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PubMedDate not supplied

Body mass index growth in a sample of U.S. children: repeated measures data analysis of the Minneapolis Children's Blood Pressure Study.

Longitudinal assessments of the body mass index (BMI) in children and adolescents are limited. The purpose of the study was to describe the growth patterns of the BMI in children and young adults. Black and White children of Minneapolis Children's Blood Pressure Study (MCBPS) were 6 to 9 years old at entry and were followed for 12 years at 19 separate visits. Those with at least five visits (n = 1,302) were included for analysis, using non-linear mixed effects models in conjunction with the Gompertz curve. The growth patterns of four sex-ethnic groups were different at three levels: starting level (SL) (kg/m(2)), asymptote level (AL) (kg/m(2)), and peak growth age (PGA) (in years). In this context, SL is the average BMI level at age 6, AL is the average BMI level when growth diminishes, and PGA is the average age at which the rate of growth in the BMI peaks. The SL (16.3 +/- 0.1) for White males was significantly greater than SL in the other three sex-ethnic groups, among which there were no significant differences. There was a significant ethnic difference in AL between Black females (25.5 +/- 0.3) and White females (24.4 +/- 0.2) and a marginally significant difference in AL between Black females and Black males (24.4 +/- 0.3). For PGA, only sex differences were significant: Black females reached the peak at the earliest age at (11.5 +/- 0.1) years, followed by White females (11.7 +/- 0.1), Black males (12.6 +/- 0.1), and White males (12.8 +/- 0.1).

Adolescent↗
PubMed2005

The impact of receiving genetic test results on general and cancer-specific psychologic distress among members of an African-American kindred with a BRCA1 mutation.

BACKGROUND: Numerous studies have examined short-term and long-term psychologic responses to genetic testing for breast/ovarian carcinoma susceptibility in clinic samples and among families who participated in genetic linkage studies. However, to the authors' knowledge, the vast majority of studies focused on non-Latino whites and women. In this prospective study, the authors investigated the psychologic impact of receiving carrier-specific BRCA1 test results as part of a genetic education/counseling intervention in female and male members of an African-American kindred with a BRCA1 mutation. METHODS: Eighty-five of 101 participating kindred members (84%) underwent genetic counseling/education and testing according to an established protocol. Participants completed in-person or telephone-administered, computer-assisted interviews. At baseline and after the receipt of test results (1 mo, 4 mos, and 12 mos), general psychologic distress (i.e., anxiety and depression) and cancer-specific distress were measured. Statistical analyses were performed using linear mixed-model approaches for longitudinal data. RESULTS: The hypothesis that mutation carriers, particularly women who had no personal history of breast carcinoma, were expected to report greater distress than noncarriers was not supported. After controlling for socioeconomic status and personal history of breast/ovarian carcinoma, noncarriers reported significant declines in the distress measures (depressive symptoms, anxiety and cancer-related worries), whereas distress was not altered markedly in carriers after genetic risk notification. CONCLUSIONS: The current findings suggested that individuals receiving BRCA1 test results who learn that they are not carriers of a deleterious mutation may experience psychologic benefits. Furthermore, those who learned that they were mutation carriers did not appear to have adverse, clinically meaningful psychologic outcomes.

Adaptation, Psychological↗
PubMed2005

Alcohol intake in adolescence and mammographic density.

Adolescent exposures may be important in the development of breast cancer later in life. We examined the association of adolescent alcohol consumption and adult mammographic density, a strong risk factor for breast cancer. Women within the Minnesota Breast Cancer Family Cohort with detailed mammogram and risk factor information (n = 1,893) formed our sample. Breast cancer cases were excluded. Adolescent alcohol consumption (before age 18) was solicited through a mailed questionnaire. Percent density (PD) was estimated using the computer-assisted thresholding program, Cumulus. Statistical analyses were performed using linear mixed effect models. Women who reported ever drinking alcohol before age 18 (n = 390; 21%) had a higher unadjusted PD than women who never drank during adolescence (mu(unadj) = 26.5% vs. 22.2%), but this difference disappeared with adjustment for risk factors for mammographic density (mu(adj) = 21.0% vs. 21.2%, p = 0.94). Adult PD was not associated with age at initiation, amount of alcohol consumed at one sitting or frequency of alcohol use before age 18. The lack of differences was seen across strata of menopausal status. There was suggestion of higher PD among heavy and more frequent drinkers (24.0%, 95% CI 21.1-26.8%) compared to lighter (21.3%, 95% CI 20.3-22.3%) and never drinkers (21.4%, 95% CI 20.9-21.9%) and also among regular adolescent drinkers who were daily or weekly adult drinkers (25.0%, 95% CI 23.0-27.0%) compared to less regular drinkers in these 2 time periods (23.0-23.4%). However, these associations were not statistically significant (p = 0.27 and p = 0.22, respectively). In summary, there was no evidence that adolescent alcohol use was associated with large and persistent effects on adult PD.

