Adiponectin Gene Polymorphisms and Type 2 Diabetes among Singaporean Chinese AdultsWan Ching Toy*, Jian-Jun Liu, Anton Kui Sing Cheng, Clara Si Hua Tan, Dawn Pingxi Lau, Melvin Deng Sheng Wong, Tavintharan Subramaniam, Chee Fang Sum and Su Chi Lim
Clinical Research Unit, Alexandra Health Pte Ltd, Singapore
- *Corresponding Author:
- Wan Ching Toy
Clinical Research Unit, Alexandra Health Pte Ltd
c/o Khoo Teck Puat Hospital, 90 Yishun Central
Singapore 768828, Republic of Singapore
Tel: 65 66022355
Fax: 65 66023772
E-mail: [email protected]
Received date September 12, 2011; Accepted date November 18, 2011; Published date November 23, 2011
Citation: Toy WC, Liu JJ, Cheng AKS, Tan CSH, Lau DP, et al. (2011) Adiponectin Gene Polymorphisms and Type 2 Diabetes among Singaporean Chinese Adults. J Diabetes Metab 2:152. doi:10.4172/2155-6156.1000152
Copyright: © 2011 Toy WC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Adiponectin is the most abundant circulating adipokine in human that regulates insulin actions. Association of adiponectin gene variations with type 2 diabetes (T2DM) has been reported albeit predominantly in non-Asian populations. Additionally, proof of variant functionality beyond statistical association is often unavailable. We studied six common (minor allele frequency ?0.05) adiponectin single nucleotide polymorphisms (SNPs) in Singaporean Chinese adults with follow-up functional genetic experiments. Methods: In a case-control study (N=588), genotyping of six common adiponectin haplotype tagging SNPs [-3964A>G(rs822396), +45T>G(rs2241766), 276C>A(rs1501299), 973G>A(rs3774262), 4551G>C(rs1063539) and 5852G>A(rs6444175)] was performed using Taqman genotyping assay. Allele-dependent differential efficiency of mRNA expression was tested with quantitative real time PCR using human subcutaneous and omental adipose tissues. Results: Distributions of genotypes for all SNPs among controls were consistent with Hardy-Weinberg Equilibrium. Single locus, genotyped-based analysis suggested borderline significant (P=0.07) association between an exon- 2 coding-synonymous +45T>G(rs2241766) and T2DM. We demonstrated that the relative mRNA expression of adiponectin gene was ~80% lower among carriers of minor G allele in human subcutaneous adipose tissue (N=43, p<0.001). The observed allele-dependent differential expression was replicated (~50% reduction) in an independent sample of human omental adipose tissue (N=52, p<0.005). Conclusions: Our data was indicative of possible association between +45T>G(rs2241766) and T2DM among Singaporean Chinese adults. Functional experiments in both human subcutaneous and omental adipose tissue suggested that polymorphisms in +45T>G(rs2241766) may be associated with differential allelic expression.