Resumen

RUIZ FERNANDEZ¹, Nelina; ISABEL GIACOPINI², María; LANDAETA DE JIMENEZ, Maritza  y  BOSCH, Virgilio. Susceptibilidad a la oxidación de las lipoproteínas de baja y muy baja densidad del plasma en escolares. An Venez Nutr [online]. 2006, vol.19, n.1, pp.25-31. ISSN 0798-0752.

Abstract The oxidative modification of plasma lipoproteins is an important step in the formation of the atherosclerotic plaque. On the other hand, there are evidences that atherogenesis begins during early stages of life, therefore it is of interest to evaluate the susceptibility to oxidative stress of plasma lipoproteins in childhood. Twenty-four children apparently healthy (7 to 9 years of age) who attended to elementary schools in Carabobo and Lara States (Venezuela) during the school period 2003-2004 were studied. Plasma VLDL and LDL were submitted to oxidation in vitro with copper and concentrations of the resulting thiobarbituric acid reacting substances (TBARS) were determinated after three hours of incubation. The susceptibility to oxidation was related to anthropometrics (weigh-height, height-age, fat area), haematologics (hemoglobin and hematocrit) and biochemicals variables (plasmatic concentration of total cholesterol, LDL-c, HDL-c, triglycerides and ferritin).  Under the conditions of our experiment, 50% of the studied children displayed oxidation of LDL, 62.5% oxidation of VLDL and 33% oxidation of both lipoproteins. The susceptibility to oxidation was not associated to anthropometrics and haematologic variables.  The oxidation of LDL was negatively correlated with concentration of plasmatic ferritin (r = -0.61, p<0.05). This last one contrasts with the role of  iron as a prooxidant agent. We propose that possibly ferropenics children present other nutritional deficits that condition a low antioxidant reserve, probably due to the intake of  diets low in antioxidants and/or cofactors of antioxidant enzymes.

Palabras clave : lipoprotein oxidation; VLDL; LDL; ferritin; atherogenesis; childhood     nutrition; children.