Adolescent↗
PubMed2006

Clinical pharmacokinetics of the PDT photosensitizers porfimer sodium (Photofrin), 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (Photochlor) and 5-ALA-induced protoporphyrin IX.

BACKGROUND AND OBJECTIVES: Photodynamic therapy (PDT) uses a photosensitizer activated by light, in an oxygen-rich environment, to destroy malignant tumors. Clinical trials of PDT at Roswell Park Cancer Institute (RPCI) use the photosensitizers Photofrin, Photochlor, and 5-ALA-induced protoporphyrin IX (PpIX). In some studies the concentrations of photosensitizer in blood, and occasionally in tumor tissue, were obtained. Pharmacokinetic (PK) data from these individual studies were pooled and analyzed. This is the first published review to compare head-to-head the PK of Photofrin and Photochlor. STUDY DESIGN/MATERIALS AND METHODS: Blood and tissue specimens were obtained from patients undergoing PDT at RPCI. Concentrations of Photofrin, Photochlor, and PpIX were measured using fluorescence analysis. A non-linear mixed effects modeling approach was used to analyze the PK data for Photochlor (up to 4 days post-infusion; two-compartment model) and a simpler multipatient-data-pooling approach was used to model PK data for both Photofrin and Photochlor (at least 150 days post-infusion; three-compartment models). Physiological parameters were standardized to correspond to a standard (70 kg; 1.818 m2 surface area) man to facilitate comparisons between Photofrin and Photochlor. RESULTS: Serum concentration-time profiles obtained for Photofrin and Photochlor showed long circulating half-lives, where both sensitizers could be found more than 3 months after intravenous infusion; however, estimated plasma clearances (standard man) were markedly smaller for Photofrin (25.8 ml/hour) than for Photochlor (84.2 ml/hour). Volumes of distribution of the central compartment (standard man) for both Photofrin and Photochlor were about the size (3.14 L, 4.29 L, respectively) of plasma volume, implying that both photosensitizers are almost 100% bound to serum components. Circulating levels of PpIX were generally quite low, falling below the level of instrument sensitivity within a few days after topical application of 5-ALA. CONCLUSION: We have modeled the PK of Photochlor and Photofrin. PK parameter estimates may, in part, explain the relatively long skin photosensitivity attributed to Photofrin but not Photochlor. Due to the potential impact and limited experimental PK data in the PDT field further clinical studies of photosensitizer kinetics in tumor and normal tissues are warranted.

Administration, Topical↗
PubMed2005

Prospective evaluation of urological effects of aging in chronic spinal cord injury by method of bladder management.

AIMS: Risk of treatment-related problems in spinal cord injury (SCI) mandates assessment of complication rates of different bladder management methods (BMMs). The current study evaluated aging-related complications of various BMMs over a 6-year period in a population with spinal cord injury for at least 20 years. MATERIALS AND METHODS: Clinical parameters were compared using a linear mixed effects model, controlling for various confounding variables, to establish complication trends with aging and their association with BMM. Results for people whose BMM was changed during the study were evaluated separately as well as in combination with the whole population. RESULTS: One hundred and ninety six people (mean age 57.4 and years post injury (YPI) 33) were evaluated on three occasions. Both age and YPI were significantly associated with rising complication rates regardless of BMM. The BMMs assessed differed in terms of complication rates. In comparison with balanced reflex voiding, straining was significantly better for renal structural abnormality. Intermittent catheterization was associated with significantly worse renal function, possibly for demographic reasons. Overall, 28.8% changed BMM during the study period, particularly, those using straining or balanced reflex voiding. The probability of change increased with age and YPI. Reasons for change of BMM were varied and there was no specific association between reason for change and BMM. CONCLUSIONS: Aging and duration of injury substantially influence urological complication rates, and BMM options differ in respect of prevalence and incidence of complications. At a late stage post injury there remains a high probability of change in BMM. The findings indicate the importance of long-term planning from the time of injury to minimize late complications.

Adult↗
PubMed2006

Longitudinal and repeated cross-sectional cluster-randomization designs using mixed effects regression for binary outcomes: bias and coverage of frequentist and Bayesian methods.

As medical applications for cluster randomization designs become more common, investigators look for guidance on optimal methods for estimating the effect of group-based interventions over time. This study examines two distinct cluster randomization designs: (1) the repeated cross-sectional design in which centres are followed over time but patients change, and (2) the longitudinal design in which individual patients are followed over time within treatment clusters. Simulations of each study design stipulated a multiplicative treatment effect (on the log odds scale), between 5 and 15 clusters in each of two treatment arms, and followed over two time periods. Estimation options included linear mixed effects models using restricted maximum likelihood (REML), generalized estimating equations (GEE), mixed effects logistic regression using both penalized quasi likelihood (PQL) and numerical integration, and Bayesian Monte Carlo analysis. For the repeated cross-sectional designs, most methods performed well in terms of bias and coverage when clusters were numerous (30) and variability across clusters of baseline risk and treatment effect was modest. With few clusters (two groups of five) and higher variability, only the Bayesian methods maintained coverage. In the longitudinal designs, the common methods of REML, GEE, or PQL performed poorly when compared to numerical integration, while Bayesian methods demonstrated less bias and better coverage for estimates of both log odds ratios and risk differences. The performance of common statistical tools for the analysis of cluster randomization designs depends heavily on the precise design, the number of clusters, and the variability of baseline outcomes and treatment effects across centres.

Bayes Theorem↗
PubMed1994

Assays for recombinant proteins: a problem in non-linear calibration.

Quantification of protein levels in biological matrices such as serum or plasma frequently relies on the techniques of immunoassay or bioassay. The relevant statistical problem is that of non-linear calibration, where one estimates analyte concentration in an unknown sample from a calibration curve fit to known standard concentrations. This paper discusses a general framework for calibration curve fit to known standard concentrations. This paper discusses a general framework for calibration inference, that of the non-linear mixed effects model. Within this framework, we consider two issues in depth: accurate characterization of intra-assay variation, and the use of empirical Bayes methods in calibration. We show that proper characterization of intra-assay variability requires pooling of information across several assay runs. Simulation work indicates that use of empirical Bayes methods may afford considerable gain in efficiency; one must weigh this gain against practical considerations in the implementation of Bayesian techniques. We illustrate the methods discussed using a cell-based bioassay for the recombinant hormone relaxin.

Bayes Theorem↗
PubMedDate not supplied

Influence of confounding factors on designs for dose-effect relationship estimates.

Three types of designs can be used to estimate the drug dose-effect relationship during phase II clinical trials: parallel-dose designs (parallel); cross-over designs (X), and dose-escalation designs ([symbol: see text]). Despite the use of non-linear mixed effect models, the potential influence of confounding factors on [symbol: see text] designs has not been previously fully elucidated; we undertook simulations to investigate this for all three experimental designs. We found that: (i) monotonic spontaneous evolution of the effect (EV) did not affect the maximum effect estimation (Emax) and the dose giving 50 per cent of this (ED50); (ii) EV similar to a regression to the mean gave rise to biases for [symbol: see text] designs; (iii) the introduction of a pharmacodynamic carry-over generates important biases and imprecision for [symbol: see text] designs, even when the carry-over is adjusted for; (iv) the introduction of non-responders resulted in bias and imprecision for both Emax and ED50 in all three designs.

Antihypertensive Agents↗
PubMed1990

Population pharmacokinetics of phenytoin in Singapore Chinese.

The pharmacokinetics of phenytoin was studied in 66 epileptic Chinese children and adults. The data were analysed by the population approach, using the non-linear mixed effect model, in the MULTI (ELS) program. There was no age or gender-related effect on either the apparent maximum elimination rate (kmax) or Michaelis-Menten constant (KM). Kmax was related to body weight 0.656. The population pharmacokinetics was similar in children and adults. Kmax and KM were estimated to be 30.72 mg.kg-0.656 day-1 and 2.307 mg.l-1, respectively. Kmax was higher than reported values, and KM was comparable to that reported in a study in Japanese, but was much lower than that reported in studies of European patients. The inter-individual variability of KM (CV 65.58%) was substantially higher than that of kmax (CV 28.49%), and the residual (intra-individual) variability was found 21.33% (CV).

Adolescent↗
PubMed1993

Determination of theophylline clearance in South African children.

