Biomedical subjects

G A Colditz

Publications and source records attributed to G A Colditz.

At least 163 records · Page 9Linked to original sources

PubMed1999

Hormones and breast cancer: evidence and implications for consideration of risks and benefits of hormone replacement therapy.

The role of estrogen replacement therapy (ERT) in the etiology of breast cancer continues to be debated. The implications for counseling women about a causal relation between hormones and breast cancer with regard to long-term use of postmenopausal hormones remain controversial. The literature on hormones and breast cancer, including articles on cell proliferation, endogenous hormone levels, epidemiologic studies, and the risk of breast cancer, is reviewed. A cause of cancer is defined as a factor that increases the probability that cancer will develop in an individual. A causal relation between female hormones and breast cancer is based on duration of use, dose-response, biologic plausibility, temporality, strength of association, and coherence. The magnitude of the increase in risk of breast cancer caused by using hormone replacement therapy (HRT) is comparable to that seen in delayed menopause. The positive relation between endogenous hormone levels and risk of breast cancer supports a biologic mechanism for this relationship. The increase in risk of breast cancer with increasing duration of use, which does not vary substantially across studies, offers further evidence for a causal relation. The reduction in total mortality with short-term use of hormones, although strongest among women with risk factors for cardiovascular disease, adds complexity to the risk-benefit tradeoff associated with the use of hormones for longer durations. All evidence supports a causal relation between both endogenous estrogens and the use of postmenopausal estrogens and progestins and breast cancer incidence in postmenopausal women. Among postmenopausal women, prior use of oral contraceptives is not related to risk of breast cancer. Strategies for relief of menopausal symptoms and long-term prevention of osteoporosis and heart disease that do not cause breast cancer are urgently needed.

Breast Neoplasms↗

PubMed1999

Dietary protein and risk of ischemic heart disease in women.

BACKGROUND: Ingestion of animal protein raises serum cholesterol in some experimental models but not in others, and ecologic studies have suggested a positive association between animal protein intake and risk of ischemic heart disease. Prospective data on the relation of protein intake to risk of ischemic heart disease are sparse. OBJECTIVE: The objective was to examine the relation between protein intake and risk of ischemic heart disease. DESIGN: The study was a prospective cohort study. RESULTS: We examined the association between dietary protein intake and incidence of ischemic heart disease in a cohort of 80082 women aged 34-59 y and without a previous diagnosis of ischemic heart disease, stroke, cancer, hypercholesterolemia, or diabetes in 1980. Intakes of protein and other nutrients were assessed with validated dietary questionnaires. We documented 939 major instances of ischemic heart disease during 14 y of follow-up. After age, smoking, total energy intake, percentages of energy from specific types of fat, and other ischemic heart disease risk factors were controlled for, high protein intakes were associated with a low risk of ischemic heart disease; when extreme quintiles of total protein intake were compared, the relative risk was 0.74 (95% CI: 0.59, 0.94). Both animal and vegetable proteins contributed to the lower risk. This inverse association was similar in women with low- or high-fat diets. CONCLUSIONS: Our data do not support the hypothesis that a high protein intake increases the risk of ischemic heart disease. In contrast, our findings suggest that replacing carbohydrates with protein may be associated with a lower risk of ischemic heart disease. Because a high dietary protein intake is often accompanied by increases in saturated fat and cholesterol intakes, application of these findings to public dietary advice should be cautious.

Adult↗

PubMed1999

Vitamin K intake and hip fractures in women: a prospective study.

BACKGROUND: Vitamin K mediates the gamma-carboxylation of glutamyl residues on several bone proteins, notably osteocalcin. High serum concentrations of undercarboxylated osteocalcin and low serum concentrations of vitamin K are associated with lower bone mineral density and increased risk of hip fracture. However, data are limited on the effects of dietary vitamin K. OBJECTIVE: We investigated the hypothesis that high intakes of vitamin K are associated with a lower risk of hip fracture in women. DESIGN: We conducted a prospective analysis within the Nurses' Health Study cohort. Diet was assessed in 72327 women aged 38-63 y with a food-frequency questionnaire in 1984 (baseline). During the subsequent 10 y of follow-up, 270 hip fractures resulting from low or moderate trauma were reported. RESULTS: Women in quintiles 2-5 of vitamin K intake had a significantly lower age-adjusted relative risk (RR: 0.70; 95% CI: 0.53, 0.93) of hip fracture than women in the lowest quintile (< 109 microg/d). Risk did not decrease between quintiles 2 and 5 and risk estimates were not altered when other risk factors for osteoporosis, including calcium and vitamin D intakes, were added to the models. Risk of hip fracture was also inversely associated with lettuce consumption (RR: 0.55; 95% CI: 0.40, 0.78) for one or more servings per day compared with one or fewer servings per week), the food that contributed the most to dietary vitamin K intakes. CONCLUSIONS: Low intakes of vitamin K may increase the risk of hip fracture in women. The data support the suggestion for a reassessment of the vitamin K requirements that are based on bone health and blood coagulation.

