Association of glycemic load with cardiovascular disease risk factors: The Women's Health Initiative Observational Study

ObjectiveAssociations between dietary glycemic load (GL) and cardiovascular disease risk factors, including plasma lipoprotein/lipid levels, blood pressure, and glucose metabolism factors, in the Women's Health Initiative Observational Study were examined.MethodsA random sample of 878 Observational Study participants (postmenopausal women 50–79 y of age) with baseline blood measurements (647 white, 104 black, 127 Hispanic) was included. Dietary GL was estimated from baseline food-frequency questionnaires, which assessed dietary intake over the previous 3 mo. At the baseline visit, participants completed demographic and health habit questionnaires, fasting blood samples were collected, anthropometric measurements were completed, and blood pressure was assessed.ResultsIn all participants combined, GL was inversely associated with high-density lipoprotein cholesterol (P for trend = 0.004) and positively associated with log₁₀-transformed triacylglycerols (P = 0.008). Although there were no statistically significant interactions of race/ethnicity with associations between GL and cardiovascular disease risk factors, stratified results were suggestive, showing that GL was positively associated with total cholesterol (P = 0.018) and low-density lipoprotein cholesterol (P = 0.038) in Hispanics. In white subjects, there was a trend of reduced high-density lipoprotein cholesterol with higher GL (P = 0.003), whereas GL was positively associated with log₁₀-transformed triacylglycerols (P = 0.015). Associations between GL and high-density lipoprotein cholesterol and between GL and triacylglycerols also differed by body mass index, although the interactions were not statistically significant.ConclusionAmong these generally healthy postmenopausal women, GL was associated with high-density lipoprotein cholesterol and triacylglycerols. Suggestive effects of race/ethnicity and body mass index on these associations need to be confirmed in larger studies.     

Association between reported alcohol intake and cognition: results from the Women's Health Initiative Memory Study

Some, but not all, observational studies have suggested that moderate levels of alcohol intake may be associated with improved cognitive function and reduced risk of cognitive decline and dementia. The authors of this 1996-2002 study used data from the Women's Health Initiative Memory Study of postmenopausal combination hormone therapy to assess cross-sectional and prospective associations of self-reported alcohol intake with cognitive function. Across 39 US academic medical centers, 4,461 community-dwelling women aged 65-79 years were followed an average of 4.2 years with annual Modified Mini-Mental State Examinations and standardized protocols for detecting mild cognitive impairment and probable dementia. Compared with no intake, intake of > or =1 drink per day was associated with higher baseline Modified Mini-Mental State Examination scores (p < 0.001) and a covariate-adjusted odds ratio of 0.40 (95% confidence interval: 0.28, 0.99) for significant declines in cognitive function. Associations with incident probable dementia and mild cognitive impairment were of similar magnitude but were not statistically significant after covariate adjustment. Associations with intakes of <1 drink per day were intermediate. Moderate levels of alcohol intake may be associated with better cognition and reduced risk of significant cognitive decline; however, confounding associations with unmeasured factors cannot be ruled out.     

Vigorous leisure activity through women's adult life: the Women's Health Initiative Observational Cohort Study

This study described differences in vigorous activity participation recalled across the life span, assessed whether reports of past vigorous activity were associated with current participation, and examined factors associated with participation in current vigorous activity among women. After the exclusion of women aged 50-54 years, the study population included 71,837 multiethnic postmenopausal women aged 55-79 years who were participating in the Women's Health Initiative Observational Cohort Study, 1993-1998. Vigorous activity was assessed retrospectively for ages 18, 35, and 50 years and currently at enrollment into the study (median age, 65 years). Current participation in vigorous activity (>3 days/week) was low and consistent across racial/ethnic groups (13-16%). The prevalence of vigorous activity declined with age, with the largest decrease in vigorous activity occurring after age 50 years for all racial/ethnic groups. Current vigorous activity was generally higher among women with a lower body mass index, not currently smoking, in excellent general health, and of higher socioeconomic status across racial/ethnic groups. These data suggest that a lower prevalence of vigorous activity in the postmenopausal period is part of a complex of health-related attitudes and behaviors that transcends race/ethnicity. The perimenopausal period may be a critical juncture at which targeted and tailored interventions may help to achieve maintenance of physical activity into the postmenopausal period.     

Dietary patterns are associated with disease risk among participants in the Women's Health Initiative Observational Study

Coronary heart disease (CHD) is the leading cause of death in women. A nested case-control study tested whether dietary patterns predicted CHD events among 1224 participants in the Women's Health Initiative-Observational Study (WHI-OS) with centrally confirmed CHD, fatal or nonfatal myocardial infarct compared to 1224 WHI-OS controls matched for age, enrollment date, race/ethnicity, and absence of CHD at baseline or follow-up. The first six principal components explained >75% of variation in dietary intakes and K-mean analysis based on these six components produced three clusters. Diet cluster 1 was rich in carbohydrate, vegetable protein, fiber, dietary vitamin K, folate, carotenoids, α-linolenic acid [18:3(n-3)], linoleic acid [18:2(n-6)], and supplemental calcium and vitamin D. Diet cluster 2 was rich in total and animal protein, arachidonic acid [20:4(n-6)], DHA [22:6(n-3)], vitamin D, and calcium. Diet cluster 3 was rich in energy, total fat, and trans fatty acids (all P < 0.01). Conditional logistic regression analysis demonstrated diet cluster 1 was associated with lower CHD risk than diet cluster 2 (reference group) adjusted for smoking, education, and physical activity [OR = 0.79 (95% CI = 0.64, 0.99); P = 0.038]. This difference was not significant after adjustment for BMI and systolic blood pressure. Diet cluster 3 was associated with higher CHD risk than diet cluster 2 [OR = 1.28 (95% CI = 1.04, 1.57); P = 0.019], but this difference did not remain significant after adjustment for smoking, education, and physical activity. Within this WHI-OS cohort, distinct dietary patterns may be associated with subsequent CHD outcomes.     

Results of an adjunct dietary intervention program in the Women's Health Initiative

OBJECTIVE: The purpose of this study was to develop, implement, and evaluate the efficacy of an intensive intervention program (IIP) based on motivational interviewing to motivate participants within the dietary study of the Women's Health Initiative (WHI) to meet the study's nutritional goals. SUBJECTS/DESIGN: WHI dietary intervention participants (n=175) from 3 clinical centers were randomly assigned to either intervention or control status. Participants assigned to IIP intervention received 3 individual motivational interviewing contacts from a dietitian, plus the usual WHI Dietary Intervention. Participants randomly assigned to IIP control received the usual WHI dietary modification (DM) Intervention. Percent of energy from fat was estimated at study baseline and at follow-up (1 year later) using the WHI Food Frequency Questionnaire. RESULTS: The change in percent energy from fat between IIP baseline and IIP 1-year follow-up was -1.2% for IIP intervention participants and +1.4% for IIP control participants, giving an overall difference of 2.6% (P<.001). Participants having the highest IIP baseline fat intake (>30% energy) showed the largest overall change in percent energy from fat between IIP baseline and IIP follow-up. CONCLUSIONS: The results of this study indicate that a protocol based on motivational interviewing and delivered through contacts with trained dietitians is an efficacious way to further lower dietary fat intake among participants exposed to ongoing intervention. These data will be useful in future intervention situations when there is a need to increase motivation to change.     

Interaction between smoking and obesity and the risk of developing breast cancer among postmenopausal women: the Women's Health Initiative Observational Study

Obesity is a well-established risk factor for postmenopausal breast cancer. Recent studies suggest that smoking increases the risk of breast cancer. However, the effect of co-occurrence of smoking and obesity on breast cancer risk remains unclear. A total of 76,628 women aged 50-79 years enrolled in the Women's Health Initiative Observational Study were followed through August 14, 2009. Cox proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals. Over an average 10.3 years of follow-up, 3,378 incident cases of invasive breast cancer were identified. The effect of smoking on the risk of developing invasive breast cancer was modified significantly by obesity status among postmenopausal women, regardless of whether the obesity status was defined by body mass index (P(interaction) = 0.01) or waist circumference (P(interaction) = 0.02). A significant association between smoking and breast cancer risk was noted in nonobese women (hazard ratio = 1.25, 95% confidence interval: 1.05, 1.47) but not in obese women (hazard ratio = 0.96, 95% confidence interval: 0.69, 1.34). In conclusion, this study suggests that the effect of smoking exposure on breast cancer risk was modified by obesity among postmenopausal women. The modification effect did not differ by general versus abdominal obesity.     

