Genetic polymorphisms of serum amyloid A1 and coronary artery disease risk

Serum amyloid A (SAA) protein is not only an inflammatory factor but also an apolipoprotein that can replace apolipoprotein A1 (apoA1) as the major apolipoprotein of high-density lipoprotein cholesterol (HDL-C). However, the relationship between genetic polymorphisms of SAA and coronary artery disease (CAD) remains unclear. A total of four single nucleotide polymorphisms (rs12218, rs4638289, rs7131332, and rs11603089) of the SAA gene were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in two independent case-control studies, one of the Han population (1416 CAD patients and 1373 control subjects) and the other of the Uygur population (588 CAD patients and 529 control subjects). We found that the rs12218 CC genotype was more frequent among the CAD patients than among the controls in both the Han (8.3% vs. 4.8%, P < 0.001) and Uygur populations (15.5% vs. 11.3%, P < 0.05). After adjustments for confounding factors, such as sex, age, smoking, drinking, hypertension, diabetes, and serum levels of triglycerides, total cholesterol, HDL, and plasma SAA, the differences remained significant in the Han (CC vs. CT+TT, P < 0.001, OR = 3.863, 95% CI: 1.755-12.477) and Uygur groups (CC vs. CT+TT, P = 0.031, OR = 3.022, 95% CI: 1.033-8.840). Genetic polymorphisms in SAA1 are associated with CAD in the Han and Uygur populations in western China.