Triglyceride-raising APOA5 genetic variants are associated with obesity and non-HDL-C in Chinese children and adolescents

Background: Although the association between the apolipoprotein A5 (APOA5) genetic variants and hypertriglyceridemia has been extensively studied, there have been few studies, particularly in children and adolescents, on the association between APOA5 genetic variants and obesity or non-high-density lipoprotein cholesterol (non-HDL-C) levels. The objective of this study was to examine whether APOA5 gene polymorphisms affect body mass index (BMI) or plasma non-HDL-C levels in Chinese child population. Methods: This was a case-control study. Single nucleotide polymorphisms (SNPs) were genotyped using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry for an association study in 569 obese or overweight and 194 healthy Chinese children and adolescents. Results: Genotype distributions for all polymorphisms in both cohorts were in accordance with the Hardy-Weinberg distribution. The frequencies of the risk alleles in rs662799 and rs651821 SNPs in APOA5 gene were all increased in obese or overweight patients compared to the controls. After adjusted for age and sex, C carriers in rs662799 had a 1.496-fold [95% confidence interval (CI): 1.074-2.084, P = 0.017] higher risk for developing obesity or overweight than subjects with TT genotype, while C carriers in rs651821 had a 1.515-fold higher risk than subjects with TT genotype (95% CI: 1.088-2.100, P = 0.014). Triglyceride (TG) and non-HDL-C concentrations were significantly different among rs662799 variants and both were higher in carriers of minor allele than in noncarriers for TG (1.64 +/- 0.96 vs. 1.33 +/- 0.67 mmol/L) (P < 0.001), and for non-HDL-C (3.23 +/- 0.92 vs. 3.02 +/- 0.80 mmol/L) (P = 0.005), respectively. There was also a trend towards increased TG and non-high-density lipoprotein cholesterol levels for rs651821 C carriers (P < 0.001 and P = 0.002, respectively). Furthermore, to confirm the independence of the associations between APOA5 gene and TG or non-HDL-C levels, multiple linear regression analysis was performed and the relationships were not eliminated by adjustment for age, sex and BMI. Conclusions: These findings suggest the TG-raising genetic variants in the APOA5 gene may influence the susceptibility of the individual to obesity, which may also contribute to an increased risk of high non-HDL-C levels in Chinese obese children and adolescents.