Additional self-monitoring tools in the dietary modification component of The Women's Health Initiative

Self-monitoring promotes behavior changes by promoting awareness of eating habits and creates self-efficacy. It is an important component of the Women's Health Initiative dietary intervention. During the first year of intervention, 74% of the total sample of 19,542 dietary intervention participants self-monitored. As the study progressed the self-monitoring rate declined to 59% by spring 2000. Participants were challenged by inability to accurately estimate fat content of restaurant foods and the inconvenience of carrying bulky self-monitoring tools. In 1996, a Self-Monitoring Working Group was organized to develop additional self-monitoring options that were responsive to participant needs. This article describes the original and additional self-monitoring tools and trends in tool use over time. Original tools were the Food Diary and Fat Scan. Additional tools include the Keeping Track of Goals, Quick Scan, Picture Tracker, and Eating Pattern Changes instruments. The additional tools were used by the majority of participants (5,353 of 10,260 or 52% of participants who were self-monitoring) by spring 2000. Developing self-monitoring tools that are responsive to participant needs increases the likelihood that self-monitoring can enhance dietary reporting adherence, especially in long-term clinical trials.     

Predictors of dietary change and maintenance in the Women's Health Initiative Dietary Modification Trial

OBJECTIVE: To identify predictors of dietary change to and maintenance of a low-fat eating pattern (<20% energy from fat, > or = 5 servings fruits/vegetables daily, and > or = 6 servings grains daily) among a cohort of postmenopausal women. Candidate predictors included intrapersonal, interpersonal, intervention program characteristics, and clinical center. DESIGN: Longitudinal study within the Women's Health Initiative Dietary Modification Trial. Dietary change was evaluated after 1 year of participation in the Women's Health Initiative Dietary Modification Trial, and dietary maintenance after 3 years. SUBJECTS: Postmenopausal women aged 50 to 79 years at baseline who were randomized to the intervention arm of the Women's Health Initiative Dietary Modification Trial (n=19,541). STATISTICAL ANALYSIS: Univariate and multivariate linear regression analysis was performed and associations evaluated between candidate predictors and each of the three dietary goals: percent energy from fat, fruit/vegetable servings, and grain servings. RESULTS: Year 1 (change) predictors of percent energy from fat (P<0.005) included being younger (beta=2.12; 70 to 79 years vs 50 to 59 years), more educated (beta=-.69; college vs high school), more optimistic (beta=-.07), attending more sessions (beta=-.69), and submitting more self-monitoring records (beta=-.74). At year 3 (maintenance), the predictors of percent energy from fat (P<0.005) included attending more sessions (beta=-.65) and submitting more self-monitoring scores (beta=-.71). The analytic model predicted 22% of the variance in fat intake at year 1 and 27% at year 3 (P<0.01). CONCLUSIONS: The strongest predictors of dietary change and maintenance were attending intervention sessions and self-monitoring dietary intake. Novel was the finding that optimism predicted dietary change.     

Selected antioxidants and risk of hormone receptor-defined invasive breast cancers among postmenopausal women in the Women's Health Initiative Observational Study

