Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Hum Mol Genet ; 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31504550

RESUMO

Although hundreds of GWAS-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 thirty studies consisting of up to 13,005 cases (≥95th percentile of 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 1,888 cases and 4,689 controls from seven cohorts of European and North/South American ancestry. In addition to observing eighteen 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 in 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 ten 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.

2.
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
3.
Int J Epidemiol ; 2018 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30107520

RESUMO

Background: Type 2 diabetes (T2D) results from a complex interplay between genetics and the environment. Several epigenome-wide association studies (EWAS) have found DNA methylation loci associated with T2D in European populations. However, data from African populations are lacking. We undertook the first EWAS for T2D among sub-Saharan Africans, aiming at identifying ubiquitous and novel DNA methylation loci associated with T2D. Methods: The Illumina 450k DNA-methylation array was used on whole blood samples of 713 Ghanaian participants (256 with T2D, 457 controls) from the cross-sectional Research on Obesity and Diabetes among African Migrants (RODAM) study. Differentially methylated positions (DMPs) for T2D and HbA1c were identified through linear regression analysis adjusted for age, sex, estimated cell counts, hybridization batch, array position and body mass index (BMI). We also did a candidate analysis of previously reported EWAS loci for T2D in non-African populations, identified through a systematic literature search. Results: Four DMPs [cg19693031 (TXNIP), cg04816311 (C7orf50), cg00574958 (CPT1A), cg07988171 (TPM4)] were associated with T2D after correction for inflation by possible systematic biases. The most strongly associated DMP-cg19693031, TXNIP (P = 2.6E-19) -showed hypomethylation in T2D cases compared with controls. Two out of the four DMPs [cg19693031 (TXNIP), cg04816311 (C7orf50)] remained associated with T2D after adjustment for BMI, and one locus [cg07988171 (TPM4)] that has not been reported previously. Conclusions: In this first EWAS for T2D in sub-Saharan Africans, we have identified four DMPs at epigenome-wide level, one of which is novel. These findings provide insight into the epigenetic loci that underlie the burden of T2D in sub-Saharan Africans.

4.
Int J Gynecol Cancer ; 28(3): 453-458, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29324537

RESUMO

OBJECTIVE: The revised version of the International Federation of Gynaecology and Obstetrics (FIGO) staging system (2014) for epithelial ovarian cancer includes a number of changes. One of these is the division of stage IV into 2 subgroups. Data on the prognostic and predictive significance of this classification are scarce. The effect of neoadjuvant chemotherapy (NACT) versus primary debulking surgery (PDS) in relation to the subclassification of FIGO stage IV is also unknown. METHODS: We used data of the EORTC 55971 trial, in which 670 patients with previous stage IIIC or IV epithelial ovarian cancer were randomly assigned to PDS or NACT; 160 patients had previous stage IV. Information on previous FIGO staging and presence of pleural effusion with positive cytology were used to classify tumors as either stage IVA or IVB. We tested the association between stage IVA/IVB and survival to evaluate the prognostic value and interactions between stage, treatment, and survival to evaluate the predictive performance. RESULTS: Among the 160 participants with previous stage IV disease, 103 (64%) were categorized as stage IVA and 57 (36%) as stage IVB tumors. Median overall survival was 24 months in FIGO stage IVA and 31 months in stage IVB patients (P = 0.044). Stage IVB patients treated with NACT had 9 months longer median overall survival compared with IVB patients undergoing PDS (P = 0.025), whereas in IVA patients, no significant difference was observed (24 vs 26 months, P = 0.48). CONCLUSIONS: The reclassification of FIGO stage IV into stage IVA or IVB was not prognostic as expected. Compared with stage IVA patients, stage IVB patients have a better overall survival and may benefit more from NACT.

5.
Clin Epigenetics ; 9: 103, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28947923

RESUMO

BACKGROUND: Epigenome-wide association studies (EWAS) have identified DNA methylation loci involved in adiposity. However, EWAS on adiposity in sub-Saharan Africans are lacking despite the high burden of adiposity among African populations. We undertook an EWAS for anthropometric indices of adiposity among Ghanaians aiming to identify DNA methylation loci that are significantly associated. METHODS: The Illumina 450k DNA methylation array was used to profile DNA methylation in whole blood samples of 547 Ghanaians from the Research on Obesity and Diabetes among African Migrants (RODAM) study. Differentially methylated positions (DMPs) and differentially methylation regions (DMRs) were identified for BMI and obesity (BMI ≥ 30 kg/m2), as well as for waist circumference (WC) and abdominal obesity (WC ≥ 102 cm in men, ≥88 cm in women). All analyses were adjusted for age, sex, blood cell distribution estimates, technical covariates, recruitment site and population stratification. We also did a replication study of previously reported EWAS loci for anthropometric indices in other populations. RESULTS: We identified 18 DMPs for BMI and 23 for WC. For obesity and abdominal obesity, we identified three and one DMP, respectively. Fourteen DMPs overlapped between BMI and WC. DMP cg00574958 annotated to gene CPT1A was the only DMP associated with all outcomes analysed, attributing to 6.1 and 5.6% of variance in obesity and abdominal obesity, respectively. DMP cg07839457 (NLRC5) and cg20399616 (BCAT1) were significantly associated with BMI, obesity and with WC and had not been reported by previous EWAS on adiposity. CONCLUSIONS: This first EWAS for adiposity in Africans identified three epigenome-wide significant loci (CPT1A, NLRC5 and BCAT1) for both general adiposity and abdominal adiposity. The findings are a first step in understanding the role of DNA methylation in adiposity among sub-Saharan Africans. Studies on other sub-Saharan African populations as well as translational studies are needed to determine the role of these DNA methylation variants in the high burden of adiposity among sub-Saharan Africans.