Theophylline clearance values in South African children were determined using 400 serum theophylline concentration measurements gathered from 109 compliant outpatients during their normal routine care. Population pharmacokinetic analysis was done using the Non-Linear Mixed Effects Model (Nonmem) to analyse the data. Nonmem was also used to estimate the influence of fixed effects (weight, age, race, gender etc) on clearance and its interindividual variability. Gender, age, and weight raised to an iterated exponent were found to be the most important demographic fixed effect parameters influencing clearance. Race was not found to be important. The weight-adjusted values of theophylline clearance decreased with increasing age. The actual values expressed in l.h-1.kg-1 were 0.0949 for children aged 1-5 y; 0.0813 for children aged 5-9 y, and 0.0660 for children of 9-16 y. The values are similar to those reported in other studies.

Adolescent↗
PubMed2003

QTL x environment interactions in rice. I. heading date and plant height.

One hundred twenty six doubled-haploid (DH) rice lines were evaluated in nine diverse Asian environments to reveal the genetic basis of genotype x environment interactions (GEI) for plant height (PH) and heading date (HD). A subset of lines was also evaluated in four water-limited environments, where the environmental basis of G x E could be more precisely defined. Responses to the environments were resolved into individual QTL x environment interactions using replicated phenotyping and the mixed linear-model approach. A total of 37 main-effect QTLs and 29 epistatic QTLs were identified. On average, these QTLs were detectable in 56% of the environments. When detected in multiple environments, the main effects of most QTLs were consistent in direction but varied considerably in magnitude across environments. Some QTLs had opposite effects in different environments, particularly in water-limited environments, indicating that they responded to the environments differently. Inconsistent QTL detection across environments was due primarily to non- or weak-expression of the QTL, and in part to significant QTL x environment interaction effects in the opposite direction to QTL main effects, and to pronounced epistasis. QTL x environment interactions were trait- and gene-specific. The greater GEI for HD than for PH in rice were reflected by more environment-specific QTLs, greater frequency and magnitude of QTL x environment interaction effects, and more pronounced epistasis for HD than for PH. Our results demonstrated that QTL x environment interaction is an important property of many QTLs, even for highly heritable traits such as height and maturity. Information about QTL x environment interaction is essential if marker-assisted selection is to be applied to the manipulation of quantitative traits.

Chromosome Mapping↗
PubMed2003

Population pharmacokinetics of gentamicin in South African newborns.

OBJECTIVE: Gentamicin population pharmacokinetics in newborns were studied with special reference to possible gender effects. METHODS: Steady-state serum levels ( n=139) were obtained from 79 neonates with a mean birth weight of 2.1 kg, mean gestational age of 35.1 weeks and mean age at the time of sampling of 4.2 days. The data were analysed using the non-linear mixed effects model (NONMEM). A one-compartment model was used to fit the data. RESULTS: The final models for clearance (CL) and volume of distribution (V) were: CL(l/h)=0.001xWGTxGAxP and V(l)=0.472xWGT, where WGT=birth weight (kg), GA=gestational age (weeks) and P=1.2 for girls and 1.0 for boys. The values of inter-individual variability in CL and V were 34% and 35%, respectively. Intra-individual variability was 5% (proportional) and 7.2% (additive). Mean (95% confidence interval) values of CL and half-life were 0.042 l h(-1) kg(-1) (0.041, 0.043 l h(-1) kg(-1)) and 8.0 h (7.7, 8.3 h), while V was 0.472 (0.428, 0.516) l/kg for all patients. CONCLUSION: Mean population pharmacokinetic values were similar to those obtained with NONMEM for gentamicin in other neonates of similar age. Gender was found to be a determinant of CL, with girls clearing faster than boys.

Anti-Bacterial Agents↗
PubMed1996

Population pharmacokinetics and pharmacodynamics of oral levodopa in parkinsonian patients.