BACKGROUND: Few studies have evaluated carotenoids and vitamins C and E in association with the risk of breast cancers defined by estrogen receptor (ER) and progesterone receptor (PR) status. OBJECTIVE: We examined the associations between dietary and supplemental intakes of these nutrients and risk of breast cancers jointly defined by both ER and PR status among postmenopausal women. DESIGN: Our investigation was conducted in the Women's Health Initiative Observational Study. After following 84 805 women for an average of 7.6 y, 2879 incident invasive breast cancer cases had been ascertained, of whom 2509 had receptor data. We used Cox proportional hazards models to assess the associations of interest. RESULTS: Dietary alpha-carotene (highest versus lowest quintile: RR = 0.83; 95% CL = 0.70, 0.99; P for trend = 0.019), beta-carotene (highest versus lowest quintile: RR = 0.78; 95% CL = 0.66, 0.94; P for trend = 0.021), and lycopene (highest versus lowest quintile: RR = 0.85; 95% CL = 0.73, 1.00; P for trend = 0.064) were inversely associated with risk of ER+PR+breast cancer, but not with other breast cancer groups jointly defined by ER and PR status. Total or supplemental beta-carotene and dietary intakes of lutein+zeaxanthin and beta-cryptoxanthin were not associated with breast cancers defined by ER and PR status. Vitamin E (regardless of source) and dietary vitamin C were not associated with breast cancer. However, total and supplemental vitamin C intake had weak positive associations with breast cancer overall. CONCLUSION: Dietary intake of certain carotenoids might be differentially associated with risk of invasive breast cancers jointly defined by ER and PR status among postmenopausal women.     

Investigating the Association of Lactation History and Postmenopausal Breast Cancer Risk in the Women's Health Initiative

Prolonged lactation (≥24 mo) has been associated with reduced breast cancer risk. This research examined this association in postmenopausal women in the Women's Health Initiative (WHI) Hormone Trial (HT) and Observational Study (OS). This retrospective cohort analysis included 69,358 predominantly overweight (65.4%), white (83.2%) postmenopausal women without breast cancer. Women in the HT were randomized to 0.625 mg conjugated equine estrogen (CEE), 0.625 CEE + 2.5 mg medroxyprogesterone acetate (CEE/MPA), or placebo. OS participants had no restrictions on hormone use. Lactation history was assessed via WHI Reproductive History Questionnaire. Most women breastfed at least 1 mo (58.0%); 35.4% breastfed 1–2 children; and 6.5% stated having breastfed ≥24mo. Women in the HT–CEE who breastfed their first child between 20–24 yr of age demonstrated a nonsignificant decreased risk of breast cancer (HR: 0.62; 95% CI: 0.38, 1.01). OS participants who reported CEE/MPA hormone use and age of first breastfeeding ≥30 yr showed a significant increased risk of breast cancer (HR: 1.66; 95% CI: 1.14, 2.41). Risk was increased if age of last breastfeeding was ≥35yr (HR: 1.50; 95% CI: 1.05, 2.14). This research did not demonstrate a significantly decreased risk of postmenopausal breast cancer in women who breastfed for ≥24 mo during their lifetime.     

Optimism and Diet Quality in the Women's Health Initiative

Diet quality has not been well studied in relation to positive psychological traits. Our purpose was to investigate the relationship between optimism and diet quality in postmenopausal women enrolled in the Women's Health Initiative observational study (OS) and clinical trials (CTs), and to determine whether optimism was associated with diet change after a 1-year dietary intervention. Diet quality was scored with the Alternate Healthy Eating Index (AHEI) and optimism assessed with the Life Orientation Test-Revised. Baseline characteristics were compared across AHEI quintiles or optimism tertiles using regression models with each variable of interest as a function of quintiles or tertiles (OS, n=87,630; CT, n=65,360). Association between optimism and baseline AHEI and change in AHEI over 1 year were tested using multivariate linear regression (CT, n=13,645). Potential interaction between optimism and trial arm and demographic/lifestyle factors on AHEI change was tested using likelihood ratio test (CT intervention, n=13,645; CT control, n=20,242). Women reporting high AHEI were non-Hispanic white, educated, physically active, past or never smokers, hormone therapy users, had lower body mass index and waist circumference, and were less likely to have chronic conditions. In the CT intervention, higher optimism was associated with higher AHEI at baseline and with greater change over 1 year (P=0.001). Effect modification by intervention status was observed (P=0.014), whereas control participants with highest optimism achieved threefold greater AHEI increase compared with those with the lowest optimism. These data support a relationship between optimism and dietary quality score in postmenopausal women at baseline and over 1 year.     

