Objective: To explore the relationship between intestinal fatty acid binding protein (FABP2) gene G54A polymorphism and simple childhood obesity, the effect of mutant 54A FABP2 gene on serum lipids and glucose metabolism.
Methods: The total of 83 subjects with overweight/obesity and 100 subjects with healthy/normal weight were involved in this study. The G54A FABP2 gene allele and genotype frequencies between control group and overweight/obesity group were detected using polymerase chain reaction (PCR) -restriction fragment length polymorphism (RFLP) technology, and DNA sequences were confirmed by DNA sequencing. The automatic biochemical analyzer was used to detect fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels. Plasma insulin (Ins) was detected by radiation immune method, free fatty acids (FFA) was tested by ELISA method, insulin resistance index ( HOMA-IR ) was also calculated. The correlation between FABP2 G54A polymorphism and the development of children' obesity was analyzed. The relation between FABP2 G54A polymorphism and abnormal blood lipid and insulin resistance was assessed.
Results: The results of study on FABP2 gene polymorphism revealed as followed. In overweight/obese groups, the frequencies of GG, GA, AA genotypes was 33.7%, 49.4% and 16.9%, respectively. In control group, the frequencies of GG, GA, AA genotypes was 51. 0% , 40. 0% and 9. 0% , respectively. The differences between two groups was statistically significant (Χ2 = 6.27, P < 0.05). In overweight/obesity group, the frequencies of alleles were 58.4% for 54G and 41.6% for 54A. In control group, the frequencies of alleles were 71.0% for 54G and 29.0% for 54A. There was significant differences (Χ2 = 6.32, P < 0.05). The plasma biochemical variables results showed that compared with the normal control group, plasma TG (P < 0.01), Ins (P < 0.05), HOMA-IR (P < 0.05) were elevated in overweight/obesity group, the difference between two groups was statistically significant. At the same time, in overweight/obesity group, the carriers of AA homozygous genotypes had significantly higher plasma TG levels than those with GG wild genotypes (P < 0.05). A increased tendency of plasma Ins, FFA levels and HOMA-IR was found in the carriers with AA homozygous genotypes, but no differences compared with those with GG wild genotypes. Compared with those with GG wild genotypes, related plasma biochemical variables in the carriers with GA heterozygous genotypes had no differences (P > 0.05).
Conclusion: The FABP2 gene G54A polymorphism is related to simple children obesity and lipid metabolism abnormality. The allele encoding in FABP2 gene may be a potential factor contributing to promoting lipid metabolism abnormality of and insulin resistance.