Showing papers by "Frank E. Speizer published in 1999"
TL;DR: These data support a protective relationship between consumption of fruit and vegetables-particularly cruciferous and green leafy vegetables and citrus fruit and juice-and ischemic stroke risk.
Abstract: ContextFew studies have evaluated the relationship between fruit and vegetable
intake and cardiovascular disease.ObjectiveTo examine the associations between fruit and vegetable intake and ischemic
stroke.Design, Setting, and SubjectsProspective cohort studies, including 75,596 women aged 34 to 59 years
in the Nurses' Health Study with 14 years of follow-up (1980-1994), and 38,683
men aged 40 to 75 years in the Health Professionals' Follow-up Study with
8 years of follow-up (1986-1994). All individuals were free of cardiovascular
disease, cancer, and diabetes at baseline.Main Outcome MeasureIncidence of ischemic stroke by quintile of fruit and vegetable intake.ResultsA total of 366 women and 204 men had an ischemic stroke. After controlling
for standard cardiovascular risk factors, persons in the highest quintile
of fruit and vegetable intake (median of 5.1 servings per day among men and
5.8 servings per day among women) had a relative risk (RR) of 0.69 (95% confidence
interval [CI], 0.52-0.92) compared with those in the lowest quintile. An increment
of 1 serving per day of fruits or vegetables was associated with a 6% lower
risk of ischemic stroke (RR, 0.94; 95% CI, 0.90-0.99; P=.01, test for trend). Cruciferous vegetables (RR, 0.68 for an increment
of 1 serving per day; 95% CI, 0.49-0.94), green leafy vegetables (RR, 0.79;
95% CI, 0.62-0.99), citrus fruit including juice (RR, 0.81; 95% CI, 0.68-0.96),
and citrus fruit juice (RR, 0.75; 95% CI, 0.61-0.93) contributed most to the
apparent protective effect of total fruits and vegetables. Legumes or potatoes
were not associated with lower ischemic stroke risk. The multivariate pooled
RR for total stroke was 0.96 (95% CI, 0.93-1.00) for each increment of 2 servings
per day.ConclusionsThese data support a protective relationship between consumption of
fruit and vegetables—particularly cruciferous and green leafy vegetables
and citrus fruit and juice—and ischemic stroke risk.
1,067 citations
TL;DR: These prospective data indicate that brisk walking and vigorous exercise are associated with substantial and similar reductions in the incidence of coronary events among women.
Abstract: Background The role of walking, as compared with vigorous exercise, in the prevention of coronary heart disease remains controversial, and data for women on this topic are sparse. Methods We prospectively examined the associations between the score for total physical activity, walking, and vigorous exercise and the incidence of coronary events among 72,488 female nurses who were 40 to 65 years old in 1986. Participants were free of diagnosed cardiovascular disease or cancer at the time of entry and completed serial detailed questionnaires about physical activity. During eight years of follow-up, we documented 645 incident coronary events (nonfatal myocardial infarction or death from coronary disease). Results There was a strong, graded inverse association between physical activity and the risk of coronary events. As compared with women in the lowest quintile group for energy expenditure (expressed as the metabolic-equivalent [MET] score), women in increasing quintile groups had age-adjusted relative risks of 0.77, 0.65, 0.54, and 0.46 for coronary events (P for trend or =6 MET) was associated with similar risk reductions (30 to 40 percent). Sedentary women who became active in middle adulthood or later had a lower risk of coronary events than their counterparts who remained sedentary. Conclusions These prospective data indicate that brisk walking and vigorous exercise are associated with substantial and similar reductions in the incidence of coronary events among women.
988 citations
TL;DR: The data suggest that greater physical activity level is associated with substantial reduction in risk of type 2 diabetes, including physical activity of moderate intensity and duration.
