Insulin receptor substrate 1 (IRS1) variants confer risk of diabetes in the Boston Puerto Rican Health Study.
OBJECTIVE
Published data concerning associations between IRS1 variants and type 2 diabetes and related traits have been inconsistent. We examined the relationship between common variants in IRS1, type 2 diabetes, and related traits including insulin resistance, hyperglycemia and DNA damage in the Boston Puerto Rican Health Study.


METHODS
We genotyped six common IRS1 variants in an adult Puerto Rican population (n=1132) and tested for association with risk of type 2 diabetes and related traits.


RESULTS
SNPs rs934167 and rs1801123 showed significant association with fasting glucose concentrations (p = 0.005 and p = 0.016, respectively) and rs934167 showed significant association with plasma insulin levels (p = 0.005). Carriers of the rs934167 minor allele had significantly higher HOMA-IR and lower QUICKI (p = 0.001 and p = 0.001, respectively), and a 40% and 58% greater likelihood of being hyperglycaemic or hyperinsulinemic (OR = 1.40 and 1.58; p = 0.013 and 0.002, respectively). However, they exhibited only a marginally significant trend towards having type 2 diabetes (OR=1.27, p = 0.077). Furthermore, carriers of the haplotype C-T of the rs934167 and rs1801123 minor alleles showed consistent patterns of associations after correction for multiple testing. In addition, the G972R (rs1801278) minor allele was significantly associated with higher urinary 8-OHdG concentrations (p = 0.020) and plasma CRP levels (p = 0.035).


CONCLUSIONS
Our results support IRS1 variants associated with type 2 diabetes risk in adult Puerto Ricans. Moreover, we report the novel finding that IRS1 variant G972R (rs1801278) may contribute to oxidative DNA damage and inflammation.
Departmennt of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, China.
Xiang
X
Feng
Katherine L
KL
Tucker
Laurence D
LD
Parnell
Jian
J
Shen
Yu-Chi
YC
Lee
José M
JM
Ordovás
Wen-Hua
WH
Ling
Chao-Qiang
CQ
Lai
D000328:Adult; D000368:Aged; D000483:Alleles; D001786:Blood Glucose; D001900:Boston / Q000453:epidemiology; D004249:DNA Damage / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology* / Q000235:genetics; D005260:Female; D056426:Genetic Loci; D006239:Haplotypes; D006630:Hispanic or Latino / Q000208:ethnology; D006801:Humans; D006943:Hyperglycemia / Q000208:ethnology / Q000235:genetics; D007249:Inflammation / Q000235:genetics; D055504:Insulin Receptor Substrate Proteins / Q000235:genetics* / Q000378:metabolism; D007333:Insulin Resistance / Q000208:ethnology / Q000235:genetics; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000235:genetics; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012959:Socioeconomic Factors
D001786:Blood Glucose; C526292:IRS1 protein, human; D055504:Insulin Receptor Substrate Proteins