Bodnar Lisa M, Catov Janet M, Wisner Katherine L, Klebanoff Mark A
Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, A742 Crabtree Hall, 130 DeSoto Street, Pittsburgh, PA 15261, USA.
Br J Nutr. 2009 Jan;101(2):278-84. doi: 10.1017/S0007114508981460. Epub 2008 Apr 23.
Serum banks from large, decades-old epidemiological studies provide a valuable opportunity to explore the contributions of in utero vitamin D exposure to fetal origins of adult diseases. We compared 25-hydroxyvitamin D (25(OH)D) by race and season (two powerful predictors of vitamin D status) in sera frozen for >or= 40 years with sera frozen for <or= 2 years to determine whether 25(OH)D is stable enough to test vitamin D-related hypotheses. Data and sera came from seventy-nine pregnant women at 29-32 weeks' gestation in the Boston Collaborative Perinatal Project (CPP; 1959-66) and 124 women at 20-36 weeks' gestation in a 2003-2006 Pittsburgh cohort study. Multivariable linear regression models were used to test main and joint effects of race and season after confounder adjustment. In both cohorts, serum 25(OH)D levels were lower among black than white women (CPP 33.3 v. 46.7 nmol/l, P<0.01; Pittsburgh 47.1 v. 89.6 nmol/l; P<0.0001) and in winter than summer (CPP 32.7 v. 47.6 nmol/l, P<0.0001; Pittsburgh 66.7 v. 89.8 nmol/l, P<0.001), with no evidence of a race x season interaction in either cohort. Differences remained significant after confounder adjustment. When CPP and Pittsburgh results were compared, there was no significant difference in the race or season effects. The similarity in the relative change in 25(OH)D in these cohorts by two powerful predictors of vitamin D status suggests that, even if 25(OH)D deteriorated somewhat, it did so similarly across samples. Therefore, trends could be obtained from the decades-old serum data that would be relevant in exploring vitamin D-related hypotheses in future studies.
来自大规模、开展了数十年的流行病学研究的血清库，为探究子宫内维生素D暴露对成人疾病胎儿起源的影响提供了宝贵机会。我们比较了种族和季节（维生素D状态的两个重要预测因素）对冷冻了≥40年的血清和冷冻了≤2年的血清中25-羟基维生素D（25(OH)D）水平的影响，以确定25(OH)D是否足够稳定，能够用于检验与维生素D相关的假设。数据和血清来自波士顿协作围产期项目（CPP；1959 - 1966年）中79名妊娠29 - 32周的孕妇，以及2003 - 2006年匹兹堡队列研究中124名妊娠20 - 36周的女性。在进行混杂因素调整后，使用多变量线性回归模型来检验种族和季节的主要及联合效应。在两个队列中，黑人女性血清25(OH)D水平均低于白人女性（CPP队列中分别为33.3和46.7 nmol/L，P<0.01；匹兹堡队列中分别为47.1和89.6 nmol/L，P<0.0001），且冬季低于夏季（CPP队列中分别为32.7和47.6 nmol/L，P<0.0001；匹兹堡队列中分别为66.7和89.8 nmol/L，P<0.001），两个队列中均未发现种族×季节的交互作用。在进行混杂因素调整后，差异仍然显著。当比较CPP和匹兹堡队列的结果时，种族或季节效应没有显著差异。这两个维生素D状态的重要预测因素在这些队列中25(OH)D相对变化的相似性表明，即使25(OH)D有所降解，不同样本的降解情况也是相似的。因此，可以从数十年前的血清数据中得出趋势，这对于在未来研究中探索与维生素D相关的假设具有重要意义。
