Adolescent endogenous sex hormones and breast density in early adulthood.

INTRODUCTION: During adolescence the breasts undergo rapid growth and development under the influence of sex hormones. Although the hormonal etiology of breast cancer is hypothesized, it remains unknown whether adolescent sex hormones are associated with adult breast density, which is a strong risk factor for breast cancer. METHODS: Percentage of dense breast volume (%DBV) was measured in 2006 by magnetic resonance imaging in 177 women aged 25-29 years who had participated in the Dietary Intervention Study in Children from 1988 to 1997. They had sex hormones and sex hormone-binding globulin (SHBG) measured in serum collected on one to five occasions between 8 and 17 years of age. Multivariable linear mixed-effect regression models were used to evaluate the associations of adolescent sex hormones and SHBG with %DBV. RESULTS: Dehydroepiandrosterone sulfate (DHEAS) and SHBG measured in premenarche serum samples were significantly positively associated with %DBV (all P trend ≤0.03) but not when measured in postmenarche samples (all P trend ≥0.42). The multivariable geometric mean of %DBV across quartiles of premenarcheal DHEAS and SHBG increased from 16.7 to 22.1 % and from 14.1 to 24.3 %, respectively. Estrogens, progesterone, androstenedione, and testosterone in pre- or postmenarche serum samples were not associated with %DBV (all P trend ≥0.16). CONCLUSIONS: Our results suggest that higher premenarcheal DHEAS and SHBG levels are associated with higher %DBV in young women. Whether this association translates into an increased risk of breast cancer later in life is currently unknown. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier, NCT00458588 April 9, 2007; NCT00000459 October 27, 1999.

Menstrual and reproductive characteristics and breast density in young women.

PURPOSE: Breast density is strongly related to breast cancer risk, but determinants of breast density in young women remain largely unknown. METHODS: Associations of reproductive and menstrual characteristics with breast density measured by magnetic resonance imaging were evaluated in a cross-sectional study of 176 healthy women, 25-29 years old, using linear mixed effects models. RESULTS: Parity was significantly inversely associated with breast density. In multivariable adjusted models that included non-reproductive variables, mean percent dense breast volume (%DBV) decreased from 20.5 % in nulliparous women to 16.0 % in parous women, while mean absolute dense breast volume (ADBV) decreased from 85.3 to 62.5 cm(3). Breast density also was significantly inversely associated with the age women started using hormonal contraceptives, whereas it was significantly positively associated with duration of hormonal contraceptive use. In adjusted models, mean %DBV decreased from 21.7 % in women who started using hormones at 12-17 years of age to 14.7 % in those who started using hormones at 22-28 years of age, while mean ADBV decreased from 86.2 to 53.7 cm(3). The age at which women started using hormonal contraceptives and duration of hormone use were inversely correlated, and mean %DBV increased from 15.8 % in women who used hormones for not more than 2.0 years to 22.0 % in women who used hormones for more than 8 years, while mean ADBV increased from 61.9 to 90.4 cm(3) over this interval. CONCLUSIONS: Breast density in young women is inversely associated with parity and the age women started using hormonal contraceptives but positively associated with duration of hormone use.

Height, adiposity and body fat distribution and breast density in young women.

INTRODUCTION: Breast density is one of the strongest risk factors for breast cancer, but determinants of breast density in young women remain largely unknown. METHODS: Associations of height, adiposity and body fat distribution with percentage dense breast volume (%DBV) and absolute dense breast volume (ADBV) were evaluated in a cross-sectional study of 174 healthy women, 25 to 29 years old. Adiposity and body fat distribution were measured by anthropometry and dual-energy X-ray absorptiometry (DXA), while %DBV and ADBV were measured by magnetic resonance imaging. Associations were evaluated using linear mixed-effects models. All tests of statistical significance are two-sided. RESULTS: Height was significantly positively associated with %DBV but not ADBV; for each standard deviation (SD) increase in height, %DBV increased by 18.7% in adjusted models. In contrast, all measures of adiposity and body fat distribution were significantly inversely associated with %DBV; a SD increase in body mass index (BMI), percentage fat mass, waist circumference and the android:gynoid fat mass ratio (A:G ratio) was each associated significantly with a 44.4 to 47.0% decrease in %DBV after adjustment for childhood BMI and other covariates. Although associations were weaker than for %DBV, all measures of adiposity and body fat distribution also were significantly inversely associated with ADBV before adjustment for childhood BMI. After adjustment for childhood BMI, however, only the DXA measures of percentage fat mass and A:G ratio remained significant; a SD increase in each was associated with a 13.8 to 19.6% decrease in ADBV. In mutually adjusted analysis, the percentage fat mass and the A:G ratio remained significantly inversely associated with %DBV, but only the A:G ratio was significantly associated with ADBV; a SD increase in the A:G ratio was associated with an 18.5% decrease in ADBV. CONCLUSION: Total adiposity and body fat distribution are independently inversely associated with %DBV, whereas in mutually adjusted analysis only body fat distribution (A:G ratio) remained significantly inversely associated with ADBV in young women. Research is needed to identify biological mechanisms underlying these associations.

