Author + information
- Rui-Xing Yin,
- Guang-Yuan Shi and
- Jia-Qi Su
The c-Maf inducing protein gene (CMIP) rs2925979 single nucleotide polymorphism (SNP) has been associated with serum high-density lipoprotein cholesterol (HDL-C) levels in the individuals of European ancestry in a previous genome-wide association study, but the reproducibility of this association has not been detected in the other populations. The aim of the present study was to explore the association of the CMIP rs2925979 SNP and several environmental factors with serum lipid levels in the Chinese Jing and Han populations.
A total of 552 unrelated subjects of Jing ethnic group and 632 participants of Han nationality were randomly selected from our previous stratified randomized samples. Information on demographics, socioeconomic status, and lifestyle factors was collected with standardized questionnaires. Genotypes of the CMIP rs2925979 SNP were determined by polymerase chain reaction and restriction fragment length polymorphism, and then confirmed by direct sequencing.
The frequencies of A and G alleles were 43.4% and 56.6% in Jing; and 42.4% and 57.6% in Han (P > 0.05); respectively. The frequencies of AA, AG and GG genotypes were 18.8%, 49.1% and 32.1% in Jing, and 18.7%, 47.4% and 33.9% in Han (P > 0.05); respectively. The genotypic distribution of the CMIP rs2925979 SNP was followed by the Hardy-Weinberg equilibrium. The AA, AG and GG genotypic frequencies of the SNP in Han but not in Jing were different between males and females (18.9%, 52.8% and 28.3% vs. 18.5%, 43.4% and 38.0%; respectively, P = 0.028). Serum HDL-C levels in the Jing population were different among the genotypes (P = 0.048), the G allele carriers had higher HDL-C levels than the G allele non-carriers. Serum total cholesterol (TC) levels in the Han population were different among the genotypes (P = 0.007), the G allele carriers had lower TC levels than the G allele non-carriers. Subgroup analyses according to sex showed that serum TC levels in Han females were different among the genotypes (P = 0.032), the G allele carriers had lower TC levels than the G allele non-carriers. Multiple linear regression analysis showed that serum HDL-C and apolipoprotein (Apo) B levels in the combined population of Jing and Han, and serum HDL-C levels and the ApoA1/ApoB ratio in Jing were correlated with genotypes (P < 0.05 for all). We also showed that serum lipid phenotypes were correlated with several environmental factors such as sex, age, height, weight, body mass index, cigarette smoking, alcohol consumption, blood glucose, and blood pressure in the Jing and Han populations, or in males and females of the both ethnic groups (P < 0.05-0.001).
Serum HDL-C levels in Jing and TC levels in Han females were different among the genotypes, the G allele carriers had higher HDL-C and lower TC levels than the G allele non-carriers. These results suggest that the association of the CMIP rs2925979 SNP and serum lipid phenotypes might have ethnic- and/or sex-specificity.