —These results support evidence from other epidemiologic studies that vasectomy increases risk of prostate cancer. A biological mechanism whereby vasectomy influences the rate of prostate cancer may be related to a diminished secretory rate of prostatic fluid following vasectomy, or, alternatively, to the postvasectomy immune response to sperm antigens, which may cross-react with tumor-associated antigens and suppress tumor immunosurveillance mechanisms. (JAMA. 1993;269:878-882)

Race and Gender Differences in Respiratory Illness Prevalence and Their Relationship to Environmental Exposures in Children 7 to 14 Years of Age

Abstract: Race and gender differences in respiratory illness prevalence rates were assessed in a cohort of 8,322 white children and 1,056 black children 7 to 14 yr of age from four U.S. cities. Boys had higher rates of wheeze, asthma, cough, phlegm, and bronchitis than girls. Black children had higher rates of persistent wheeze, shortness of breath with wheeze, asthma, chronic cough, and chronic phlegm than white children. We examined whether the racial disparity in respiratory illness prevalence could be accounted for by environmental exposures and socioeconomic factors. The proportion of families without a parent who had graduated from high school was higher for blacks than for whites, as was the proportion of single-parent households. Black children took up smoking less frequently; their mothers smoked fewer cigarettes. Personal and maternal smoking predicted higher rates of persistent wheeze, chronic cough, chronic phlegm, and chest illness. The relative odds for persistent wheeze were 1.34 (1.07, 1.69) for smoking children compared with nonsmoking children. The relative odds for persistent wheeze were 1.35 (1.13, 1.60) for children whose mother smoked > 30 cigarettes per day versus children with no maternal smoke exposure. Other predictors of respiratory illnesses included parental respiratory illness, parental education, only-child status, single-parent household, air conditioner use, and body mass index. Nevertheless, adjustment for socioeconomic factors, environmental exposures, and body habitus did not significantly reduce the excess respiratory illness prevalence observed among black children. The adjusted relative odds were 1.47 (1.25, 1.74) for persistent wheeze and 1.57 (1.17, 2.10) for asthma for black children versus white children.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary Function Growth Velocity in Children 6 to 18 Years of Age

Abstract: Pulmonary function growth rate varies with a child's stage of growth. Since attained pulmonary function reflects the cumulative effects of growth, insults, and repair, rate of growth may be a more sensitive indicator of a child's current pulmonary health status. The sample for analyses included 2,478 white boys and 2,785 white girls followed annually by questionnaire and spirometry. Empirically derived annual growth velocities, peak velocity (Vpk), and age at which peak velocity occurred (Agepk) were determined for height, FVC, FEV1, and FEF25–75 for each child. Mean velocity curves for height, FVC, FEV1, and FEF25–75, stratified by sex and Agepk of height (an indicator for early, middle, or late maturity) were produced as a function of age. The differences between Agepk of FVC, FEV1, and FEF25–75 and Agepk of height (i.e., the lag period) were compared by sex and by the indicator of maturity. Linear regression analyses were performed to investigate associations between Vpk and Agepk of height, as well as...

Recall and selection bias in reporting past alcohol consumption among breast cancer cases.

Abstract: Recall and selection bias are well-recognized potential problems in case-control studies of alcohol and cancer, but few analyses have attempted to assess the direction and the magnitude of these potential biases. We thus examined alcohol consumption in relation to risk of breast cancer using dietary questionnaires administered both before and after the diagnosis of breast cancer in the Nurses' Health Study (United States). Among cohort members who completed a dietary questionnaire in 1986 and who were free of cancer, 616 were diagnosed with breast cancer during follow-up to December 1989. These cases and 1,277 controls (a random sample of cohort members who did not develop cancer up to 1990) then were sent another questionnaire inquiring about their diet in 1985. Four hundred and ninety-four cases (80.2 percent) and 999 controls (78.2 percent) responded to the second questionnaire. The analysis based on the prospective (1986) questionnaire demonstrated an elevated risk of breast cancer among women who drank 30 or more g of alcohol daily (about two drinks) relative to nondrinkers (odds ratio [OR]=1.55, 95 percent confidence interval [CI]=1.01–2.39). The analysis based on the retrospective questionnaire also indicated a similar but slightly attenuated elevation of risk of breast cancer among women who drank at least 30 g daily (OR=1.42, CI=0.85–2.40). In these data, bias due to selection and recall had only minor effects on reported intake of alcohol consumption.

