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1.
Environ Res ; 180: 108817, 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31627156

RESUMO

BACKGROUND: Air pollutants are suggested to be related to type 2 diabetes (T2D). Since several high quality papers on air pollutants and T2D have been published beyond the last reviews, an extended systematic review is highly warranted. We review epidemiological studies to quantify the association between air pollutants and T2D, and to answer if diabetes patients are more vulnerable to air pollutants. METHODS: We systematically reviewed the databases of PubMed and Web of Science based on the guidelines of the Preferred Reporting Items for Systematic review and Meta-analysis (PRISMA). We calculated odds ratios (OR) or hazard ratios (HR) and their 95% confidence intervals (CI) to assess the strength of the associations between air pollutants [e.g., particulate matter with diameter ≤ 2.5 µm (PM2.5), particulate matter with diameter ≤ 10 µm (PM10), and nitrogen dioxide (NO2)] and T2D. We evaluated the quality and risk of bias of the included studies and graded the credibility of the pooled evidence using several recommended tools. We also performed sensitivity analysis, meta-regression analysis, and publication bias test. RESULTS: Out of 716 articles identified, 86 were used for this review and meta-analysis. Meta-analyses showed significant associations of PM2.5 with T2D incidence (11 studies; HR = 1.10, 95% CI = 1.04-1.17 per 10 µg/m3 increment; I2 = 74.4%) and prevalence (11 studies; OR = 1.08; 95% CI = 1.04-1.12 per 10 µg/m3 increment; I2 = 84.3%), of PM10 with T2D prevalence (6 studies; OR = 1.10; 95% CI = 1.03-1.17 per 10 µg/m3 increment; I2 = 89.5%) and incidence (6 studies; HR = 1.11; 95% CI = 1.00-1.22 per µg/m3 increment; I2 = 70.6%), and of NO2 with T2D prevalence (11 studies; OR = 1.07; 95% CI = 1.04-1.11 per 10 µg/m3 increment; I2 = 91.1%). The majority of studies on glucose-homoeostasis markers also showed increased risks with higher air pollutants levels, but the studies were too heterogeneous for meta-analysis. Overall, patients with diabetes might be more vulnerable to PM. CONCLUSIONS: Recent publications strengthened the evidence for adverse effects of ambient air pollutants exposure (especially for PM) on T2D and that diabetic patients might be more vulnerable to air pollutants exposure.

2.
Hum Mol Genet ; 28(19): 3327-3338, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504550

RESUMO

Although hundreds of genome-wide association studies-implicated loci have been reported for adult obesity-related traits, less is known about the genetics specific for early-onset obesity and with only a few studies conducted in non-European populations to date. Searching for additional genetic variants associated with childhood obesity, we performed a trans-ancestral meta-analysis of 30 studies consisting of up to 13 005 cases (≥95th percentile of body mass index (BMI) achieved 2-18 years old) and 15 599 controls (consistently <50th percentile of BMI) of European, African, North/South American and East Asian ancestry. Suggestive loci were taken forward for replication in a sample of 1888 cases and 4689 controls from seven cohorts of European and North/South American ancestry. In addition to observing 18 previously implicated BMI or obesity loci, for both early and late onset, we uncovered one completely novel locus in this trans-ancestral analysis (nearest gene, METTL15). The variant was nominally associated with only the European subgroup analysis but had a consistent direction of effect in other ethnicities. We then utilized trans-ancestral Bayesian analysis to narrow down the location of the probable causal variant at each genome-wide significant signal. Of all the fine-mapped loci, we were able to narrow down the causative variant at four known loci to fewer than 10 single nucleotide polymorphisms (SNPs) (FAIM2, GNPDA2, MC4R and SEC16B loci). In conclusion, an ethnically diverse setting has enabled us to both identify an additional pediatric obesity locus and further fine-map existing loci.

