Ingesta de hierro y gen HFE en varones adultos de Buenos Aires / Iron intake and HFE gen in male adults from Buenos Aires

RESUMEN

El consumo excesivo de hierro (Fe) en portadores de mutaciones en el gen HFE puede resultar en sobrecarga. Para evaluar el riesgo de sobrecarga de Fe fueron investigados 166 varones adultos donantes de sangre de la ciudad de Buenos Aires. Se estimó la ingesta diaria de Fe (IFe), de Fe hemínico y de Fe proveniente de harinas enriquecidas con SO4Fe. Se determinó ferritina sérica y porcentaje de saturación de transferrina (criterio de sobrecarga de Fe ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%). Las mutaciones C282Y, H63D y S65C fueron investigadas en sangre mediante PCR-RFLP. Todos los participantes cubrieron ampliamente el requerimiento estimado promedio de Fe (6 mg Fe/día) y 3.0% superó el máximo tolerable (45 mg Fe/día). El Fe hemínico correspondió al 9.4% de la IFe y el de harinas enriquecidas al 47.7%. Se observó una asociación entre el aumento de IFe y el de ferritina sérica (p = 0.0472), y el 2.3% de los donantes presentaron ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%. El 29.3% de los donantes eran portadores de los genotipos H63D, S65C o C282Y, asociados a hemocromatosis hereditaria, y tenían valores de saturación de transferrina significativamente mayores a los de los donantes wild type (p = 0.0167). Si bien la incidencia clínica de hemocromatosis hereditaria fue baja en el grupo estudiado (1.2%), el consumo excesivo de Fe plantea un riesgo potencial para la salud de individuos que ignoran sus antecedentes familiares de sobrecarga de Fe.

ABSTRACT

Excess iron (Fe) intake in subjects carrying certain mutations in the HFE gene may result in Fe overload. To estimate risk of Fe overload, 166 male blood donors (19-65 years) from Buenos Aires city were investigated. Daily Fe intake (FeI), hem Fe intake, and Fe intake from SO4Fe enriched flours were estimated (SARA Computer Program and Food Composition Table, USDA). Serum ferritin and transferrin saturation were determined; criteria for Fe overload was serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. HFE genotypes C282Y, H63D and S65C were analyzed by PCR-RFLP in blood samples. No participant presented FeI lower than the estimated average requirement (6 mg Fe/day) and 3.0% was over the upper level (45 mg Fe/day). Hem Fe and Fe from flour enrichment were 9.4% and 47.7% of daily Fe intake, respectively. A significant association was observed between the increase in serum ferritin (ng/ml) and the increase in FeI (p = 0.0472); 2.3% of the donors presented serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. Genotypes associated with hereditary hemochromatosis (H63D, S65C and C282Y) were found in 29.3% of the donors. The percentage of transferrin saturation was higher in subjects carrying mutation than in wild type subjects (p = 0.0167). Although penetrance of hereditary hemochromatosis in the studied group was only 1.2%, an excessive Fe intake could enhance adverse effects in individuals unaware of any family history of Fe overload.