Stephanie M. George

Amount of time spent in sedentary behaviors and cause-specific mortality in US adults

BACKGROUND Sedentary behaviors predominate modern life, yet we do not fully understand the adverse effects of these behaviors on mortality after considering the benefits of moderate-vigorous physical activity (MVPA). OBJECTIVE We tested the hypotheses that higher amounts of overall sitting time and television viewing are positively associated with mortality and described the independent and combined effects of these sedentary behaviors and MVPA on mortality. DESIGN In the NIH-AARP Diet and Health Study, we examined 240,819 adults (aged 50-71 y) who did not report any cancer, cardiovascular disease, or respiratory disease at baseline. Mortality was ascertained over 8.5 y. RESULTS Sedentary behaviors were positively associated with mortality after adjustment for age, sex, education, smoking, diet, race, and MVPA. Participants who reported the most television viewing (≥7 h compared with <1 h/d) were at greater risk of all-cause (HR: 1.61; 95% CI: 1.47, 1.76), cardiovascular (HR: 1.85; 95% CI: 1.56, 2.20), and cancer (HR: 1.22; 95% CI: 1.06, 1.40) mortality after adjustment for MVPA. Overall sitting was associated with all-cause mortality. Even among adults reporting high levels of MVPA (>7 h/wk), high amounts of television viewing (≥7 h/d) remained associated with increased risk of all-cause (HR: 1.47; 95% CI: 1.20, 1.79) and cardiovascular (HR: 2.00; 95% CI: 1.33, 3.00) mortality compared with those reporting the least television viewing (<1 h/d). CONCLUSIONS Time spent in sedentary behaviors was positively associated with mortality, and participation in high levels of MVPA did not fully mitigate health risks associated with prolonged time watching television. Adults should be encouraged to reduce time spent in sedentary behaviors, when possible, and to participate in MVPA at recommended levels. The NIH-AARP Diet and Health Study was registered at clinicaltrials.gov as NCT00340015.

The Dietary Patterns Methods Project: Synthesis of Findings across Cohorts and Relevance to Dietary Guidance

The Dietary Patterns Methods Project (DPMP) was initiated in 2012 to strengthen research evidence on dietary indices, dietary patterns, and health for upcoming revisions of the Dietary Guidelines for Americans, given that the lack of consistent methodology has impeded development of consistent and reliable conclusions. DPMP investigators developed research questions and a standardized approach to index-based dietary analysis. This article presents a synthesis of findings across the cohorts. Standardized analyses were conducted in the NIH-AARP Diet and Health Study, the Multiethnic Cohort, and the Womens Health Initiative Observational Study (WHI-OS). Healthy Eating Index 2010, Alternative Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet, and Dietary Approaches to Stop Hypertension (DASH) scores were examined across cohorts for correlations between pairs of indices; concordant classifications into index score quintiles; associations with all-cause, cardiovascular disease (CVD), and cancer mortality with the use of Cox proportional hazards models; and dietary intake of foods and nutrients corresponding to index quintiles. Across all cohorts in women and men, there was a high degree of correlation and consistent classifications between index pairs. Higher diet quality (top quintile) was significantly and consistently associated with an 11-28% reduced risk of death due to all causes, CVD, and cancer compared with the lowest quintile, independent of known confounders. This was true for all diet index-mortality associations, with the exception of AHEI-2010 and cancer mortality in WHI-OS women. In all cohorts, survival benefit was greater with a higher-quality diet, and relatively small intake differences distinguished the index quintiles. The reductions in mortality risk started at relatively lower levels of diet quality. Higher scores on each of the indices, signifying higher diet quality, were associated with marked reductions in mortality. Thus, the DPMP findings suggest that all 4 indices capture the essential components of a healthy diet.

Performance of the Automated Self-Administered 24-hour Recall relative to a measure of true intakes and to an interviewer-administered 24-h recall

BACKGROUND The Automated Self-Administered 24-hour Recall (ASA24), a freely available Web-based tool, was developed to enhance the feasibility of collecting high-quality dietary intake data from large samples. OBJECTIVE The purpose of this study was to assess the criterion validity of ASA24 through a feeding study in which the true intake for 3 meals was known. DESIGN True intake and plate waste from 3 meals were ascertained for 81 adults by inconspicuously weighing foods and beverages offered at a buffet before and after each participant served him- or herself. Participants were randomly assigned to complete an ASA24 or an interviewer-administered Automated Multiple-Pass Method (AMPM) recall the following day. With the use of linear and Poisson regression analysis, we examined the associations between recall mode and 1) the proportions of items consumed for which a match was reported and that were excluded, 2) the number of intrusions (items reported but not consumed), and 3) differences between energy, nutrient, food group, and portion size estimates based on true and reported intakes. RESULTS Respondents completing ASA24 reported 80% of items truly consumed compared with 83% in AMPM (P = 0.07). For both ASA24 and AMPM, additions to or ingredients in multicomponent foods and drinks were more frequently omitted than were main foods or drinks. The number of intrusions was higher in ASA24 (P < 0.01). Little evidence of differences by recall mode was found in the gap between true and reported energy, nutrient, and food group intakes or portion sizes. CONCLUSIONS Although the interviewer-administered AMPM performed somewhat better relative to true intakes for matches, exclusions, and intrusions, ASA24 performed well. Given the substantial cost savings that ASA24 offers, it has the potential to make important contributions to research aimed at describing the diets of populations, assessing the effect of interventions on diet, and elucidating diet and health relations. This trial was registered at clinicaltrials.gov as NCT00978406.