3.
JAMA Netw Open ; 2(9): e1910915, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31539074

RESUMO

Importance: Observational studies have shown associations of birth weight with type 2 diabetes (T2D) and glycemic traits, but it remains unclear whether these associations represent causal associations. Objective: To test the association of birth weight with T2D and glycemic traits using a mendelian randomization analysis. Design, Setting, and Participants: This mendelian randomization study used a genetic risk score for birth weight that was constructed with 7 genome-wide significant single-nucleotide polymorphisms. The associations of this score with birth weight and T2D were tested in a mendelian randomization analysis using study-level data. The association of birth weight with T2D was tested using both study-level data (7 single-nucleotide polymorphisms were used as an instrumental variable) and summary-level data from the consortia (43 single-nucleotide polymorphisms were used as an instrumental variable). Data from 180 056 participants from 49 studies were included. Main Outcomes and Measures: Type 2 diabetes and glycemic traits. Results: This mendelian randomization analysis included 49 studies with 41 155 patients with T2D and 80 008 control participants from study-level data and 34 840 patients with T2D and 114 981 control participants from summary-level data. Study-level data showed that a 1-SD decrease in birth weight due to the genetic risk score was associated with higher risk of T2D among all participants (odds ratio [OR], 2.10; 95% CI, 1.69-2.61; P = 4.03 × 10-5), among European participants (OR, 1.96; 95% CI, 1.42-2.71; P = .04), and among East Asian participants (OR, 1.39; 95% CI, 1.18-1.62; P = .04). Similar results were observed from summary-level analyses. In addition, each 1-SD lower birth weight was associated with 0.189 SD higher fasting glucose concentration (ß = 0.189; SE = 0.060; P = .002), but not with fasting insulin, 2-hour glucose, or hemoglobin A1c concentration. Conclusions and Relevance: In this study, a genetic predisposition to lower birth weight was associated with increased risk of T2D and higher fasting glucose concentration, suggesting genetic effects on retarded fetal growth and increased diabetes risk that either are independent of each other or operate through alterations of integrated biological mechanisms.

4.
Sci Rep ; 9(1): 12675, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481742

RESUMO

While the association between early life determinants and the development of the gut microbiome composition in infancy has been widely investigated, a potential persistent influence of early life determinants on the gut microbial community after its stabilization at later childhood remains largely unknown. Therefore, we aimed to identify the association between several early life determinants and the gut microbiome composition in six-year-old children from the LISA birth cohort. A total number of 166 fecal samples were analyzed using 16S rRNA gene-based barcoding to assess bacterial diversity pattern. The bacterial profiles were investigated for their association with maternal smoking during pregnancy, mode of delivery, breastfeeding, antibiotic treatment between one and two years of age, gender and socioeconomic status (SES). While alpha and beta diversity of the infants' gut microbiome remained unaffected, amplicon sequence variants (ASVs) annotated to Firmicutes and Actinobacteria responded to early life determinants, mostly to feeding practice and antibiotics use. ASVs associated to Bacteriodetes remained unaffected. Our findings indicate that early life determinants could have a long-term sustainable effect on the gut microflora of six-year-old children, however, associations with early life determinates are weaker than reported for infants.

5.
Nat Genet ; 51(5): 804-814, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31043758

RESUMO

Birth weight variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. In expanded genome-wide association analyses of own birth weight (n = 321,223) and offspring birth weight (n = 230,069 mothers), we identified 190 independent association signals (129 of which are novel). We used structural equation modeling to decompose the contributions of direct fetal and indirect maternal genetic effects, then applied Mendelian randomization to illuminate causal pathways. For example, both indirect maternal and direct fetal genetic effects drive the observational relationship between lower birth weight and higher later blood pressure: maternal blood pressure-raising alleles reduce offspring birth weight, but only direct fetal effects of these alleles, once inherited, increase later offspring blood pressure. Using maternal birth weight-lowering genotypes to proxy for an adverse intrauterine environment provided no evidence that it causally raises offspring blood pressure, indicating that the inverse birth weight-blood pressure association is attributable to genetic effects, and not to intrauterine programming.


