Findings from the Quebec Family Study on the Etiology of Obesity: Genetics and Environmental Highlights.
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ABSTRACT:
SUBMITTER: Chaput JP
PROVIDER: S-EPMC3920031 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background and aims: Obesity is a major health problem worldwide. Given the heterogeneous obesity phenotype, an optimal obesity stratification would improve clinical management. Since obesity has a strong genetic component, we aimed to develop a polygenic risk score (PRS) to stratify obesity according to the genetic background of the individuals. Methods: A total of 231 single nucleotide polymorphisms (SNP) significantly associated to body mass index (BMI) from 21 genome-wide association studies were genotyped or imputed in 881 subjects from the Quebec Family Study (QFS). The population was randomly split into discovery (80%; n = 704) and validation (20%; n = 177) samples with similar obesity (BMI ≥ 30) prevalence (27.8% and 28.2%, respectively). Family-based associations with obesity were tested for every SNP in the discovery sample and a weighed and continuous PRS231 was constructed. Generalized linear mixed effects models were used to test the association of PRS231 with obesity in the QFS discovery sample and validated in the QFS replication sample. Furthermore, the Fatty Acid Sensor (FAS) Study (n = 141; 27.7% obesity prevalence) was used as an independent sample to replicate the results. Results: The linear trend test demonstrated a significant association of PRS231 with obesity in the QFS discovery sample (ORtrend = 1.19 [95% CI, 1.14-1.24]; P = 2.0x10-16). We also found that the obesity prevalence was significantly greater in the higher PRS231 quintiles compared to the lowest quintile. Significant and consistent results were obtained in the QFS validation sample for both the linear trend test (ORtrend = 1.16 [95% CI, 1.07-1.26]; P = 6.7x10-4), and obesity prevalence across quintiles. These results were partially replicated in the FAS sample (ORtrend = 1.12 [95% CI, 1.02-1.24]; P = 2.2x10-2). PRS231 explained 7.5%, 3.2%, and 1.2% of BMI variance in QFS discovery, QFS validation, and FAS samples, respectively. Conclusions: These results revealed that genetic background in the form of a 231 BMI-associated PRS has a significant impact on obesity, but a limited potential to accurately stratify it. Further studies are encouraged on larger populations.
| S-EPMC6796792 | biostudies-literature
Project description:UCP3 is a mitochondrial membrane transporter that is postulated to uncouple oxidative phosphorylation from ATP synthesis producing heat instead of ATP. Human UCP3 is mainly expressed in skeletal muscle, which plays an important role in energy homeostasis and substrate oxidation. Therefore, UCP3 is a good candidate gene for obesity.We analyzed, among 734 subjects from the Québec Family Study, a new GA repeat microsatellite located in intervening sequence (IVS) 6 (GAIVS6) in UCP3 gene, and two already described restriction fragment length polymorphisms (RFLP) Y210Y(C-->T) and V102I(G-->A). Covariance analysis across genotypes for different adiposity, resting energy expenditure, and glucose metabolism variables was undertaken with age and sex, plus body fat and body mass for nonadiposity phenotypes, as covariates.We found strong associations between GAIVS6 and body mass index (p = 0.0001), fat mass (p = 0.0005), percentage body fat (p = 0.0004), the sum of six skinfold thickness (p = 0.0001), and leptin level (p = 0.0001). Homozygote for the GAIVS6 240 bp alleles (15% frequency in QFS) showed higher adiposity than subjects with the GAIVS6 238 bp allele (70% in QFS). The exons, the 5' untranslated region (UTR), and the exon-intron junctions of UCP3 gene from subjects homozygote for either GAIVS6 238 bp or 240 bp alleles were sequenced in search for mutations. Variants 5'UTR-55C-->T and Y210Y(C-->T) were detected, whereas IVS4-36C-->T was uncovered, but no new exonic or splice junction mutation was observed. RFLP Y210Y(C-->T) was not associated to adiposity in QFS; V1021(G-->A) showed no variation.Our results suggest that some alleles of UCP3 are involved in the etiology of human obesity.
| S-EPMC1950055 | biostudies-other
Project description:Recently, Mahalanobis distance (DM) was suggested as a statistical measure of physiological dysregulation in aging individuals. We constructed DM variants using sets of biomarkers collected at the two visits of the Long Life Family Study (LLFS) and performed joint analyses of longitudinal observations of DM and follow-up mortality in LLFS using joint models. We found that DM is significantly associated with mortality (hazard ratio per standard deviation: 1.31 [1.16, 1.48] to 2.22 [1.84, 2.67]) after controlling for age and other covariates. GWAS of random intercepts and slopes of DM estimated from joint models found a genome-wide significant SNP (rs12652543, p=7.2×10-9) in the TRIO gene associated with the slope of DM constructed from biomarkers declining in late life. Review of biological effects of genes corresponding to top SNPs from GWAS of DM slopes revealed that these genes are broadly involved in cancer prognosis and axon guidance/synapse function. Although axon growth is mainly observed during early development, the axon guidance genes can function in adults and contribute to maintenance of neural circuits and synaptic plasticity. Our results indicate that decline in axons' ability to maintain complex regulatory networks may potentially play an important role in the increase in physiological dysregulation during aging.
