{"title":"当对有限数量的理论受试者使用视黄醇同位素稀释进行基于人群的建模时，一种保持维生素A总体内储存预测准确性的方法。","authors":"Michael H Green, Joanne Balmer Green","doi":"10.1016/j.tjnut.2025.01.015","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Retinol isotope dilution (RID) equations are used to predict vitamin A total body stores (TBS). Including population-based (\"super-subject\") modeling with RID provides group-specific values for the equation coefficients.</p><p><strong>Objectives: </strong>The objective was to test an approach that would accommodate a limited super-subject sample size without compromising accuracy in RID predictions of TBS.</p><p><strong>Methods: </strong>We used Simulation, Analysis and Modeling software to simulate fraction of dose in plasma (FD<sub>p</sub>) at 16 times from 3 h to 56 d after tracer ingestion in 20 theoretical adults. Then, we modeled geometric mean FD<sub>p</sub> (\"full dataset\") to determine group mean TBS and the coefficients Fa (FD in stores) and S (specific activity in plasma/stores) in the RID equation TBS (μmol) = FaS/plasma retinol specific activity. Using the same FD<sub>p</sub> data, we also generated 4 datasets with reduced subject numbers at times other than that designated for RID (day 21). Then, we adjusted individual FD<sub>p</sub> using the ratio (individual FD<sub>p</sub> on day 21/mean FD<sub>p</sub> on day 21; \"adjusted datasets\"), modeled each, and determined TBS and FaS for comparison with the full dataset values.</p><p><strong>Results: </strong>Mean ratio of model-predicted TBS for adjusted/full dataset was 0.962 (range: 0.920-1.06) and for FaS, it was 0.945 (day 14), 0.971 (day 21), and 0.984 (day 28).</p><p><strong>Conclusions: </strong>For these theoretical data, adjusting individual FD<sub>p</sub> values based on relationship to the group mean FD<sub>p</sub> at an appropriate time (21 d) maintains the accuracy of model predictions of TBS and the RID composite coefficient FaS. If these results are confirmed using real data, values for FaS determined in a small super-subject study can be applied to confidently predict TBS by RID in that group's individuals. This approach will be especially useful when resources are limited for studies of vitamin A status in community settings.</p>","PeriodicalId":16620,"journal":{"name":"Journal of Nutrition","volume":" ","pages":""},"PeriodicalIF":3.7000,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A Method That Maintains Accuracy in the Prediction of Vitamin A Total Body Stores When Population-Based Modeling of a Limited Number of Theoretical Subjects Is Used With Retinol Isotope Dilution.\",\"authors\":\"Michael H Green, Joanne Balmer Green\",\"doi\":\"10.1016/j.tjnut.2025.01.015\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Retinol isotope dilution (RID) equations are used to predict vitamin A total body stores (TBS). Including population-based (\\\"super-subject\\\") modeling with RID provides group-specific values for the equation coefficients.</p><p><strong>Objectives: </strong>The objective was to test an approach that would accommodate a limited super-subject sample size without compromising accuracy in RID predictions of TBS.</p><p><strong>Methods: </strong>We used Simulation, Analysis and Modeling software to simulate fraction of dose in plasma (FD<sub>p</sub>) at 16 times from 3 h to 56 d after tracer ingestion in 20 theoretical adults. Then, we modeled geometric mean FD<sub>p</sub> (\\\"full dataset\\\") to determine group mean TBS and the coefficients Fa (FD in stores) and S (specific activity in plasma/stores) in the RID equation TBS (μmol) = FaS/plasma retinol specific activity. Using the same FD<sub>p</sub> data, we also generated 4 datasets with reduced subject numbers at times other than that designated for RID (day 21). Then, we adjusted individual FD<sub>p</sub> using the ratio (individual FD<sub>p</sub> on day 21/mean FD<sub>p</sub> on day 21; \\\"adjusted datasets\\\"), modeled each, and determined TBS and FaS for comparison with the full dataset values.</p><p><strong>Results: </strong>Mean ratio of model-predicted TBS for adjusted/full dataset was 0.962 (range: 0.920-1.06) and for FaS, it was 0.945 (day 14), 0.971 (day 21), and 0.984 (day 28).</p><p><strong>Conclusions: </strong>For these theoretical data, adjusting individual FD<sub>p</sub> values based on relationship to the group mean FD<sub>p</sub> at an appropriate time (21 d) maintains the accuracy of model predictions of TBS and the RID composite coefficient FaS. If these results are confirmed using real data, values for FaS determined in a small super-subject study can be applied to confidently predict TBS by RID in that group's individuals. This approach will be especially useful when resources are limited for studies of vitamin A status in community settings.</p>\",\"PeriodicalId\":16620,\"journal\":{\"name\":\"Journal of Nutrition\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":3.7000,\"publicationDate\":\"2025-01-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Nutrition\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1016/j.tjnut.2025.01.015\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"NUTRITION & DIETETICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nutrition","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.tjnut.2025.01.015","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"NUTRITION & DIETETICS","Score":null,"Total":0}
A Method That Maintains Accuracy in the Prediction of Vitamin A Total Body Stores When Population-Based Modeling of a Limited Number of Theoretical Subjects Is Used With Retinol Isotope Dilution.
Background: Retinol isotope dilution (RID) equations are used to predict vitamin A total body stores (TBS). Including population-based ("super-subject") modeling with RID provides group-specific values for the equation coefficients.
Objectives: The objective was to test an approach that would accommodate a limited super-subject sample size without compromising accuracy in RID predictions of TBS.
Methods: We used Simulation, Analysis and Modeling software to simulate fraction of dose in plasma (FDp) at 16 times from 3 h to 56 d after tracer ingestion in 20 theoretical adults. Then, we modeled geometric mean FDp ("full dataset") to determine group mean TBS and the coefficients Fa (FD in stores) and S (specific activity in plasma/stores) in the RID equation TBS (μmol) = FaS/plasma retinol specific activity. Using the same FDp data, we also generated 4 datasets with reduced subject numbers at times other than that designated for RID (day 21). Then, we adjusted individual FDp using the ratio (individual FDp on day 21/mean FDp on day 21; "adjusted datasets"), modeled each, and determined TBS and FaS for comparison with the full dataset values.
Results: Mean ratio of model-predicted TBS for adjusted/full dataset was 0.962 (range: 0.920-1.06) and for FaS, it was 0.945 (day 14), 0.971 (day 21), and 0.984 (day 28).
Conclusions: For these theoretical data, adjusting individual FDp values based on relationship to the group mean FDp at an appropriate time (21 d) maintains the accuracy of model predictions of TBS and the RID composite coefficient FaS. If these results are confirmed using real data, values for FaS determined in a small super-subject study can be applied to confidently predict TBS by RID in that group's individuals. This approach will be especially useful when resources are limited for studies of vitamin A status in community settings.
期刊介绍：
The Journal of Nutrition (JN/J Nutr) publishes peer-reviewed original research papers covering all aspects of experimental nutrition in humans and other animal species; special articles such as reviews and biographies of prominent nutrition scientists; and issues, opinions, and commentaries on controversial issues in nutrition. Supplements are frequently published to provide extended discussion of topics of special interest.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
