Associations of the apolipoprotein A-I gene polymorphism and serum lipid levels in the Guangxi Hei Yi Zhuang and Han populations.

Hei Yi Zhuang is an isolated subgroup of the Zhuang minority in China. Little is known about the effects of the genetic variants on serum lipid profiles in this population. The present study was undertaken to estimate the effects of the apolipoprotein (apo) A-I gene polymorphism adjacent to the initiate transcription site (-75 bp G/A) on the serum lipid levels in the Hei Yi Zhuang and Han populations. A total of 474 subjects of Hei Yi Zhuang and 564 subjects of Han Chinese were surveyed by a stratified randomized cluster sampling. Serum lipid levels were measured, and apoA-I gene polymorphism determined by polymerase chain reaction and restriction fragment length polymorphism. The frequencies of G and A alleles were 70.25 and 29.75% in Hei Yi Zhuang, and 65.96 and 34.04% in Han (P<0.05), respectively. The genotypic frequencies in Han were significantly different between males and females, subjects with normal TG (< or =1.70 mmol/l) and those with high TG (>1.70 mmol/l), or subjects with normal apoA-I (> or =1.20 g/l) and those with abnormal apoA-I (<1.20 g/l; P<0.05-0.01), respectively. The levels of LDL-C and apoA-I in Hei Yi Zhuang were higher in GG genotype than in AA or GA genotype (P<0.05 for each), but the levels of TG was lower in AA genotype than in GA genotype (P<0.05). There were also significant differences in serum TG levels among the three genotypes in Hei Yi Zhuang (P<0.05). The levels of HDL-C in Han were higher in GG genotype than in AA genotype (P<0.05), but the levels of TG in Han were lower in GG genotype than in GA genotype (P<0.05). The levels of apoA-I in Hei Yi Zhuang and the levels of HDL-C and apoB in Han were significantly correlated with genotype (P<0.05 for all). Hypertriglyceridemia was negatively associated with genotype in Hei Yi Zhuang (P<0.01). There were significant differences in the apoA-I -75 bp G/A between the Hei Yi Zhuang and Han populations. An association of the apoAI -75 bp G/A and serum TG, LDL-C and apoA-I levels in Hei Yi Zhuang and serum TG, HDL-C and apoB levels in Han was also observed in this study.