The aims were to examine the potential of FFQ data to explain intake variation in a WHI Feeding Study and to compare association parameter estimates and their precision from studies based on biomarker-calibrated FFQ intake in larger WHI cohorts, with those previously presented.
Serum-based intake measures were augmented by using FFQ data in a WHI Feeding Study (n = 153). Corresponding calibration equations were generated, both in a companion Nutritional Biomarker Study (n = 436) and in the previously mentioned subcohort (n = 5488), by regressing these intake measures on dietary data and participant characteristics, for α- and β-carotene, lutein plus zeaxanthin, and α-tocopherol. The supplemental value of FFQ data was considered by examining the fraction of feeding study intake variation explained by these regression models. Calibrated intake and disease association analyses were evaluated by comparisons with previously reported subcohort results.
The inclusion of FFQ data led to some increases in feeding study intake variation explained (total R2 of ∼50%). Calibrated intake estimates explained 25-75% of serum-based intake variation, whether developed using either of the 2 cohort subsamples. Related disease associations for micronutrients were precisely estimated in larger WHI cohorts (n = 76,691) but were often closer to the null compared with previously reported associations.
FFQ data may usefully augment blood concentrations in estimating the intake of carotenoids and tocopherols. Calibrated intake estimates using FFQ, dietary supplement, and participant characteristics only may require further justification to ensure reliable estimation of related disease associations.
目的是检查FFQ数据在WHI喂养研究中解释摄入量变化的潜力,并比较基于较大WHI队列中生物标志物校准的FFQ摄入量的研究的关联参数估计及其精度。
通过在WHI喂养研究中使用FFQ数据来增强基于血清的摄入测量(n=153)。
纳入FFQ数据导致喂养研究摄入量变化的一些增加(总R2为50%)。
FFQ数据在估计类胡萝卜素和生育酚的摄入量时可以有效地增加血液浓度。