Comparing Indices of Diet Quality With Chronic Disease Mortality Risk in Postmenopausal Women in the Women's Health Initiative Observational Study: Evidence to Inform National Dietary Guidance

Poor diet quality is thought to be a leading risk factor for years of life lost. We examined how scores on 4 commonly used diet quality indices-the Healthy Eating Index 2010 (HEI), the Alternative Healthy Eating Index 2010 (AHEI), the Alternate Mediterranean Diet (aMED), and the Dietary Approaches to Stop Hypertension (DASH)-are related to the risks of death from all causes, cardiovascular disease (CVD), and cancer among postmenopausal women. Our prospective cohort study included 63,805 participants in the Womens Health Initiative Observational Study (from 1993-2010) who completed a food frequency questionnaire at enrollment. Cox proportional hazards models were fit using person-years as the underlying time metric. We estimated multivariate hazard ratios and 95% confidence intervals for death associated with increasing quintiles of diet quality index scores. During 12.9 years of follow-up, 5,692 deaths occurred, including 1,483 from CVD and 2,384 from cancer. Across indices and after adjustment for multiple covariates, having better diet quality (as assessed by HEI, AHEI, aMED, and DASH scores) was associated with statistically significant 18%-26% lower all-cause and CVD mortality risk. Higher HEI, aMED, and DASH (but not AHEI) scores were associated with a statistically significant 20%-23% lower risk of cancer death. These results suggest that postmenopausal women consuming a diet in line with a priori diet quality indices have a lower risk of death from chronic disease.

Fruit and vegetable intake and risk of cancer: a prospective cohort study

BACKGROUND There is probable evidence that some types of fruit and vegetables provide protection against many cancers. OBJECTIVE We hypothesized that fruit and vegetable intakes are inversely related to the incidence of total cancers among women and men aged >50 y. DESIGN We performed a prospective study among the cohort of the National Institutes of Health-AARP Diet and Health Study. We merged the MyPyramid Equivalents Database (version 1.0) with food-frequency-questionnaire data to calculate cup equivalents for fruit and vegetables. From 1995 to 2003, we identified 15,792 and 35,071 cancer cases in 195,229 women and 288,109 men, respectively. We used Cox proportional hazards models to estimate multivariate relative risks (RRs) and 95% CIs associated with the highest compared with the lowest quintile (Q) of fruit and vegetable intakes. RESULTS Fruit intake was not associated with the risk of total cancer among women (RR(Q5 vs Q1) = 0.99; 95% CI: 0.94, 1.05; P trend = 0.059) or men (RR(Q5 vs Q1) = 0.98; 95% CI: 0.95, 1.02; P for trend = 0.17). Vegetable intake was not associated with risk of total cancer among women (RR(Q5 vs Q1) = 1.04; 95% CI: 0.98, 1.09; P for trend = 0.084), but was associated with a significant decrease in risk in men (RR(Q5 vs Q1) = 0.94; 95% CI: 0.91, 0.97; P trend = 0.004). This significant finding among men was no longer evident when we limited the analysis to men who never smoked (RR(Q5 vs Q1) = 0.97; 95% CI: 0.91, 1.04; P for trend = 0.474). CONCLUSIONS Intake of fruit and vegetables was generally unrelated to total cancer incidence in this cohort. Residual confounding by smoking is a likely explanation for the observed inverse association with vegetable intake among men.

Improving Self-Reports of Active and Sedentary Behaviors in Large Epidemiologic Studies

Questionnaires that assess active and sedentary behaviors in large-scale epidemiologic studies are known to contain substantial errors. We present three options for improving measures of physical activity behaviors in large-scale epidemiologic studies, discuss the problems and prospects for each of these options, and highlight a new direction for measuring these behaviors in such studies.