A Prospective Study of Aspirin Use and Cataract Extraction in Women

Abstract: • We examined the association between aspirin use and the rates of cataract extraction during 8 years of follow-up in a large prospective study of women, the Nurses' Health Study. From 1980 to 1988, we documented 448 senile cataracts diagnosed and extracted during 434 680 person-years of follow-up. While we observed a modest positive association at the higher doses of aspirin use in the age-adjusted analyses, no association was found after accounting for other cataract risk factors (relative risk for ≥20 years of use, 1.08; 95% confidence interval, 0.84 to 1.39). Among women who consumed seven or more tablets per week for 20 or more years, there was no suggestion of protection; if anything, a nonsignificantly elevated risk was observed (relative risk, 1.31; 95% confidence interval, 0.94 to 1.80). We observed no consistent difference in the relationship between aspirin use and cataract when assessed by age. Overall, we found no evidence to support the substantial reduction in risk of cataract among aspirin users as reported in several previous studies.

Airway responsiveness in young black and white women.

Abstract: The prevalence and severity of asthma appears to be greater in blacks than in whites. To determine if racial differences in airway responsiveness may explain these findings, methacholine challenge tests from 62 black and 238 white women 20 to 35 yr of age were evaluated. Subjects served as controls for a case-control study of the relation of airway responsiveness and preterm labor. Standardized questionnaires were used to obtain information on age, obstetrical history, education, income, cigarette smoking, medication use, and respiratory illnesses and symptoms. Total serum IgE was measured using a radioimmunoassay. Methacholine challenge testing was performed on all subjects 6 wk after delivery, and the provocative dose causing a 20% decrease in FEV1 (PD20) was calculated. Black women in the study had more pregnancies and children, were younger, less well educated and more impoverished, and reported greater cigarette smoking and less medication use than did the white women. Additionally, black women had h...

Assessment of health effects in epidemiologic studies of air pollution.

Abstract: As we increasingly recognize the complexity of the pollutants in indoor and outdoor microenvironments, a broad array of inhaled mixtures has assumed scientific, public health, and regulatory import...

Introduction and recommendations: working group on indoor air and other complex mixtures.

Abstract: Air in indoor and outdoor environments typically contains many gaseous and particulate pollutants that may affect adversely any individual at sufficiently high concentrations and more sensitive ind

Seasonal and allergenic predictors of bronchial responsiveness to distilled water.

Abstract: To evaluate a possible seasonal change in bronchial responsiveness and the relation of such change to atopy, we administered 2,537 bronchial challenge tests in winter and spring to a dynamic population cohort of children 7 to 10 yr of age. The bronchial challenge test consisted of 10 min of tidal inhalation of an aerosol of ultrasonically nebulized distilled water; the resulting percentage decrease in FEV1 (dFEV1%) was recorded. Atopy was determined on the basis of skin-test positivity (any wheal with a diameter greater than that obtained with a positive control) to seven allergens (cat dander, dog dander, house-dust mite, birch, raygrass, orchard grass, and Alternaria). Greater bronchial responsiveness in winter was independently and significantly predicted by a physician's diagnosis of asthma (difference in dFEV1%, 5.6; 95% confidence intervals [95% CI], 2.8 to 8.5; p = 0.0001) and by shortness of breath (difference in dFEV1%, 4.2; 95% CI, 2.1 to 6.3; p = 0.0001). These factors were also predictive of g...

Railroad Diesel Exhaust: Concentration and Mutagenicity

Abstract: High volume fixed location samples of particles and vapor phase components were collected on filters and XAD-2 resin, respectively, to study the concentration and mutagenicity of diesel exhaust in locomotive repair shops at four railroads. The geometric mean concentrations were 96 μg/m3 [geometric standard deviation (GSD) = 2.14] for 23 samples of respirable particles, 164 μg/m3 (GSD = 1.86) for 26 samples of total particles, and 432 μg/m3 for 9 samples of vapor phase components. Approximately 30 to 40 percent of the particle mass was extractable in dichloromethane. Chemical class separation of these extracts by normal phase liquid chromatography yielded nearly half the mass in the aliphatic fraction, less than one third in the aromatic fraction, and about one quarter in the polar fraction. Extracts of particle samples were found to be mutagenic in the Salmonella typhimurium forward mutation assay system. Most of this activity was in the polar fraction. None of the vapor phase samples tested cont...