Evaluation of risk equations for prediction of short-term coronary heart disease events in patients with long-standing type 2 diabetes: the Translating Research into Action for Diabetes (TRIAD) study.

BACKGROUND: To evaluate the U.K. Prospective Diabetes Study (UKPDS) and Framingham risk equations for predicting short-term risk of coronary heart disease (CHD) events among adults with long-standing type 2 diabetes, including those with and without preexisting CHD. METHODS: Prospective cohort of U.S. managed care enrollees aged ≥ 18 years and mean diabetes duration of more than 10 years, participating in the Translating Research into Action for Diabetes (TRIAD) study, was followed for the first occurrence of CHD events from 2000 to 2003. The UKPDS and Framingham risk equations were evaluated for discriminating power and calibration. RESULTS: A total of 8303 TRIAD participants, were identified to evaluate the UKPDS (n = 5914, 120 events), Framingham-initial (n = 5914, 218 events) and Framingham-secondary (n = 2389, 374 events) risk equations, according to their prior CHD history. All of these equations exhibited low discriminating power with Harrell's c-index <0.65. All except the Framingham-initial equation for women and the Framingham-secondary equation for men had low levels of calibration. After adjsusting for the average values of predictors and event rates in the TRIAD population, the calibration of these equations greatly improved. CONCLUSIONS: The UKPDS and Framingham risk equations may be inappropriate for predicting the short-term risk of CHD events in patients with long-standing type 2 diabetes, partly due to changes in medications used by patients with diabetes and other improvements in clinical care since the Frmaingham and UKPDS studies were conducted. Refinement of these equations to reflect contemporary CHD profiles, diagnostics and therapies are needed to provide reliable risk estimates to inform effective treatment.

Thiazolidinediones, cardiovascular disease and cardiovascular mortality: translating research into action for diabetes (TRIAD).

BACKGROUND: Studies have associated thiazolidinedione (TZD) treatment with cardiovascular disease (CVD) and questioned whether the two available TZDs, rosiglitazone and pioglitazone, have different CVD risks. We compared CVD incidence, cardiovascular (CV), and all-cause mortality in type 2 diabetic patients treated with rosiglitazone or pioglitazone as their only TZD. METHODS: We analyzed survey, medical record, administrative, and National Death Index (NDI) data from 1999 through 2003 from Translating Research Into Action for Diabetes (TRIAD), a prospective observational study of diabetes care in managed care. Medications, CV procedures, and CVD were determined from health plan (HP) administrative data, and mortality was from NDI. Adjusted hazard rates (AHR) were derived from Cox proportional hazard models adjusted for age, sex, race/ethnicity, income, history of diabetic nephropathy, history of CVD, insulin use, and HP. RESULTS: Across TRIAD's 10 HPs, 1,815 patients (24%) filled prescriptions for a TZD, 773 (10%) for only rosiglitazone, 711 (10%) for only pioglitazone, and 331 (4%) for multiple TZDs. In the seven HPs using both TZDs, 1,159 patients (33%) filled a prescription for a TZD, 564 (16%) for only rosiglitazone, 334 (10%) for only pioglitazone, and 261 (7%) for multiple TZDs. For all CV events, CV, and all-cause mortality, we found no significant difference between rosiglitazone and pioglitazone. CONCLUSIONS: In this relatively small, prospective, observational study, we found no statistically significant differences in CV outcomes for rosiglitazone- compared to pioglitazone-treated patients. There does not appear to be a pattern of clinically meaningful differences in CV outcomes for rosiglitazone- versus pioglitazone-treated patients.

Calcium plus vitamin D supplementation and the risk of fractures.

