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Ahmad S.,Lund University | Zhao W.,University of Pennsylvania | Renstrom F.,Lund University | Rasheed A.,Center for Non Communicable Diseases Pakistan | And 24 more authors.
International Journal of Obesity | Year: 2016

Background:Obesity is a complex disease caused by the interplay of genetic and lifestyle factors, but identification of gene-lifestyle interactions in obesity has remained challenging. Few large-scale studies have reported use of genome-wide approaches to investigate gene-lifestyle interactions in obesity.Methods:In the Pakistan Risk of Myocardial Infraction Study, a cross-sectional study based in Pakistan, we calculated body mass index (BMI) variance estimates (square of the residual of inverse-normal transformed BMI z-score) in 14 131 participants and conducted genome-wide heterogeneity of variance analyses (GWHVA) for this outcome. All analyses were adjusted for age, age 2, sex and genetic ancestry.Results:The GWHVA analyses identified an intronic variant, rs140133294, in the FLJ33544 gene in association with BMI variance (P-value=3.1 × 10-8). In explicit tests of gene × lifestyle interaction, smoking was found to significantly modify the effect of rs140133294 on BMI (P interaction =0.0005), whereby the minor allele (T) was associated with lower BMI in current smokers, while positively associated with BMI in never smokers. Analyses of ENCODE data at the FLJ33534 locus revealed features indicative of open chromatin and high confidence DNA-binding motifs for several transcription factors, providing suggestive biological support for a mechanism of interaction.Conclusions:In summary, we have identified a novel interaction between smoking and variation at the FLJ33534 locus in relation to BMI in people from Pakistan. © 2016 Macmillan Publishers Limited. All rights reserved.

Saleheen D.,Center for Non Communicable Diseases | Saleheen D.,University of Cambridge | Alexander M.,University of Cambridge | Rasheed A.,Center for Non Communicable Diseases | And 59 more authors.
Arteriosclerosis, Thrombosis, and Vascular Biology | Year: 2010

Objective-: To examine variants at the 9p21 locus in a case-control study of acute myocardial infarction (MI) in Pakistanis and to perform an updated meta-analysis of published studies in people of European ancestry. Methods and Results-: A total of 1851 patients with first-ever confirmed MI and 1903 controls were genotyped for 89 tagging single-nucleotide polymorphisms at locus 9p21, including the lead variant (rs1333049) identified by the Wellcome Trust Case Control Consortium. Minor allele frequencies and extent of linkage disequilibrium observed in Pakistanis were broadly similar to those seen in Europeans. In the Pakistani study, 6 variants were associated with MI (P<10-2) in the initial sample set, and in an additional 741 cases and 674 controls in whom further genotyping was performed for these variants. For Pakistanis, the odds ratio for MI was 1.13 (95% CI, 1.05 to 1.22; P=2×10-3) for each copy of the C allele at rs1333049. In comparison, a meta-analysis of studies in Europeans yielded an odds ratio of 1.31 (95% CI, 1.26 to 1.37) for the same variant (P=1×10-3 for heterogeneity). Meta-analyses of 23 variants, in up to 38 250 cases and 84 820 controls generally yielded higher values in Europeans than in Pakistanis. Conclusion-: To our knowledge, this study provides the first demonstration that variants at the 9p21 locus are significantly associated with MI risk in Pakistanis. However, association signals at this locus were weaker in Pakistanis than those in European studies. © 2010 American Heart Association, Inc.

Ahmad S.,Lund University | Zhao W.,University of Pennsylvania | Renstrom F.,Lund University | Rasheed A.,Center for Non Communicable Diseases Pakistan | And 20 more authors.
BMC Medical Genetics | Year: 2015

