Changes in vitamin D status of overweight and obese 6 to 12- year old children: Results from a 1 year, family-centred lifestyle intervention
Notice bibliographique
Résumé
Background: Vitamin D status is lower in Canadian children who are overweight or obese compared to children of healthy weights. Objective: The objectives of this study are 1) to determine the vitamin D status of overweight and obese children, 2) to examine the association between changes in fat mass (FM) and vitamin D status, and 3) to determine if there is a relationship between regional adiposity and blood concentrations of 25-hydroxyvitamin D (25(OH)D).Methods: Data was collected at baseline, and then every 3 months for a one year period, from participants enrolled in the McGill Youth and Lifestyle Intervention with Food and Exercise (MYLIFE) study (NCT01290016); healthy children aged 6-12 y with body mass index (BMI)-for-age >85th percentile were included. Chemiluminescence immunoassay was used to measure plasma 25(OH)D. Standard measurements of weight, height and waist circumference (WC) were taken at each visit; BMI and BMI z-scores were calculated (WHO AnthroPlus, Geneva, Switzerland, 2009). Body composition was measured using dual-energy X-ray absorptiometry to determine whole body and regional adiposity. Z-scores for adiposity indicators were calculated based on reference data from the National Health and Nutrition Examination Survey; children were then separated into tertiles based on these z-scores. Constitutive and facultative skin pigmentation was measured using a hand-held spectrophotometer in order to determine Fitzpatrick skin types. Children were categorized according to cutaneous UVB synthesis period. Ethnicity was self-disclosed and pubertal status was reported at baseline and categorized according to Tanner stages. Differences in 25(OH)D among tertiles of each adiposity indicator (eg: % body fat (%BF), FM, WC) were tested using a mixed model ANOVA. Logistic regression was used to determine the odds ratio of not meeting recommended 25(OH)D cutoffs. Results: Data from 101 children (46 boys and 55 girls) were used in this study. The mean 25(OH)D concentration at baseline was 59.8 ± 1.3 nmol/L, with no significant difference between sexes (p=0.740). Boys had lower %BF (p=0.012), greater BMI z-scores (p=0.001) and greater WC (p=0.013) than girls. After one year, those who decreased FM appeared to have better plasma 25(OH)D than those who maintained or gained FM (59.2 vs. 55.3 nmol/L; p=0.310), although significance was not reached. Every kg increase in FM was associated to increased odds of not reaching plasma 25(OH)D cutoffs of 75 nmol/L (OR: 1.2, 95% CI: 1.1-1.4, p=0.006). Arm fat (OR: 2.6, 95% CI: 1.3-5.2, p=0.009) was associated to greater odds of missing the cutoff than leg fat (OR: 1.6, 95% CI: 1.1-2.3, p=0.009). Android:gynoid fat patterning was not significant (p=0.066). Conclusion: Adiposity in overweight and obese children, irrespective of location, has an inverse relationship with vitamin D status. Therefore, adiposity likely needs to be considered when establishing dietary intake recommendations to match population cutoffs for vitamin D status. Future large-scale longitudinal research is required to examine if a reduction in FM would lead to a significant increase in vitamin D status.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».