Abstract: ContextAlthough many studies suggest that physical activity may reduce risk
of type 2 diabetes, the role of moderate-intensity activity such as walking
is not well understood.ObjectivesTo examine the relationship of total physical activity and incidence
of type 2 diabetes in women and to compare the benefits of walking vs vigorous
activity as predictors of subsequent risk of type 2 diabetes.Design and SettingThe Nurses' Health Study, a prospective cohort study that included detailed
data for physical activity from women surveyed in 11 US states in 1986, with
updates in 1988 and 1992.ParticipantsA total of 70,102 female nurses aged 40 to 65 years who did not have
diabetes, cardiovascular disease, or cancer at baseline (1986).Main Outcome MeasureRisk of type 2 diabetes by quintile of metabolic equivalent task (MET)
score, based on time spent per week on each of 8 common physical activities,
including walking.ResultsDuring 8 years of follow-up (534,928 person-years), we documented 1419
incident cases of type 2 diabetes. After adjusting for age, smoking, alcohol
use, history of hypertension, history of high cholesterol level, and other
covariates, the relative risks (RRs) of developing type 2 diabetes across
quintiles of physical activity (least to most) were 1.0, 0.77, 0.75, 0.62,
and 0.54 (P for trend <.001); after adjusting
for body mass index (BMI), RRs were 1.0, 0.84, 0.87, 0.77, and 0.74 (P for trend = .002). Among women who did not perform vigorous
activity, multivariate RRs of type 2 diabetes across quintiles of MET score
for walking were 1.0, 0.91, 0.73, 0.69, and 0.58 (P
for trend <.001). After adjusting for BMI, the trend remained statistically
significant (RRs were 1.0, 0.95, 0.80, 0.81, 0.74; P
for trend = .01). Faster usual walking pace was independently associated with
decreased risk. Equivalent energy expenditures from walking and vigorous activity
resulted in comparable magnitudes of risk reduction.ConclusionsOur data suggest that greater physical activity level is associated
with substantial reduction in risk of type 2 diabetes, including physical
activity of moderate intensity and duration.
928 citations
TL;DR: The BMI has a strong, independent, and positive association with risk of adult-onset asthma, and the increasing prevalence of obesity in developed nations may help explain concomitant increases in asthma prevalence.
Abstract: Background Obesity and asthma are common disorders, and their prevalence rates continue to rise. Although individuals with asthma may gain weight as a result of activity limitations, the relationship between body mass index (BMI), which is calculated as weight in kilograms divided by the square of height in meters, and risk of developing asthma is not known. Methods We performed a prospective cohort study of female US registered nurses in the Nurses' Health Study II. In 1991, after excluding women who died with probable asthma or with incomplete data, there were 85,911 participants, aged 26 to 46 years. The main outcome measure was self-report of physician-diagnosed asthma with recent use of an asthma medication. Results From 1991 to 1995, we identified 1596 incident cases of asthma. In a multivariate model controlling for 9 potential confounding factors (including age, race, smoking, physical activity, and energy intake), the relative risks of asthma for 6 increasing categories of BMI in 1991 were 0.9, 1.0 (reference), 1.1, 1.6, 1.7, and 2.7 ( P for trend P for trend Conclusions The BMI has a strong, independent, and positive association with risk of adult-onset asthma. The increasing prevalence of obesity in developed nations may help explain concomitant increases in asthma prevalence.
831 citations
TL;DR: The data do not support the existence of an important protective effect of dietary fiber against colorectal cancer or adenoma against women with no history of cancer, inflammatory bowel disease, or familial polyposis.
Abstract: Background A high intake of dietary fiber has been thought to reduce the risk of colorectal cancer and adenoma. Methods We conducted a prospective study of 88,757 women, who were 34 to 59 years old and had no history of cancer, inflammatory bowel disease, or familial polyposis, who completed a dietary questionnaire in 1980. During a 16-year follow-up period, 787 cases of colorectal cancer were documented. In addition, 1012 patients with adenomas of the distal colon and rectum were found among 27,530 participants who underwent endoscopy during the follow-up period. Results After adjustment for age, established risk factors, and total energy intake, we found no association between the intake of dietary fiber and the risk of colorectal cancer; the relative risk for the highest as compared with the lowest quintile group with respect to fiber intake was 0.95 (95 percent confidence interval, 0.73 to 1.25). No protective effect of dietary fiber was observed when we omitted adjustment for total energy intake, whe...
670 citations
TL;DR: 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 betweenStearic Acid and otheraturated fatty acids in typical diets.
646 citations
TL;DR: The association of birthweight with type 2 diabetes during adulthood in a large cohort of U.S. women born from 1921 to 1946 is assessed and the validity of self-reported birthweight was assessed.
Abstract: Even after adjustment for adult body mass index and maternal history of diabetes, birthweight was found to be inversely associated with risk for type 2 diabetes during adulthood.
548 citations
TL;DR: The findings suggest that the excess risk of breast cancer associated with alcohol consumption may be reduced by adequate folate intake.
