Genome-wide association study on coronary artery disease in type 1 diabetes Suggests beta-dufensin 127 as a risk locus

Aims Diabetes is a known risk factor for coronary artery disease (CAD). There is accumulating evidence that CAD pathogenesis differs for individuals with type 1 diabetes (T1D). However, the genetic background has not been extensively studied. We aimed to discover genetic loci increasing CAD susceptibility, especially in T1D, to examine the function of these discoveries and to study the role of the known risk loci in T1D. Methods and results We performed the largest genome-wide association study to date for CAD in T1D, comprising 4869 individuals with T1D (cases/controls: 941/3928). Two loci reached genome-wide significance, rs1970112 in CDKN2B-AS1 [odds ratio (OR) =1.32, P = 1.50 x 10(-8)], and rs6055069 on DEFB127 promoter (OR= 4.17, P= 2.35 x 10(-9)), with consistent results in survival analysis. The CDKN2B-AS1 variant replicated (P = 0.04) when adjusted for diabetic kidney disease in three additional T1D cohorts (cases/controls: 434/3123). Furthermore, we explored the function of the lead discoveries with a cardio-phenome-wide analysis. Among the eight suggestive loci (P < 1 x 10(-6)), rs70962766 near B3GNT2 associated with central blood pressure, rs1344228 near CNTNAP5 with intima media thickness, and rs2112481 on GRAMD2B promoter with serum leucocyte concentration. Finally, we calculated genetic risk scores for individuals with T1D with the known susceptibility loci. General population risk variants were modestly but significantly associated with CAD also in T1D (P=4.21 x 10(-7)). Conclusion While general population CAD risk loci had limited effect on the risk in T1D, for the first time, variants at the CDKN2B-AS1 locus were robustly associated with CAD in individuals with T1D. The novel finding on beta-defensin DEFB127 promoter provides a link between diabetes, infection susceptibility, and CAD, although pending on future confirmation. [GRAPHICS] .

Automated summary

This study aimed to identify genetic loci increasing coronary artery disease (CAD) susceptibility in individuals with type 1 diabetes (T1D). Two loci, CDKN2B-AS1 and DEFB127, were found to be significantly associated with CAD in T1D individuals. Additionally, the study explored the function of other genetic loci and found that general population risk variants were modestly but significantly associated with CAD in T1D.