BACKGROUND: The efficacy of calcium with vitamin D supplementation for preventing hip and other fractures in healthy postmenopausal women remains equivocal. METHODS: We recruited 36,282 postmenopausal women, 50 to 79 years of age, who were already enrolled in a Women's Health Initiative (WHI) clinical trial. We randomly assigned participants to receive 1000 mg of elemental [corrected] calcium as calcium carbonate with 400 IU of vitamin D3 daily or placebo. Fractures were ascertained for an average follow-up period of 7.0 years. Bone density was measured at three WHI centers. RESULTS: Hip bone density was 1.06 percent higher in the calcium plus vitamin D group than in the placebo group (P<0.01). Intention-to-treat analysis indicated that participants receiving calcium plus vitamin D supplementation had a hazard ratio of 0.88 for hip fracture (95 percent confidence interval, 0.72 to 1.08), 0.90 for clinical spine fracture (0.74 to 1.10), and 0.96 for total fractures (0.91 to 1.02). The risk of renal calculi increased with calcium plus vitamin D (hazard ratio, 1.17; 95 percent confidence interval, 1.02 to 1.34). Censoring data from women when they ceased to adhere to the study medication reduced the hazard ratio for hip fracture to 0.71 (95 percent confidence interval, 0.52 to 0.97). Effects did not vary significantly according to prerandomization serum vitamin D levels. CONCLUSIONS: Among healthy postmenopausal women, calcium with vitamin D supplementation resulted in a small but significant improvement in hip bone density, did not significantly reduce hip fracture, and increased the risk of kidney stones. (ClinicalTrials.gov number, NCT00000611.).

Calcium plus vitamin D supplementation and the risk of colorectal cancer.

BACKGROUND: Higher intake of calcium and vitamin D has been associated with a reduced risk of colorectal cancer in epidemiologic studies and polyp recurrence in polyp-prevention trials. However, randomized-trial evidence that calcium with vitamin D supplementation is beneficial in the primary prevention of colorectal cancer is lacking. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 36,282 postmenopausal women from 40 Women's Health Initiative centers: 18,176 women received 500 mg of elemental calcium as calcium carbonate with 200 IU of vitamin D3 [corrected] twice daily (1000 mg of elemental calcium and 400 IU of vitamin D3) and 18,106 received a matching placebo for an average of 7.0 years. The incidence of pathologically confirmed colorectal cancer was the designated secondary outcome. Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case-control study. RESULTS: The incidence of invasive colorectal cancer did not differ significantly between women assigned to calcium plus vitamin D supplementation and those assigned to placebo (168 and 154 cases; hazard ratio, 1.08; 95 percent confidence interval, 0.86 to 1.34; P=0.51), and the tumor characteristics were similar in the two groups. The frequency of colorectal-cancer screening and abdominal symptoms was similar in the two groups. There were no significant treatment interactions with baseline characteristics. CONCLUSIONS: Daily supplementation of calcium with vitamin D for seven years had no effect on the incidence of colorectal cancer among postmenopausal women. The long latency associated with the development of colorectal cancer, along with the seven-year duration of the trial, may have contributed to this null finding. Ongoing follow-up will assess the longer-term effect of this intervention. (ClinicalTrials.gov number, NCT00000611.).

Estrogen plus progestin and risk of benign proliferative breast disease.

Women with benign proliferative breast disease are at increased risk of subsequent breast cancer. Estrogens and progesterone exert proliferative effects on mammary epithelium, and combined hormone replacement therapy has been associated with increased breast cancer risk. We tested the effect of conjugated equine estrogen plus progestin on the risk of benign proliferative breast disease in the Women's Health Initiative (WHI) randomized controlled trial. In the WHI trial of estrogen plus progestin, 16,608 postmenopausal women were randomly assigned either to 0.625 mg/day of conjugated equine estrogen plus 2.5 mg/day of medroxyprogesterone acetate or to placebo. Baseline and annual breast exams and mammograms were required. The trial was terminated early (average follow-up, 5.5 years). We identified women who had had a biopsy for benign breast disease, and subjected histologic sections from the biopsies to standardized review. Overall, 178 incident cases of benign proliferative breast disease were ascertained in the estrogen plus progestin group and 99 in the placebo group. The use of estrogen plus progestin was associated with a 74% increase in the risk of benign proliferative breast disease [hazard ratio, 1.74; 95% confidence interval (CI), 1.35-2.25]. For benign proliferative breast disease without atypia the hazard ratio was 2.00 (95% CI, 1.50-2.66), while for atypical hyperplasia it was 0.76 (95% CI, 0.38-1.52). The risk varied little by levels of baseline characteristics. The results of this study suggest that the use of estrogen plus progestin may increase the risk of benign proliferative breast disease.

Usefulness of baseline lipids and C-reactive protein in women receiving menopausal hormone therapy as predictors of treatment-related coronary events.