| S-EPMC7185144 | biostudies-literature
Project description:Sixty years ago, the actinomycetes, which include members of the genus Streptomyces, with their bacterial cellular dimensions but a mycelial growth habit like fungi, were generally regarded as a possible intermediate group, and virtually nothing was known about their genetics. We now know that they are bacteria, but with many original features. Their genome is linear with a unique mode of replication, not circular like those of nearly all other bacteria. They transfer their chromosome from donor to recipient by a conjugation mechanism, but this is radically different from the E. coli paradigm. They have twice as many genes as a typical rod-shaped bacterium like Escherichia coli or Bacillus subtilis, and the genome typically carries 20 or more gene clusters encoding the biosynthesis of antibiotics and other specialised metabolites, only a small proportion of which are expressed under typical laboratory screening conditions. This means that there is a vast number of potentially valuable compounds to be discovered when these 'sleeping' genes are activated. Streptomyces genetics has revolutionised natural product chemistry by facilitating the analysis of novel biosynthetic steps and has led to the ability to engineer novel biosynthetic pathways and hence 'unnatural natural products', with potential to generate lead compounds for use in the struggle to combat the rise of antimicrobial resistance.
| S-EPMC6781119 | biostudies-literature
Project description:The special design of the Long Life Family Study provides a unique opportunity to investigate the genetics of human longevity by analyzing data on exceptional lifespans in families. In this article, we performed two series of genome wide association studies of human longevity which differed with respect to whether missing lifespan data were predicted or not predicted. We showed that the use of predicted lifespan is most beneficial when the follow-up period is relatively short. In addition to detection of strong associations of SNPs in APOE, TOMM40, NECTIN2, and APOC1 genes with longevity, we also detected a strong new association with longevity of rs1927465, located between the CYP26A1 and MYOF genes on chromosome 10. The association was confirmed using data from the Health and Retirement Study. We discuss the biological relevance of the detected SNPs to human longevity.
| S-EPMC6175028 | biostudies-literature
Project description:The overall objective of the heritage project is to study the role of the genotype in cardiovascular,metabolic and hormonal responses to aerobic exercise training and the contribution of regular exercise to changes in several cardiovascular disease and diabetes risk factors. PLEASE NOTE THE POST-TRAINING GENE CHIP FILES HAVE NEVER BEEN RELEASED ON GEO. PLEASE ALSO NOTE THAT DUE TO THE OUTDATED INSULIN ASSAY UTILISED IN THE HERITAGE STUDY, THE INSULIN DATA WAS NOT COMPARABLE WITH ANY MORE RECENT MODERN STUDIES.
2013-06-12 | GSE47874 | GEO
Project description:The overall objective of the heritage project is to study the role of the genotype in cardiovascular,metabolic and hormonal responses to aerobic exercise training and the contribution of regular exercise to changes in several cardiovascular disease and diabetes risk factors. The study cohort in this analysis consists of 473 Caucasian subjects (230 male and 243 female) from 99 nuclear families who completed M-bM-^IM-%58 of the prescribed 60 exercise-training sessions.The phenotypic expression of each individualM-bM-^@M-^Ys genotype is assessed under two well-defined environmental conditions, the pre- and post-training conditions. Here we have made the pre-training data available as used in the article Phillips BE, Williams JP, Gustafsson T, Bouchard C, Rankinen T, et al. (2013) Molecular Networks of Human Muscle Adaptation to Exercise and Age. PLoS Genet 9(3): e1003389. doi:10.1371/journal.pgen.1003389 52 U133+2 profiles (17M-bM-^@M-^S63 yr) generated from pre-exercise muscle biopsy samples from the HERITAGE Family Study. Heritage_pre dataset.