Assuntos
Peso ao Nascer/genética , Adulto , Pressão Sanguínea/genética , Estatura/genética , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/genética , Feminino , Desenvolvimento Fetal/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Cardiopatias/etiologia , Cardiopatias/genética , Humanos , Recém-Nascido , Masculino , Herança Materna/genética , Troca Materno-Fetal/genética , Doenças Metabólicas/etiologia , Doenças Metabólicas/genética , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Gravidez , Fatores de Risco
6.
Sci Rep ; 9(1): 5053, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30911015

RESUMO

Childhood obesity prevalence is rising in countries worldwide. A variety of etiologic factors contribute to childhood obesity but little is known about underlying biochemical mechanisms. We performed an individual participant meta-analysis including 1,020 pre-pubertal children from three European studies and investigated the associations of 285 metabolites measured by LC/MS-MS with BMI z-score, height, weight, HOMA, and lipoprotein concentrations. Seventeen metabolites were significantly associated with BMI z-score. Sphingomyelin (SM) 32:2 showed the strongest association with BMI z-score (P = 4.68 × 10-23) and was also closely related to weight, and less strongly to height and LDL, but not to HOMA. Mass spectrometric analyses identified SM 32:2 as myristic acid containing SM d18:2/14:0. Thirty-five metabolites were significantly associated to HOMA index. Alanine showed the strongest positive association with HOMA (P = 9.77 × 10-16), while acylcarnitines and non-esterified fatty acids were negatively associated with HOMA. SM d18:2/14:0 is a powerful marker for molecular changes in childhood obesity. Tracing back the origin of SM 32:2 to dietary source in combination with genetic predisposition will path the way for early intervention programs. Metabolic profiling might facilitate risk prediction and personalized interventions in overweight children.

8.
Artigo em Inglês | MEDLINE | ID: mdl-29991034

RESUMO

Growth characteristics during periods of early developmental plasticity are linked with later health outcomes and with disease risks. Infant growth is modulated by genetic and exogenous factors including nutrition. We try to explore their underlying mechanisms using targeted metabolomic profiling of small molecules in biological samples using high-performance liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) to quantify hundreds of molecules in small biosamples, e.g., 50 µL plasma. In the large German LISA birth cohort study, cord blood lysophosphatidylcholines and fatty acids were closely associated with infant birth weight, with a nonsignificant trend towards an association with infant weight gain and later BMI. Studies in infants randomized to different protein intakes in the European CHOP Study show conventional high protein intakes to markedly increase plasma-indispensable amino acids (AA), particularly branched-chain AA (BCAA), while exceeding the infant's capacity of BCAA breakdown, and an increase in the dispensable AA tyrosine previously associated with insulin resistance. In a path model analysis of the relationship of infant plasma AA, growth factors, and infant growth, AA were generally found to induce a stronger response of insulin than IGF-I although effects of individual AA were very different. We conclude that targeted improvement in nutrient supply in pregnancy and infancy may offer large opportunities for promoting desirable child growth patterns and long-term health.

9.
Hum Mol Genet ; 27(17): 3113-3127, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29931343

RESUMO

Prior studies suggest dental caries traits in children and adolescents are partially heritable, but there has been no large-scale consortium genome-wide association study (GWAS) to date. We therefore performed GWAS for caries in participants aged 2.5-18.0 years from nine contributing centres. Phenotype definitions were created for the presence or absence of treated or untreated caries, stratified by primary and permanent dentition. All studies tested for association between caries and genotype dosage and the results were combined using fixed-effects meta-analysis. Analysis included up to 19 003 individuals (7530 affected) for primary teeth and 13 353 individuals (5875 affected) for permanent teeth. Evidence for association with caries status was observed at rs1594318-C for primary teeth [intronic within ALLC, odds ratio (OR) 0.85, effect allele frequency (EAF) 0.60, P 4.13e-8] and rs7738851-A (intronic within NEDD9, OR 1.28, EAF 0.85, P 1.63e-8) for permanent teeth. Consortium-wide estimated heritability of caries was low [h2 of 1% (95% CI: 0%: 7%) and 6% (95% CI 0%: 13%) for primary and permanent dentitions, respectively] compared with corresponding within-study estimates [h2 of 28% (95% CI: 9%: 48%) and 17% (95% CI: 2%: 31%)] or previously published estimates. This study was designed to identify common genetic variants with modest effects which are consistent across different populations. We found few single variants associated with caries status under these assumptions. Phenotypic heterogeneity between cohorts and limited statistical power will have contributed; these findings could also reflect complexity not captured by our study design, such as genetic effects which are conditional on environmental exposure.