Blood lipids and high-sensitivity C-reactive protein (hs-CRP) are altered by hormone therapy. The goal of the present study was to determine whether lipids and hs-CRP have predictive value for hormone therapy benefit or risk for coronary heart disease events in postmenopausal women without previous cardiovascular disease. A nested case-control study was performed in the Women's Health Initiative hormone trials. Baseline lipids and hs-CRP were obtained from 271 incident patients with coronary heart disease (cases) and 707 controls. In a combined trial analysis, favorable lipid status at baseline tended to predict better coronary heart disease outcomes when using conjugated equine estrogen (CEE) with or without medroxyprogesterone acetate (MPA). Women with a low-density lipoprotein (LDL)/high-density lipoprotein (HDL) cholesterol ratio <2.5 had no increase in risk of coronary heart disease when using CEE with or without MPA (odds ratio 0.60, 95% confidence interval 0.34 to 1.06), whereas women with an LDL/HDL cholesterol ratio > or =2.5 had increased risk of coronary heart disease (odds ratio 1.73, 95% confidence interval 1.18 to 2.53, p for interaction = 0.02). Low hs-CRP added marginally to the value of LDL/HDL ratio <2.5 when predicting coronary heart disease benefit on hormone therapy. In conclusion, postmenopausal women with undesirable lipid levels had excess coronary heart disease risk when using CEE with or without MPA. However, women with favorable lipid levels, especially LDL/HDL cholesterol ratio <2.5, did not have increased risk of coronary heart disease with CEE with or without MPA irrespective of hs-CRP.

Estrogen plus progestin and the risk of coronary heart disease.

BACKGROUND: Recent randomized clinical trials have suggested that estrogen plus progestin does not confer cardiac protection and may increase the risk of coronary heart disease (CHD). In this report, we provide the final results with regard to estrogen plus progestin and CHD from the Women's Health Initiative (WHI). METHODS: The WHI included a randomized primary-prevention trial of estrogen plus progestin in 16,608 postmenopausal women who were 50 to 79 years of age at base line. Participants were randomly assigned to receive conjugated equine estrogens (0.625 mg per day) plus medroxyprogesterone acetate (2.5 mg per day) or placebo. The primary efficacy outcome of the trial was CHD (nonfatal myocardial infarction or death due to CHD). RESULTS: After a mean follow-up of 5.2 years (planned duration, 8.5 years), the data and safety monitoring board recommended terminating the estrogen-plus-progestin trial because the overall risks exceeded the benefits. Combined hormone therapy was associated with a hazard ratio for CHD of 1.24 (nominal 95 percent confidence interval, 1.00 to 1.54; 95 percent confidence interval after adjustment for sequential monitoring, 0.97 to 1.60). The elevation in risk was most apparent at one year (hazard ratio, 1.81 [95 percent confidence interval, 1.09 to 3.01]). Although higher base-line levels of low-density lipoprotein cholesterol were associated with an excess risk of CHD among women who received hormone therapy, higher base-line levels of C-reactive protein, other biomarkers, and other clinical characteristics did not significantly modify the treatment-related risk of CHD. CONCLUSIONS: Estrogen plus progestin does not confer cardiac protection and may increase the risk of CHD among generally healthy postmenopausal women, especially during the first year after the initiation of hormone use. This treatment should not be prescribed for the prevention of cardiovascular disease.

Risk of cardiovascular disease by hysterectomy status, with and without oophorectomy: the Women's Health Initiative Observational Study.

BACKGROUND: Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in women and may vary by hysterectomy (or oophorectomy) status. This study compared CVD risk factors and rates between postmenopausal women who had and had not undergone hysterectomy, with or without oophorectomy. METHODS AND RESULTS: This analysis was conducted on 89 914 women in the Women's Health Initiative (WHI) Observational Study. Participants reported demographic characteristics, medical history, dietary habits, physical activity, medications, and previous hysterectomy (with or without oophorectomy). Baseline weight, height, waist circumference, and blood pressure were measured. CVD events were ascertained during 5.1 years of mean follow-up and adjudicated with standard criteria. Black, Hispanic, and American Indian women had higher rates of hysterectomy than white women (52.9%, 44.6%, and 49.2% versus 40.0%, respectively), and Asian/Pacific Islander women had lower rates (33.8%). Women with a hysterectomy (regardless of oophorectomy status) had an adverse risk profile at baseline compared with women with no hysterectomy, including a higher proportion of hypertension, diabetes, high cholesterol, obesity, and lower education, income, and physical activity (all P<0.01). Total mortality and fatal and nonfatal CVD were higher among women with a hysterectomy. Hysterectomy (regardless of oophorectomy status) was a significant predictor of CVD (HR: 1.26, P<0.001). After adjustment for demographic variables and CVD risk factors, the effect was reduced and nonsignificant. CONCLUSIONS: Women with a hysterectomy had a worse risk profile and higher prevalence and incidence of CVD in this cohort. Multivariate models suggest that hysterectomy is not the major determinant of this outcome; rather, CVD risk may be due to the more adverse initial risk profile of women who had undergone hysterectomy.

Diet and sex hormones in boys: findings from the dietary intervention study in children.

CONTEXT: Diet reportedly alters serum sex hormone concentrations in adults, but little is known about the influence of diet during puberty on these hormones. OBJECTIVE: We aimed to determine whether an intervention to lower fat intake during adolescence alters serum sex hormone concentrations and progression through puberty. DESIGN: In 1990-1997, we conducted an ancillary study to the Dietary Intervention Study in Children, a multicenter, randomized, controlled clinical trial to test the safety and efficacy of a cholesterol-lowering dietary intervention in children. PARTICIPANTS: Healthy, prepubertal, 8 to 10 yr olds with elevated low-density lipoprotein cholesterol were randomized to usual care or a behavioral intervention. Of 362 randomized Dietary Intervention Study in Children boys, 354 participated in the ancillary study. Eighty-four percent of boys attended last visits when their median time on trial was 7.1 yr. INTERVENTION: The behavioral intervention continued throughout the duration of the trial and promoted a diet with 28% energy from total fat, less than 8% from saturated fat, 9% or less from polyunsaturated fat, and less than 75 mg cholesterol per 1000 kcal. OUTCOME MEASURES: The main outcome measure for boys formulated before study initiation was non-SHBG bound testosterone concentration. Secondary outcomes included serum total testosterone, dihydrotestosterone, androstenedione, estradiol, estrone, SHBG, and Tanner stage. RESULTS: There were no significant treatment group differences in boys' serum hormone levels, SHBG, or Tanner stages at any individual visit or over the course of the trial when evaluated by longitudinal models. CONCLUSION: Modest reductions in total fat, saturated fat, and possibly energy intake do not alter progression through puberty or serum sex hormone concentrations in adolescent boys.

Prevalence and determinants of electrocardiographic left ventricular hypertrophy among a multiethnic population of postmenopausal women (The Women's Health Initiative).

Our objectives were to determine the prevalence and factors related to left ventricular hypertrophy (LVH) among older women for commonly used electrocardiographic criteria. LVH is a potent risk factor for cardiovascular disease, especially among women. However, its value has been limited, in part, by the use of different electrocardiographic criteria and the lack of a clearly defined standard for the general population. A total of 3,613 eligible women, aged 50 to 79 years, underwent medical history, physical measurements, and biochemical determinations and had behavioral factors recorded at baseline. Three LVH indexes were derived from computer measurement of the electrocardiogram: hypertrophied left ventricular mass > or =171.04 g (HLVM); Cornell voltage > or =2,200 microV; and Minnesota Code items. The prevalence of LVH ranged from <1% to 13% when stratified by age, ethnicity, and scoring technique. Baseline traits differed significantly for those meeting the LVH criteria. Predictors (p <0.01) of HLVM were age (odds ratio 0.66), height (odds ratio 1.47), waist/hip ratio (odds ratio 1.30), systolic blood pressure (odds ratio 1.18); low-density lipoprotein cholesterol (odds ratio 0.97), log insulin (odds ratio 2.10), dietary kilocalories (odds ratio 1.16), weekly energy expenditure (odds ratio 0.53), hypertension (odds ratio 1.61), current estrogen use (odds ratio 0.60), and current smoker (odds ratio 0.47). The presence of the metabolic syndrome was related to all LVH indexes, with odds ratios of 4.95, 2.24, and 2.35, respectively, for HLVM, Cornell voltage, and Minnesota Code. In conclusion, the prevalence of LVH varied by ethnicity and the electrocardiographic index used. However, the baseline traits, especially the factors associated with the metabolic syndrome, were consistently and strongly related to all LVH indexes, particularly HLVM. Intervention on these factors may provide strategies for reducing LVH, a strong independent risk factor for cardiovascular morbidity and mortality among women.

Prior hormone therapy and breast cancer risk in the Women's Health Initiative randomized trial of estrogen plus progestin.

