Abstract: Objective: To evaluate the foot microcirculation in type 2 diabetes mellitus and impaired glucose tolerance patients using contrast-enhanced ultrasound. Methods: Contrast-enhanced ultrasound (CEUS) was performed for examining the blood flow of right foot great toe (TIC) in 56 patients with type 2 diabetes mellitus but without diabetic foot (DM group), 15 patients with impaired glucose tolerance (IGT group) and 12 male control subjects(control group). DM group was divided into two groups according to the course of DM: DM(A) group with course <10 years and DM(B) group with course≥10 years. All the subjects were elderly male patients. Perfusion characteristics of CEUS and parameters of TIC were analyzed. Results: Compared with control group, CEUS image showed lower microvascular density and pale in appearance in IGT, DM and DM(B) groups. Peak intensity (PI) and area under time-intensity curve (AUC) in IGT, DM(A) and DM(B) groups were significantly reduced (P<0.05); PI and AUC of DM(B) group were lower than those of IGT and DM(A) group (P<0.05); and no significant differences in PI and AUC were found between IGT and DM(A) group (P>0.05). The arrival times (AT) and time to peak (TTP) tended to be increased with the extension of DM course, but the difference was not statistically significant (P>0.05). Conclusions: Contrast-enhanced ultrasound can detect the change in foot microcirculation of DM and IGT patients before diabetic foot occurres.

Key words: Type 2 diabetes mellitus, Impaired glucose tolerance, Contrast-enhanced ultrasound, Microcirculation