title: Physical activity assessment: biomarkers and self-report of activity-related energy expenditure in the WHI.
abstract: We used a biomarker of activity-related energy expenditure (AREE) to assess measurement properties of self-reported physical activity and to determine the usefulness of AREE regression calibration equations in the Women's Health Initiative. Biomarker AREE, calculated as the total energy expenditure from doubly labeled water minus the resting energy expenditure from indirect calorimetry, was assessed in 450 Women's Health Initiative participants (2007-2009). Self-reported AREE was obtained from the Arizona Activity Frequency Questionnaire (AAFQ), the 7-Day Physical Activity Recall (PAR), and the Women's Health Initiative Personal Habits Questionnaire (PHQ). Eighty-eight participants repeated the protocol 6 months later. Reporting error, measured as log(self-report AREE) minus log(biomarker AREE), was regressed on participant characteristics for each instrument. Body mass index was associated with underreporting on the AAFQ and PHQ but overreporting on PAR. Blacks and Hispanics underreported physical activity levels on the AAFQ and PAR, respectively. Underreporting decreased with age for the PAR and PHQ. Regressing logbiomarker AREE on logself-reported AREE revealed that self-report alone explained minimal biomarker variance (R(2) = 7.6, 4.8, and 3.4 for AAFQ, PAR, and PHQ, respectively). R(2) increased to 25.2, 21.5, and 21.8, respectively, when participant characteristics were included. Six-month repeatability data adjusted for temporal biomarker variation, improving R(2) to 79.4, 67.8, and 68.7 for AAFQ, PAR, and PHQ, respectively. Calibration equations "recover" substantial variation in average AREE and valuably enhance AREE self-assessment.
authors: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, M4-B402, Seattle, WA 98109–1024, USA. mneuhous@fhcrc.org
authors: Marian L
authors: ML
authors: Neuhouser
authors: Chongzhi
authors: C
authors: Di
authors: Lesley F
authors: LF
authors: Tinker
authors: Cynthia
authors: C
authors: Thomson
authors: Barbara
authors: B
authors: Sternfeld
authors: Yasmin
authors: Y
authors: Mossavar-Rahmani
authors: Marcia L
authors: ML
authors: Stefanick
authors: Stacy
authors: S
authors: Sims
authors: J David
authors: JD
authors: Curb
authors: Michael
authors: M
authors: Lamonte
authors: Rebecca
authors: R
authors: Seguin
authors: Karen C
authors: KC
authors: Johnson
authors: Ross L
authors: RL
authors: Prentice
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D011939:Mental Recall; D009043:Motor Activity; D017698:Postmenopause; D011446:Prospective Studies; D057566:Self Report; D011795:Surveys and Questionnaires; D014481:United States; D016387:Women's Health
chemical_list: D015415:Biomarkers