ObjectiveTo investigate the relationship between the insulin resistance(IR) and serum levels of retinol binding protein 4(RBP4), nonestesterified fatty acid(NEFA) and homocysteine(Hcy) in patients with different courses of type 2 diabetes mellitus(T2DM).

MethodsA total of 145 patients with T2DM were divided into the group A(disease duration < 6 months), group B(disease duration of 6 months to 5 years) and group C(disease duration >5 years), and 50 patients without diabetes were set as the group D.The height, body mass, waist circumference, systolic blood pressure in four groups were measured, the levels of fasting blood glucose, fasting insulin, high-density lipoprotein cholesterol(HDL-C), low density lipoprotein cholesterol(LDL-C), total cholesterol, three acyl glycerin, glycosylated hemoglobin, RBP4, NEFA and Hcy in four groups were detected, the insulin resistance index(HOMA IR), waist hip ratio, body mass index in four groups were calculated, and the correlation of IR with serum levels of RBP, NEFA and Hcy in patients with different courses of T2DM were analyzed.

ResultsThe differences of the levels of SBP, WHR, BMI, FPG, FINS, TG, CHO, HDL, LDL, HbA1c and HOMA-IR among group A, group B and group C were statistically significant(P < 0.05~P < 0.01), and the differences of above indexes between A, B, C groups and D group were statistically significant(P < 0.05~P < 0.01).The differences of the serum levels of RBP4, NEFA and Hcy among A, B and C groups were ere statistically significant(P < 0.01), and which were significantly higher than those in group D(P < 0.01).The serum levels of RBP4, NEFA and Hcy were positively correlated with HOMA-IR and the correlation coefficients of those were 0.503, 0.877, and 0.842, respectively(P < 0.05 to P < 0.01).

ConclusionsWith the lengthening of the disease course of T2DM, the IR is more significant, which may be related to the increasing of serum levels of RBP4, NEFA and Hcy.