Abstract P457: Age Dependence of Genetic Risk Scores in Relation to Coronary Artery Disease

Abstract

Background: Coronary artery disease (CAD) is an age-related multi-factorial disease with a high public health burden. Genetic loci for CAD have been discovered and collectively predict CAD risk independent of traditional risk factors. It remains unclear whether age modifies the genetic predisposition to CAD. Methods: A total of 173,315 Caucasian subjects from the UK Biobank were included in this study, including 26,472 CAD patients with age of onset ranging from 32 to 78 years old, and 146,843 control subjects > 60 years old without CAD. CAD diagnosis was extracted from in-patient Hospital Episode Statistics (HES) and National Death Registry based on ICD-10 and OPCS-4 codes. CAD genetic risk score (GRS) was calculated based on the 161 known CAD loci. Sub-GRSs for body mass index (BMI, 16 loci), blood pressure (BP, 26 loci) and lipids (17 loci) were constructed to examine the genetic risk for CAD from certain intermediate trait. The CAD GRSs among onset age groups were compared to the controls using linear regression models, controlling for sex, BMI, creatinine, c-reactive protein, high density lipoprotein, low density lipoprotein, triglyceride, diabetes, heart failure history, hypertension and smoking status. The sub-GRSs were compared using the same models, excluding sub-GRS specific intermediate traits. Interactions of age groups and GRSs were tested using logistic regression models for CAD status, controlling for the same variables described above. Association analyses of each GRS were performed within each category of CAD age at onset comparing to controls. Results: Compared to the controls, the mean CAD GRS in CAD patients with age of onset ≤ 50 years was 0.58 standard deviations (SD) higher (95% CI 0.53-0.63), followed by CAD age of onset between 50 and 60 years (0.50 SD higher, 95% CI 0.48-0.52), between 60 and 70 years (0.35 SD higher, 95% CI 0.33-0.37), and > 70 years (0.25 SD higher, 95% CI 0.21-0.29). The sub-GRSs showed the similar trend. Age of onset stratified analysis revealed a significant CAD GRS-age interaction (p<0.001) on CAD risk where genetic effect is stronger among those early onset CAD patients - the odds ratios (OR) per CAD GRS SD among subjects with CAD onset age ≤ 50, 50 to 60, 60 to 70, > 70 years were 1.80 (95% CI 1.71-1.89), 1.66 (95% CI 1.62-1.70), 1.44 (1.41-1.47), 1.29 (95%CI 1.24-1.35), respectively. Among the three sub-GRSs, significant GRS-age interactions were observed for BP sub-GRS and lipids sub-GRS but not BMI sub-GRS. Conclusion: The observed gene-age interaction indicates that the genetic susceptibility for CAD decreases for older subjects. The contribution of the CAD GRS to CAD risk is almost 64% lower in those developing CAD at age > 70 years compared to those ≤ 50 years. Future considerations and applications of CAD genetic risk in precision medicine needs to include age of onset to accurately evaluate the genetic contribution.