Abstract: ContextFolate is involved in DNA synthesis and methylation
and may reduce breast cancer risk, particularly among women with
greater alcohol consumption.ObjectivesTo assess the association between folate intake and
risk of breast cancer and whether higher folate intake may reduce
excess risk among women who consume alcohol.DesignProspective cohort study performed in 1980, with 16 years
of follow-up.Setting and ParticipantsA total of 88,818 women who
completed the dietary questionnaire section of the Nurses' Health
Study in 1980.Main Outcome MeasureIncidence of invasive breast cancer by levels
of folate and alcohol intake.ResultsA total of 3483 cases of breast cancer were documented.
Total folate intake was not associated with overall risk of breast
cancer. However, among women who consumed at least 15 g/d of alcohol,
the risk of breast cancer was highest among those with low folate
intake. For total folate intake of at least 600 µg/d compared with
150 to 299 µg/d, the multivariate relative risk (RR) was 0.55 (95%
confidence interval [CI], 0.39-0.76; P for
trend=.001). This association was only slightly
attenuated after additional adjustment for intake of beta carotene,
lutein/zeaxanthin, preformed vitamin A, and total vitamins C and E. The
risk of breast cancer associated with alcohol intake was strongest
among women with total folate intake of less than 300 µg/d (for
alcohol intake ≥15 g/d vs <15 g/d, multivariate RR, 1.32; 95% CI,
1.15-1.50). For women who consumed at least 300 µg/d of total folate,
the multivariate RR for intake of at least 15 g/d of alcohol vs less
than 15 g/d was 1.05 (95% CI, 0.92-1.20). Current use of multivitamin
supplements, the major source of folate, was associated with lower
breast cancer risk among women who consumed at least 15 g/d of alcohol
(for current users of supplements vs never users, RR, 0.74; 95% CI,
0.59-0.93).ConclusionsOur findings suggest that the excess risk of breast
cancer associated with alcohol consumption may be reduced by adequate
folate intake.
454 citations
TL;DR: It is suggested that consumption of up to 1 egg per day is unlikely to have substantial overall impact on the risk of CHD or stroke among healthy men and women.
Abstract: ContextReduction in egg consumption has been widely
recommended to lower blood cholesterol levels and prevent coronary
heart disease (CHD). Epidemiologic studies on egg consumption and risk
of CHD are sparse.ObjectiveTo examine the association between egg consumption and
risk of CHD and stroke in men and women.Design and SettingTwo prospective cohort studies, the Health
Professionals Follow-up Study (1986-1994) and the Nurses' Health Study
(1980-1994).ParticipantsA total of 37,851 men aged 40 to 75 years at
study outset and 80,082 women aged 34 to 59 years at study
outset, free of cardiovascular disease, diabetes, hypercholesterolemia,
or cancer.Main Outcome MeasuresIncident nonfatal myocardial
infarction, fatal CHD, and stroke corresponding to daily egg
consumption as determined by a food-frequency questionnaire.ResultsWe documented 866 incident cases of CHD and 258
incident cases of stroke in men during 8 years of follow-up and 939
incident cases of CHD and 563 incident cases of stroke in women during
14 years of follow-up. After adjustment for age, smoking, and other
potential CHD risk factors, we found no evidence of an overall
significant association between egg consumption and risk of CHD or
stroke in either men or women. The relative risks (RRs) of CHD across
categories of intake were less than 1 per week (1.0), 1 per week
(1.06), 2 to 4 per week (1.12), 5 to 6 per week (0.90), and ≥1 per day
(1.08) (P for trend=.75) for men; and less
than 1 per week (1.0), 1 per week (0.82), 2 to 4 per week (0.99), 5 to
6 per week (0.95), and ≥1 per day (0.82) (P for
trend=.95) for women. In subgroup analyses, higher egg
consumption appeared to be associated with increased risk of CHD only
among diabetic subjects (RR of CHD comparing more than 1 egg per day
with less than 1 egg per week among diabetic men, 2.02 [95%
confidence interval, 1.05-3.87; P for
trend=.04], and among diabetic women, 1.49
[0.88-2.52; P for trend=.008]).ConclusionsThese findings suggest that consumption of up to 1 egg
per day is unlikely to have substantial overall impact on the risk of
CHD or stroke among healthy men and women. The apparent increased risk
of CHD associated with higher egg consumption among diabetic
participants warrants further research.
444 citations
TL;DR: The hypothesis that higher fiber intake, particularly from cereal sources, reduces the risk of CHD is supported, and the association between long-term intake of total dietary fiber as well as fiber from different sources and risk ofCHD in women is examined.
