Delineation of the Individual Effects of Vitamin E Isoforms on Early Life Incident Wheezing.

OBJECTIVES: To test the hypothesis that maternal plasma alpha-tocopherol levels are associated with protection from childhood wheeze and that this protection is modified by gamma-tocopherol. STUDY DESIGN: We conducted a prospective nested study in the Infant Susceptibility to Pulmonary Infections and Asthma Following Respiratory Syncytial Virus Exposure birth cohort of 652 children with postpartum maternal plasma vitamin E isoforms used as a surrogate for pregnancy concentrations. Our outcomes were wheezing and recurrent wheezing over a 2-year period, ascertained using validated questionnaires. We assessed the association of alpha- and gamma-tocopherol with wheezing outcomes using multivariable adjusted logistic regression, and tested for interaction between the isoforms with respect to the risk for wheezing outcomes. RESULTS: Children with wheezing (n = 547, n = 167; 31%) and recurrent wheezing (n = 545, n = 55; 10.1%) over a 2-year period were born to mothers with significantly lower postpartum maternal plasma concentrations of alpha-tocopherol, P = .016 and P = .007, respectively. In analyses of IQR increases, alpha-tocopherol was associated with decreased risk of wheezing (aOR 0.70 [95% CI 0.53,0.92]) and recurrent wheezing (aOR 0.63 [95% CI 0.42,0.95]). For gamma-tocopherol, the aOR for wheezing was 0.79 (95% CI 0.56-1.10) and the aOR for recurrent wheezing was 0.56 (95% CI 0.33-0.94, with nonmonotonic association). The association of alpha-tocopherol with wheezing was modified by gamma-tocopherol (P interaction = .05). CONCLUSIONS: Increases in postpartum maternal plasma alpha-tocopherol isoform concentrations were associated with decreased likelihood of wheezing over a 2-year period. Gamma-tocopherol modified this association.

Relación del colesterol total con la concentración sérica de tocoferoles, un estudio probabilístico en preescolares mexicanos / Relation of total cholesterol in serum tocopherols

Estudios epidemiologicos han demostrado el efecto del estado nutricional de los tocoferoles y el desarrollo de enfermedades cardiovasculares, las cuales son cada vez mas frecuentes en edades tempranas de la vida. Este trabajo relaciona el colesterol total con las concentraciones sericas de tocoferoles en una poblacion de ninos mexicanos, evaluando ademas su estado antioxidante y oxidante. De octubre a diciembre de 2003, se cuantifico en suero a-tocoferol, γ-tocoferol y colesterol total en 1155 niños (12-59 meses) residentes de localidades urbanas y rurales; se evaluo la capacidad antioxidante y el estado oxidante con la produccion de TBARS. Los ninos con cifras de colesterol > 240 mg/dL fue de 577.3 ± 200.8 μg/dL. Sin embargo, cuando se expresaron los tocoferoles en relacion con el colesterol total (μmol/mmol), se observo que los niños con + 1.19), lo que los ubicaba en un adecuado estado nutricional de a-tocoferol, a diferencia del grupo con > 240 mg/dL de colesterol en quienes la relacion fue baja (1.93 ± 0.69). No se observaron diferencias en la capacidad antioxidante del suero, pero si en la produccion de TBARS para los niños con > 200 mg/dL de colesterol. En preescolares los incrementos en el colesterol total limitan la disponibilidad de tocoferoles sericos para los lipidos circulantes, esta condicion a traves del tiempo puede condicionar el desarrollo prematuro de lesiones vasculares mediadas por estres oxidativo.

Epidemiological studies have shown the effect of nutritional status of tocopherols and development of cardiovascular diseases that now are more frequent during early years of life. In this work we evaluated the association between the total cholesterol and serum levels of tocopherols in a population of Mexican children in whom we measured the oxidant status and antioxidant capacity (December 2003). In 1155 children (12-59 months) residents of urban and rural locations we quantified in serum a-tocopherol, γ-tocopherol and total cholesterol; the antioxidant capacity and oxidative status were evaluated with the production of TBARS. Children with serum cholesterol > 240 mg/dL cholesterol recorded an average of 577.3 ± 200.8 μg/dL. However, when tocopherols were expressed in relation to total cholesterol (μmol/mmol) found that children with > 240 mg/dL of cholesterol in whom the relationship was low (1.93 ± 0.69). There were no differences in serum antioxidant capacity, but if in the production of TBARS for children with > 200 mg/dL cholesterol. In preschools the increases in total cholesterol limits the availability of serum tocopherol for circulating lipids, this condition over time could determine the early development of vascular injury mediated by oxidative stress.