OBJECTIVE: The population pharmacokinetics and pharmacodynamics of a standardised oral test dose of levodopa have been determined in patients with mild to severe Parkinson's disease using parametric, non-linear mixed effect modelling with the program NON-MEM. Levodopa plasma concentration data and motor effect behaviour (tapping times) were obtained from 46 patients, for whom a total of 970 observations were available (approximately 21 pharmacokinetic and pharmacodynamic observations per patient). The pharmacokinetic-pharmacodynamic model used was a one-compartment first-order absorption model linked to the sigmoid EMax representation of the Hill equation via an equilibration rate-constant, ke0. The model was also tested via a reduction in the number of pharmacokinetic and pharmacodynamic data points to a total of four to eight per patient. RESULTS: In the final regression models the Hoehn and Yahr (HY) status of the patient and duration of disease (DUR) were found to be important determinants of the pharmacodynamic parameters for levodopa. The pharmacokinetic parameters were not significantly affected by any covariates. A test group of 16 additional parkinsonian patients was used to evaluate the predictive performance of the population parameters. The predictive performance of the pharmacokinetic-pharmacodynamic modelling using the full and reduced data sets was evaluated in NONMEM using posthoc, Bayesian forecasting. Statistically insignificant bias existed among predicted and observed levodopa concentrations, whereas the pharmacodynamic model underpredicted the observed tapping times. There was little difference in the pharmacokinetic-pharmacodynamic predictive performance among results for the full and the reduced data sets. CONCLUSION: In a clinical setting knowledge of the population pharmacokinetic and pharmacodynamic parameters for oral levodopa may prove useful in estimating the duration of the drug's beneficial motor activity in patients with mild to severe Parkinson's disease (Hoehn and Yahr status I-IV).

Administration, Oral↗
PubMed2002

Estimation of glomerular filtration rate in children.

The aim of this study was to develop a method to predict the glomerular filtration rate (GFR) in children by using the population pharmacokinetic approach. This powerful approach is widely used for drug development in order to study relationships between patients' characteristics (demographic, morphological, biological covariates) and pharmacokinetic parameters. For the first time, (51)Cr-EDTA plasma concentrations from 64 children (development data set) were analyzed using the Non-linear Mixed Effects Model (NONMEM) program to determine the most appropriate equation to relate (51)Cr-EDTA clearance (as a measurement of GFR) and patient characteristics. The most predictive equation was based on body weight, square height, and plasma creatinine (PCr, determined by the Jaffé method). This equation was then validated using the data from a further 33 patients. This equation produced estimates of GFR that were less biased and more precise than those obtained using the widely used Schwartz formula. The coefficient of correlation between estimated and actual GFR was 0.83, and the 10th to 90th percentiles for percentage errors were -20% to +30%. Finally, analysis of the whole data set (97 patients) led to an equation (i.e., GFR (ml/min)=[56.7 x Body weight (kg)+0.142 x Length(2)(cm)]/PCr ( microM)) very similar to that obtained from the development data set. This equation would be useful for estimating GFR in children when isotopic determination of the (51)Cr-EDTA clearance cannot be performed.

Adolescent↗
PubMed2006

Response diversity of Arabidopsis thaliana ecotypes in elevated [CO2] in the field.

Free Air [CO(2)] Enrichment (FACE) allows for plant growth under fully open-air conditions of elevated [CO(2)] at concentrations expected to be reached by mid-century. We used Arabidopsis thaliana ecotypes Col-0, Cvi-0, and WS to analyze changes in gene expression and metabolite profiles of plants grown in "SoyFACE" (http://www.soyface.uiuc.edu/), a system of open-air rings within which [CO(2)] is elevated to approximately 550 ppm. Data from multiple rings, comparing plants in ambient air and elevated [CO(2)], were analyzed by mixed model ANOVA, linear discriminant analysis (LDA) and data-mining tools. In elevated [CO(2)], decreases in the expression of genes related to chloroplast functions characterized all lines but individual members of distinct multi-gene families were regulated differently between lines. Also, different strategies distinguished the lines with respect to the regulation of genes related to carbohydrate biosynthesis and partitioning, N-allocation and amino acid metabolism, cell wall biosynthesis, and hormone responses, irrespective of the plants' developmental status. Metabolite results paralleled reactions seen at the level of transcript expression. Evolutionary adaptation of species to their habitat and intrinsic genetic plasticity seem to determine the nature of responses to elevated [CO(2)]. Irrespective of their underlying genetic diversity, and evolutionary adaptation to different habitats, a small number of common, predominantly stress-responsive, signature transcripts appear to characterize responses of the Arabidopsis ecotypes in FACE.

Analysis of Variance↗
PubMed1992

Mixed-type inhibition of bovine lung angiotensin converting enzyme by lisinopril and its dansyl derivative.

The steady-state inhibition of bovine lung angiotensin converting enzyme (ACE; EC 3.4.15.1) by the slow-binding inhibitor lisinopril and its dansyl derivative conformed to a linear mixed inhibition model with inhibitor binding to ES as well as to E. Studied at pH8, 35 degrees, and using N-(3-[2-furyl]-acryloyl)phe-gly-gly as substrate, the approach to steady-state activity at different substrate concentrations pointed to slow isomerizations in both EI and EIS. While an inhibitory scheme involving a single I-binding site adequately accounts for the data presented, information relating to the primary structure of ACE brings up a two-site alternative which remains to be tested.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Inhibition of radiation-induced up-regulation of leukocyte adhesion to endothelial cells with the platelet-activating factor inhibitor, BN52021.

