Investigation of Genetic Variation in Scavenger Receptor Class B, Member 1 ( SCARB1 ) and Association with Serum Carotenoids

Objective To investigate association of scavenger receptor class B, member 1 ( SCARB1 ) genetic variants with serum carotenoid levels of lutein (L) and zeaxanthin (Z) and macular pigment optical density (MPOD). Design A cross-sectional study of healthy adults aged 20 to 70. Participants We recruited 302 participants after local advertisement. Methods We measured MPOD by customized heterochromatic flicker photometry. Fasting blood samples were taken for serum L and Z measurement by high-performance liquid chromatography and lipoprotein analysis by spectrophotometric assay. Forty-seven single nucleotide polymorphisms (SNPs) across SCARB1 were genotyped using Sequenom technology. Association analyses were performed using PLINK to compare allele and haplotype means, with adjustment for potential confounding and correction for multiple comparisons by permutation testing. Replication analysis was performed in the TwinsUK and Carotenoids in Age-Related Eye Disease Study (CAREDS) cohorts. Main Outcome Measures Odds ratios for MPOD area, serum L and Z concentrations associated with genetic variations in SCARB1 and interactions between SCARB1 and gender. Results After multiple regression analysis with adjustment for age, body mass index, gender, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, smoking, and dietary L and Z levels, 5 SNPs were significantly associated with serum L concentration and 1 SNP with MPOD ( P