Validity of Diet and Activity Measures in Men

描述（由申请人提供）：饮食和癌症的大型前瞻性研究通常不支持基于动物和生态发现的假设；一种可能的解释是，对饮食的评估存在较大的测量误差。因此，NCI要求在现有队列中进行一系列协作验证/校准研究，该研究采用通用设计，采用多种自我报告和生物标志物测量饮食和身体活动，包括双标记水（DLW）、尿氮（UN）和运动监测仪。因此，我们建议在750名男性中进行这样的研究。拟议的研究将补充一项非常类似的研究，NCI正在资助妇女，使用许多相同的方法，在护士健康研究的参与者中。这两项研究将产生巨大的协同效应。在拟议的研究中，375名男性将参加正在进行的卫生专业人员随访研究（HPFS），这将具有特别的价值，因为已经收集了丰富的数据。其他375名参与者将从波士顿地区的HMO哈佛朝圣者医疗保健中心（Harvard Pilgrim Health Care）抽取。这个参与者池将允许更广泛的社区代表，非裔美国人的过采样，并有可能与临床数据库联系。在HPFS中，我们已经使用多种摄入测量和饮食血浆生物标志物收集了广泛的饮食数据；这将允许在23年期间对饮食评估方法的有效性进行评估。建议的研究设计将由两个FFQ组成，间隔一年；在这些测量之间的一年中，我们将收集四次NCI自动自我管理的24小时召回（ASA24），两份7天饮食记录和饮食生物标志物，包括一次使用双标签水（DLW）评估能量消耗，四次24小时尿氮（蛋白质摄入量的测量），钠和钾，以及两份空腹血液样本用于评估脂肪酸，标准脂质，类胡萝卜素和叶酸。身体活动将通过修改后的帕芬巴格身体活动问卷进行两次评估（与FFQ一起），使用NCI开发的自动化系统进行4次24小时召回，通过客观身体活动监测仪进行两次评估，并由DLW进行评估。在来自波士顿地区的575名男性中（来自HPFS和HMO），我们还将评估DEXA和静息代谢率，以完善能量消耗测量。这些多重测量将允许评估与饮食和身体活动评估方法相关的误差结构，特别是每种方法随时间变化的影响以及方法之间的相关误差。这将提供不同测量方法的相对效度和绝对效度的信息，并为已发表的饮食和癌症文献的解释（允许测量误差校正）和未来验证/校准研究的设计提供信息。进一步的分析将指出根据总能量摄入调整营养摄入的最佳方法，这对解释流行病学发现至关重要。

DESCRIPTION (provided by applicant): Large prospective studies of diet and cancer have often not supported hypotheses that were based on animal and ecological findings; one possible explanation could be large measurement errors in the assessment of diet. Thus, NCI had requested proposals for a series of collaborative validation/calibration studies imbedded in existing cohorts using a common design with multiple self-reported and biomarker measures of diet and physical activity including doubly labeled water (DLW), urinary nitrogen (UN) and motion monitors. We therefore propose to conduct such a study among 750 men. The proposed study will complement a very similar study that NCI is funding in women, utilizing many of the same methods, among participants in the Nurses' Health Studies. The two studies will provide substantial synergy. For the proposed study, 375 men will be participants in the ongoing Health Professionals Follow-up Study (HPFS), which will be of particular value because of the rich data already collected. The other 375 participants will be drawn from Harvard Pilgrim Health Care, a Boston-area HMO. This participant pool will permit a broader representation of the community, with oversampling of African-Americans, and the potential with linkage to the clinical database. In HPFS, we have already collected extensive dietary data using multiple measures of intake and plasma biomarkers of diet; this will allow the evaluation of the validity of dietary assessment methods over a 23-year period. The proposed study design will consist of two FFQ's one year apart; in the year between these measures we will collect four NCI automated self-administered 24-hour recalls (ASA24), two 7-day dietary records, and biomarkers of diet including one assessment of energy expenditure using doubly-labeled water (DLW), four 24-hour urinary measures of nitrogen (a measure of protein intake), sodium and potassium, and two fasting blood samples for assessment of fatty acids, standard lipids, carotenoids, and folate. Physical activity will be assessed twice (together with the FFQ's) by the modified Paffenbarger physical activity questionnaire, by four 24-hour recalls using an automated system developed by the NCI, twice by an objective physical activity monitor, and by DLW. In the 575 men from the Boston area (from the HPFS and the HMO), we will also assess DEXA and resting metabolic rate to refine energy expenditure measures. These multiple measurements will allow an evaluation of the error structure associated with dietary and physical activity assessment methods, in particular the influences of variation over time for each method and correlated errors between methods. This will provide information of the relative and absolute validity of the different measures, and inform the interpretation of the published literature on diet and cancer (allowing for measurement error correction) and the design of future validation/calibration studies. Additional analyses will indicate the optimal approaches to adjust nutrient intakes for total energy intake, which is critical for the interpretation of epidemiologic findings. PUBLIC HEALTH RELEVANCE: The proposed validation/calibration study will provide quantitative data on the validity of the methods that have been used in cohort studies to measure diet and physical activity. This information would greatly enhance the value of the data that have been collected and would also provide invaluable guidance for the design and collection of future data on diet and physical activity and cancer by other investigators, resulting in great benefit to public health.