Background: Multiple genetic variants have been reliably associated with obesity-related traits in Europeans, but little is known about their associations and interactions with lifestyle factors in South Asians. Methods: In 16,157 Pakistani adults (8232 controls; 7925 diagnosed with myocardial infarction [MI]) enrolled in the PROMIS Study, we tested whether: a) BMI-associated loci, individually or in aggregate (as a genetic risk score - GRS), are associated with BMI; b) physical activity and smoking modify the association of these loci with BMI. Analyses were adjusted for age, age2, sex, MI (yes/no), and population substructure. Results: Of 95 SNPs studied here, 73 showed directionally consistent effects on BMI as reported in Europeans. Each additional BMI-raising allele of the GRS was associated with 0.04 (SE = 0.01) kg/m2 higher BMI (P = 4.5 × 10-14). We observed nominal evidence of interactions of CLIP1 rs11583200 (P interaction = 0.014), CADM2 rs13078960 (P interaction = 0.037) and GALNT10 rs7715256 (P interaction = 0.048) with physical activity, and PTBP2 rs11165643 (P interaction = 0.045), HIP1 rs1167827 (P interaction = 0.015), C6orf106 rs205262 (P interaction = 0.032) and GRID1 rs7899106 (P interaction = 0.043) with smoking on BMI. Conclusions: Most BMI-associated loci have directionally consistent effects on BMI in Pakistanis and Europeans. There were suggestive interactions of established BMI-related SNPs with smoking or physical activity. © 2015 Ahmad et al.

Keenan T.,University of Pennsylvania | Keenan T.,Massachusetts General Hospital | Zhao W.,University of Pennsylvania | Rasheed A.,Center for Non Communicable Diseases | And 61 more authors.
Journal of the American College of Cardiology | Year: 2016

Background Although epidemiological studies have reported positive associations between circulating urate levels and cardiometabolic diseases, causality remains uncertain. Objectives Through a Mendelian randomization approach, we assessed whether serum urate levels are causally relevant in type 2 diabetes mellitus (T2DM), coronary heart disease (CHD), ischemic stroke, and heart failure (HF). Methods This study investigated 28 single nucleotide polymorphisms known to regulate serum urate levels in association with various vascular and nonvascular risk factors to assess pleiotropy. To limit genetic confounding, 14 single nucleotide polymorphisms exclusively associated with serum urate levels were used in a genetic risk score to assess associations with the following cardiometabolic diseases (cases/controls): T2DM (26,488/83,964), CHD (54,501/68,275), ischemic stroke (14,779/67,312), and HF (4,526/18,400). As a positive control, this study also investigated our genetic instrument in 3,151 gout cases and 68,350 controls. Results Serum urate levels, increased by 1 SD due to the genetic score, were not associated with T2DM, CHD, ischemic stroke, or HF. These results were in contrast with previous prospective studies that did observe increased risks of these 4 cardiometabolic diseases for an equivalent increase in circulating urate levels. However, a 1 SD increase in serum urate levels due to the genetic score was associated with increased risk of gout (odds ratio: 5.84; 95% confidence interval: 4.56 to 7.49), which was directionally consistent with previous observations. Conclusions Evidence from this study does not support a causal role of circulating serum urate levels in T2DM, CHD, ischemic stroke, or HF. Decreasing serum urate levels may not translate into risk reductions for cardiometabolic conditions. © 2016 American College of Cardiology Foundation.

Peden J.F.,University of Oxford | Hopewell J.C.,University of Oxford | Saleheen D.,Center for Non Communicable Diseases Pakistan | Saleheen D.,University of Cambridge | And 107 more authors.
Nature Genetics | Year: 2011

Genome-wide association studies have identified 11 common variants convincingly associated with coronary artery disease (CAD), a modest number considering the apparent heritability of CAD. All of these variants have been discovered in European populations. We report a meta-analysis of four large genome-wide association studies of CAD, with -4575,000 genotyped SNPs in a discovery dataset comprising 15,420 individuals with CAD (cases) (8,424 Europeans and 6,996 South Asians) and 15,062 controls. There was little evidence for ancestry-specific associations, supporting the use of combined analyses. Replication in an independent sample of 21,408 cases and 19,185 controls identified five loci newly associated with CAD (P < 5- 10 8 in the combined discovery and replication analysis): LIPA on 10q23, PDGFD on 11q22, ADAMTS7-MORF4L1 on 15q25, a gene rich locus on 7q22 and KIAA1462 on 10p11. The CAD-associated SNP in the PDGFD locus showed tissue-specific cis expression quantitative trait locus effects. These findings implicate new pathways for CAD susceptibility. © 2011 Nature America, Inc. All rights reserved.

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