Abstract: ContextEpidemiological studies of men suggest that dietary
fiber intake protects against coronary heart disease (CHD), but data on
this association in women are sparse.ObjectiveTo examine the association between long-term intake of
total dietary fiber as well as fiber from different sources and risk of
CHD in women.Design and SettingThe Nurses' Health Study, a large, prospective
cohort study of US women followed up for 10 years from 1984. Dietary
data were collected in 1984, 1986, and 1990, using a validated
semiquantitative food frequency questionnaire.ParticipantsA total of 68,782 women aged 37 to 64 years
without previously diagnosed angina, myocardial infarction (MI),
stroke, cancer, hypercholesterolemia, or diabetes at baseline.Main Outcome MeasureIncidence of acute MI or death due to CHD by
amount of fiber intake.ResultsResponse rate averaged 80% to 90% during the
10-year follow-up. We documented 591 major CHD events (429 nonfatal MIs
and 162 CHD deaths). The age-adjusted relative risk (RR) for major CHD
events was 0.53 (95% confidence interval [CI], 0.40-0.69) for women
in the highest quintile of total dietary fiber intake (median, 22.9
g/d) compared with women in the lowest quintile (median, 11.5 g/d).
After controlling for age, cardiovascular risk factors, dietary
factors, and multivitamin supplement use, the RR was 0.77 (95% CI,
0.57-1.04). For a 10-g/d increase in total fiber intake (the difference
between the lowest and highest quintiles), the multivariate RR of total
CHD events was 0.81 (95% CI, 0.66-0.99). Among different sources of
dietary fiber (eg, cereal, vegetables, fruit), only cereal fiber was
strongly associated with a reduced risk of CHD (multivariate RR, 0.63;
95% CI, 0.49-0.81 for each 5-g/d increase in cereal fiber).ConclusionsOur findings in women support the hypothesis that
higher fiber intake, particularly from cereal sources, reduces the risk
of CHD.
434 citations
TL;DR: The data provide support for the hypothesis that diabetes is associated with an increased risk of colorectal cancer in women and suggest that type 2 diabetes mellitus may increase the risk of this cancer.
Abstract: Background: The remarkable similarity of lifestyle and environmental risk factors f or t ype 2 ( non-insulindependent) diabetes mellitus and colon cancer has led to the hypothesis that diabetes may increase the risk of this cancer. We prospectively examined the relationship between diabetes and risk of colorectal cancer in a cohort of 118 403 women aged 30 through 55 years who were without previously diagnosed cancer at baseline in 1976. Methods: The women, who were enrolled in the Nurses’ Health Study, were assessed for history of diabetes at baseline and during follow-up by use of biennial questionnaires. Self-reported diabetes was validated by information obtained from a supplemental questionnaire on symptoms and treatment and was confirmed by medical record review in a sample of the participants. Incident cases of colorectal cancer were ascertained through medical record review. All reported P values are twosided. Results: During 18 years of follow-up (2 001 061 person-years), we documented 892 new cases of colorectal cancer. After adjustment for age, body mass index (weight in kg/height in m 2 ), physical activity, and other covariates, relative risks (RRs) were 1.43 (95% confidence interval [CI] = 1.10‐1.87; P = .009) for colorectal cancer, 1.49 (95% CI = 1.09‐2.06; P = .01) for colon cancer, 1.11 (95% CI = 0.56‐2.21; P = .76) for rectal cancer, 1.56 (95% CI = 1.07‐ 2.28; P = .02) for advanced colorectal cancer, and 2.39 (95% CI = 1.46‐3.92; P = .0005) for fatal colorectal cancer. Conclusion: Our data provide support for the hypothesis that diabetes is associated with an increased risk of colorectal cancer in women. [J Natl Cancer Inst 1999;91:542‐7]
TL;DR: Consumption of fruits and vegetables high in specific carotenoids and vitamins may reduce premenopausal breast cancer risk.