OBJECTIVES: To assess the extent to which prior hormone therapy modifies the breast cancer risk found with estrogen plus progestin (E+P) in the Women's Health Initiative (WHI) randomized trial. METHODS: Subgroup analyses of prior hormone use on invasive breast cancer incidence in 16,608 postmenopausal women in the WHI randomized trial of E+P over an average 5.6 years of follow-up. RESULTS: Small but statistically significant differences were found between prior HT users and non-users for most breast cancer risk factors but Gail risk scores were similar. Duration of E+P use within the trial (mean 4.4 years, S.D. 2.0) did not vary by prior use. Among 4311 prior users, the adjusted hazard ratio (HR) for E+P versus placebo was 1.96 (95% confidence interval [CI]: 1.17-3.27), significantly different (p=0.03) from that among 12,297 never users (HR 1.02; 95% CI: 0.77-1.36). The interaction between study arm and follow-up time was significant overall (p=0.01) and among never users (p=0.02) but not among prior users (p=0.10). The cumulative incidence over time for the E+P and placebo groups appeared to cross after about 3 years in prior users, and after about 5 years in women with no prior use. No interaction was found with duration (p=0.08) or recency of prior use (p=0.17). Prior hormone use significantly increased the E+P hazard ratio for larger, more advanced tumors. CONCLUSION: A safe interval for combined hormone use could not be reliably defined with these data. However, the significant increase in breast cancer risk in the trial overall after only 5.6 years of follow-up, initially concentrated in women with prior hormone exposure, but with increasing risk over time in women without prior exposure, suggests that durations only slightly longer than those in the WHI trial are associated with increased risk of breast cancer. Longer-term exposure and follow-up data are needed.

Application of national screening criteria for blood pressure and cholesterol to perimenopausal women: prevalence of hypertension and hypercholesterolemia in the Study of Women's Health Across the Nation.

National screening guidelines for hypertension and cholesterol were applied to the multiethnic sample of perimenopausal women (N = 1349) in the Study of Women's Health Across the Nation (SWAN). To reduce low-density lipoprotein, lifestyle modification was indicated in 9.5% of patients and drug therapy in 5%. Chinese and Japanese women were least likely and African Americans were most likely to require interventions. Among all women, 27% were prehypertensive, 23% were hypertensive (blood pressure >140/90 mm Hg or treated), and 9.1% were untreated hypertensive. Untreated hypertension was lowest among Japanese and Chinese and highest among Hispanic and African-American women. Among all hypertensives, 60.5% were treated and only 58.5% of those treated were controlled. Control rates were lowest among African Americans and Hispanics. In this relatively low-risk population, a significant proportion of women with hypertension or hypercholesterolemia were either not treated, not treated adequately, or had borderline risk factors that would benefit from lifestyle interventions to prevent the need for future drug treatment.

Diet and sex hormones in girls: findings from a randomized controlled clinical trial.

BACKGROUND: Results of several studies have suggested that diet during adolescence may influence the risk of breast cancer in adulthood. We evaluated whether an intervention to lower fat intake among adolescent girls altered their serum concentrations of sex hormones that, in adults, are related to breast cancer development. METHODS: We conducted an ancillary hormone study among 286 of the 301 girls who participated between 1988 and 1997 in the Dietary Intervention Study in Children, in which healthy, prepubertal, 8- to 10-year-olds with elevated low-density lipoprotein cholesterol were randomly assigned to usual care or to a behavioral intervention that promoted a low-fat diet. Median time on the intervention was 7 years. Blood samples collected before randomization and at the year 1, year 3, year 5, and last visits were assayed to determine the girls' serum levels of sex hormones. All P values are two-sided. RESULTS: At the year 5 visit, girls in the intervention group had 29.8% (95% confidence interval [CI] = 5.4% to 47.9%; P =.02) lower estradiol, 30.2% (95% CI = 7.0% to 47.7%; P =.02) lower non-sex hormone binding globulin-bound estradiol, 20.7% (95% CI = 4.7% to 34.0%; P =.02) lower estrone, and 28.7% (95% CI = 5.1% to 46.5%; P =.02) lower estrone sulfate levels during the follicular phase of the menstrual cycle and 27.2% (95% CI = 5.7% to 53.1%; P =.01) higher testosterone levels during the luteal phase of the menstrual cycle than did girls in the usual care group. At the last visit, the luteal phase progesterone level was 52.9% (95% CI = 20.0% to 72.3%) lower for girls in the intervention group than for girls in the usual care group (P =.007). CONCLUSION: Modest reductions in fat intake during puberty are associated with changes in sex hormone concentrations that are consistent with alterations in the function of the hypothalamic-pituitary-ovarian axis. Whether these changes influence breast cancer risk is currently unknown.

Low-fat dietary pattern and risk of invasive breast cancer: the Women's Health Initiative Randomized Controlled Dietary Modification Trial.