10.
Int J Obes (Lond) ; 42(7): 1249-1264, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29717267

RESUMO

BACKGROUND/OBJECTIVES: A number of meta-analyses suggest an association between any maternal smoking in pregnancy and offspring overweight obesity. Whether there is a dose-response relationship across number of cigarettes and whether this differs by sex remains unclear. SUBJECT/METHODS: Studies reporting number of cigarettes smoked during pregnancy and offspring BMI published up to May 2015 were searched. An individual patient data meta-analysis of association between the number of cigarettes smoked during pregnancy and offspring overweight (defined according to the International Obesity Task Force reference) was computed using a generalized additive mixed model with non-linear effects and adjustment for confounders (maternal weight status, breastfeeding, and maternal education) and stratification for sex. RESULTS: Of 26 identified studies, 16 authors provided data on a total of 238,340 mother-child-pairs. A linear positive association was observed between the number of cigarettes smoked and offspring overweight for up to 15 cigarettes per day with an OR increase per cigarette of 1.03, 95% CI = [1.02-1.03]. The OR flattened with higher cigarette use. Associations were similar in males and females. Sensitivity analyses supported these results. CONCLUSIONS: A linear dose-response relationship of maternal smoking was observed in the range of 1-15 cigarettes per day equally in boys and girls with no further risk increase for doses above 15 cigarettes.

12.
Eur Respir J ; 49(4)2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28446555

RESUMO

Vitamin D plays a role in the development of the immune system and the lung, as well as in airway remodelling. Therefore, this study investigated the association between serum 25-hydroxyvitamin D (25(OH)D) concentrations and spirometric lung function parameters at age 15 years.In the German birth cohorts GINIplus and LISAplus, lung function testing by spirometry and 25(OH)D measurements were performed during the 15-year follow-up examinations. Valid lung function measurements pre- and/or post-bronchodilation and serum 25(OH)D concentrations, which were adjusted for the date of blood sampling to account for seasonal variability, were available for 2607 adolescents. Associations between 25(OH)D concentrations and spirometric parameters were analysed using generalised additive models adjusted for confounding factors.Serum 25(OH)D concentrations were significantly associated with forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC measured before bronchodilation after adjustment for potential confounders: FEV1 increased by 10 mL (95% CI 2-17), FVC by 20 mL (95% CI 12-28) and FEV1/FVC decreased by 0.177% (95% CI -0.286 to -0.067) per 10 nmol·L-1 increase in 25(OH)D concentrations. Flow rates (forced expiratory flow rates at 25, 50 and 75% of exhaled FVC (FEF25, FEF50, FEF75) and mean flow rate between 25 and 75% of FVC (FEF25-75)) were not associated with vitamin D. Similar associations were observed for lung function parameters measured after bronchodilation.Vitamin D concentrations are positively associated with volume-related lung function parameters pre- and post-bronchodilation, suggesting structural changes in peripheral airways.


Assuntos
Pulmão/fisiologia , Vitamina D/análogos & derivados , Adolescente , Estudos Transversais , Feminino , Seguimentos , Fluxo Expiratório Forçado , Volume Expiratório Forçado , Alemanha , Humanos , Masculino , Análise de Regressão , Espirometria , Volume de Ventilação Pulmonar , Vitamina D/sangue
13.
Obes Facts ; 10(2): 85-100, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28376503

RESUMO

BACKGROUND/AIMS: Fetal metabolism may be changed by the exposure to maternal factors, and the route to obesity may already set in utero. Cord blood metabolites might predict growth patterns and later obesity. We aimed to characterize associations of cord blood with birth weight, postnatal weight gain, and BMI in adolescence. METHODS: Over 700 cord blood samples were collected from infants participating in the German birth cohort study LISAplus. Glycerophospholipid fatty acids (GPL-FA), polar lipids, non-esterified fatty acids (NEFA), and amino acids were analyzed with a targeted, liquid chromatography-tandem mass spectrometry based metabolomics platform. Cord blood metabolites were related to growth factors by linear regression models adjusted for confounding variables. RESULTS: Cord blood metabolites were highly associated with birth weight. Lysophosphatidylcholines C16:1, C18:1, C20:3, C18:2, C20:4, C14:0, C16:0, C18:3, GPL-FA C20:3n-9, and GPL-FA C22:5n-6 were positively related to birth weight, while higher cord blood concentrations of NEFA C22:6, NEFA C20:5, GPL-FA C18:3n-3, and PCe C38:0 were associated with lower birth weight. Postnatal weight gain and BMI z-scores in adolescents were not significantly associated with cord blood metabolites after adjustment for multiple testing. CONCLUSION: Potential long-term programming effects of the intrauterine environment and metabolism on later health cannot be predicted with profiling of the cord blood metabolome.


Assuntos
Peso ao Nascer , Sangue Fetal/química , Metaboloma/fisiologia , Ganho de Peso , Índice de Massa Corporal , Estudos de Coortes , Ácidos Graxos/sangue , Feminino , Humanos , Recém-Nascido , Lipídeos/sangue , Masculino
14.
J Clin Periodontol ; 44(4): 372-381, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28036117

RESUMO

AIM: This cross-sectional study was repeated at two time points and investigated the influence of gingivitis, smoking and body mass index (BMI) on the systemic inflammatory markers high-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL6) in 10- and 15-year-olds. MATERIALS AND METHODS: The study sample of two birth cohorts, i.e. GINIplus and LISAplus, from the Munich centre consisted of 806 and 846 subjects who were evaluated at 10- and 15-year follow-ups respectively. Children and their parents completed questionnaires on participant-related lifestyle information. Gingivitis was measured at the sextant level using a simplified sulcus-bleeding index. Serum hs-CRP and IL6 levels were obtained from blood samples. Multiple logistic regressions adjusting for lifestyle-related factors and other confounders were performed to assess associations between the specified variables. RESULTS: There were no associations between gingivitis and the inflammatory markers hs-CRP and IL6 in 10-year-olds. In 15-year-olds, gingivitis (aOR: 2.17; 95% CI: 1.25-3.77); daily smoking (aOR: 6.27; 95% CI: 1.39-28.39); and being overweight/obese (aOR: 4.95; 95% CI: 0.73-33.68) were identified as significantly influencing factors for elevated hs-CRP values. Oral hygiene did not influence hs-CRP. CONCLUSION: In this study, hs-CRP was positively associated with gingivitis, smoking daily and overweight/obesity among 15-year-olds.


Assuntos
Proteína C-Reativa/análise , Gengivite/sangue , Interleucina-6/sangue , Estilo de Vida , Adolescente , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Fumar/sangue
15.
Clin Oral Investig ; 21(7): 2283-2290, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27928689

RESUMO

OBJECTIVE: We examined whether fluoride/vitamin D supplementation in the first year of life is associated with caries or molar incisor hypomineralization (MIH) at 10 years of age. METHODS: The study population consisted of 406 children for whom information on fluoride/vitamin D supplementation during the first year of life was available. Dental examination at the age of 10 included caries and MIH registration. The results of logistic regression models were adjusted for gender, age, BMI, parental education, and equivalent income. RESULTS: Children receiving supplementation during the entire first year of life had a significantly lower probability of having caries-related restorations in primary teeth in comparison to those who received supplementation for less than 6 months (fluoride supplementation: odds ratio (OR) for d3-4mfs 2.47 (1.32-4.63), for fs 2.70 (1.43-5.10); vitamin D supplementation: OR for d3-4mfs 2.08 (1.00-4.32), fs 2.50 (1.19-5.25)). The majority of logistic regression analyses indicated no association between supplementation and MIH. CONCLUSIONS: It was found a consistent significant caries-preventive effect in the primary dentition of children who received fluoride (256/372)/vitamin D supplementation (274/376) in all 12 months over the first year of life; no effects were observed for permanent dentition. The high parental interest in supplementation is linked to an imbalance of the study groups. Furthermore, tooth brushing frequency, use of fluoride toothpastes and/or other oral hygiene products were not recorded during the observation period which may also confound the results. CLINICAL RELEVANCE: Fluoride/vitamin D supplementation can be used in children for preventing caries in the primary dentition.


Assuntos
Cárie Dentária/prevenção & controle , Hipoplasia do Esmalte Dentário/patologia , Fluoretos/administração & dosagem , Vitamina D/administração & dosagem , Administração Oral , Criança , Pré-Escolar , Cárie Dentária/epidemiologia , Hipoplasia do Esmalte Dentário/epidemiologia , Feminino , Alemanha , Humanos , Lactente , Masculino , Comprimidos , Dente Decíduo
16.
Nature ; 538(7624): 248-252, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27680694

RESUMO

Birth weight (BW) has been shown to be influenced by both fetal and maternal factors and in observational studies is reproducibly associated with future risk of adult metabolic diseases including type 2 diabetes (T2D) and cardiovascular disease. These life-course associations have often been attributed to the impact of an adverse early life environment. Here, we performed a multi-ancestry genome-wide association study (GWAS) meta-analysis of BW in 153,781 individuals, identifying 60 loci where fetal genotype was associated with BW (P < 5 × 10-8). Overall, approximately 15% of variance in BW was captured by assays of fetal genetic variation. Using genetic association alone, we found strong inverse genetic correlations between BW and systolic blood pressure (Rg = -0.22, P = 5.5 × 10-13), T2D (Rg = -0.27, P = 1.1 × 10-6) and coronary artery disease (Rg = -0.30, P = 6.5 × 10-9). In addition, using large -cohort datasets, we demonstrated that genetic factors were the major contributor to the negative covariance between BW and future cardiometabolic risk. Pathway analyses indicated that the protein products of genes within BW-associated regions were enriched for diverse processes including insulin signalling, glucose homeostasis, glycogen biosynthesis and chromatin remodelling. There was also enrichment of associations with BW in known imprinted regions (P = 1.9 × 10-4). We demonstrate that life-course associations between early growth phenotypes and adult cardiometabolic disease are in part the result of shared genetic effects and identify some of the pathways through which these causal genetic effects are mediated.


Assuntos
Envelhecimento/genética , Peso ao Nascer/genética , Doença da Artéria Coronariana/genética , Diabetes Mellitus Tipo 2/genética , Feto/metabolismo , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Adulto , Antropometria , Pressão Sanguínea/genética , Montagem e Desmontagem da Cromatina , Estudos de Coortes , Conjuntos de Dados como Assunto , Feminino , Loci Gênicos/genética , Variação Genética/genética , Impressão Genômica/genética , Genótipo , Glucose/metabolismo , Glicogênio/biossíntese , Humanos , Insulina/metabolismo , Masculino , Fenótipo , Transdução de Sinais
17.
J Am Acad Child Adolesc Psychiatry ; 55(10): 896-905.e6, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27663945

RESUMO

OBJECTIVE: The aims of this study were to elucidate the influence of common genetic variants on childhood attention-deficit/hyperactivity disorder (ADHD) symptoms, to identify genetic variants that explain its high heritability, and to investigate the genetic overlap of ADHD symptom scores with ADHD diagnosis. METHOD: Within the EArly Genetics and Lifecourse Epidemiology (EAGLE) consortium, genome-wide single nucleotide polymorphisms (SNPs) and ADHD symptom scores were available for 17,666 children (<13 years of age) from nine population-based cohorts. SNP-based heritability was estimated in data from the three largest cohorts. Meta-analysis based on genome-wide association (GWA) analyses with SNPs was followed by gene-based association tests, and the overlap in results with a meta-analysis in the Psychiatric Genomics Consortium (PGC) case-control ADHD study was investigated. RESULTS: SNP-based heritability ranged from 5% to 34%, indicating that variation in common genetic variants influences ADHD symptom scores. The meta-analysis did not detect genome-wide significant SNPs, but three genes, lying close to each other with SNPs in high linkage disequilibrium (LD), showed a gene-wide significant association (p values between 1.46 × 10(-6) and 2.66 × 10(-6)). One gene, WASL, is involved in neuronal development. Both SNP- and gene-based analyses indicated overlap with the PGC meta-analysis results with the genetic correlation estimated at 0.96. CONCLUSION: The SNP-based heritability for ADHD symptom scores indicates a polygenic architecture, and genes involved in neurite outgrowth are possibly involved. Continuous and dichotomous measures of ADHD appear to assess a genetically common phenotype. A next step is to combine data from population-based and case-control cohorts in genetic association studies to increase sample size and to improve statistical power for identifying genetic variants.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Estudos de Casos e Controles , Criança , Estudos de Coortes , Feminino , Genética Populacional/métodos , Estudo de Associação Genômica Ampla , Humanos , Masculino
18.
Hum Mol Genet ; 25(18): 4127-4142, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27559109

RESUMO

More than a million childhood diarrhoeal episodes occur worldwide each year, and in developed countries a considerable part of them are caused by viral infections. In this study, we aimed to search for genetic variants associated with diarrhoeal disease in young children by meta-analyzing genome-wide association studies, and to elucidate plausible biological mechanisms. The study was conducted in the context of the Early Genetics and Lifecourse Epidemiology (EAGLE) consortium. Data about diarrhoeal disease in two time windows (around 1 year of age and around 2 years of age) was obtained via parental questionnaires, doctor interviews or medical records. Standard quality control and statistical tests were applied to the 1000 Genomes imputed genotypic data. The meta-analysis (N = 5758) followed by replication (N = 3784) identified a genome-wide significant association between rs8111874 and diarrhoea at age 1 year. Conditional analysis suggested that the causal variant could be rs601338 (W154X) in the FUT2 gene. Children with the A allele, which results in a truncated FUT2 protein, had lower risk of diarrhoea. FUT2 participates in the production of histo-blood group antigens and has previously been implicated in the susceptibility to infections, including Rotavirus and Norovirus Gene-set enrichment analysis suggested pathways related to the histo-blood group antigen production, and the regulation of ion transport and blood pressure. Among others, the gastrointestinal tract, and the immune and neuro-secretory systems were detected as relevant organs. In summary, this genome-wide association meta-analysis suggests the implication of the FUT2 gene in diarrhoeal disease in young children from the general population.


Assuntos
Diarreia/genética , Fucosiltransferases/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Alelos , Pré-Escolar , Diarreia/patologia , Feminino , Genótipo , Humanos , Lactente , Masculino , Polimorfismo de Nucleotídeo Único
19.
Sleep ; 39(10): 1859-1869, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27568811

RESUMO

STUDY OBJECTIVES: Low or excessive sleep duration has been associated with multiple outcomes, but the biology behind these associations remains elusive. Specifically, genetic studies in children are scarce. In this study, we aimed to: (1) estimate the proportion of genetic variance of sleep duration in children attributed to common single nucleotide polymorphisms (SNPs), (2) identify novel SNPs associated with sleep duration in children, and (3) investigate the genetic overlap of sleep duration in children and related metabolic and psychiatric traits. METHODS: We performed a population-based molecular genetic study, using data form the EArly Genetics and Life course Epidemiology (EAGLE) Consortium. 10,554 children of European ancestry were included in the discovery, and 1,250 children in the replication phase. RESULTS: We found evidence of significant but modest SNP heritability of sleep duration in children (SNP h2 0.14, 95% CI [0.05, 0.23]) using the LD score regression method. A novel region at chromosome 11q13.4 (top SNP: rs74506765, P = 2.27e-08) was associated with sleep duration in children, but this was not replicated in independent studies. Nominally significant genetic overlap was only found (rG = 0.23, P = 0.05) between sleep duration in children and type 2 diabetes in adults, supporting the hypothesis of a common pathogenic mechanism. CONCLUSIONS: The significant SNP heritability of sleep duration in children and the suggestive genetic overlap with type 2 diabetes support the search for genetic mechanisms linking sleep duration in children to multiple outcomes in health and disease.


Assuntos
Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Sono/genética , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Humanos , Estudos Longitudinais , Masculino , Fatores de Tempo
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