Adult↗

PubMed1999

Dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease among women.

BACKGROUND: Experimental studies in laboratory animals and humans suggest that alpha-linolenic acid (18:3n-3) may reduce the risk of arrhythmia. OBJECTIVE: The objective was to examine the association between dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease (IHD). DESIGN: This was a prospective cohort study. The intake of alpha-linolenic acid was derived from a 116-item food-frequency questionnaire completed in 1984 by 76283 women without previously diagnosed cancer or cardiovascular disease. RESULTS: During 10 y of follow-up, we documented 232 cases of fatal IHD and 597 cases of nonfatal myocardial infarction. After adjustment for age, standard coronary risk factors, and dietary intake of linoleic acid and other nutrients, a higher intake of alpha-linolenic acid was associated with a lower relative risk (RR) of fatal IHD; the RRs from the lowest to highest quintiles were 1.0, 0.99, 0.90, 0.67, and 0.55 (95% CI: 0.32, 0.94; P for trend = 0.01). For nonfatal myocardial infarction there was only a modest, nonsignificant trend toward a reduced risk when extreme quintiles were compared (RR: 0.85; 95% CI: 0.61, 1.19; P for trend = 0.50). A higher intake of oil and vinegar salad dressing, an important source of alpha-linolenic acid, was associated with reduced risk of fatal IHD when women who consumed this food > or =5-6 times/wk were compared with those who rarely consumed this food (RR: 0.46; 95% CI: 0.27, 0.76; P for trend = 0.001). CONCLUSIONS: This study supports the hypothesis that a higher intake of alpha-linolenic acid is protective against fatal IHD. Higher consumption of foods such as oil-based salad dressing that provide polyunsaturated fats, including alpha-linolenic acid, may reduce the risk of fatal IHD.

Adult↗

PubMed1999

A prospective study of carotenoid and vitamin A intakes and risk of cataract extraction in US women.

BACKGROUND: Oxidation of lens proteins plays a central role in the formation of age-related cataracts, suggesting that dietary antioxidants may play a role in prevention. However, the relation between specific antioxidants and risk of cataract remains uncertain. OBJECTIVE: Our objective was to examine prospectively the association between carotenoid and vitamin A intakes and cataract extraction in women. METHODS: A prospective cohort of registered female nurses aged 45-71 y and free of diagnosed cancer was followed; in 1980, 50461 were included and others were added as they became 45 y of age for a total of 77466. Information on nutrient intake was assessed by repeated administration of a food-frequency questionnaire during 12 y of follow-up. RESULTS: During 761762 person-years of follow-up, 1471 cataracts were extracted. After age, smoking, and other potential cataract risk factors were controlled for, those with the highest intake of lutein and zeaxanthin had a 22% decreased risk of cataract extraction compared with those in the lowest quintile (relative risk: 0.78; 95% CI: 0.63, 0.95; P for trend = 0.04). Other carotenoids (alpha-carotene, beta-carotene, lycopene, and beta-cryptoxanthin), vitamin A, and retinol were not associated with cataract in multivariate analysis. Increasing frequency of intakes of spinach and kale, foods rich in lutein, was associated with a moderate decrease in risk of cataract. CONCLUSIONS: Lutein and zeaxanthin and foods rich in these carotenoids may decrease the risk of cataracts severe enough to require extraction.

Adolescent↗

PubMed1999

Dietary saturated fats and their food sources in relation to the risk of coronary heart disease in women.

BACKGROUND: Metabolic studies suggest that saturated fatty acids differ in their effects on blood lipids. OBJECTIVE: The objective was to examine the associations between intakes of individual saturated fatty acids and their food sources in relation to the risk of coronary heart disease (CHD). DESIGN: This was a prospective cohort study of 80082 women in the Nurses' Health Study aged 34-59 y. Subjects had no known cardiovascular disease, cancer, hypercholesterolemia, or diabetes, and completed validated food-frequency questionnaires in 1980. RESULTS: During 14 y of follow-up, we documented 939 incident cases of major CHD events. In multivariate analyses in which age, smoking, and other covariates were controlled for, intakes of short- to medium-chain saturated fatty acids (4:0-10:0) were not significantly associated with the risk of CHD. In contrast, intakes of longer-chain saturated fatty acids (12:0-18:0) were each separately associated with a small increase in risk. The multivariate RR for a 1% energy increase from stearic acid was 1.19 (95% CI: 1.02, 1.37). The ratio of polyunsaturated to saturated fat was strongly and inversely associated with CHD risk (multivariate RR for a comparison of the highest with the lowest deciles: 0.58; 95% CI: 0.41, 0.83; P for trend < 0.0001). Conversely, higher ratios of red meat to poultry and fish consumption and of high-fat to low-fat dairy consumption were associated with significantly greater risk. CONCLUSION: A distinction between stearic acid and other saturated fats does not appear to be important in dietary advice to reduce CHD risk, in part because of the high correlation between stearic acid and other saturated fatty acids in typical diets.

Adult↗

PubMed1999

Overweight, weight concerns, and bulimic behaviors among girls and boys.

OBJECTIVE: To assess the prevalence rates and correlates of overweight, concern with weight, and bulimic behaviors. METHOD: A survey was completed by a population-based sample of 16,114 boys and girls aged 9 to 14 years. RESULTS: Although fewer girls (19%) than boys (26%) were overweight, more girls (25% versus 22%) perceived themselves as overweight (p < .001). The proportion of girls reporting trying to lose weight increased with age (p < .001). The prevalence of binge eating at least monthly increased with age among the girls, but remained stable among the boys. The prevalence of purging was low (< or = 1%) and comparable between genders until age 13. Among the 13- and 14-year-olds, girls were significantly more likely than boys to report using laxatives or vomiting to control weight (p < or = .001). Purging was independently positively associated with stage of pubertal development (girls: odds ratio [OR] = 2.1, 95% confidence interval [CI] 1.6-2.7; boys: OR = 1.5, 95% CI 1.0-2.2) and overweight (girls: OR = 1.9, 95% CI 1.2-3.0; boys: OR = 2.7, 95% CI 1.4-5.1). CONCLUSIONS: Misperception of being overweight and concern with weight were common. Purging was a very rare behavior, but increased with pubertal development. Among the girls, the prevalence increased sharply around the onset of adolescence.

Adolescent↗

PubMed1999

Economic costs of obesity and inactivity.

PURPOSE: The purpose of this paper is to assess the economic costs of inactivity (including those attributable to obesity). These costs represent one summary of the public health impact of increasingly sedentary populations in countries with established market economies. Components of the costs of illness include direct costs resulting from treatment of morbidity and indirect costs caused by lost productivity (work days lost) and forgone earnings caused by premature mortality. METHODS: We searched the Medline database for studies reporting the economic costs of obesity or inactivity, or cost of illness. From the identified references those relating to obesity or conditions attributable to obesity were reviewed. Chronic conditions related to inactivity include coronary heart disease (CHD), hypertension, Type II diabetes, colon cancer, depression and anxiety, osteoporotic hip fractures, and also obesity. Increasing adiposity, or obesity, is itself a direct cause of Type II diabetes, hypertension, CHD, gallbladder disease, osteoarthritis and cancer of the breast, colon, and endometrium. The most up-to-date estimates were extracted. To estimate the proportion of disease that could be prevented by eliminating inactivity or obesity we calculated the population-attributable risk percent. Prevalence based cost of illness for the U.S. is in 1995 dollars. RESULTS: The direct costs of lack of physical activity, defined conservatively as absence of leisure-time physical activity, are approximately 24 billion dollars or 2.4% of the U.S. health care expenditures. Direct costs for obesity defined as body mass index greater than 30, in 1995 dollars, total 70 billion dollars. These costs are independent of those resulting from lack of activity. CONCLUSION: Overall, the direct costs of inactivity and obesity account for some 9.4% of the national health care expenditures in the United States. Inactivity, with its wide range of health consequences, represents a major avoidable contribution to the costs of illness in the United States and other countries with modern lifestyles that have replaced physical labor with sedentary occupations and motorized transportation.

Absenteeism↗

PubMed1999

Prospective study of aspirin use and risk of stroke in women.

BACKGROUND AND PURPOSE: In secondary prevention, aspirin reduces risk of ischemic stroke. In primary prevention of stroke, however, the role of aspirin is uncertain, especially in women. METHODS: In 1980, 79 319 women in the Nurses' Health Study cohort, 34 to 59 years of age and free of diagnosed cardiovascular disease, cancer, and rheumatoid arthritis, completed questionnaires that included information on aspirin use. Data on aspirin use were updated in 1982, 1984, and 1988. By 1994, after 994 231 person-years of follow-up, 503 incident strokes (295 ischemic strokes, 100 subarachnoid hemorrhages, 52 intraparenchymal hemorrhages, and 56 strokes of undetermined type) were documented. RESULTS: There was no clear relationship between aspirin use and risk of total stroke; risk was slightly reduced among women who took 1 to 6 aspirin per week and slightly increased among women who took 7 or more aspirin per week. Women who took 1 to 6 aspirin per week had a lower risk of large-artery occlusive infarction compared with women who reported no aspirin use; after simultaneous adjustment for other cardiovascular risk factors and selected nutrients, the multivariate relative risk was 0.50 (95% CI 0.29 to 0.85, P=0.01). Women who took 15 or more aspirin per week had an excess risk of subarachnoid hemorrhage; the multivariate relative risk was 2.02 (95% CI 1.04 to 3.91, P for trend=0.02). The reduction in large-artery occlusive infarction with aspirin was of greater magnitude for older, hypertensive, or smoking women than for younger, nonhypertensive, or nonsmoking women; the elevation in subarachnoid hemorrhage with aspirin was also more apparent for older or hypertensive women than for younger or nonhypertensive women. Aspirin use was not associated with risk of other subtypes of stroke. CONCLUSIONS: These prospective data indicate that women who take 1 to 6 aspirin per week have a reduced risk of large-artery occlusive infarction, but those who use 15 or more aspirin per week have an increased risk of subarachnoid hemorrhage. This observational study suggests benefits of aspirin for ischemic stroke with low frequency of use and hazards for hemorrhagic stroke with high frequency of use, particularly among older or hypertensive women. Thus, the effect on total stroke will depend on the dose of aspirin and the distribution of stroke subtypes and risk factors in the population.

Adult↗

PubMed1999

Prospective study of calcium, potassium, and magnesium intake and risk of stroke in women.

BACKGROUND AND PURPOSE: High intakes of calcium, potassium, and magnesium have been hypothesized to reduce risks of cardiovascular disease, but only a few prospective studies have examined intakes of these cations in relation to risk of stroke. METHODS: In 1980, 85 764 women in the Nurses' Health Study cohort, aged 34 to 59 years and free of diagnosed cardiovascular disease and cancer, completed dietary questionnaires from which we calculated intakes of calcium, potassium, and magnesium. By 1994, after 1.16 million person-years of follow-up, 690 incident strokes (129 subarachnoid hemorrhages, 74 intraparenchymal hemorrhages, 386 ischemic strokes, and 101 strokes of undetermined type) had been documented. RESULTS: Intakes of calcium, potassium, and magnesium were each inversely associated with age- and smoking-adjusted relative risks of ischemic stroke, excluding embolic infarction of nonatherogenic origin (n=347). Adjustment for other cardiovascular risk factors, including history of hypertension, attenuated these associations, particularly for magnesium intake. In a multivariate analysis, women in the highest quintile of calcium intake had an adjusted relative risk of ischemic stroke of 0.69 (95% CI, 0.50 to 0.95; P for trend=0.03) compared with those in the lowest quintile; for potassium intake the corresponding relative risk was 0.72 (95% CI, 0.51 to 1.01; P for trend=0.10). Further simultaneous adjustment for calcium and potassium intake suggested an independent association for calcium intake. The association of risk with calcium intake did not appear to be log linear; the increase in risk was limited to the lowest quintile of intake, and intakes > approximately 600 mg/d did not appear to reduce risk of stroke further. The inverse association with calcium intake was stronger for dairy than for nondairy calcium intake. Intakes of calcium, potassium, and magnesium were not related to risk of other stroke subtypes. CONCLUSIONS: Low calcium intake, and perhaps low potassium intake, may contribute to increased risk of ischemic stroke in middle-aged American women. It remains possible that women in the lowest quintile of calcium intake had unknown characteristics that made them susceptible to ischemic stroke.

