Codon 54 polymorphism of the fatty acid binding protein gene and insulin resistance in the Japanese population

Aim To determine the relationship of the polymorphism at codon 54 of the in testinal fatty acid binding protein gene (FABP2) with insulin resistance an d susceptibility to Type 2 diabetes mellitus (DM) in the Japanese populatio n. Methods We evaluated the polymorphism by the polymerase chain reaction-rest riction fragment length polymorphism (PCR-RFLP) in 150 Type 2 DM patients a nd 147 healthy control subjects. The frequency of alleles encoding threonin e (Thr54) and alanine (Ala54) at codon 54 of FABP2 in Type 2 DM patients wa s compared with that of healthy controls. Insulin sensitivity was assessed by the hyperinsulinaemic euglycaemic clamp in Type 2 DM patients with Ala54 homozygotes, Ala54/Thr54 heterozygotes and Thr54 homozygotes and by homeos tasis model assessment (HOMA) in the nondiabetic group. Results The frequency of alleles encoding Ala54 and Thr54 was 0.59 and 0.41 in Type 2 DM patients, respectively, similar to that observed in nondiabet ic controls (0.64 for Ala54 and 0.36 for Thr54). Insulin sensitivity was no t significantly different between subjects with and without Thr54 allele ei ther within the DM group or healthy controls. Conclusions The allele encoding threonine in the FABP2 does not predispose to Type 2 DM or insulin resistance in the Japanese population.