Nutrient and Physical Activity Biomarker Studies in the WHI • 544 women completed two-week DLW protocol with urine and 544 women completed two-week DLW protocol with urine and blood collection and with FFQ and other questionnaire blood collection and with FFQ and other questionnaire data collection (50% intervention, 50% control). A 20% data collection (50% intervention, 50% control). A 20% reliability subsample repeated protocol, separated by reliability subsample repeated protocol, separated by about 6 months from original data collection. about 6 months from original data collection. (NBS) (NBS) • Biomarker study among 450 women in the WHI Observational Biomarker study among 450 women in the WHI Observational Study for evaluating and comparing measurement Study for evaluating and comparing measurement properties of dietary and physical activity assessment properties of dietary and physical activity assessment approaches (frequencies, records, and recalls) and their approaches (frequencies, records, and recalls) and their combination. A 20% reliability subsample again included combination. A 20% reliability subsample again included (NPAAS) (NPAAS) . . Human feeding study currently enrolling 150 WHI women Human feeding study currently enrolling 150 WHI women in Seattle, toward developing biomarkers for additional in Seattle, toward developing biomarkers for additional nutrients/foods nutrients/foods (NPAAS2) (NPAAS2)
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Nutrient and Physical Activity Biomarker Studies
in the WHI
• 544 women completed two-week DLW protocol with urine and blood 544 women completed two-week DLW protocol with urine and blood collection and with FFQ and other questionnaire data collection collection and with FFQ and other questionnaire data collection (50% intervention, 50% control). A 20% reliability subsample (50% intervention, 50% control). A 20% reliability subsample repeated protocol, separated by about 6 months from original data repeated protocol, separated by about 6 months from original data collection. collection. (NBS)(NBS)
• Biomarker study among 450 women in the WHI Observational Study Biomarker study among 450 women in the WHI Observational Study for evaluating and comparing measurement properties of dietary for evaluating and comparing measurement properties of dietary and physical activity assessment approaches (frequencies, records, and physical activity assessment approaches (frequencies, records, and recalls) and their combination. A 20% reliability subsample and recalls) and their combination. A 20% reliability subsample again included again included (NPAAS)(NPAAS)
. . Human feeding study currently enrolling 150 WHI women in Seattle, Human feeding study currently enrolling 150 WHI women in Seattle, toward developing biomarkers for additional nutrients/foods toward developing biomarkers for additional nutrients/foods (NPAAS2)(NPAAS2)
Acknowledgments
NBS and NPAAS Coordinators: NBS and NPAAS Coordinators: Marian Neuhouser, Lesley Tinker, FHCRCMarian Neuhouser, Lesley Tinker, FHCRC
NBS and NPAAS Clinical Center PIs:NBS and NPAAS Clinical Center PIs:Shirley Beresford - SeattleShirley Beresford - Seattle Judy Ockene - U MassJudy Ockene - U Mass
Regression Calibration Coefficients for Log-Regression Calibration Coefficients for Log-Transformed Total Energy, Total Protein and Transformed Total Energy, Total Protein and
Percent Energy from Protein Percent Energy from Protein (Neuhouser et al, AJE, (Neuhouser et al, AJE, 2008)2008)
Geometric Mean
(95 % Confidence Interval)
Energy (kcal/day) Protein (g/day) % of Energy from Protein
Geometric means and 95% confidence intervals for uncalibrated dietary intakes as estimated by the Women’s Health Initiative (WHI) Food Frequency Questionnaire, and for calibrated intakes using nutritional biomarker data in the WHI Dietary Modification trial comparison group (DM)
and Observational Study (OS)(Prentice et al, AJE, 2009)
Body fat deposition and energy and protein associations with disease risk
Increase in body mass fat deposition (e.g. increased Increase in body mass fat deposition (e.g. increased BMI) over time may be the principal mediator of energy BMI) over time may be the principal mediator of energy and cancer, CVD, and diabetes associations.and cancer, CVD, and diabetes associations.
But, analyses that include BMI in calibration equation But, analyses that include BMI in calibration equation but not in disease risk model require specialized but not in disease risk model require specialized methods (Prentice and Huang, 2011, Can J Stat)methods (Prentice and Huang, 2011, Can J Stat)
NBS calibration equations also used for other NBS calibration equations also used for other purposes(e.g. protein in relation to both frailty and purposes(e.g. protein in relation to both frailty and kidney function (Jeannette Beasley)kidney function (Jeannette Beasley)
Calibration Equation Coefficients (β), Standard Errors (SE), and Percent of Biomarker Variation Explained (R2) from Regression of
Log(biomarker) on Log(self-report), and Other Factors among 450 Observational Study Women
Energy
Prentice RL, Mossavar-Rahmani Y, Huang Y et al (2011, AJE)
Lessons from Studies of Dietary Consumption Effects on Chronic Disease
Control of dietary assessment measurement errors key to Control of dietary assessment measurement errors key to reliable nutritional associations with chronic disease.reliable nutritional associations with chronic disease.
Simple calibration equations that incorporate any of the of Simple calibration equations that incorporate any of the of the dietary assessments considered may be adequate for the dietary assessments considered may be adequate for epidemiologic purposes, for energy, protein and protein epidemiologic purposes, for energy, protein and protein density. Biomarker data across a time period relevant to density. Biomarker data across a time period relevant to disease risk are needed. disease risk are needed.
Development of objective measures for other Development of objective measures for other nutrients/aspects of physical activity, and methodologic nutrients/aspects of physical activity, and methodologic research as to how to use existing nutritional measures, research as to how to use existing nutritional measures, should have a high priority in nutritional epidemiology should have a high priority in nutritional epidemiology research agenda.research agenda.
Can estimate odds ratios (Sugar et al, 2007, Biometrics), or hazard ratios (Shaw and Prentice, 2011, to appear Biometrics), corresponding to Z from cohort data on W and subcohort data on X.
Hazard Ratio Estimation
Under a joint normality assumption for (Z, r + e) given V, conditional expectation of Z of the form
E (Z│Q,V) = b0 + b1Q + b2V and
E(Z I Q,V) = E (W │Q,V)
•Calibrated estimates of Z from linear regression of W on (Q,V) in the biomarker subsample
•Regression calibration estimation of hazard ratios by inserting calibrated consumption estimates in Cox regression, and using a bootstrap procedure for standard error estimation
Hazard Ratio Estimates for a 20% Increment in Nutrient Consumption in Women’s Health Initiative
(Prentice et al, AJE, 2009; Prentice et al, Epidemiol, 2011)
Hazard Ratio Estimates for a 20% Increment in Calibrated FFQ Energy, Protein, and Protein Density in Relation to
Various Cardiovascular Disease Outcomes, from 80,330 Women Enrolled in the WHI Dietary
Modification Trial Comparison Group or Observational Study