Variants in STAT5B associate with serum TC and LDL-C levels

Context: Known genetic variants influencing serum lipid levels do not adequately account for the observed population variability of these phenotypes. The GH/signal transducers and activators of transcription (STAT) signaling pathway is an evolutionary conserved system that exerts strong effects on metabolism, including that of lipids. Research Design and Methods: We analyzed the association of 11 single-nucleotide polymorphisms (SNP) spanning the STAT5B/STAT5A/STAT3 locus with serum lipid levels in six European populations (n = 5162 nondiabetic individuals). Results: After adjustment for age, sex, alcohol use, smoking, and body mass index, we identified STAT5Bvariants(rs8082391andrs8064638)innovelassociationwithtotal cholesterol (TC; P=0.001and P = 0.002) and low-density lipoprotein cholesterol (P = 0.002 and P = 0.004) levels. The minor alleles of these single-nucleotide polymorphisms were significantly enriched in hyperlipidemic individuals across the six discovery populations (P=0.004 and P=0.006). In transgenic mice deficient for hepatic STAT5A and STAT5B, reduced serum TC levels coincided with reduced hepatic cholesterol biosynthesis as demonstrated using gene expression profiling and pathway enrichment analysis. Conclusions: Genetic variants in STAT5B are associated with TC and low-density lipoprotein cholesterol levels among six populations. Mechanistically, STAT5B transcriptionally regulates hepatic cholesterol homeostasis.