2013-06-12 | E-GEOD-47874 | biostudies-arrayexpress
Project description:BackgroundWe present findings from the Pneumonia Etiology Research for Child Health (PERCH) site in Bamako, Mali.MethodsCases were patients 28 days to 59 months of age, admitted to hospital with severe or very severe pneumonia (2005 World Health Organization definition). Community controls were frequency matched by age. Both provided nasopharyngeal and oropharyngeal swabs for multiplex polymerase chain reaction and Streptococcus pneumoniae culture. Cases underwent blood culture and induced sputum culture for Mycobacterium tuberculosis. A subset had pleural fluid and lung aspirates collected for culture and polymerase chain reaction. Primary analyses included participants with negative or unknown HIV status (HIV-) and cases with abnormal chest radiographs (CXR+). Cases and controls were compared using logistic regression adjusting for age. Etiologic fractions were calculated by a Bayesian nested partially latent class analysis, the PERCH integrated analysis.ResultsBetween January 1, 2012, and January 14, 2014, we enrolled 241 CXR+/HIV- cases and 725 HIV- controls. Compared with controls, cases were more likely to have moderate-to-severe wasting (43.1% vs. 14.1%, P < 0.001) and stunting (26.6% vs. 9.4%, P < 0.001). Predominant etiologies were respiratory syncytial virus [24.0%; 95% credible interval (CrI): 18.3%-31.1%], S. pneumoniae (15.2%; 95% CrI: 9.5-21.6), human metapneumovirus (11.8%; 95% CrI: 8.3%-16.2%) and parainfluenza virus type 3 (9.0%; 95% CrI: 5.8%-13.3%). Case fatality was 13.3%, with Staphylococcus aureus, Pneumocystis jirovecii and Haemophilus influenzae type b predominating (40% of fatal cases).ConclusionsPERCH uncovered high case fatality among children with severe pneumonia in Mali, highlighting a role for new interventions (eg, respiratory syncytial virus vaccines) and a need to improve vaccine coverage and strengthen healthcare delivery.
| S-EPMC8448406 | biostudies-literature
Project description:BackgroundChildhood pneumonia in developing countries is the foremost cause of morbidity and death. Fresh information on etiology is needed, considering the changing epidemiology of pneumonia in the setting of greater availability of effective vaccines, changing antibiotic use and improved access to care. We report here the Zambia site results of the Pneumonia Etiology Research for Child Health study on the etiology of pneumonia among HIV-uninfected children in Lusaka, Zambia.MethodsWe conducted a case-control study of HIV-uninfected children age 1-59 months admitted with World Health Organization-defined severe or very severe pneumonia to a large tertiary care hospital in Lusaka. History, physical examination, chest radiographs (CXRs), blood cultures and nasopharyngeal/oropharyngeal swabs were obtained and tested by polymerase chain reaction and routine microbiology for the presence of 30 bacteria and viruses. From age and seasonally matched controls, we tested blood and nasopharyngeal/oropharyngeal samples. We used the Pneumonia Etiology Research for Child Health integrated analysis to determine the individual and population etiologic fraction for individual pathogens as the cause of pneumonia.ResultsAmong the 514 HIV-uninfected case children, 208 (40.5%) had abnormal CXRs (61 of 514 children were missing CXR), 8 (3.8%) of which had positive blood cultures. The overall mortality was 16.0% (82 deaths). The etiologic fraction was highest for respiratory syncytial virus [26.1%, 95% credible interval (CrI): 17.0-37.7], Mycobacterium tuberculosis (12.8%, 95% CrI: 4.3-25.3) and human metapneumovirus (12.8%, CrI: 6.1-21.8).ConclusionsChildhood pneumonia in Zambia among HIV-uninfected children is most frequently caused by respiratory syncytial virus, M. tuberculosis and human metapneumovirus, and the mortality remains high.
| S-EPMC8448410 | biostudies-literature
Project description:BackgroundPneumonia remains the leading infectious cause of death among children <5 years, but its cause in most children is unknown. We estimated etiology for each child in 2 Bangladesh sites that represent rural and urban South Asian settings with moderate child mortality.MethodsAs part of the Pneumonia Etiology Research for Child Health study, we enrolled children 1-59 months of age with World Health Organization-defined severe and very severe pneumonia, plus age-frequency-matched controls, in Matlab and Dhaka, Bangladesh. We applied microbiologic methods to nasopharyngeal/oropharyngeal swabs, blood, induced sputum, gastric and lung aspirates. Etiology was estimated using Bayesian methods that integrated case and control data and accounted for imperfect sensitivity and specificity of the measurements.ResultsWe enrolled 525 cases and 772 controls over 24 months. Of the cases, 9.1% had very severe pneumonia and 42.0% (N = 219) had infiltrates on chest radiograph. Three cases (1.5%) had positive blood cultures (2 Salmonella typhi, 1 Escherichia coli and Klebsiella pneumoniae). All 4 lung aspirates were negative. The etiology among chest radiograph-positive cases was predominantly viral [77.7%, 95% credible interval (CrI): 65.3-88.6], primarily respiratory syncytial virus (31.2%, 95% CrI: 24.7-39.3). Influenza virus had very low estimated etiology (0.6%, 95% CrI: 0.0-2.3). Mycobacterium tuberculosis (3.6%, 95% CrI: 0.5-11.0), Enterobacteriaceae (3.0%, 95% CrI: 0.5-10.0) and Streptococcus pneumoniae (1.8%, 95% CrI: 0.0-5.9) were the only nonviral pathogens in the top 10 etiologies.ConclusionsChildhood severe and very severe pneumonia in young children in Bangladesh is predominantly viral, notably respiratory syncytial virus.
| S-EPMC8448409 | biostudies-literature