Assuntos
Grupo com Ancestrais do Continente Africano/genética , Metilação de DNA , DNA/sangue , Epigenômica/métodos , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla/métodos , Obesidade/genética , Índice de Massa Corporal , Carnitina O-Palmitoiltransferase/genética , Feminino , Gana , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade Abdominal/sangue , Obesidade Abdominal/genética , RNA Longo não Codificante/genética , Circunferência da Cintura
7.
Nat Commun ; 8: 15805, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28613276

RESUMO

Reduced cardiac vagal control reflected in low heart rate variability (HRV) is associated with greater risks for cardiac morbidity and mortality. In two-stage meta-analyses of genome-wide association studies for three HRV traits in up to 53,174 individuals of European ancestry, we detect 17 genome-wide significant SNPs in eight loci. HRV SNPs tag non-synonymous SNPs (in NDUFA11 and KIAA1755), expression quantitative trait loci (eQTLs) (influencing GNG11, RGS6 and NEO1), or are located in genes preferentially expressed in the sinoatrial node (GNG11, RGS6 and HCN4). Genetic risk scores account for 0.9 to 2.6% of the HRV variance. Significant genetic correlation is found for HRV with heart rate (-0.74

8.
Eur J Obstet Gynecol Reprod Biol ; 202: 36-40, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27156154

RESUMO

OBJECTIVE: Available treatment options in couples with unexplained or mild male subfertility are intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH) and in vitro fertilisation (IVF). IUI-COH is a less invasive treatment that is often used before proceeding with IVF. Yet as the IVF success rates might be higher and time to pregnancy shorter, expedited access to IVF might be the preferred option. To identify couples that could benefit from immediate IVF over IUI-COH, we assessed whether female age, duration of subfertility or prewash total motile count (TMC) can help to identify couples that would benefit from IVF over IUI-COH. STUDY DESIGN: We performed a secondary data-analysis of a multicentre open-label randomised controlled trial in three university and six teaching hospitals in the Netherlands. 116 couples with unexplained or mild male subfertility were randomised to one cycle of IVF with elective single embryo transfer with subsequent frozen-thawed embryo transfers or 3 cycles of IUI-COH. The primary outcome was an ongoing pregnancy within 4 months after randomisation. Our aim was to explore a possible differential effect of specific markers on the effectiveness of treatment. We chose to therefore assess female age, duration of subfertility and TMC as these have previously been identified as predictors. For each prognostic factor we developed a logistic regression model to predict ongoing pregnancy with that prognostic factor, treatment and a factor-by-treatment interaction term. RESULTS: Female age and duration of subfertility were not associated with better ongoing pregnancy chances after IVF compared to IUI-COH (p-value for interaction=0.65 and 0.26, respectively). Only when TMC was lower than 110 (×10(6)spermatozoa/mL), the probability of ongoing pregnancy was higher in women allocated to IVF (p-value for interaction=0.06). CONCLUSION: In couples with unexplained or mild male subfertility, a low TMC might lead to higher pregnancy rates after IVF than after IUI-COH. This finding needs to be validated in a larger trial before it can be applied in clinical practice.


Assuntos
Transferência Embrionária , Fertilização In Vitro , Infertilidade/terapia , Inseminação Artificial , Adulto , Feminino , Humanos , Masculino , Indução da Ovulação , Gravidez , Taxa de Gravidez
9.
Intern Emerg Med ; 11(3): 327-40, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26370238

RESUMO

Many ethnic minorities in Europe have a higher type 2 diabetes (T2D) prevalence than their host European populations. The risk size differs between ethnic groups, but the extent of the differences in the various ethnic minority groups has not yet been systematically quantified. We conducted a meta-analysis of published data on T2D in various ethnic minority populations resident in Europe compared to their host European populations. We systematically searched MEDLINE (using PUBMED) and EMBASE for papers on T2D prevalence in ethnic minorities in Europe published between 1994 and 2014. The ethnic minority groups were classified into five population groups by geographical origin: South Asian (SA), Sub-Saharan African (SSA), Middle Eastern and North African (MENA), South and Central American (SCA), and Western Pacific (WP). Pooled odds ratios with corresponding 95 % confidence interval (CI) were calculated using Review Manager 5.3. Twenty articles were included in the analysis. Compared with the host populations, SA origin populations had the highest odds for T2D (3.7, 95 % CI 2.7-5.1), followed by MENA (2.7, 95 % CI 1.8-3.9), SSA (2.6, 95 % CI 2.0-3.5), WP (2.3, 95 % CI 1.2-4.1), and lastly SCA (1.3, 95 % CI 1.1-1.6). Odds ratios were in all ethnic minority populations higher for women than for men except for SCA. Among SA subgroups, compared with Europeans, Bangladeshi had the highest odds ratio of 6.2 (95 % CI 3.9-9.8), followed by Pakistani (5.4, 95 % CI 3.2-9.3) and Indians (4.1, 95 % CI 3.0-5.7). The risk of T2D among ethnic minority groups living in Europe compared to Europeans varies by geographical origin of the group: three to five times higher among SA, two to four times higher among MENA, and two to three times higher among SSA origin. Future research and policy initiatives on T2D among ethnic minority groups should take the interethnic differences into account.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/etnologia , Grupos Étnicos/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Grupos Minoritários/estatística & dados numéricos , Idoso , Diabetes Mellitus Tipo 2/terapia , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Medição de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA