RESUMO
BACKGROUND: Recent genome wide association studies (GWAS) and previous positional linkage studies have identified more than 50 single nucleotide polymorphisms (SNPs) associated with obesity, mostly in Europeans. We aimed to assess the contribution of some of these SNPs to obesity risk and to the variation of related metabolic traits, in Mexican children. METHODS: The association of six European obesity-related SNPs in or near FTO, NPC1, ENPP1, NEGR1, GNPDA2 and MC4R genes with risk of obesity was tested in 1,463 school-aged Mexican children (N(cases) = 514; N(controls) = 949). We also assessed effects of these SNPs on the variation of body mass index (BMI), fasting serum insulin levels, fasting plasma glucose levels, total cholesterol and triglyceride levels, in a subset of 1,171 nonobese Mexican children. RESULTS: We found a significant effect of GNPDA2 rs10938397 on risk of obesity (odds ratio [OR] = 1.30; P = 1.34 × 10-3). Furthermore, we found nominal associations between obesity risk or BMI variation and the following SNPs: ENPP1 rs7754561, MC4R rs17782313 and NEGR1 rs2815752. Importantly, the at-risk alleles of both MC4R rs17782313 and NPC1 rs1805081 showed significant effect on increased fasting glucose levels (ß = 0.36 mmol/L; P = 1.47 × 10(-3)) and decreased fasting serum insulin levels (ß = -0.10 µU/mL; P = 1.21 × 10(-3)), respectively. CONCLUSION: Our present results suggest that some obesity-associated SNPs previously reported in Europeans also associate with risk of obesity, or metabolic quantitative traits, in Mexican children. Importantly, we found new associations between MC4R and fasting glucose levels, and between NPC1 and fasting insulin levels.
Assuntos
Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Obesidade/genética , Polimorfismo de Nucleotídeo Único/genética , Aldose-Cetose Isomerases/genética , Alelos , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Índice de Massa Corporal , Proteínas de Transporte/genética , Moléculas de Adesão Celular Neuronais/genética , Criança , Estudos Transversais , Feminino , Seguimentos , Proteínas Ligadas por GPI/genética , Frequência do Gene , Genótipo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Glicoproteínas de Membrana/genética , México/epidemiologia , Proteína C1 de Niemann-Pick , Obesidade/etnologia , Diester Fosfórico Hidrolases/genética , Proteínas/genética , Pirofosfatases/genética , Receptor Tipo 4 de Melanocortina/genética , Fatores de RiscoRESUMO
PURPOSE: Low levels of physical activity (PA) are associated with persistent obesity. Adolescent obesity is linked to adult morbidity and premature mortality. This study examined a model of perceived parental influence in Mexican older adolescents to uncover contemporaneous family and personal predictors of Mexican older adolescents' PA. METHOD: Participants 16- to 25-years-old (n = 3,908), Mexican college applicants, underwent a health screen and filled out questionnaires which included information on PA and potential correlates. A logistic regression model was used to ascertain family factors (socioeconomic status, conflict about PA, and perceived parental PA) and individual factors (age, sex, body mass index, depressive symptoms, enjoyment of PA, and sedentary behaviors) associated with adolescents' PA. RESULTS: Most participants reported being physically active (61.5%); less than half reported physically active parents (40.0%). Perceived parental PA (odds ratio [OR] = 8.67, p ≤ .0001), enjoyment of PA (OR = 2.11, p ≤ .0001), and conflicts about PA (OR = 1.16, p ≤ .0001) were important positive predictors of adolescents' PA. CONCLUSION: PA among Mexican older adolescents is influenced by parental PA. The role of conflicts about PA is likely to be influenced by culture and may indicate that older adolescents' PA is not completely accepted by parents.
Assuntos
Conflito Familiar , Comportamentos Relacionados com a Saúde/etnologia , Atividade Motora , Relações Pais-Filho , Adolescente , Estudos Transversais , Feminino , Humanos , Atividades de Lazer , Modelos Logísticos , Masculino , México , Obesidade/psicologia , Adulto JovemRESUMO
Cardiovascular disease (CVD) is a major cause of mortality in the Republic of Mexico, and metabolic syndrome, a complex of CVD risk factors, is increasingly prevalent. To date, however, there have been few studies of the genetic epidemiology of metabolic syndrome in Mexico. As a first step in implementing the GEMM Family Study, a large, multicenter collaborative study, we recruited 375 individuals in 21 extended families, without ascertainment on disease, at 9 medical institutions across Mexico. Participants were measured for anthropometric (stature, weight, waist circumference) and hemodynamic (blood pressure, heart rate) phenotypes; glucose, cholesterol, and triglyceride levels were measured in fasting blood. Variance components-based quantitative genetic analyses were performed using SOLAR. All phenotypes except diastolic blood pressure were significantly heritable. Consistent with the definition of metabolic syndrome, many phenotypes exhibited significant environmental correlation, and significant genetic correlations were found between measures of adiposity and fasting glucose and fasting triglyceride levels. These preliminary data represent the first heritability estimates for many of these phenotypes in the Republic of Mexico and indicate that this study design offers excellent power for future gene discovery relative to metabolic disease.
