Association Of The LIPC Rs1532085 SNP And Serum Lipid Traits In The Chinese Maonan And Han Populations

Background: Cardiovascular disease(CVD)is the leading cause of mortality,morbidity,disability,functional decline and healthcare costs.The increased incidence of CVD in the world has been linked to dyslipidemia.It was widely realized that dyslipidemia as a serious risk factor for CVD is a multifactorial and complicated disease caused by genetic factors,including lipid-associated gene variants and environmental factors and their interactions.Recently,genome wide association studies(GWASs)have identified that genetic variant of the LIPC rs1532085 was associated with serum high-density lipoprotein cholesterol(HDL-C)and triglyceride(TG)levels.The hepatic lipase gene(LIPC)is known to play an important role in the lipid and lipoprotein metabolism pathway,but the association of the LIPC rs1532085 single nucleotide polymorphism(SNP)and serum lipid profiles has not been previously reported in different racial/ethnic groups.The aim of this study was to detect the association of the LIPC rs1532085 SNP and several environmental factors with serum lipid levels in the Guangxi minority Maonan and local Han populations.Methods: The study populations included 801 unrelated subjects(305 males,38.07% and 496 females,61.92%)of Han and 833 unrelated participants(335 males,40.21% and 498 females,59.78%)of Maonan.They were randomly selected from our previous stratified randomized samples.The participants were all agricultural workers from Huanjiang Maonan Autonomous County,Guangxi Zhuang Autonomous Region,People's Republic of China.The Epidemiological investigation adopts international standardization method,following a common protocol.Information on demographics,socioeconomic status,and lifestyle factors was collected with standardized questionnaires.Several parameters such as blood pressure,height,weight,waist circumference,and body mass index(BMI)were measured.A fasting venous blood sample was drawn from the participants.A part of the sample was collected into glass tubes and used to determine serum lipid levels.Another part of the sample was transferred to tubes with anticoagulants and used to extract deoxyribonucleic acid(DNA).Genomic DNA of the samples was isolated from peripheral blood leucocytes according to the phenol-chloroform method.Genotyping of the LIPC rs1532085 SNP was performed by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).The statistical analyses were performed with the statistical software package SPSS 24.0(SPSS Inc.,Chicago,Illinois).Results: The percentages of cigarette smoking,the levels of waist circumference,systolic blood pressure,diastolic blood pressure,pulse pressure,TG and apolipoprotein(Apo)B were higher in Maonan than in Han(P < 0.05-0.001),but the percentages of alcohol consumption,HDL-C levels and the Apo A1/Apo B ratio were lower in Maonan than in Han(P < 0.05-0.001).The values of gender ratio,age structure,body height,weight,BMI,total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C)and Apo A1 were not different between the two ethnic groups(P > 0.05 for all).The genotypic distribution in the two ethnic groups was followed Hardy-Weinberg equilibrium(HWE).The frequencies of A and G alleles were 46.19% and 53.80% in Han,and 50.66% and 49.33% in Maonan population(P < 0.05),respectively.The frequencies of AA,AG and GG genotypes were 22.34%,47.70% and 29.96% in Han,and 24.96%,51.38% and 23.64% in Maonan(P < 0.05);respectively.The genotypic and allelic frequencies of the SNP were also different between Han males and females(P < 0.01 for each)but not between Maonan males and females.The levels of TC,TG,LDL-C,Apo A1 and Apo B were different between the AA and AG/GG genotypes(P < 0.05-0.001)in Han but not in Maonan,the G allele carriers had lower TC,TG,LDL-C,Apo A1 and Apo B levels than the G allele non-carriers.In the sex subgroup analyses,the G allele carriers had lower TC,TG,LDL-C and Apo A1 levels in Han females but not in males(P < 0.05-0.001).The correlations between serum TC and LDL-C levels in Han and LIPC rs1532085 SNP genotypes were found by multiple linear regression analyses(P < 0.05 for each).When the correlation of serum lipid parameters and the genotypes was analyzed according to two genders,we found that serum TC,LDL-C and Apo A1 in Han females were correlated with genotypes(P < 0.05 for all).Several environmental factors such as ethnic group,gender,age,height,weight,BMI,waist circumference,systolic and diastolic blood pressure,pulse pressure,fasting blood glucose,alcohol consumption and cigarette smoking in both ethnic groups or in males and females were also correlated with serum lipid parameters(P < 0.05-0.001).Conclusions: This study showed that the association of the LIPC rs1532085 SNP and serum lipid profiles is different between the Maonan and Han populations and between males and females in the both ethnic groups.These results suggest that there may be a racial/ethnic-and/or sex-specific association of the LIPC rs1532085 SNP and serum lipid levels.