Dietary Glycemic Index, Glycemic Load, and Risk of Cancer: A Prospective Cohort Study

Previous studies have provided limited evidence for a harmful effect of high glycemic index and dietary glycemic load on cancer. The authors analyzed associations among glycemic index, glycemic load, and risk of cancer in women and men in the National Institutes of Health-AARP Diet and Health Study. Published glycemic index values were assigned to 225 foods/food groups. Glycemic load was calculated by multiplying the glycemic index, carbohydrate content, and intake frequency of individual foods reported on a food frequency questionnaire. From 1995 through 2003, the authors identified 15,215 and 33,203 cancer cases in women and men, respectively. Cox proportional hazards models were used to estimate multivariate relative risks and 95% confidence intervals. For women and men, respectively, the relative risks for total cancer for high versus low glycemic index were 1.03 (P(trend)=0.217) and 1.04 (P(trend)=0.012) and, for glycemic load, were 0.90 (P(trend)=0.024) and 0.93 (P(trend)=0.01). Associations with total cancer held only among the overweight for glycemic index and among those of healthy weight for glycemic load. These findings suggest that glycemic index and glycemic load are not strong predictors of cancer incidence. The direction and small magnitude of associations might be explained by the manner in which high glycemic index and glycemic load track with overall diet and lifestyle patterns.

Beyond Recreational Physical Activity: Examining Occupational and Household Activity, Transportation Activity, and Sedentary Behavior in Relation to Postmenopausal Breast Cancer Risk

OBJECTIVES We prospectively examined nonrecreational physical activity and sedentary behavior in relation to breast cancer risk among 97 039 postmenopausal women in the National Institutes of Health-AARP Diet and Health Study. METHODS We identified 2866 invasive and 570 in situ breast cancer cases recorded between 1996 and 2003 and used Cox proportional hazards regression to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs). RESULTS Routine activity during the day at work or at home that included heavy lifting or carrying versus mostly sitting was associated with reduced risk of invasive breast cancer (RR = 0.62; 95% CI = 0.42, 0.91; P(trend) = .024). CONCLUSIONS Routine activity during the day at work or home may be related to reduced invasive breast cancer risk. Domains outside of recreation time may be attractive targets for increasing physical activity and reducing sedentary behavior among postmenopausal women.

Comparison of Interviewer-Administered and Automated Self-Administered 24-Hour Dietary Recalls in 3 Diverse Integrated Health Systems

Twenty-four-hour dietary recalls provide high-quality intake data but have been prohibitively expensive for large epidemiologic studies. This studys goal was to assess whether the web-based Automated Self-Administered 24-Hour Recall (ASA24) performs similarly enough to the standard interviewer-administered, Automated Multiple-Pass Method (AMPM) 24-hour dietary recall to be considered a viable alternative. In 2010-2011, 1,081 adults from 3 integrated health systems in Detroit, Michigan; Marshfield, Wisconsin; and Kaiser-Permanente Northern California participated in a field trial. A quota design ensured a diverse sample by sex, age, and race/ethnicity. Each participant was asked to complete 2 recalls and was randomly assigned to 1 of 4 protocols differing by type of recall and administration order. For energy, the mean intakes were 2,425 versus 2,374 kcal for men and 1,876 versus 1,906 kcal for women by AMPM and ASA24, respectively. Of 20 nutrients/food groups analyzed and controlling for false discovery rate, 87% were judged equivalent at the 20% bound. ASA24 was preferred over AMPM by 70% of the respondents. Attrition was lower in the ASA24/AMPM study group than in the AMPM/ASA24 group, and it was lower in the ASA24/ASA24 group than in the AMPM/AMPM group. ASA24 offers the potential to collect high-quality dietary intake information at low cost with less attrition.

Postdiagnosis Diet Quality Is Inversely Related to a Biomarker of Inflammation Among Breast Cancer Survivors

Background: Inflammation and immune response have potential prognostic implications for breast cancer survivors. We examined how postdiagnosis diet quality is cross-sectionally related to biomarkers of inflammation and adipose-derived hormones among breast cancer survivors and determined whether physical activity or body size modified any observed associations. Methods: Participants included 746 women diagnosed with stage 0 to IIIA breast cancer. Thirty months after diagnosis, the women completed food frequency questionnaires. We scored diet quality with the Healthy Eating Index (HEI)-2005. Serum concentrations of C-reactive protein (CRP), serum amyloid A, leptin, and adiponectin were measured in fasting 30 mL blood samples. Log biomarker values were regressed on quartiles of HEI-2005 scores in multivariate models, and β scores were exponentiated and expressed as geometric means within quartiles of HEI-2005 scores. Results: Women with better versus poor quality postdiagnosis diets, as defined by higher HEI-2005 scores (Q4 versus Q1), had lower concentrations of CRP (1.6 mg/L versus 2.5 mg/L), but no significant difference in concentrations of serum amyloid A, leptin, or adiponectin. Among women not engaging in recreational physical activity after diagnosis, better diet quality was associated with lower CRP concentrations (2.5 mg/L versus 5.0 mg/L), but no association was observed among women engaging in any recreational physical activity (1.4 mg/L versus 1.6 mg/L; P heterogeneity = 0.03). Conclusions: Among breast cancer survivors, a better-quality diet seems to be associated with lower levels of chronic inflammation. Impact: Lower levels of chronic inflammation have been associated with improved survival after breast cancer. Cancer Epidemiol Biomarkers Prev; 19(9); 2220–8. ©2010 AACR.