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Ying Wu,
Lindsay L Waite,
Anne U Jackson,
Wayne H-H Sheu,
Steven Buyske,
Devin Absher,
Donna K Arnett,
Eric Boerwinkle,
Lori L Bonnycastle,
Cara L Carty, [......],
Tzung-Dau Wang,
Michael Boehnke,
Christopher A Haiman,
Yii-Der I Chen,
Charles Kooperberg,
Themistocles L Assimes,
Dana C Crawford,
Chao A Hsiung,
Kari E North,
Karen L Mohlke
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ABSTRACT: Genome-wide association studies (GWAS) have identified ∼100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, in individuals of African American (n = 6,832), East Asian (n = 9,449), and European (n = 10,829) ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1×10(-4) in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies.
PLoS Genetics 03/2013; 9(3):e1003379. · 8.69 Impact Factor
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Khanh-Dung H Nguyen,
Vasyl Pihur,
Santhi K Ganesh,
Ankit Rakha,
Richard S Cooper, Steven C Hunt,
Barry I Freeman,
Joe Coresh,
Linda W H Kao,
Alanna C Morrison,
Eric Boerwinkle,
Georg B Ehret,
Aravinda Chakravarti
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ABSTRACT: Rationale: Hypertension (HTN) affects ~30% of adults in industrialized countries and is the major risk factor for cardiovascular disease. Objective: We sought to study the genetic effect of coding and conserved non-coding variants in syndromic HTN genes on systolic (SBP) and diastolic (DBP) blood pressure to assess their overall impact on essential hypertension (EH). Methods and Results: We resequenced 11 genes (AGT, CYP11B1, CYP17A1, HSD11B2, NR3C1, NR3C2, SCNN1A, SCNN1B, SCNN1G, WNK1 and WNK4) in 560 European (EA) and African (AA) ancestry GenNet participants with extreme SBP. We investigated genetic associations of 2,535 variants with BP in 19,997 EAs and 6,069 AAs in three types of analyses. First, we studied the combined effects of all variants in GenNet. Second, we studied 1000 Genomes imputed polymorphic variants in 9,747 EA and 3,207 AA ARIC subjects. Lastly, we genotyped 37 missense and common noncoding variants in 6,591 EAs and 6,521 individuals (3,659 EA/2,862 AA) from the CLUE and FBPP studies. None of the variants individually reached significant false-discovery rates (FDR≤0.05) for SBP and DBP. However, upon pooling all coding and non-coding variants we identified at least 5 loci (AGT, CYP11B1, NR3C2, SCNN1G and WNK1), with higher association at evolutionary conserved sites. Conclusions: Both rare and common variants at these genes affect BP in the general population with modest effects sizes (<0.05 standard deviation units) and much larger sample sizes are required to assess the impact of individual genes. Collectively, conserved noncoding variants affect BP to a greater extent than missense mutations.
Circulation Research 11/2012; · 9.49 Impact Factor
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ABSTRACT: Whereas the initial focus of bariatric surgery primarily focused on weight loss and was considered by many clinicians and the public as a cosmetic-driven procedure, this surgical therapy is now recognized as a successful approach to reducing cardiovascular disease risk and the only substantial and sustainable weight loss treatment for most severely obese patients. In addition, as a result of the multiple metabolic-related benefits associated with bariatric surgery, efforts to understand physiologic and biochemical mechanisms have led to a dramatic increase in scientific discovery. This review focuses on bariatric research conducted during the past two decades in relation to cardiovascular disease risk and the effects of this surgical therapy on diabetes. Cardiovascular and diabetes mortality and morbidity associated with bariatric surgery are reviewed. The opportunity for bariatric (and/or metabolic) surgery to provide a preventive strategy for cardiovascular disease and diabetes as well as treatment therapy is presented for clinical consideration.
Current Atherosclerosis Reports 10/2012; · 2.66 Impact Factor
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Massimo Mangino,
Shih-Jen Hwang,
Timothy D Spector, Steven C Hunt,
Masayuki Kimura,
Annette L Fitzpatrick,
Lene Christiansen,
Inge Petersen,
Clara C Elbers,
Tamara Harris, [......],
Fridtjof Thomas,
Elad Ziv,
Bruce M Psaty,
Joshua C Bis,
Jerome I Rotter,
Kent D Taylor,
Erin Smith,
Nicholas J Schork,
Daniel Levy,
Abraham Aviv
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ABSTRACT: Leukocyte telomere length (LTL) is associated with a number of common age-related diseases and is a heritable trait. Previous genome wide association studies (GWAS) identified two loci on chromosomes 3q26.2 (TERC) and 10q24.33 (OBFC1) that are associated with the inter-individual LTL variation. We performed a meta-analysis of 9,190 individuals from six independent GWAS and validated our findings in 2,226 individuals from four additional studies. We confirmed previously reported associations with OBFC1 (rs9419958 P=9.1x10(-11)) and with the telomerase RNA component TERC (rs1317082, P=1.1x10(-8)). We also identified two novel genomic regions associated with LTL variation that map near a conserved telomere maintenance complex component 1 (CTC1; rs3027234, P=3.6 × 10(-8)) on chromosome17p13.1 and zinc finger protein 676 (ZNF676; rs412658, P=3.3 × 10(-8)) on 19p12. The minor allele of rs3027234 was associated with both shorter LTL and lower expression of CTC1. Our findings are consistent with the recent observations that point mutations in CTC1 cause short telomeres in both Arabidopsis and humans affected by a rare Mendelian syndrome. Overall our results provide novel insights into the genetic architecture of inter-individual LTL variation in the general population.
Human Molecular Genetics 09/2012; · 7.64 Impact Factor
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Ted D Adams,
Lance E Davidson,
Sheldon E Litwin,
Ronette L Kolotkin,
Michael J LaMonte,
Robert C Pendleton,
Michael B Strong,
Russell Vinik,
Nathan A Wanner,
Paul N Hopkins, [......],
James M Walker,
Tom V Cloward,
R Tom Nuttall,
Ahmad Hammoud,
Jessica L J Greenwood,
Ross D Crosby,
Rodrick McKinlay,
Steven C Simper,
Sherman C Smith, Steven C Hunt
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ABSTRACT: Extreme obesity is associated with health and cardiovascular disease risks. Although gastric bypass surgery induces rapid weight loss and ameliorates many of these risks in the short term, long-term outcomes are uncertain.
To examine the association of Roux-en-Y gastric bypass (RYGB) surgery with weight loss, diabetes mellitus, and other health risks 6 years after surgery.
A prospective Utah-based study conducted between July 2000 and June 2011 of 1156 severely obese (body mass index [BMI] ≥ 35) participants aged 18 to 72 years (82% women; mean BMI, 45.9; 95% CI, 31.2-60.6) who sought and received RYGB surgery (n = 418), sought but did not have surgery (n = 417; control group 1), or who were randomly selected from a population-based sample not seeking weight loss surgery (n = 321; control group 2).
Weight loss, diabetes, hypertension, dyslipidemia, and health-related quality of life were compared between participants having RYGB surgery and control participants using propensity score adjustment.
Six years after surgery, patients who received RYGB surgery (with 92.6% follow-up) lost 27.7% (95% CI, 26.6%-28.9%) of their initial body weight compared with 0.2% (95% CI, -1.1% to 1.4%) gain in control group 1 and 0% (95% CI, -1.2% to 1.2%) in control group 2. Weight loss maintenance was superior in patients who received RYGB surgery, with 94% (95% CI, 92%-96%) and 76% (95% CI, 72%-81%) of patients receiving RYGB surgery maintaining at least 20% weight loss 2 and 6 years after surgery, respectively. Diabetes remission rates 6 years after surgery were 62% (95% CI, 49%-75%) in the RYGB surgery group, 8% (95% CI, 0%-16%) in control group 1, and 6% (95% CI, 0%-13%) in control group 2, with remission odds ratios (ORs) of 16.5 (95% CI, 4.7-57.6; P < .001) vs control group 1 and 21.5 (95% CI, 5.4-85.6; P < .001) vs control group 2. The incidence of diabetes throughout the course of the study was reduced after RYGB surgery (2%; 95% CI, 0%-4%; vs 17%; 95% CI, 10%-24%; OR, 0.11; 95% CI, 0.04-0.34 compared with control group 1 and 15%; 95% CI, 9%-21%; OR, 0.21; 95% CI, 0.06-0.67 compared with control group 2; both P < .001). The numbers of participants with bariatric surgery-related hospitalizations were 33 (7.9%), 13 (3.9%), and 6 (2.0%) for the RYGB surgery group and 2 control groups, respectively.
Among severely obese patients, compared with nonsurgical control patients, the use of RYGB surgery was associated with higher rates of diabetes remission and lower risk of cardiovascular and other health outcomes over 6 years.
JAMA The Journal of the American Medical Association 09/2012; 308(11):1122-31. · 30.03 Impact Factor
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ABSTRACT: Telomere length (TL) dynamics in vivo are defined by TL and its age-dependent change, brought about by cell replication. Leukocyte TL (LTL), which reflects TL in hematopoietic stem cells (HSCs), becomes shorter with age. In contrast, sperm TL, which reflects TL in the male germ cells, becomes longer with age. Moreover, offspring of older fathers display longer LTL. Thus far, no study has examined LTL and sperm TL relations with age in the same individuals, nor considered their implications for the paternal age at conception (PAC) effect on offspring LTL. We report that in 135 men (mean age: 34.4 years; range: 18-68 years) on average, LTL became shorter by 19 bp/year (r = -0.3; P = 0.0004), while sperm TL became longer by 57 bp/year (r = 0.32; P = 0.0002). Based on previously reported replication rates of HSCs and male germ cells, we estimate that HSCs lose 26 bp per replication. However, male germ cells gain only 2.48 bp per replication. As TL is inherited in an allele-specific manner, the magnitude of the PAC effect on the offspring's LTL should be approximately half of age-dependent sperm-TL elongation. When we compared the PAC effect data from previous studies with sperm-TL data from this study, the result was consistent with this prediction. As older paternal age is largely a feature of contemporary humans, we suggest that there may be progressive elongation of TL in future generations. In this sense, germ cell TL dynamics could be driving the evolution of TL in modern humans and perhaps telomere-related diseases in the general population.
Molecular Human Reproduction 07/2012; 18(11):517-22. · 3.85 Impact Factor
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ABSTRACT: Identifying metabolic syndrome (MetS) genes is important for novel drug development and health care. This study extends the findings on human chromosome 3p26-25 for an identified obesity-insulin factor QTL, with an LOD score above 3. A focused association analysis comprising up to 9578 African American and Caucasian subjects from the HyperGEN Network (908 African Americans and 1025 whites), the Family Heart Study (3035 whites in time 1 and 1943 in time 2), and the Framingham Heart Study (1317 in Offspring and 1320 in Generation 3) was performed. The homologous mouse region was explored in an F(16) generation of an advanced intercross between the LG/J and SM/J inbred strains, in an experiment where 1002 animals were fed low-fat (247 males; 254 females) or high-fat (253 males; 248 females) diets. Association results in humans indicate pleiotropic effects for SNPs within or surrounding CNTN4 on obesity, lipids and blood pressure traits and for SNPs near IL5RA, TRNT1, CRBN, and LRRN1 on central obesity and blood pressure. Linkage analyses of this region in LG/J×SM/J mice identify a highly significant pleiotropic QTL peak for insulin and glucose levels, as well as response to glucose challenge. The mouse results show that insulin and glucose levels interact with high and low fat diets and differential gene expression was identified for Crbn and Arl8b. In humans, ARL8B resides ~137kbps away from BHLHE40, expression of which shows up-regulation in response to insulin treatment. This focused human genetic analysis, incorporating mouse research evidenced that 3p26-25 has important genetic contributions to MetS components. Several of the candidate genes have functions in the brain. Their interaction with MetS and the brain warrants further investigation.
Metabolism: clinical and experimental 03/2012; 61(8):1129-41. · 2.59 Impact Factor
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ABSTRACT: Vitamin D and serum lipid levels are risk factors for cardiovascular disease. We sought to determine if vitamin D (25OHD) interacts at established lipid loci potentially explaining additional variance in lipids.
1060 individuals from Utah families were used to screen 14 loci for SNPs potentially interacting with dietary 25OHD on lipid levels. Identified putative interactions were evaluated for (1) greater effect size in subsamples with winter measures, (2) replication in an independent sample, and (3) lack of gene-environment interaction for other correlated dietary factors. Maximum likelihood models were used to evaluate interactions. The replicate sample consisted of 2890 individuals from the Family Heart Study. Putative 25OHD receptor binding site modifying SNPs were identified and allele-specific, 25OHD-dependent APOA5 promoter activity examined using luciferase expression assays. An additional sample with serum 25OHD measures was analyzed.
An rs3135506-25OHD interaction influencing HDL-C was identified. The rs3135506 minor allele was more strongly associated with low HDL-C in individuals with low winter dietary 25OHD in initial and replicate samples (p=0.0003 Utah, p=0.002 Family Heart); correlated dietary factors did not explain the interaction. SNP rs10750097 was identified as a putative causative polymorphism, was associated with 25OHD-dependent changes in APOA5 promoter activity in HEP3B and HEK293 cells (p<0.01), and showed similar interactions to rs3135506 in family cohorts. Linear interactions were not significant in samples with serum 25OHD measures; however, genotype-specific differences were seen at deficient 25OHD levels.
A 25OHD receptor binding site modifying APOA5 promoter polymorphism is associated with lower HDL-C in 25OHD deficient individuals.
Atherosclerosis 03/2012; 222(1):167-74. · 3.79 Impact Factor
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ABSTRACT: Few studies have evaluated the long-term outcomes of bariatric surgery patients in relation to obese individuals not participating in weight loss interventions. Our objective was to evaluate the 6-year changes in health-related quality of life (HRQOL) in gastric bypass (GB) patients versus 2 obese groups not undergoing surgical weight loss. The study setting was a bariatric surgery practice.
A total of 323 GB patients were compared with 257 individuals who sought but did not undergo gastric bypass and 272 population-based obese individuals using weight-specific (Impact of Weight on Quality of Life-Lite) and general (Medical Outcomes Study Short-Form 36 Health Survey) HRQOL questionnaires at baseline and 2 and 6 years later.
At 6 years, compared with the controls, the GB group exhibited significant improvements in all domains of weight-specific and most domains of general HRQOL (i.e., all physical and some mental/psychosocial). The 6-year percentage of excess weight loss correlated significantly with improvements in both weight-specific and physical HRQOL. The HRQOL scores were fairly stable from 2 to 6 years for the GB group, with small decreases in HRQOL corresponding to some weight regain.
GB patients demonstrated significant improvements in most aspects of HRQOL at 6 years compared with 2 nonsurgical obese groups. Despite some weight regain and small decreases in HRQOL from 2 to 6 years postoperatively, the HRQOL was relatively stable. These results support the effectiveness of weight loss achieved with gastric bypass surgery for improving and maintaining long-term HRQOL.
Surgery for Obesity and Related Diseases 01/2012; 8(5):625-33. · 3.93 Impact Factor
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Cara J Büsst,
Lisa D S Bloomer,
Katrina J Scurrah,
Justine A Ellis,
Timothy A Barnes,
Fadi J Charchar,
Peter Braund,
Paul N Hopkins,
Nilesh J Samani, Steven C Hunt,
Maciej Tomaszewski,
Stephen B Harrap
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ABSTRACT: Variants in the gene encoding the γ-subunit of the epithelial sodium channel (SCNN1G) are associated with both Mendelian and quantitative effects on blood pressure. Here, in 4 cohorts of 1611 white European families composed of a total of 8199 individuals, we undertook staged testing of candidate single-nucleotide polymorphisms for SCNN1G (supplemented with imputation based on data from the 1000 Genomes Project) followed by a meta-analysis in all of the families of the strongest candidate. We also examined relationships between the genotypes and relevant intermediate renal phenotypes, as well as expression of SCNN1G in human kidneys. We found that an intronic single-nucleotide polymorphism of SCNN1G (rs13331086) was significantly associated with age-, sex-, and body mass index-adjusted blood pressure in each of the 4 populations (P<0.05). In an inverse variance-weighted meta-analysis of this single-nucleotide polymorphism in all 4 of the populations, each additional minor allele copy was associated with a 1-mm Hg increase in systolic blood pressure and 0.52-mm Hg increase in diastolic blood pressure (SE=0.33, P=0.002 for systolic blood pressure; SE=0.21, P=0.011 for diastolic blood pressure). The same allele was also associated with higher 12-hour overnight urinary potassium excretion (P=0.04), consistent with increased epithelial sodium channel activity. Renal samples from hypertensive subjects showed a nonsignificant (P=0.07) 1.7-fold higher expression of SCNN1G compared with normotensive controls. These data provide genetic and phenotypic evidence in support of a role for a common genetic variant of SCNN1G in blood pressure determination.
Hypertension 12/2011; 58(6):1073-8. · 6.21 Impact Factor
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ABSTRACT: We sought to examine whether ε4 carrier status modifies the relation between body mass index (BMI) and HDL. The National Heart, Lung, and Blood Institute Family Heart Study included 657 families with high family risk scores for coronary heart disease and 588 randomly selected families of probands in the Framingham, Atherosclerosis Risk in Communities, and Utah Family Health Tree studies. We selected 1402 subjects who had ε4 carrier status available. We used generalized estimating equations to examine the interaction between BMI and ε4 allele carrier status on HDL after adjusting for age, gender, smoking, alcohol intake, mono- and poly-unsaturated fat intake, exercise, comorbidities, LDL, and family cluster.
The mean (standard deviation) age of included subjects was 56.4(11.0) years and 47% were male. Adjusted means of HDL for normal, overweight, and obese BMI categories were 51.2(± 0.97), 45.0(± 0.75), and 41.6(± 0.93), respectively, among 397 ε4 carriers (p for trend < 0.0001) and 53.6(± 0.62), 51.3(± 0.49), and 45.0(± 0.62), respectively, among 1005 non-carriers of the ε4 allele (p-value for trend < 0.0001). There was no evidence for an interaction between BMI and ε4 status on HDL(p-value 0.39).
Our findings do not support an interaction between ε4 allele status and BMI on HDL.
Lipids in Health and Disease 09/2011; 10:167. · 2.17 Impact Factor
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Georg B Ehret,
Patricia B Munroe,
Kenneth M Rice,
Murielle Bochud,
Andrew D Johnson,
Daniel I Chasman,
Albert V Smith,
Martin D Tobin,
Germaine C Verwoert,
Shih-Jen Hwang, [......],
Marjo-Riitta Järvelin,
Bruce M Psaty,
Gonçalo R Abecasis,
Aravinda Chakravarti,
Paul Elliott,
Cornelia M van Duijn,
Christopher Newton-Cheh,
Daniel Levy,
Mark J Caulfield,
Toby Johnson
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ABSTRACT: Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.
Nature 09/2011; 478(7367):103-9. · 36.28 Impact Factor
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ABSTRACT: A recent meta-analysis of genome-wide linkage scans of blood pressure (BP) in the large (N = 13,044) Family Blood Pressure Program (FBPP) identified five quantitative trait loci (QTLs) on chromosomes 6, 8, 20, and 21. We conducted follow-up fine mapping studies in 1,251 African (AA) and 1,254 European American (EA) participants of the Hypertension Genetic Epidemiology Network (HyperGEN).
Ethnic-specific linear mixed effects models were used to test associations of BP with genotyped and imputed single nucleotide polymorphisms (SNPs) contained in the logarithm of odds (LOD) score ≥2 interval under each of the QTL peaks. We used multipoint variance components models to perform linkage analysis conditional on each significant SNP in the QTL region to see if the SNP explained the QTL.
Three intergenic SNPs (rs898164, rs2876587, rs6935795) on chromosome 6p22.3 were significantly associated with pulse pressure (using appropriate Bonferroni correction). Conditioning on the significant SNPs reduced the chromosome 6 QTL linkage evidence by 14-30%. Both AAs and EAs exhibited suggestive associations between BP and intronic SNPs on chromosomes 8q24.12 (genes: OPG in AAs, SAMD12 in EAs), 20q13.12 (genes: SLC13A3 in AAs, SLC12A5 in EAs), and 21q21.1 (genes: C21orf34 in AAs, BC039377 in EAs).
Significant associations with common SNPs explained less than 1/3 of the QTL evidence. Our results cannot refute the hypothesis that rare variants account for most of the statistical evidence for the FBPP linkage peaks. Whole genome resequencing can identify the variants driving the linkage peaks and genome-wide association study (GWAS) hits thereby spurring investigations to deepen our understanding of hypertension pathophysiology.
American Journal of Hypertension 08/2011; 24(11):1227-33. · 3.18 Impact Factor
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ABSTRACT: Telomere length/DNA content has been measured in epidemiological/clinical settings with the goal of testing a host of hypotheses related to the biology of human aging, but often the conclusions of these studies have been inconsistent. These inconsistencies may stem from various reasons, including the use of different telomere length measurement techniques. Here, we report the first impartial evaluation of measurements of leukocyte telomere length by Southern blot of the terminal restriction fragments and quantitative PCR (qPCR) of telomere DNA content, expressed as the ratio of telomeric product (T)/single copy gene (S) product. Blind measurements on the same samples from 50 donors were performed in two independent laboratories on two different occasions. Both the qPCR and Southern blots displayed highly reproducible results as shown by r values > 0.9 for the correlations between results obtained by either method on two occasions. The inter-assay CV measurement for the qPCR was 6.45%, while that of the Southern blots was 1.74%. The relation between the results generated by Southern blots versus those generated by qPCR deviated from linearity. We discuss the ramifications of these findings with regard to measurements of telomere length/DNA content in epidemiological/clinical circumstances.
Nucleic Acids Research 08/2011; 39(20):e134. · 8.03 Impact Factor
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ABSTRACT: Neuropeptide Y (NPY) is an appetite hormone that acts centrally to control feeding behavior. The 5' and exon 2 regions of NPY2R, one of five NPY receptor genes, have been weakly and inconsistently implicated with obesity. With the ATG start site of the gene at the beginning of exon 2, single-nucleotide polymorphisms (SNPs) across intron 1 may show stronger associations with obesity than expected. Two 5' SNPs, three intron 1 SNPs, and one synonymous exon 2 SNP were genotyped on 2,985 white Utah subjects. Previously associated FTO, NPY, NPY1R, MC4R, PPARGC1A, OR7D4, and four NPFFR2 SNPs were also genotyped and related to BMI. One NPY2R 5' SNP (rs12649641, P = 0.008), an exon 2 SNP (rs2880415, P = 0.009), and an intron 1 SNP (rs17376826, P = 7 × 10(-6)) were each significantly associated with BMI. All three SNPs, plus FTO (rs9939609, P = 1.5 × 10(-6)) and two NPFFR2 SNPs (rs4129733, P = 3.7 × 10(-13) and rs11940196, 4.2 × 10(-10)) remained significant in a multiple regression additive model. Diplotypes using the estimated haplotypes of NPY2R, NPFFR2, and MC4R were significantly associated with BMI (P = 1.0 × 10(-10), 3.2 × 10(-8), and 1.1 × 10(-4), respectively). Haplotypes of NPY2R, NPFFR2, and MC4R, plus the FTO SNP, explained 9.6% of the BMI variance. SNP effect sizes per allele for the four genes ranged from 0.8 to 3.5 kg/m(2). We conclude that haplotypes containing the rs17376826 SNP in intron 1 of NPY2R have strong associations with BMI, some NPFFR2 haplotypes are strongly protective against or increase risk of obesity, and both NPY2R and NPFFR2 play important roles in obesity predisposition independent of FTO and MC4R.
Obesity 08/2011; 19(11):2241-7. · 4.28 Impact Factor
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Nathan E Wineinger,
Nicholas M Pajewski,
Richard E Kennedy,
Mary K Wojczynski,
Laura K Vaughan, Steven C Hunt,
C Charles Gu,
Dabeeru C Rao,
Rachel Lorier,
Ulrich Broeckel,
Donna K Arnett,
Hemant K Tiwari
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ABSTRACT: African Americans are a genetically diverse population with a high burden of many, common heritable diseases. However, our understanding of genetic variation in African Americans is substandard because of a lack of published population-based genetic studies. We report the distribution of copy-number variation (CNV) in African Americans collected as part of the Hypertension Genetic Epidemiology Network (HyperGEN) using the Affymetrix 6.0 array and the CNV calling algorithms Birdsuite and PennCNV. We present population estimates of CNV from 446 unrelated African-American subjects randomly selected from the 451 families collected within HyperGEN. Although the majority of CNVs discovered were individually rare, we found the frequency of CNVs to be collectively high. We identified a total of 11 070 CNVs greater than 10 kb passing quality control criteria that were called by both algorithms - leading to an average of 24.8 CNVs per person covering 2214 kb (median). We identified 1541 unique copy-number variable regions, 309 of which did not overlap with the Database of Genomic Variants. These results provide further insight into the distribution of CNV in African Americans.
European journal of human genetics: EJHG 06/2011; 19(12):1271-5. · 3.56 Impact Factor
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Madhumathi Rao,
Amy K Mottl,
Shelley A Cole,
Jason G Umans,
Barry I Freedman,
Donald W Bowden,
Carl D Langefeld,
Caroline S Fox,
Qiong Yang,
Adrienne Cupples,
Sudha K Iyengar, Steven C Hunt,
Thomas A Trikalinos
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ABSTRACT: Several genome scans have explored the linkage of chronic kidney disease phenotypes to chromosomic regions with disparate results. Genome scan meta-analysis (GSMA) is a quantitative method to synthesize linkage results from independent studies and assess their concordance.
We searched PubMed to identify genome linkage analyses of renal function traits in humans, such as estimated glomerular filtration rate (GFR), albuminuria, serum creatinine concentration and creatinine clearance. We contacted authors for numerical data and extracted information from individual studies. We applied the GSMA nonparametric approach to combine results across 14 linkage studies for GFR, 11 linkage studies for albumin creatinine ratio, 11 linkage studies for serum creatinine and 4 linkage studies for creatinine clearance.
No chromosomal region reached genome-wide statistical significance in the main analysis which included all scans under each phenotype; however, regions on Chromosomes 7, 10 and 16 reached suggestive significance for linkage to two or more phenotypes. Subgroup analyses by disease status or ethnicity did not yield additional information.
While heterogeneity across populations, methodologies and study designs likely explain this lack of agreement, it is possible that linkage scan methodologies lack the resolution for investigating complex traits. Combining family-based linkage studies with genome-wide association studies may be a powerful approach to detect private mutations contributing to complex renal phenotypes.
Nephrology Dialysis Transplantation 05/2011; 27(2):647-56. · 3.40 Impact Factor
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ABSTRACT: Health-related quality of life (HRQOL) is impaired in severely obese individuals presenting for bariatric surgery. Little is known about the relationship between cardiorespiratory fitness (CRF) and HRQOL in these individuals. We hypothesized that better HRQOL would be reported by those with higher CRF. In 326 gastric bypass patients (mean BMI = 46.5 ± 7.0; mean age=40.9 ± 10.1; 83.4% female), pre-surgical CRF was quantified as duration (minutes) of a submaximal treadmill test to 80% of age-predicted maximal heart rate (MHR). Patients completed both a general measure of HRQOL [the Medical Outcome Short Form 36 (SF-36)] and a weight-specific measure of HRQOL [Impact of Weight on Quality of Life--Lite]. Mean HRQOL scores were examined, controlling for age, gender, and BMI. Mean treadmill duration was 9.9 ± 3.1 min, and percent age-predicted MHR was 81.2 ± 3.0%. Higher cardiorespiratory fitness tended to be associated with better physical and weight-specific HRQOL. Adjustment for differences in gender, age, and BMI attenuated the significance of associations between fitness and physical measures from the SF-36, whereas adjustment eliminated significance of associations between fitness and weight-specific HRQOL in most cases. Results suggest that CRF confers some HRQOL benefits in severely obese adults, though these benefits may largely be explained by differences in age, gender, and BMI.
Obesity Surgery 04/2011; 21(4):457-64. · 3.29 Impact Factor
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ABSTRACT: Several genes that influence HDL-C, LDL-C, and triglyceride levels have been identified. The effects of genetic polymorphisms on lipid levels may be age dependent. We replicated 17 of these previously identified associations and then used cross-sectional and longitudinal analysis to investigate age-SNP interaction effects. The rs646776 SNP at the SORT1 locus showed an age interaction that was significant in cross-sectional analyses of 1350 individuals from Utah (p = 0.0003) and in 2977 individuals from the NHLBI Family Heart Study (p = 0.007) as well as in longitudinal analysis of a subsample of 1099 individuals from the Utah cohort that had been followed for over 20 years (p = 0.0001). The rs646776 genotype-specific difference in LDL-C levels was significantly greater for younger individuals than for older individuals. These findings may help elucidate the mode of action of the SORT1 gene and impact potential therapeutic interventions targeting this pathway.
Atherosclerosis 03/2011; 217(1):139-41. · 3.79 Impact Factor
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Jeannette Simino,
Gang Shi,
Rezart Kume,
Karen Schwander,
Michael A Province,
C Charles Gu,
Sharon Kardia,
Aravinda Chakravarti,
Georg Ehret,
Richard A Olshen, [......],
Low-Tone Ho,
Xiaofeng Zhu,
Cashell Jaquish,
Dina Paltoo,
Richard S Cooper,
Alan Weder,
J David Curb,
Eric Boerwinkle, Steven C Hunt,
Dabeeru C Rao
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ABSTRACT: A preliminary genome-wide linkage analysis of blood pressure in the Family Blood Pressure Program (FBPP) was reported previously. We harnessed the power and ethnic diversity of the final pooled FBPP dataset to identify novel loci for blood pressure thereby enhancing localization of genes containing less common variants with large effects on blood pressure levels and hypertension.
We performed one overall and 4 race-specific meta-analyses of genome-wide blood pressure linkage scans using data on 4,226 African-American, 2,154 Asian, 4,229 Caucasian, and 2,435 Mexican-American participants (total N = 13,044). Variance components models were fit to measured (raw) blood pressure levels and two types of antihypertensive medication adjusted blood pressure phenotypes within each of 10 subgroups defined by race and network. A modified Fisher's method was used to combine the P values for each linkage marker across the 10 subgroups.
Five quantitative trait loci (QTLs) were detected on chromosomes 6p22.3, 8q23.1, 20q13.12, 21q21.1, and 21q21.3 based on significant linkage evidence (defined by logarithm of odds (lod) score ≥3) in at least one meta-analysis and lod scores ≥1 in at least 2 subgroups defined by network and race. The chromosome 8q23.1 locus was supported by Asian-, Caucasian-, and Mexican-American-specific meta-analyses.
The new QTLs reported justify new candidate gene studies. They may help support results from genome-wide association studies (GWAS) that fall in these QTL regions but fail to achieve the genome-wide significance.
American Journal of Hypertension 03/2011; 24(3):347-54. · 3.18 Impact Factor