PURPOSE: The inflammatory process is likely involved in normal tissue damage after radiation exposure, yet few studies have directly evaluated the factors that might be involved in the regulation of inflammation after irradiation in vivo. We tested the hypothesis that platelet-activating factor, a neutrophil agonist synthesized by endothelial cells, is involved in the upregulation of radiation-induced leukocyte-endothelial cell interactions by using an inhibitor of its receptor, BN52021. METHODS AND MATERIALS: Fischer-344 rats with dorsal skin-fold window chambers were randomized to three experimental groups: control (sham irradiation); 6 Gy radiation; and 6 Gy + BN52021. BN52021 (0.5 mg/kg) was administered 5 min prior to 6 Gy radiation. Leukocytes were stained in vivo with i.v. acridine orange for visualization with fluorescent microscopy. Venous vessel diameters were measured and number of rolling leukocytes were counted per 30-s period. The number of adhering leukocytes per unit surface area was also determined. Differences among the three experimental groups for rolling and adhering leukocytes were analyzed using a mixed-effects linear model with vessel shear rate used as a covariate. Results are reported as means +/- standard errors. RESULTS: Irradiation caused upregulation of leukocyte rolling, as compared with sham-treated controls (p = 0.04): the BN compound in addition to radiation did not downregulate this effect. Irradiation also upregulated leukocyte adhesion (p < 0.001), but the addition of BN52021 prior to irradiation blocked this effect. The drug did not affect heart rate or blood pressure. CONCLUSIONS: These results support the hypothesis that radiation-induced upregulation of leukocyte adhesion is mediated by platelet-activating factor. These results are consistent with prior reports that platelet-activating factor is not involved in leukocyte rolling, which involves separate families of adhesion molecules from those that regulate adhesion. BN52021, a ginkolide, or other related drugs might provide a useful pharmacological means to prevent or ameliorate inflammatory pathways that are invoked after radiation exposure.

Animals↗
PubMed2025

Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program.

BACKGROUND: Low vitamin D concentrations are common-especially among those with darker pigmented skin-and are frequently observed during pregnancy. Given its important role in brain development, inadequate gestational vitamin D may impair child cognitive development. OBJECTIVES: We aimed to evaluate associations of gestational vitamin D concentrations with childhood cognitive scores, explore whether this relationship differs by self-reported race, and examine sensitive exposure windows within pregnancy. METHODS: This prospective cohort study included 912 mother-child dyads (37.3% Black, 52.3% White) from the Environmental influences on Child Health Outcomes program. 25-hydroxyvitamin D [25(OH)D] concentrations were measured in prenatal or cord blood collected between 4 and 42 wk gestation (median: 23 wk). Children's cognition was assessed at ages 7-12 y using the NIH Toolbox Cognition Battery. Relationships of 25(OH)D and cognitive scores were examined using mixed-effects linear models adjusted for confounders. Potential sensitive periods were explored by estimating population 25(OH)D patterns across gestation for varying levels of the cognitive outcomes. RESULTS: Mean gestational 25(OH)D was 23.8 ng/mL (SD: 10.0 ng/mL). Each 10-ng/mL increase was associated with greater overall (&#x3b2;: 1.11; 95% CI: 0.08, 2.14) and fluid cognition scores (&#x3b2;: 1.21; 95% CI: 0.07, 2.34), but not crystallized cognition. Although these associations were not significantly modified by self-reported race, associations appeared stronger in children of Black mothers (&#x3b2;: 2.99; 95% CI: 0.82, 5.16) than those in non-Black mothers (&#x3b2;: 0.43; 95% CI: -0.93, 1.78) for fluid cognition. Early pregnancy may be a critical exposure period, evidenced by the greatest divergence in the pattern of 25(OH)D during this period between the mothers of children in the 90th and those in the 10th percentiles of cognitive outcomes. CONCLUSIONS: Gestational 25(OH)D concentrations were positively associated with cognitive scores, especially in children of Black mothers. Given higher deficiency risk among Black women, vitamin D repletion before or in early pregnancy may be an important strategy for reducing racial disparities in child neurodevelopment.

Humans↗