[Relation of total cholesterol in serum tocopherols, probabilistic study in Mexican children]. / Relación del colesterol total con la concentración sérica de tocoferoles, un estudio probabilístico en preescolares mexicanos.

Epidemiological studies have shown the effect of nutritional status of tocopherols and development of cardiovascular diseases that now are more frequent during early years of life. In this work we evaluated the association between the total cholesterol and serum levels of tocopherols in a population of Mexican children in whom we measured the oxidant status and antioxidant capacity (December 2003). In 1155 children (12-59 months) residents of urban and rural locations we quantified in serum alpha-tocopherol, gamma-tocopherol and total cholesterol; the antioxidant capacity and oxidative status were evaluated with the production of TBARS. Children with serum cholesterol < 170 mg/dL had an average of 472.5 +/- 179.6 microg/dL tocopherol in serum and > or = 240 mg/dL cholesterol recorded an average of 577.3 +/- 200.8 microg/dL. However, when tocopherols were expressed in relation to total cholesterol (micromol/mmol) found that children with < 170 mg/dL had the highest ratios (3.06 +/-1.19) which places them in an adequate nutritional status of tocopherol, unlike the group with > or = 240 mg/dL of cholesterol in whom the relationship was low (1.93 +/- 0.69). There were no differences in serum antioxidant capacity, but if in the production of TBARS for children with > or = 200 mg/dL cholesterol. In preschools the increases in total cholesterol limits the availability of serum tocopherol for circulating lipids, this condition over time could determine the early development of vascular injury mediated by oxidative stress.

Associations of n-6 and n-3 polyunsaturated fatty acids and tocopherols with proxies of membrane stability and subcutaneous fat sites in male elite swimmers.

We hypothesize that membrane stability of elite swimmers adapted to chronic intense training is dependent on polyunsaturated fatty acids (PUFAs) and tocopherols in blood pools and that the composition of PUFA in plasma nonesterified fatty acids (NEFAs) might be associated with specific subcutaneous fat sites. Our aims were to investigate in male elite swimmers the associations of n-6 and n-3 PUFA and alpha- and gamma-tocopherols with proxies of membrane stability (phase angle and erythrocyte osmotic fragility) and of PUFA in plasma NEFA with specific skinfolds. Brazilian male elite swimmers (n = 20) under regular training for an average of 4.1 h/d and 6.1 d/wk took part in the study. Blood samples were obtained once after 18-hour rest and an overnight fast. Fatty acids were determined in plasma NEFA and erythrocytes by gas chromatolography and tocopherols were determined in plasma and erythrocytes by high-performance liquid chromatography. The status of PUFA was assessed as mean melting point, PUFA index [(Sigman-6 + Sigman-3) / (Sigman-7 + Sigman-9)] and docosahexaenoic acid indices (22:5n-6/22:4n-6 and 22:6n-3/22:5n-6 ratios) calculated from erythrocyte fatty acids. Phase angle was associated with an index of docosahexaenoic acid inadequacy (22:5n-6/22:4n-6; r = -0.53, P = .019) and with 22:5n-3 in erythrocytes (r = 0.51, P = .024), and erythrocyte osmotic fragility was associated with plasma alpha-tocopherol (r = -0.51, P = .05), which is a biomarker of vitamin E status. Plasma NEFAs 18:3n-3 and 20:4n-6 were positively associated with skinfolds of the trunk and arms (r = 0.49-0.59, P = .011-.043). The data presented indicate that n-3 PUFA and vitamin E states possibly improve membrane stability in elite swimmers and that the extent of specific anatomic sites of subcutaneous adipose tissue in the upper body might contribute to the composition of NEFA in the resting state.