Ectonucleotide pyrophosphatase/phosphodiesterase 1, which downregulates insulin signaling by inhibiting insulin-receptor tyrosine kinase activity, is encoded by the ENPP1 gene. Common variants in ENPP1 have been associated with body mass index (BMI), diabetes and glycemia related traits in populations of European Ancestry, but data in African ancestry populations are sparse. Our objective was to evaluate common ENPP1 variants for association with diabetes and glycemia related traits in a high risk Afro-Caribbean population. Thirty-four single nucleotide polymorphisms (SNPs) based on pair-wise tagging (r2 > 0.80; MAF > 0.05) were successfully genotyped in 380 cases and 1,455 controls without diabetes. Associations with BMI, fasting glucose, fasting insulin and HOMA-IR were also analyzed in non-diabetic controls. The most interesting association was observed between rs1044498 K121 allele and lower BMI (age-adjusted P = 0.018). Nominal associations were observed with ENPP1 SNPs and fasting glucose (age-and BMI-adjusted P=0.001 to 0.020). Also, six SNPs showed nominal evidence for association (P < 0.05) with diabetes in one or more genotypic model. The most significant associations were observed with SNPs in intron 11 (rs17060836; OR=1.32 [1.04-1.67]; dominant P = 0.019), two SNPs in intron 1 (rs703184, rs7749493; OR= 0.78 to 1.39) and three SNPs in the 3' untranslated region (rs7754561, rs7769993 and rs9373000; OR = 0.69-1.38). In this population of Afro-Caribbean men, the ENPP1-rs1044498 the K121 allele and intronic variants may modulate BMI and glucose. Also, variants in the 3' UTR confer an increased risk of developing diabetes confirming and extending reports in European and African Americans. After accounting for multiple testing, we conclude that ENPP1 is not a major contributor to diabetes related traits; nevertheless, our results reveal that variants in the ENPP1 gene may modulate BMI and maintain glucose homeostasis in this population of Afro-Caribbean men. These studies are of public health relevance or importance because they contribute epidemiologic information to the genetic etiology of type 2 diabetes in men of African ancestry.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-11302010-111743 |
| Date | 31 January 2011 |
| Creators | Leak, Tennille S |
| Contributors | Candace M. Kammerer, Ph.D., Joseph M. Zmuda, Ph.D., Anne B. Newman, M.D., M.P.H. |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-11302010-111743/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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