Obesity is a leading risk factor for metabolic and cardiovascular diseases and its prevalence has more than doubled since the 1980's, with the greatest burden carried by minority populations. Large-scale genome-wide associations studies (GWAS) have identified >70 genetic loci that are unequivocally associated with obesity-related traits primarily in European descent populations. So far, no large-scale GWAS for any obesity-related traits have been performed in Hispanic /Latinos (HL) populations, despite their increased prevalence of obesity. Although classified under one 'ethnic label', HL populations are incredibly diverse and genetically highly admixed with recent origins from Europe, Africa and the Americas. Hence, genome-wide association will necessitate a large collaborative effort and the use of advanced statistical methods (that go far beyond standard GWAS analyses) to account for and leverage their high degree of genetic diversity. Here, we propose to perform the first large-scale genomic study in search of obesity-susceptibility loci in HL populations.
For aim 1, we have assembled the world's GWAS studies in HL populations, including >50,000 HL men and women with high-density SNP array data. Genome-wide imputation to multiethnic reference panels from the 1000 Genomes Project and other unique Amerindian resources will allow for comprehensive testing of common and low frequency variation present in HL populations as well as provide a rich resource for addressing genetic risk heterogeneity at obesity-related loci across HL sub-populations. To elucidate racial/ethnic transferability and fine-map association signals in aim 2, we will leverage data from large-scale GWAS of obesity-related traits in AA and EA populations that are available to us through our work with AA (n>50,000) and EA (GIANT consortium, n>200,000) consortia.
In aim 3, we will employ functional analyses in Drosophila and bioinformatic data-mining tools to identify and characterize the target genes and functional alleles, and link associations with biological pathways. We are uniquely positioned and experienced to establish a large-scale collaboration to study the genomics of obesity in HLs. Our proposal is also unique and innovative for taking a GWAS study to the next translational stage, with an experimental research aim for further characterization of obesity specific genetic effects. Our study may improve the understanding of the genomic etiology of obesity, knowledge which may be used to reduce the burden of disease in underserved and understudied minority populations.

Public Health Relevance

This study proposes to investigate the importance of genetic variation on obesity susceptibility in Hispanic / Latino populations. The proposed study will advance the understanding of the genetics influencing obesity in minorities; groups that are often overlooked in genetic studies. Findings from this study have the potential to identify important pathways for disease prediction, intervention and treatment, knowledge which may be used to reduce the burden of disease in underserved and understudied minority populations.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK101855-03
Application #
9127221
Study Section
Genetics of Health and Disease Study Section (GHD)
Program Officer
Karp, Robert W
Project Start
2014-08-15
Project End
2017-07-31
Budget Start
2016-08-01
Budget End
2017-07-31
Support Year
3
Fiscal Year
2016
Total Cost
$684,404
Indirect Cost
$82,123
Name
University of North Carolina Chapel Hill
Department
Public Health & Prev Medicine
Type
Schools of Public Health
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Gong, J; Nishimura, K K; Fernandez-Rhodes, L et al. (2018) Trans-ethnic analysis of metabochip data identifies two new loci associated with BMI. Int J Obes (Lond) 42:384-390
Hu, Yao; Raffield, Laura M; Polfus, Linda M et al. (2018) A common TCN1 loss-of-function variant is associated with lower vitamin B12 concentration in African Americans. Blood 131:2859-2863
Evangelou, Evangelos (see original citation for additional authors) (2018) Genetic analysis of over 1 million people identifies 535 new loci associated with blood pressure traits. Nat Genet 50:1412-1425
Burkart, Kristin M; Sofer, Tamar; London, Stephanie J et al. (2018) A Genome-Wide Association Study in Hispanics/Latinos Identifies Novel Signals for Lung Function. The Hispanic Community Health Study/Study of Latinos. Am J Respir Crit Care Med 198:208-219
Speakman, J R; Loos, R J F; O'Rahilly, S et al. (2018) GWAS for BMI: a treasure trove of fundamental insights into the genetic basis of obesity. Int J Obes (Lond) 42:1524-1531
Loos, Ruth Jf (2018) The genetics of adiposity. Curr Opin Genet Dev 50:86-95
Fernández-Rhodes, Lindsay; Malinowski, Jennifer R; Wang, Yujie et al. (2018) The genetic underpinnings of variation in ages at menarche and natural menopause among women from the multi-ethnic Population Architecture using Genomics and Epidemiology (PAGE) Study: A trans-ethnic meta-analysis. PLoS One 13:e0200486
Turcot, Valérie (see original citation for additional authors) (2018) Protein-altering variants associated with body mass index implicate pathways that control energy intake and expenditure in obesity. Nat Genet 50:26-41
Graff, Mariaelisa; Emery, Leslie S; Justice, Anne E et al. (2017) Genetic architecture of lipid traits in the Hispanic community health study/study of Latinos. Lipids Health Dis 16:200
Fernández-Rhodes, Lindsay; Robinson, Whitney R; Sotres-Alvarez, Daniela et al. (2017) Accuracy of Self-reported Weight in Hispanic/Latino Adults of the Hispanic Community Health Study/Study of Latinos. Epidemiology 28:847-853

Showing the most recent 10 out of 20 publications