Abstract: Background: Data on intake of specific carotenoids and breast cancer risk are limited. Furthermore, studies of vitamins A, C, and E in relation to breast cancer risk are inconclusive. We have conducted a large, prospective study to evaluate long-term intakes of these nutrients and breast cancer risk. Methods: We examined, by use of multivariate analysis, associations between intakes of specific carotenoids, vitamins A, C, and E , consumption of fruits and vegetables, and breast cancer risk in a cohort of 83 234 women (aged 33‐60 years in 1980) who were participating in the Nurses’ Health Study. Through 1994, we identified 2697 incident cases of invasive breast cancer (784 premenopausal and 1913 postmenopausal). Results: Intakes of b-carotene from food and supplements, lutein/zeaxanthin, and vitamin A from foods were weakly inversely associated with breast cancer risk in premenopausal women. Strong inverse associations were found for increasing q uintiles o f a-carotene, b-carotene, lutein/zeaxanthin, total vitamin C from foods, and total vitamin A among premenopausal women with a positive family history of breast cancer. An inverse association was also found for increasing quintiles of b-carotene among premenopausal women who consumed 15 g or more of alcohol per day. Premenopausal women who consumed five or more servings per day of fruits and vegetables had modestly lower risk of breast cancer than those who had less than two servings per day (relative risk [RR] = 0.77; 95% confidence interval [CI] = 0.58‐1.02); this association was stronger among premenopausal women who had a positive family history of breast cancer (RR = 0.29; 95% CI = 0.13‐0.62) or those who consumed 15 g or more of alcohol per day (RR = 0.53; 95% CI = 0.27‐1.04). Conclusions: Consumption of fruits
TL;DR: No evidence was found that lower intake of total fat or specific major types of fat was associated with a decreased risk of breast cancer, and no significant association of risk was evident with any major type of fat.
Abstract: ContextHigh intakes of fat and specific fatty acids,
including total, animal, saturated, polyunsaturated, and
trans-unsaturated fats, have been postulated to increase
breast cancer risk.ObjectiveTo determine whether intakes of fat and fatty acids are
associated with breast cancer.Design and SettingCohort study (Nurses' Health Study) conducted
in the United States beginning in 1976.ParticipantsA total of 88,795 women free of cancer in
1980 and followed up for 14 years.Main Outcome MeasureRelative risk (RR) of invasive breast cancer
for an incremental increase of fat intake, ascertained by food
frequency questionnaire in 1980, 1984, 1986, and 1990.ResultsA total of 2956 women were diagnosed as having breast
cancer. Compared with women obtaining 30.1% to 35% of energy from
fat, women consuming 20% or less had a multivariate RR of breast
cancer of 1.15 (95% confidence interval [CI], 0.73-1.80). In
multivariate models, the RR (95% CI) for a 5%-of-energy increase was
0.97 (0.94-1.00) for total fat, 0.98 (0.96-1.01) for animal fat, 0.97
(0.93-1.02) for vegetable fat, 0.94 (0.88-1.01) for saturated fat, 0.91
(0.79-1.04) for polyunsaturated fat, and 0.94 (0.88-1.00) for
monounsaturated fat. For a 1% increase in energy from
trans-unsaturated fat, the values were 0.92 (0.86-0.98), and
for a 0.1% increase in energy from omega-3 fat from fish, the values
were 1.09 (1.03-1.16). In a model including fat, protein, and energy,
the RR for a 5% increase in total fat, which can be interpreted as the
risk of substituting this amount of fat for an equal amount of energy
from carbohydrate, was 0.96 (95% CI, 0.93-0.99). In similar models, no
significant association of risk was evident with any major types of
fat.ConclusionWe found no evidence that lower intake of total fat or
specific major types of fat was associated with a decreased risk of
breast cancer.
TL;DR: Low calcium intake, and perhaps low potassium intake, may contribute to increased risk of ischemic stroke in middle-aged American women.
Abstract: 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.
TL;DR: Prospective data suggest that higher plasma prolactin levels are associated with an increased risk of breast cancer in postmenopausal women.
Abstract: Background: In animal studies, prolactin has been found to be important for mammary epithelial development and its administration has been shown consistently to increase the rate of mammary tumor formation. Previous epidemiologic studies of prolactin and breast cancer risk in postmenopausal women have been limited in size, and the results have been inconsistent. We conducted a nested case‐control study within the prospective Nurses’ Health Study cohort to better determine the relationship between plasma prolactin levels and postmenopausal breast cancer risk. Methods: Blood samples were collected from cohort members during the period from 1989 through 1990. Prolactin levels were measured by use of a microparticle enzyme immunoassay. Included in this analysis were 306 postmenopausal women who were di
TL;DR: The prevalence of interstitial cystitis in the United States is more than 50% greater than previously reported and 3-fold greater than that reported in Europe.
TL;DR: Lutein and zeaxanthin and foods rich in these carotenoids may decrease the risk of cataracts severe enough to require extraction, and increasing frequency of intakes of spinach and kale, foodsrich in lutein, was associated with a moderate decrease in risk ofCataract.
TL;DR: Simulations show that the symmetric bi-directional case-crossover design can substantially control for temporal confounding by design although it is not as efficient (66%) as Poisson regression analysis.