The association of whole grain consumption with incident type 2 diabetes: the Women's Health Initiative Observational Study

PurposeWhole grains may offer protection from diabetes by decreasing energy intake, preventing weight gain, and direct effects on insulin resistance. This study examined associations of whole and refined grains with incident type 2 diabetes (T2D) ascertained by self-reported medication use in a cohort of postmenopausal women.MethodsWe included 72,215 women free of diabetes at baseline from the Women's Health Initiative Observational Study. Whole grain consumption was categorized as 0, less than 0.5, 0.5 to 1.0, 1.0 to less than 1.5, 1.5 to less than 2.0, and 2.0 or more servings per day. Proportional hazards regression was performed to estimate hazard ratios (HR) and 95% confidence intervals adjusting for potential confounders.ResultsThere were 3465 cases of incident T2D over median follow-up of 7.9 years. Adjusted for age and energy intake per day, successively increasing categories of whole grain consumption were associated with statistically significant reduced risk of incident T2D (HRs, 1.00, 0.83, 0.73, 0.69, 0.61, and 0.57; P for trend < 0.0001). Results were attenuated after adjustment for confounders and other dietary components. The reduction in risk of T2D was greater among nonsmokers and those who maintained their weight within 5 pounds with higher consumption of whole grains than smokers and women who gained more weight.ConclusionsThis large, prospective study found an inverse dose–response relationship between whole grain consumption and incident T2D in postmenopausal women.     

Association between dietary fiber and serum C-reactive protein

BACKGROUND: High sensitivity C-reactive protein (CRP) is a marker of acute inflammation recently recognized as an independent predictor of future cardiovascular disease and diabetes. The identification of modifiable factors, such as diet, that influence serum CRP concentrations may provide the means for reducing the risk of these diseases. Data on longitudinal associations between dietary fiber intake and CRP are currently lacking. OBJECTIVE: The purpose of this study was to examine longitudinal associations between dietary fiber intake and CRP. DESIGN: Data collection took place at baseline and quarterly (every 13 wk) thereafter for a total of 5 visits, each including measurements of body composition, CRP, diet, and physical activity. Relations between serum CRP and dietary fiber were assessed by using linear mixed models and logistic regression, adjusted for covariates. RESULTS: A total of 524 subjects had multiple measurements of CRP and dietary factors. The average total dietary fiber intake was 16.11 g/d. Average serum CRP was 1.78 mg/L. We observed an inverse association between intake of total dietary fiber (separately for soluble and insoluble fiber) and CRP concentrations in both cross-sectional and longitudinal analyses. The likelihood of elevated CRP concentrations was 63% lower (OR: 0.37; 95% CI: 0.16, 0.87) in participants in the highest quartile of total fiber intake than in participants in the lowest quartile. CONCLUSIONS: Our results suggest that dietary fiber is protective against high CRP, which supports current recommendations for a diet high in fiber.     

Antioxidant supplement use in Women's Health Initiative participants

BACKGROUND: Although antioxidant supplements are widely available and commonly used in the United States, there is a lack of detailed information on their use, including types of supplements used, doses, duration of use, and changes in use over time. METHODS: Antioxidant supplement use was assessed in participants in the Clinical Trial (n = 68,133) and Observational Study (n = 93,676) of the Women's Health Initiative. In-person interviews and a computerized inventory procedure were used to collect data on supplement use during baseline clinic visits from 1993 through 1998. RESULTS: Antioxidant supplements were widely consumed. For example, 55.5% of participants reported taking supplemental vitamin C in some form. Supplement use was positively associated with age, education, and physical activity. Most antioxidants were consumed through multivitamins. However, high doses were commonly consumed from single supplements, with 43.9% using single vitamin C supplements taking >500 mg and 86.1% using single vitamin E supplements taking >200 IU daily. Except for beta-carotene, there were increases in the use of all supplements from 1993 to 1998. CONCLUSIONS: This report demonstrates the feasibility of collecting comprehensive dietary supplement use data in large studies. These data may aid in the design of supplement use questionnaires, which could help to prevent misclassification error in epidemiologic studies of diet and disease.