The impact of codon 54 variation in intestinal fatty acid binding protein gene on the pathogenesis of diabetes mellitus in Chinese

Objective To investigate whether or not the intestinal fatty acid binding p rotein gene (FABP2)-Ala54Thr variation is related to non-insulin dependent diabetes mellitus (NIDDM), obesity, dyslipidemia and glucose stimulated ins ulin secretion (GSIS) in Chinese. Methods The FABP2-Ala54Thr variation was detected by PCR/Hhal digestion in 231 Chinese subjects (116 with normal glucose tolerance (NGT), 54 with impa ired glucose tolerance (IGT) and 61 with NIDDM). Plasma glucose, insulin an d C-peptide levels before and after 75 g glucose load as well as fasting li pid profile were determined. Results (1) The Ala54 and Thr54 allele frequencies in Chinese were 0.71 and 0.29 respectively; (2) The FABP2-Ala54Thr variation was neither associated with fasting and post-challenged plasma glucose levels nor with NIDDM; (3) This variation was neither associated with fasting lipid profile nor with obesity; (4) The IGT subjects with genotype Thr54( +) (Thr54 homozygotes an d heterozygotes) had lower fasting, 2-hour and total C-peptide levels and s maller AUC representing lesser C-peptide secretion after glucose challenge than those with genotype Thr54(-) (Ala54 homozygotes) (P = 0.04, 0.03, 0.01 and 0.01 respectively). The serum insulin levels changed in the same tende ncy. Conclusions The glucose stimulated insulin secretion (GSIS) reserve of isle t beta-cells is more limited in subjects with FABP2-Thr54( +) genotype than in those with FABP2-Thr54( -) genotype. It suggests that FABP2-codon 54 va riation might contribute to the insufficient insulin secretion in the devel opment of NIDDM in Chinese.