Abstract: We assessed the impact of summertime haze episodes on twice daily peak flow measurements of children in Philadelphia, Pennsylvania. Height-adjusted peak flows were regressed on weather and air pollution concentrations. Lower morning peak flows were associated with exposure to inhalable particulate matter (-2.94 liters/minute/18 microg/m3, 95% confidence limits (CL) = -0.56, -5.33), and fine sulfate particles (-2.44 liters/minute/8 microg/m3, 95% CL = -0.36, -4.51). Particle-strong acidity and the coarse particle mass were weakly associated with lower peak flow. Acutely lower peak flows in children were associated with fine sulfate particles, but only weakly with the acidity of the fine particles.
Journal Article•
TL;DR: It is suggested that the A2 allele of CYP17 modifies endogenous hormone levels, but is not a strong independent risk factor for breast cancer.
Abstract: The A2 allele of CYP17 has been associated with polycystic ovarian syndrome, elevated levels of certain steroid hormones in premenopausal women, and increased breast cancer risk. We prospectively assessed the association between the A2 allele of CYP17 and breast cancer risk in a case-control study nested within the Nurses' Health Study cohort. We also evaluated associations between this CYP17 genotype and plasma steroid hormone levels among postmenopausal controls not using hormone replacement to assess the biological significance of this genetic variant. Women with the A2 allele were not at an increased risk of incident breast cancer [OR (odds ratio), 0.85; 95% CI (confidence interval), 0.65-1.12] or advanced breast cancer (OR, 0.84; 95% CI, 0.54-1.32). We did observe evidence that the inverse association of late age at menarche with breast cancer may be modified by the CYP17 A2 allele. The protective effect of later age at menarche was only observed among women without the A2 allele (A1/A1 genotype: for age at menarche > or =13 versus <13; OR, 0.57; 95% CI, 0.36-0.90; A1/A2 and A2/A2 genotypes: OR, 1.05; 95% CI, 0.76-1.45; P for interaction = 0.07). Among controls, we found women with the A2/A2 genotype to have elevated levels of estrone (+14.3%, P = 0.01), estradiol (+13.8%, P = 0.08), testosterone (+8.6%, P = 0.34), androstenedione (+17.1%, P = 0.06), dehydroepiandrosterone (+14.4%, P = 0.02), and dehydroepiandrosterone sulfate (+7.2%, P = 0.26) compared with women with the A1/A1 genotype. These data suggest that the A2 allele of CYP17 modifies endogenous hormone levels, but is not a strong independent risk factor for breast cancer.
TL;DR: It is suggested that greater waist circumference increases risk of breast cancer, especially among postmenopausal women who are otherwise at lower risk because of never having used estrogen replacement hormones.
Abstract: This study examined prospectively the associations of waist circumference and waist:hip circumference ratio with risk of breast cancer. A total of 47,382 US registered nurses who reported their waist and hip circumferences in 1986 were followed up through May 1994 for identification of incident cases of breast cancer. During 333,097 person-years of follow-up, 1,037 invasive breast cancers were diagnosed. In proportional hazards analyses, waist circumference was nonsignificantly related to risk of premenopausal breast cancer but was significantly associated with postmenopausal breast cancer after adjustment for established breast cancer risk factors (for the highest quintile of waist circumference vs. the lowest, relative risk (RR) = 1.34; 95% confidence interval (CI): 1.05, 1.72). When the analysis was limited to postmenopausal women who had never received hormone replacement therapy, a stronger positive association was found (RR = 1.88; 95% CI: 1.25, 2.85). After the data were further controlled for body mass index, the positive association was only slightly attenuated (RR = 1.83; 95% CI: 1.12, 2.99). Among past and current postmenopausal hormone users, no significant associations were found. Similar but slightly weaker associations were observed between waist:hip ratio and breast cancer risk. These data suggest that greater waist circumference increases risk of breast cancer, especially among postmenopausal women who are otherwise at lower risk because of never having used estrogen replacement hormones.
TL;DR: The 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.
TL;DR: A high intake of vitamin B6 was inversely associated with risk of kidney stone formation, and routine restriction of vitamin C to prevent stone formation appears unwarranted.
