| Objective Hepatic lipase (HL) plays an important role in lipoprotein metabolism. It hydrolyzes triglycerides from plasma lipoproteins and thus takes part in the metabolism of triglyceride-rich lipoprotein remnants and high density lipoproteins (HDL). HL activity can affect the lipoprotein metabolism, in particular, changes in the concentration of HDL. Many studies show that the HL gene (LIPC) promoter polymorphisms influence the expression of HL, increase plasma HDL concentration, and increase small but dense white low-density lipoproteins (LDL) and other atherosclerotic lipoprotein levels. Thus, LIPC promoter polymorphisms are associated with coronary heart disease. But the results of these studies are not consistent. Bai Ku Yao (White-trousers Yaos), a isolated subgroup of Yao minority in China, is named because all of the men wear white knee-length knickerbockers. The population size is about 30,000. The special customs and culture of Bai Ku Yao, including their clothing, intra-ethnic marriages, ballad, funerals, Bronze Drum, alcohol intake, and spinning top activities are still completely conserved to the present day. Little is known about the association between the HL gene promoter polymorphism and the serum lipid levels in this population. Therefore, the present study was undertaken to determine the LIPC polymorphism at the -250G/A locus and its association with serum lipid levels in Bai Ku Yao and Han populations.Methods A total of 778 subjects of Bai Ku Yao and 648 participants of Han Chinese aged 15-80 were surveyed by a stratified random cluster sampling. Information on demographic, socio-economic status, cigarette smoking, alcohol consumption, and physical activity was collected with standard questionnaires. Blood pressure, height, weight, serum lipid and apolipoprotein levels were measured, and body mass index was calculated as a measure of weight relative to height. Gene polymorphism was determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) combined with gel electrophoresis, and then confirmed by direct sequencing. The results were compared with those in 648 matched subjects of Han Chinese from the same region.Results (1)Serum levels of total cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein cholesterol (LDL-C) and ApoA1 were significantly lower in Bai Ku Yao than in Han population (P<0.01 for all). There were no significant differences in triglyceride (TG) and ApoB levels between the both ethnic groups (P>0.05 for each). (2)The frequencies of GG, GA and AA genotypes were 50.0%, 40.2% and 6.7% in Bai Ku Yao, and 33.6%, 54.0% and 12.3% in Han (P<0.001); respectively. The frequencies of G and A alleles were 71.7% and 28.3% in Bai Ku Yao, and 60.6% and 39.4% in Han (P <0.001). (3) In the Han population, the levels of TC, LDL-C and ApoB in GG genotype were significantly lower than those in GA/AA genotype (P<0.01). No difference in the remaining lipid parameters was found among the three genotypes in the both ethnic groups (P>0.05 for all). The levels of ApoB were correlated with genotype in Han population (P<0.01), and the levels of TC were associated with genotype in Bai Ku Yao (P<0.05).(4)Logistic regression analysis showed that the genotype was associated with TC levels in Bai Ku Yao(P <0.05), while the genotype was associated with ApoB levels in the Han population (P <0.01).Conclusions There were significant differences in the genotypic and allelic frequencies of the LIPC -250G/A polymorphism between Bai Ku Yao and Han populations. The levels of TC, TG, LDL-C and Apo B and the ratio of ApoA1 to ApoB were correlated with genotype in Han, whereas the levels of TC were associated with genotype in Bai Ku Yao. The difference in lipid profiles between the Guangxi Bai Ku Yao and Han populations may result from different genetic and environmental factors. |
PDF Full Text Request