Adult↗

PubMed1999

Workplace exposure to passive smoking and risk of cardiovascular disease: summary of epidemiologic studies.

We reviewed the published epidemiologic studies addressing the relationship between workplace exposure to environmental tobacco smoke (ETS) and cardiovascular disease risk in three case-control studies and three cohort studies. Although the point estimates of risk for cardiovascular disease exceeded 1.0 in five of six studies, none of the relative risks was statistically significant because of the small number of cardiovascular end points occurring in individual studies. In common with most epidemiologic investigations of the health risks of ETS, none of the workplace studies included independent biochemical validation of ETS exposure. In contrast to the evidence on increased cardiovascular disease risk from exposure to spousal ETS, studies of ETS exposure in the workplace are still sparse and inconclusive. Conversely, there is no biologically plausible reason to believe that the hazards of ETS exposure that have been demonstrated in the home should not also apply to the workplace.

Epidemiologic Studies↗

PubMed1999

Exposure to the mass media and weight concerns among girls.

OBJECTIVE: To assess the influence of the media on girls' weight concerns, weight control/loss behaviors, and perceptions of body weight and shape. DESIGN: Cross-sectional survey completed in school. The questionnaire assessed body weight, dissatisfaction with body weight and shape, exposure to fashion magazines, the impact of media on feelings about weight and shape, attributes of and preferences for body types, and whether subjects had gone on a diet to lose weight or initiated exercise because of an article in a magazine. SETTING: Mandatory physical education class in public elementary, junior high, and high schools. PARTICIPANTS: Subjects included 548 5th- through 12th-grade girls in a working-class suburb in the northeastern United States. OUTCOME MEASURES: Perceived influence of fashion magazines on body dissatisfaction, idea of the perfect body shape, dieting to lose weight, and initiating an exercise program. RESULTS: Pictures in magazines had a strong impact on girls' perceptions of their weight and shape. Of the girls, 69% reported that magazine pictures influence their idea of the perfect body shape, and 47% reported wanting to lose weight because of magazine pictures. There was a positive linear association between the frequency of reading women's magazines and the prevalence of having dieted to lose weight because of a magazine article, initiating an exercise program because of a magazine article, wanting to lose weight because of pictures in magazines, and feeling that pictures in magazines influence their idea of the perfect body shape. In multivariate logistic regression models controlling for weight status (overweight vs not overweight), school level (elementary vs junior high school, elementary vs high school), and race/ethnic group, girls who were frequent readers of fashion magazines were two to three times more likely than infrequent readers to diet to lose weight because of a magazine article (odds ratio [OR] = 2.11, 95% confidence interval [CI]: 1.19-3.75); to exercise to lose weight because of a magazine article (OR = 3.02, 95% CI: 1.77-5.17); and to feel that magazines influence what they believe is the ideal body shape (OR = 2.81; 95% CI: 1.72-4.58). In addition, moderate-frequency readers were more likely than infrequent readers of fashion magazines to report exercising because of a magazine article (OR = 1.94; 95% CI: 1.14-3.30) and feeling that magazines influence what they believe is the ideal body shape (OR = 2.03; 95% CI: 1.30-3.15). DISCUSSION: The majority of the preadolescent and adolescent girls in this school-based study were unhappy with their body weight and shape. This discontentment was strongly related to the frequency of reading fashion magazines. Although previous studies have concluded that the print media promotes an unrealistically thin body ideal, which in turn is at least partially responsible for promoting eating disorders, the present study is the first that we are aware of to assess directly the impact of the print media on the weight and body shape beliefs of young girls. We observed that the frequency of reading fashion magazines was positively associated with the prevalence of having dieted to lose weight, having gone on a diet because of a magazine article, exercising to lose weight or improve body shape, and deciding to exercise because of a magazine article. Given the substantial health risk associated with overweight and the fact that during the past 2 decades the prevalence of overweight has increased sharply among children and adolescents, it is not prudent to suggest that overweight girls should accept their body shape and not be encouraged to lose weight. However, aspiring to look like underweight models may have deleterious psychological consequences. The results suggest that the print media aimed at young girls could serve a public health role by refraining from relying on models who are severely underweight and printing more articles on the benefits of physical

Adolescent↗

PubMed1999

Weight concerns, weight control behaviors, and smoking initiation.