Abstract: Urinary oxalate is an important determinant of calcium oxalate kidney stone formation. High doses of vitamin B6 may decrease oxalate production, whereas vitamin C can be metabolized to oxalate. This study was conducted to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. The relation between the intake of vitamins B6 and C and the risk of symptomatic kidney stones were prospectively studied in a cohort of 85,557 women with no history of kidney stones. Semiquantitative food-frequency questionnaires were used to assess vitamin consumption from both foods and supplements. A total of 1078 incident cases of kidney stones was documented during the 14-yr follow-up period. A high intake of vitamin B6 was inversely associated with risk of stone formation. After adjusting for other dietary factors, the relative risk of incident stone formation for women in the highest category of B6 intake (> or =40 mg/d) compared with the lowest category ( or =1500 mg/d) compared with the lowest category (<250 mg/d) was 1.06 (95% confidence interval, 0.69 to 1.64). Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted.
TL;DR: Higher vegetable consumption, particularly of carrots, may significantly reduce the risk of lung cancer, but dietary modification cannot be considered a substitute for smoking prevention and cessation.
Abstract: Background: Although substantial evidence suggests that higher intake of fruits and vegetables can reduce the adverse impact of smoking on lung cancer risk, great uncertainty exists regarding the specific foods and their constituents that are protective. We therefore examine prospectively the relation between cigarette smoking and lung cancer incidence among women, and quantify the associations between dietary antioxidants, other nutrients, and lung cancer risk.
TL;DR: It is suggested that snoring may increase risk of hypertension in women, independent of age, body mass index, waist circumference, and other lifestyle factors.
Abstract: Whether snoring increases the risk of hypertension remains unclear The authors examined the association between snoring and risk of hypertension in a cohort of 73,231 US female nurses aged 40-65 years and without diagnosed cardiovascular disease or cancer in 1986 Blood pressure levels and physician-diagnosed hypertension were self-reported through validated questionnaires During 8 years of follow-up, 7,622 incident cases of physician-diagnosed hypertension were reported Older age, smoking, body mass index, waist circumference, waist-hip ratio, weight gain, less physical activity, and sleeping on the back were directly associated with regular snoring After adjustment for age, body mass index, waist circumference, and other covariates, snoring was associated with a significantly higher prevalence of hypertension at baseline (odds ratio = 122, 95% confidence interval (CI): 116, 127 for occasional snoring and odds ratio = 143, 95% CI: 133, 15 for regular snoring) In prospective analyses using incident cases of hypertension as the outcome, the multivariate relative risks of hypertension were 129 (95% CI: 122, 137) for occasional snoring and 155 (95% CI: 142, 170) for regular snoring In addition, snoring was associated with significantly higher systolic and diastolic blood pressure levels These data suggest that snoring may increase risk of hypertension in women, independent of age, body mass index, waist circumference, and other lifestyle factors
TL;DR: Greater dietary intake of certain meats and fats was associated with a higher risk of non-Hodgkin's lymphoma and their potential mechanisms deserve further examination.
Abstract: Background: Non-Hodgkin's lymphoma occurs more frequently in individuals with suppressed immune status, and some types of dietary fat and protein have been associated with decreased immune responses. In this study, we examined the intake of specific types of dietary fat and protein in relation to the risk of non-Hodgkin's lymphoma. Methods: We documented 199 incident cases of non-Hodgkin's lymphoma in a cohort of 88 410 women, who were enrolled in the Nurses' Health Study and were aged 34-60 years in 1980, during 14 years of follow-up. Relative risks of the disease and 95% confidence intervals (95% CIs) were calculated. All P values are two-sided and were considered to be statistically significant for P<.05. Results: Intake of saturated fat was associated with an increase in risk that was not statistically significant; the multivariate relative risk for the highest versus the lowest quintiles of intake was 1.4 (95% CI = 0.7-3.0; P for trend = .42). Intake of beef, pork, or lamb as a main dish was associated with a statistically significantly increased risk of non-Hodgkin's lymphoma; the multivariate relative risk for consumption of these meats at least once per day as compared with less than once per week was 2.2 (95% Cl = 1.1-4.4; P for trend =.002). Higher intake of trans unsaturated fat was also statistically significantly associated with an increased risk of the disease; the multivariate relative risk for the highest versus the lowest quintiles was 2.4 (95% CI = 1.3-4.6; P for trend =.01). Higher intake of red meat cooked by broiling or barbecuing-but not by roasting, pan-frying, or boiling or stewing-was associated with an increase in risk that was not statistically significant. Conclusions: Greater dietary intake of certain meats and fats was associated with a higher risk of non-Hodgkin's Iymphoma These relationships and their potentia mechanisms deserve further examination.
TL;DR: Findings support a potentially important role for low-level lead exposure as a risk factor for hypertension among non-occupationally exposed women.
