Abstract
OBJECTIVES: To assess the percentage of women of childbearing age with suboptimal levels of folate for protecting against neural tube defects (<906 nM), and assess folate status among the elderly.
METHODS: A total of 1,035 anonymous blood samples from a centralized clinical laboratory, with a catchment area across the Greater Toronto Area, were assessed for red blood cell (RBC) folate concentrations using a chemiluminescent immunoassay. Folate analysis was requested by physicians as part of clinical care. Available data included age, sex, and RBC folate concentration. Descriptive statistics were used to characterize the percent of women who had suboptimal blood folate concentrations, and a multiple regression was used to analyze determinants of folate status.
RESULTS: Our data from 2013 show that 7% of women of childbearing age (15–45 years) had RBC folate concentrations below 906 nM, a substantially lower percentage than in our 2006 study (40%). Results from the multiple regression showed that age is a significant positive predictor of higher RBC folate status (p < 0.001).
CONCLUSION: Compared to our earlier data, we report a significant decrease in the suboptimal folate status among women of childbearing age. We also show that age is a predictor of higher RBC folate levels. Our data are limited due to a lack of information regarding patient or physician characteristics, and to the nature of our sample, yet our results are consistent with the continued increase in folate status observed among several population-level studies in the US and Canada post-fortification. Further research is needed to determine the reasons for and future implications of this continued increase in the elderly.
Keywords: Folic acid, prenatal supplementation, folic acid fortification, population-level data, RBC folate, public health initiatives, population health
Résumé
OBJECTIFS : Évaluer le pourcentage de femmes en âge de procréer ayant des niveaux sous-optimaux de folates protégeant contre les anomalies du tube neural (<906 nM) et évaluer le bilan en folates chez les personnes âgées.
MÉTHODE : Nous avons évalué les concentrations en folates érythrocytaires dans 1 035 échantillons de sang anonymes provenant d’un laboratoire clinique centralisé servant la région du Grand Toronto, à l’aide d’un immunodosage en chimioluminescence. Les analyses de folates avaient été demandées par des médecins dans le cadre de soins cliniques. Les données disponibles étaient l’âge, le sexe et la concentration en folates érythrocytaires. Nous avons eu recours à la statistique descriptive pour caractériser le pourcentage de femmes ayant des concentrations sous-optimales de folates sanguins, et à la régression multiple pour analyser les déterminants du bilan en folates.
RÉSULTATS : Nos données de 2013 montrent que 7% des femmes en âge de procréer (15–45 ans) avaient des concentrations en folates érythrocytaires inférieures à 906 nM, un pourcentage considérablement plus bas que dans notre étude de 2006 (40%). Les résultats de la régression multiple montrent que l’âge est un prédicteur positif significatif des bilans élevés en folates érythrocytaires (p < 0,001).
CONCLUSION : Comparativement à nos données antérieures, nous constatons une diminution significative des bilans en folates sous-optimaux chez les femmes en âge de procréer. Nous montrons aussi que l’âge est un prédicteur des niveaux de folates érythrocytaires élevés. Nos données sont limitées par le manque d’information sur les caractéristiques des patients ou des médecins et par la nature de notre échantillon, mais nos résultats sont conformes à la hausse continue du bilan en folates observée dans plusieurs études populationnelles menées aux États-Unis et au Canada après l’enrichissement des aliments. Il faudrait pousser la recherche pour déterminer les raisons et les conséquences futures de cette hausse continue chez les personnes âgées.
Mots Clés: acide folique, supplémentation prénatale, enrichissement en acide folique, données populationnelles, folates érythrocytaires, initiatives de santé publique, santé des populations
Footnotes
Conflict of Interest: G. Koren has been a paid consultant for Duchesnay Inc., producers of prenatal multivitamins. The company supported research projects in his laboratory. B. Kapur and M. Shere have no conflict of interest to declare.
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