CONTEXT: The hypothesis that a low-fat dietary pattern can reduce breast cancer risk has existed for decades but has never been tested in a controlled intervention trial. OBJECTIVE: To assess the effects of undertaking a low-fat dietary pattern on breast cancer incidence. DESIGN AND SETTING: A randomized, controlled, primary prevention trial conducted at 40 US clinical centers from 1993 to 2005. PARTICIPANTS: A total of 48,835 postmenopausal women, aged 50 to 79 years, without prior breast cancer, including 18.6% of minority race/ethnicity, were enrolled. INTERVENTIONS: Women were randomly assigned to the dietary modification intervention group (40% [n = 19,541]) or the comparison group (60% [n = 29,294]). The intervention was designed to promote dietary change with the goals of reducing intake of total fat to 20% of energy and increasing consumption of vegetables and fruit to at least 5 servings daily and grains to at least 6 servings daily. Comparison group participants were not asked to make dietary changes. MAIN OUTCOME MEASURE: Invasive breast cancer incidence. RESULTS: Dietary fat intake was significantly lower in the dietary modification intervention group compared with the comparison group. The difference between groups in change from baseline for percentage of energy from fat varied from 10.7% at year 1 to 8.1% at year 6. Vegetable and fruit consumption was higher in the intervention group by at least 1 serving per day and a smaller, more transient difference was found for grain consumption. The number of women who developed invasive breast cancer (annualized incidence rate) over the 8.1-year average follow-up period was 655 (0.42%) in the intervention group and 1072 (0.45%) in the comparison group (hazard ratio, 0.91; 95% confidence interval, 0.83-1.01 for the comparison between the 2 groups). Secondary analyses suggest a lower hazard ratio among adherent women, provide greater evidence of risk reduction among women having a high-fat diet at baseline, and suggest a dietary effect that varies by hormone receptor characteristics of the tumor. CONCLUSIONS: Among postmenopausal women, a low-fat dietary pattern did not result in a statistically significant reduction in invasive breast cancer risk over an 8.1-year average follow-up period. However, the nonsignificant trends observed suggesting reduced risk associated with a low-fat dietary pattern indicate that longer, planned, nonintervention follow-up may yield a more definitive comparison. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT00000611.

Low-fat dietary pattern and risk of colorectal cancer: the Women's Health Initiative Randomized Controlled Dietary Modification Trial.

CONTEXT: Observational studies and polyp recurrence trials are not conclusive regarding the effects of a low-fat dietary pattern on risk of colorectal cancer, necessitating a primary prevention trial. OBJECTIVE: To evaluate the effects of a low-fat eating pattern on risk of colorectal cancer in postmenopausal women. DESIGN, SETTING, AND PARTICIPANTS: The Women's Health Initiative Dietary Modification Trial, a randomized controlled trial conducted in 48,835 postmenopausal women aged 50 to 79 years recruited between 1993 and 1998 from 40 clinical centers throughout the United States. INTERVENTIONS: Participants were randomly assigned to the dietary modification intervention (n = 19,541; 40%) or the comparison group (n = 29,294; 60%). The intensive behavioral modification program aimed to motivate and support reductions in dietary fat, to increase consumption of vegetables and fruits, and to increase grain servings by using group sessions, self-monitoring techniques, and other tailored and targeted strategies. Women in the comparison group continued their usual eating pattern. MAIN OUTCOME MEASURE: Invasive colorectal cancer incidence. RESULTS: A total of 480 incident cases of invasive colorectal cancer occurred during a mean follow-up of 8.1 (SD, 1.7) years. Intervention group participants significantly reduced their percentage of energy from fat by 10.7% more than did the comparison group at 1 year, and this difference between groups was mostly maintained (8.1% at year 6). Statistically significant increases in vegetable, fruit, and grain servings were also made. Despite these dietary changes, there was no evidence that the intervention reduced the risk of invasive colorectal cancer during the follow-up period. There were 201 women with invasive colorectal cancer (0.13% per year) in the intervention group and 279 (0.12% per year) in the comparison group (hazard ratio, 1.08; 95% confidence interval, 0.90-1.29). Secondary analyses suggested potential interactions with baseline aspirin use and combined estrogen-progestin use status (P = .01 for each). Colorectal examination rates, although not protocol defined, were comparable between the intervention and comparison groups. Similar results were seen in analyses adjusting for adherence to the intervention. CONCLUSION: In this study, a low-fat dietary pattern intervention did not reduce the risk of colorectal cancer in postmenopausal women during 8.1 years of follow-up. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT00000611.

Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial.