OBJECTIVE: To examine the cross-sectional relationships between weight concerns, weight control behaviors, and initiation of tobacco use among youths. STUDY DESIGN: Smoking status, weight concerns, and weight control behaviors were assessed in a cross-sectional sample of 16 862 children, 9 to 14 years of age, in 1996. Logistic regression was used to examine the relationship between weight concerns, weight control behaviors, and early stages of smoking initiation (precontemplation, contemplation, and experimentation). All analyses were adjusted for age, body mass index, and known predictors of initiation. RESULTS: Approximately 9% of participants had experimented with cigarettes, and 6% were contemplating cigarette smoking. Contemplation of tobacco use was associated with misperception of being overweight (boys: odds ratio [OR], 1.65; 95% confidence interval [CI], 1.10-2.48), unhappiness with appearance (girls: OR, 2.05; 95% CI, 1.48-2.84; boys: OR, 1.60; 95% CI, 1.05-2. 42), and a tendency to change eating patterns around peers (girls: OR, 2.87; 95% CI, 2.28-3.62; boys: OR, 1.83; 95% CI, 1.25-2.66). Experimentation with cigarettes was associated with daily exercise to control weight among boys (OR, 1.92; 95% CI, 1.07-3.43) and with monthly purging (OR, 2.54; 95% CI, 1.27-5.07) and daily dieting among girls (OR, 1.79; 95% CI, 1.09-2.96). CONCLUSIONS: Our findings suggest that, among both girls and boys, contemplation of smoking is positively related to weight concerns. Experimentation seems to be positively related to weight control behaviors. It is important for both pediatricians and comprehensive school health programs to address healthy methods of weight maintenance and to dispel the notion of tobacco use as a method of weight control.

Adolescent↗

PubMed1999

Lifetime health and economic benefits of weight loss among obese persons.

OBJECTIVES: This study estimated the lifetime health and economic benefits of sustained modest weight loss among obese persons. METHODS: We developed a dynamic model of the relationship between body mass index (BMI) and the risks and costs of 5 obesity-related diseases: hypertension, hypercholesterolemia, type 2 diabetes, coronary heart disease (CHD), and stroke. We then calculated the lifetime health and economic benefits of a sustained 10% reduction in body weight for men and women aged 35 to 64 years with mild, moderate, and severe obesity. RESULTS: Depending on age, gender, and initial BMI, a sustained 10% weight loss would (1) reduce the expected number of years of life with hypertension, hypercholesterolemia, and type 2 diabetes by 1.2 to 2.9, 0.3 to 0.8, and 0.5 to 1.7, respectively; (2) reduce the expected lifetime incidence of CHD and stroke by 12 to 38 cases per 1000 and 1 to 13 cases per 1000, respectively; (3) increase life expectancy by 2 to 7 months; and (4) reduce expected lifetime medical care costs of these 5 diseases by $2200 to $5300. CONCLUSIONS: Sustained modest weight loss among obese persons would yield substantial health and economic benefits.

Adult↗

PubMed1999

Smoking and risk of total and fatal prostate cancer in United States health professionals.

Studies that have examined the relationship between cigarette use and prostate cancer incidence have yielded inconsistent results, although most studies have suggested that smoking is related to the occurrence of fatal prostate cancer. We evaluated prospectively the relationship between cigarette smoking and total, distant metastatic, and fatal prostate cancer in 47,781 male health professionals throughout the United States followed with questionnaires. From 1986 to 1994, we documented 1369 men with prostate cancer (excluding stage A1). One hundred fifty-two of the men had distant metastatic disease at diagnosis, and 103 fatal cases occurred from 1986 to 1994. Early (before age 30), late (within recent 10 years), and lifetime cumulative smoking history were unrelated to risk of total prostate cancer. However, men who had smoked 15 or more pack-years of cigarettes within the preceding 10 years were at higher risk of distant metastatic prostate cancer [multivariate relative risk (RR), 1.81; 95% confidence interval (CI), 1.05-3.11; P (trend), 0.03] and fatal prostate cancer [RR, 2.06; CI, 1.08-3.90; P (trend), 0.02] relative to nonsmokers. Within 10 years after quitting, the excess risk among smokers is eliminated. The higher rate of fatal prostate cancer among smokers did not appear to result from confounding by diet or other lifestyle factors, different screening behavior between smokers and nonsmokers, or from other smoking-related comorbidities. Our results indicate that although smoking was unrelated to prostate cancer incidence, recent tobacco use had a substantial impact on the occurrence of fatal prostate cancer.

