Indexed on: 08 Nov '11Published on: 08 Nov '11Published in: Circulation. Cardiovascular genetics
Multiple genetic loci have been associated with blood lipid levels. We tested the hypothesis that persons with an unfavorable lipid gene profile would experience a greater increase in lipid levels and a higher incidence of abnormal lipid levels relative to those with more-favorable lipid gene profiles.A total of 9328 individuals of European descent (aged 45-64 years) in the ARIC (Atherosclerosis Risk in Communities) study were followed for 9 years. Separate gene scores were created for each lipid phenotype on the basis of 95 loci identified in a published genome-wide association study of >100 000 people of European-descent. Adjusted linear and survival models were used to estimate associations with lipid levels and incidence of lipid-lowering medication or abnormal lipid levels. Age and sex interactions were also explored. The cross-sectional difference (mg/dL) per 1 SD was -1.89 for high-density lipoprotein cholesterol (HDL-C), 9.5 for low-density lipoprotein cholesterol (LDL-C), and 22.8 for triglycerides (P<5×10(-34) for all). Longitudinally, overall triglyceride levels rose over time, and each 1-SD greater triglyceride gene score was associated with an average increase in triglyceride levels of 0.3 mg/dL (P=0.003) over 3 years. The HDL-C, LDL-C, and total cholesterol gene scores were not related to change. All lipid gene scores were positively related to incidence of abnormal lipid levels over follow-up (hazard ratios per SD range, 1.15-1.36).Associations of genetic variants with lipid levels over time are complex. The triglyceride gene score was positively related to change in triglycerides levels, but similar longitudinal results were not observed for LDL-C or HDL-C levels. Unfavorable gene scores were nevertheless related to higher incidence of abnormal levels.