CONTEXT: Multiple epidemiologic studies and some trials have linked diet with cardiovascular disease (CVD) prevention, but long-term intervention data are needed. OBJECTIVE: To test the hypothesis that a dietary intervention, intended to be low in fat and high in vegetables, fruits, and grains to reduce cancer, would reduce CVD risk. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial of 48,835 postmenopausal women aged 50 to 79 years, of diverse backgrounds and ethnicities, who participated in the Women's Health Initiative Dietary Modification Trial. Women were randomly assigned to an intervention (19,541 [40%]) or comparison group (29,294 [60%]) in a free-living setting. Study enrollment occurred between 1993 and 1998 in 40 US clinical centers; mean follow-up in this analysis was 8.1 years. INTERVENTION: Intensive behavior modification in group and individual sessions designed to reduce total fat intake to 20% of calories and increase intakes of vegetables/fruits to 5 servings/d and grains to at least 6 servings/d. The comparison group received diet-related education materials. MAIN OUTCOME MEASURES: Fatal and nonfatal coronary heart disease (CHD), fatal and nonfatal stroke, and CVD (composite of CHD and stroke). RESULTS: By year 6, mean fat intake decreased by 8.2% of energy intake in the intervention vs the comparison group, with small decreases in saturated (2.9%), monounsaturated (3.3%), and polyunsaturated (1.5%) fat; increases occurred in intakes of vegetables/fruits (1.1 servings/d) and grains (0.5 serving/d). Low-density lipoprotein cholesterol levels, diastolic blood pressure, and factor VIIc levels were significantly reduced by 3.55 mg/dL, 0.31 mm Hg, and 4.29%, respectively; levels of high-density lipoprotein cholesterol, triglycerides, glucose, and insulin did not significantly differ in the intervention vs comparison groups. The numbers who developed CHD, stroke, and CVD (annualized incidence rates) were 1000 (0.63%), 434 (0.28%), and 1357 (0.86%) in the intervention and 1549 (0.65%), 642 (0.27%), and 2088 (0.88%) in the comparison group. The diet had no significant effects on incidence of CHD (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.90-1.06), stroke (HR, 1.02; 95% CI, 0.90-1.15), or CVD (HR, 0.98; 95% CI, 0.92-1.05). Excluding participants with baseline CVD (3.4%), the HRs (95% CIs) for CHD and stroke were 0.94 (0.86-1.02) and 1.02 (0.90-1.17), respectively. Trends toward greater reductions in CHD risk were observed in those with lower intakes of saturated fat or trans fat or higher intakes of vegetables/fruits. CONCLUSIONS: Over a mean of 8.1 years, a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women and achieved only modest effects on CVD risk factors, suggesting that more focused diet and lifestyle interventions may be needed to improve risk factors and reduce CVD risk. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT00000611.

Ethnic differences in insulin sensitivity and beta-cell function in premenopausal or early perimenopausal women without diabetes: the Study of Women's Health Across the Nation (SWAN).

OBJECTIVE: To assess differences in insulin sensitivity and beta-cell function between nondiabetic premenopausal or early perimenopausal non-Hispanic white women and African American, Chinese American, Japanese American, and non-Mexican-American Latino women. RESEARCH DESIGN AND METHODS: Homeostasis model assessments (HOMAs) of insulin sensitivity (HOMA%S) and beta-cell function (HOMA%beta) were used. Stepwise multivariable ethnic-specific ANCOVA models were used to compare HOMA%S and HOMA%beta between non-Hispanic whites and each of the four ethnic groups. RESULTS: HOMA%S was lower in African Americans, Chinese Americans, and Japanese Americans when compared with non-Hispanic white women after correcting for waist circumference, presence of impaired fasting glucose, and site. Significant differences persisted only between African Americans and non-Hispanic whites after inclusion of triglycerides in the model. Triglycerides indirectly corrected for the differences in HOMA%S in the other two groups. There were no differences in HOMA%S between the non-Mexican-American Latinos and the non-Hispanic whites. Japanese Americans and Chinese Americans had lower HOMA%beta than non-Hispanic whites, whereas African Americans had higher HOMA%beta than non-Hispanic whites after correcting for confounders. HOMA%beta was similar between non-Mexican-American Latinos and non-Hispanic whites. CONCLUSIONS: These data suggest that type 2 diabetes prevention strategies for African-American women should initially target decreased insulin sensitivity, whereas strategies for Japanese-American and Chinese-American women may initially need to target both decreased insulin sensitivity and beta-cell function. Previous studies of Mexican-American populations may not apply to non-Mexican-American Latino women.