ABSTRACT
BACKGROUND: The brain-derived neurotrophic factor (BDNF) rs6265 (G196A; Val66Met) single nucleotide polymorphism has been associated with BMI and obesity in distinct populations, both adult and pediatric, with contradictory results involving either Val or Met as the risk variant. AIM OF THE STUDY: To determine the association between the BDNF Val66Met polymorphism and BMI in Mexican children and adolescents. METHODS: BDNF Val66Met genotyping by restriction fragment length polymorphism and nutritional status characterized by their BMI-for-age z-scores (BAZ) from pediatric volunteers (n = 498) were analyzed by Fisher's exact test association analysis. Standardized residuals (R) were used to determine which genotype/allele had the major influence on the significant Fisher's exact test statistic. Odds ratios were analyzed to measure the association between genotype and normal weight (≥-2 SD < + 1 SD) and overweight (≥ + 1 SD, including obesity, Ow + Ob) status with 95% confidence intervals to estimate the precision of the effect as well as 95% credible intervals to obtain the most probable estimate. RESULTS: Comparisons between GG (Val/Val), GA (Val/Met) and AA (Met/Met) genotypes or Met homozygotes vs. Val carriers (combination of GG and GA genotypes) showed significant differences (p = 0.034 and p = 0.037, respectively) between normal weight and the combined overweight and obese pediatric subjects. Our data showed that children/adolescents homozygous for the A allele have increased risk of overweight compared to the Val carriers (Bayes OR = 4.2, 95% CI**[1.09-33.1]). CONCLUSION: This is the first study showing the significant association between the BDNF rs6265 AA (Met/Met) genotype and overweight/obesity in Mexican pediatric population.
Subject(s)
Brain-Derived Neurotrophic Factor/genetics , Genetic Predisposition to Disease , Pediatric Obesity/genetics , Polymorphism, Single Nucleotide , Adolescent , Bayes Theorem , Case-Control Studies , Child , Child, Preschool , Female , Genetic Markers , Genotype , Humans , Male , Mexico , Odds RatioABSTRACT
Introducción. La leucemia linfoblástica aguda es la neoplasia maligna más frecuente en la infancia. En la actualidad, el impacto de la quimioterapia ha resultado en una mayor supervivencia, aunque los resultados son diferentes entre los países. Metodología. Se revisó la literatura médica disponible en Medline sobre el informe de supervivencia global y supervivencia libre de enfermedad en niños con leucemia linfoblástica aguda, desde finales de los años setenta hasta el 2007. Se analizó la supervivencia de acuerdo con el desarrollo económico del país (países desarrollados y en vías de desarrollo), y por edad, sexo, tipo celular y cuenta leucocitaria al diagnóstico. Resultados. En países desarrollados se ha observado un incremento en la supervivencia global a cinco años, de 60% en 1984 a 83.5% en el 2007, y en la supervivencia libre de enfermedad, de 48.5% a 83.5%. En los países en desarrollo, hasta el 2006, el promedio de supervivencia global y libre de enfermedad continuaba en, aproximadamente, 60%. La supervivencia con respecto a la edad es más favorable en los niños de 1 a 9 años (>80%) que en los mayores de 10 años (70-80%). Con respecto al sexo es 5% mayor en las mujeres que en los varones; con respecto al tipo celular es 10% mayor en leucemias de células B que en células T y, de acuerdo con la cifra de leucocitos, cuando la cifra resulta <10,000 mm³ al diagnóstico es 20% mayor que cuando los valores son >10,000 mm³. Existe escasa información para los países en desarrollo. Conclusiones. La supervivencia de los pacientes con leucemia linfoblástica aguda sigue en aumento, sobre todo la supervivencia libre de enfermedad. Los factores pronóstico de edad, sexo, tipo celular y celularidad continúan siendo válidos. Es necesario realizar más estudios en países en vías de desarrollo.
Background. Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood. The impact of chemotherapy has resulted in improved survival, although results have not been the same for all countries. Methods. We reviewed the available medical literature in Medline on reports of overall and disease-free survival in children with ALL from the late 1970s to 2007. Survival was analyzed according to economic development (developed and developing countries) and according to age, sex, cell type and leukocyte count at diagnosis. Results. In developed countries there has been an increase in overall 5-year survival from 60% in 1984 to 83.5% in 2007 and for disease-free survival from 48.5% to 83.5%. This was not registered in developing countries where until 2006 the average overall survival and disease-free survival was ~60%. At diagnosis, prognostic factors related with higher survival rates are age (1 to 9 years), sex (females), type of leukemia (B-cell leukemia) and leukocyte count <10,000 mm³. Information regarding survival rates is very scarce. Conclusions. Survival of children with ALL is increasing, particularly disease-free survival rates. Prognostic factors related to survival are age, sex, cell type and leukocyte count. Further studies are needed in developing countries.