Adult↗

PubMed1999

Prospective study of alcohol consumption patterns in relation to symptomatic gallstone disease in men.

Although the association between alcohol intake and gallstone disease has been characterized previously, the relation between alcohol consumption patterns, specific types of alcoholic beverages, and risk for cholelithiasis has not been addressed systematically. These issues were examined prospectively in a cohort of men who were free from symptomatic gallstone disease in 1986 and were followed to 1996. During follow-up, 2.4% of the men reported newly symptomatic gallstones that were diagnosed by ultrasonography or x-ray, or a cholecystectomy. After adjusting for other known or suspected risk factors, an increase in the amount of alcohol consumed was associated with a decreased risk of symptomatic gallstone disease. An increase in frequency of alcohol consumption also was related to decreased risk. Combining the reports of quantity and frequency of alcohol intake, a consumption pattern that reflected frequent intake (5-7 days/week) of any given amount of alcohol was associated with a decreased risk, as compared with nondrinkers. In contrast, infrequent alcohol intake (1-2 days/week) showed no significant association with risk. All alcoholic beverage types were inversely associated with risk of symptomatic gallstone disease, independent of patterns of consumption. These results suggest that frequent, moderate intake of alcohol decreases the risk for symptomatic gallstone disease, in contrast to infrequent or episodic alcohol intake. Recommendations regarding the benefit of moderate quantities of alcohol for gallstone discase should be weighed against the potential health hazards of alcohol consumption.

Adult↗

PubMed1999

A prospective study of vitamin supplement intake and cataract extraction among U.S. women.

We prospectively examined the association between vitamin supplement intake and the incidence of cataract extraction during 12 years of follow-up in a cohort of 47,152 female nurses. Women were 45 years or older and free of diagnosed cancer in 1980; others were added as they reached 45 years of age, for a total of 73,956 women. During 720,082 years of follow-up, 1,377 senile cataracts were diagnosed and extracted. Those who used multivitamins or separate supplements of vitamin C, E, or A did not have decreased risks of cataract as compared with nonusers even for use of 10 or more years. After adjusting for cataract risk factors, including cigarette smoking, body mass index, and diabetes mellitus, users of vitamin C supplements for 10 or more years had a relative risk (RR) of 0.95 [95% confidence interval (CI) = 0.76-1.20]. Associations were stronger among long-term vitamin C supplement users who were never-smokers (RR = 0.71; 95% CI = 0.47-1.08) and less than 60 years of age (RR = 0.72; 95% CI = 0.49-1.04). These findings suggest that there is little overall benefit of long-term use of vitamin supplements for risk of cataracts requiring extraction.

Adult↗

PubMed1999

Association of age and reproductive factors with benign breast tissue composition.

Reproductive breast cancer risk factors are hypothesized to act by increasing exposure of the breast to endogenous estrogens, but few studies have quantitatively examined the association of these risk factors with breast tissue composition. This study is part of a case-control study of breast histological characteristics and breast cancer risk, nested within the Nurses' Health Study, a prospective study of 121,700 registered nurses. We studied 300 women who had not been diagnosed with breast cancer, but for whom we obtained slides from a prior benign breast biopsy. We used a computer-assisted image analysis technique to assess the proportion of epithelial and fibrous stromal tissue on benign breast biopsy slides, excluding obvious mass lesions. Mean epithelial proportion was 5.3% (0.1-23%), and mean stromal proportion was 58.7% (3-93%). Women with proliferative breast disease without atypia had higher epithelial and stromal proportions than women with nonproliferative breast disease (P < 0.001). Postmenopausal women had a lower epithelial proportion (P = 0.01), and increasing age at biopsy was associated with decreasing stromal proportion among postmenopausal parous women (P = 0.004). Among premenopausal women, increasing years since last birth was associated with lower epithelial proportion (P < 0.001). Other reproductive risk factors were not independently associated with epithelial or stromal proportion. Epithelial and stromal breast tissue were associated with different factors with the exception of proliferative breast disease, which was associated with an increase in both epithelial and stromal proportion. The quantitative measurement of epithelial and stromal proportion may be useful for measuring changes in breast composition.

Age Factors↗