Abstract: OBJECTIVES: The role of lead exposure as a risk factor for hypertension is less well defined among women than among men. This case-control study assessed the relation of blood and bone lead concentrations to hypertension in women. METHODS: Cases and controls were a subsample of women from the Nurses' Health Study. Hypertension was defined as a physician diagnosis of hypertension between 1988 and 1994 or measured systolic blood pressure > or = 140 mm Hg or diastolic blood pressure > or = 90 mm Hg. RESULTS: Mean (SD) blood lead concentration was 0.15 (0.11) mumol/L; mean tibia and patella lead concentrations by K-x-ray fluorescence were 13.3 (9.0) and 17.3 (11.1) micrograms/g, respectively. After adjustment for potentially confounding factors, an increase from the 10th to the 90th percentile of patella lead values (25 micrograms/g) was associated with approximately 2-fold (95% confidence interval = 1.1, 3.2) increased risk of hypertension. There was no association between hypertension and either blood or ti...
TL;DR: The data provide evidence against a substantially increased risk of breast cancer associated with GSTM1 and/or GSTT1 homozygous gene deletions and breast cancer risk was not substantially modified by cigarette smoking.
Abstract: Background: The enzymes encoded by the glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism (mainly inactivation, but activation is possible) of a wide range of carcinogens that are ubiquitous in the environment; the enzyme encoded by the GSTT1 gene may also be active in endogenous mutagenic processes. Homozygous deletions of the GSTM1 and GSTT1 genes are commonly found in the population and result in a lack of enzyme activity. This study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and breast cancer risk. Methods: Our study included 466 women with incident cases of breast cancer occurring from May 1989 through May 1994 and 466 matched control subjects. These individuals were part of a prospective cohort of U.S. women (i.e., the Nurses' Health Study). Odds ratios (ORs) and 95% confidence intervals (CIs) from conditional logistic regression models were used to estimate the association between genetic polymorphisms and breast cancer risk. Results: The GSTM1 and GSTT1 null genotypes were not associated with an increased risk of breast cancer (OR = 1.05 [95% CI = 0.80-1.37] for GSTM1 null; OR = 0.86 [95% CI = 0.61-1.21] for GSTT1 null). On the contrary, a suggestion of a decreased risk of breast cancer associated with the GSTT1 null genotype was observed among premenopausal women. When considered together, no combination of the GSTM1 and GSTT1 genotypes was associated with an increased risk of breast cancer. The relationship between GSTM1 and GSTT1 gene deletions and breast cancer risk was not substantially modified by cigarette smoking. Conclusions: Our data provide evidence against a substantially increased risk of breast cancer associated with GSTM1 and/or GSTT1 homozygous gene deletions.
TL;DR: It is indicated 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 aspirinper week have an increased risk of subarachnoid hemorrhage.
Abstract: 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...
TL;DR: Risk of premenopausal melanoma may be increased among women who are current OC users, particularly among those with longer durations of use.
Abstract: Melanoma has been increasing in white populations. Incidence rates rise steeply in women until about age 50, suggesting oestrogen as a possible risk factor. Oestrogens can increase melanocyte count and melanin content and cause hyperpigmentation of the skin. We examined prospectively the association between oral contraceptive (OC) use and diagnoses of superficial spreading and nodular melanoma among 183 693 premenopausal white women in the Nurses’ Health Study (NHS) and the Nurses’ Health Study II (NHS II) cohorts. One hundred and forty six cases were confirmed in NHS during follow-up from 1976 to 1994, and 106 cases were confirmed in NHS II from 1989 to 1995. Skin reaction to sun exposure, sunburn history, mole counts, hair colour, family history of melanoma, parity, height and body mass index were also assessed and included in logistic regression models. A significant twofold increase in risk of melanoma (relative risk (RR) = 2.0, 95% confidence interval (CI) 1.2–3.4) was observed among current OC users compared to never users. Risk was further increased among current users with 10 or more years of use (RR = 3.4, 95% CI 1.7–7.0). Risk did not appear elevated among past OC users, even among those with longer durations of use, and risk did not decline linearly with time since last use. In conclusion, risk of premenopausal melanoma may be increased among women who are current OC users, particularly among those with longer durations of use. Further research is needed to determine whether low-dose oestrogen pills in particular are associated with an increase in risk and to describe possible interactions between OC use and sun exposure or other risk factors for melanoma. © 1999 Cancer Research Campaign
TL;DR: No increased frequency of any immunologic abnormalities in women exposed to silicone breast implants, except for anti-ssDNA, which has unknown clinical relevance.