RESUMO
The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function.
Assuntos
Arsênio/toxicidade , Calpaína/genética , Diabetes Mellitus Tipo 2/patologia , Exposição Ambiental/efeitos adversos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/patologia , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Poluentes Ambientais/toxicidade , Feminino , Genótipo , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores de RiscoRESUMO
BACKGROUND: Polybrominated diphenyl ethers (PBDE), which are used as flame retardants, have been found to be higher in residents of California than of other parts of the United States. OBJECTIVES: We aimed to investigate the role of immigration to California on PBDE levels in Latino children. METHODS: We compared serum PBDE concentrations in a population of first-generation Mexican-American 7-year-old children (n = 264), who were born and raised in California [Center for Health Analysis of Mothers and Children of Salinas (CHAMACOS) study], with 5-year-old Mexican children (n = 283), who were raised in the states in Mexico where most CHAMACOS mothers had originated (Proyecto Mariposa). RESULTS: On average, PBDE serum concentrations in the California Mexican-American children were three times higher than their mothers' levels during pregnancy and seven times higher than concentrations in the children living in Mexico. The PBDE serum concentrations were higher in the Mexican-American children regardless of length of time their mother had resided in California or the duration of the child's breast-feeding. These data suggest that PBDE serum concentrations in these children resulted primarily from postnatal exposure. CONCLUSIONS: Latino children living in California have much higher PBDE serum levels than their Mexican counterparts. Given the growing evidence documenting potential health effects of PBDE exposure, the levels in young children noted in this study potentially present a major public health challenge, especially in California. In addition, as PBDEs are being phased out and replaced by other flame retardants, the health consequences of these chemical replacements should be investigated and weighed against their purported fire safety benefits.
Assuntos
Éteres Difenil Halogenados/sangue , California , Criança , Pré-Escolar , DDT/sangue , Diclorodifenil Dicloroetileno/sangue , Feminino , Retardadores de Chama , Humanos , Masculino , Americanos Mexicanos , GravidezRESUMO
La Agencia Internacional de Investigación en Cáncer, de la OMS (International Agency for Research on Cancer IARC), ha reconocido una relación causa efecto entre la infección por Helicobacter pylori (Hp) y el cáncer de estómago, de tal magnitud que la presencia de dicha infección aumenta aproximadamante 4 veces el riesgo de padecer cáncer. En este trabajo se presentan los resultados de la asociación de la infección por Hp y la incidencia de cáncer de estómago, que ocupa actualmente el segundo lugar en la mortalidad por neoplasias malignas en la Ciudad de México, los cuales se obtuvieron por medio de un estudio epidemiológico, en el que participaron 109 pacientes de cáncer gástrico y 177 controles hospitlarios. Se estimó que en la población estudiada, la infección por Helicobacter pylori, estuvo presente en el 87.2 por ciento de los casos, comparado con un 82.5 por ciento de los controles. La razón de momios de padecer cáncer de estómago dado que se está infectado por Hp, resultó de 1.44 IC 95 por ciento 0.7 2.8. Además, se calculó que si se erradicara la infección por Hp en la población general, la incidencia de cáncer de estómago se reduciría en al menos 26.6 por ciento. La implementación de mejores condiciones sanitarias y el desarrollo de una vacuna eficaz que prevenga la infección por Hp así como la existencia de tratamientos cada vez más efectivos para erradicar la bacteria representan ahora, un reto para la prevencion y el control poblacional del cáncer gástrico