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Variantes genéticas y asociaciones de las concentraciones de 25-hidroxivitamina D con los principales resultados
Gregory P Levin1, Cassianne Robinson-Cohen, Ian H de Boer
1Department of Biostatistics, University of Washington, Seattle, USA.
JAMA
|November 15, 2012
Resumen
Los bajos niveles de vitamina D aumentan el riesgo de enfermedades crónicas, pero las variaciones genéticas en el receptor de vitamina D (VDR) pueden alterar esta asociación. Este estudio identificó una variante específica del gen VDR que modifica los riesgos para la salud relacionados con la baja vitamina D.
Área de la Ciencia:
- Genética y Biología Molecular.
- Ciencias de la Nutrición Ciencias de la Nutrición
- Epidemiología La epidemiología.
- Gerontología Gerontología.
Sus antecedentes:
- Un nivel bajo de 25-hidroxivitamina D en suero está relacionado con un mayor riesgo de diversas enfermedades crónicas.
- La vitamina D requiere la conversión a su forma activa (1,25-dihidroxivitamina D) para la actividad biológica.
- Las diferencias individuales en el metabolismo de la vitamina D pueden influir en el impacto clínico de los niveles medidos de vitamina D.
Objetivo del estudio:
- Determinar si las variaciones genéticas comunes en los genes clave de la vía de la vitamina D modifican la asociación entre los niveles bajos de 25-hidroxivitamina D y los principales resultados de salud.
- Los genes investigados incluyen los de la proteína de unión a la vitamina D, la megalina, la cubilina, el CYP27B1, el CYP24A1 y el receptor de vitamina D (VDR).
Principales métodos:
- Se analizaron 141 polimorfismos de un solo nucleótido (SNP) en 1514 participantes blancos del Estudio de Salud Cardiovascular (CHS).
- Se midieron los niveles séricos de 25-hidroxivitamina D, y los participantes fueron seguidos durante una mediana de 11 años.
- Se realizaron metanálisis de replicación en tres cohortes independientes basadas en la comunidad: Salud, Envejecimiento y Composición Corporal de los Estados Unidos, Invecchiare in Chianti italiano y Estudio Longitudinal de Hombres Adultos de Uppsala sueco.
Principales resultados:
- Cinco SNPs mostraron interacciones con bajos niveles de 25-hidroxivitamina D en la fase de descubrimiento.
- Se replicó una interacción significativa que involucra una variante del gen del receptor de vitamina D (VDR) (rs7968585).
- En los participantes de CHS, el bajo nivel de 25-hidroxivitamina D se asoció con un mayor riesgo de un resultado compuesto (fractura de cadera, infarto de miocardio, cáncer, mortalidad) solo en individuos con uno o dos alelos menores en rs7968585; no se observó asociación en aquellos con cero alelos menores.
Conclusiones:
- La asociación entre niveles bajos de 25-hidroxivitamina D en suero y los principales resultados de salud puede estar modulada por variaciones genéticas comunes.
- Específicamente, las diferencias genéticas dentro del receptor de vitamina D (VDR) influyen en las consecuencias clínicas de los bajos niveles de vitamina D.
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