The Change Of Cutaneous Microflow And The Factors Related To It In Upper Limbs Of Type 2 Diabetes

ObjectiveTo study the relationship between cutaneous microflow and the duration of type 2 diabetes,and to investigate clinical factors which effect microvascular function. Materials and Methods41 type 2 diabetes patients were selected from the department of endocrinology, Beijing Tongren hospital.They were divided into two groups:21patients whose duration of diabetes were less than 5 years, involving 12 males and 9 females, aged from 33 to 70 years old;20 patients whose duration were more than 15 years, involving 12 males and 8 females, aged from 50 to 77 years old. The healthy control were selected from NanFaXin Town, ShunYi District. There were 13 males and 16 females, aged 38 to 79 years old.Post-Occlusion Reactive Hyperemia(PORH)was applied to obstruct the left forearm and left dorsum of hand flow. Cutaneous microflow were measured by Laser Doppler Flowmetry (LDF). The microvascular function was evaluated by the extent of endothelium-dependent vasodilation.ResultsThe maxim cutaneous microflow (PUmax) in type 2 diabetes with shorter duration (28.90±9.00 in left forearm and 36.06±12.46 in dorsum of hand) was much more than those with longer duration(20.35±7.28 in left forearm and 25.36±9.09 in dorsum of hand, P<0.01). So was the reactive hyperemia(2.63±1.44 vs. 1.68±0.89 in left forearm and 3.61±1.75 vs.2.10±1.08 in dorsum of hand, P<0.01). However, there was no significant difference between the control and the patients with shorterduration(P>0.05).In addition, the correlation analysis revealed a significant negative correlation between the duration of diabetes and PUmax (r=-0.506,-0.475 respectively in the forearm and dorsum of hand, P<0.01). An inverse correlation was also found between the duration and the reactive hyperemia speed (r=-0.443,-0.529 respectively, P<0.01). In multiple stepwise regression, the duration of diabetes firstly enter the equation of the PUmax and the reactive hyperemia speed (β=-0.509,-0.661 respectively in the forearm,P<0.01;β=-0.525,-0.581 respectively in the dorsum of hand, P<0.01).Aging enter the regression equation of the PUmax and the hyperemia speed of the dorsum of hand in the control(r2=0.146,β=-0.382,P<0.05;r2=0.210,β=-0.458,P<0.05, respectively).Aging also enter the equation of minimal microflow(PUmin)of the forearm in the diabetes group(r2=0.141,β=0.375,P<0.05);The postprandial blood glucose enter the regression of PUmax in the dorsum of hand (β=-0.355,P<0.05)and C-peptide entered the regression equation of hyperemia speed in the forearm(β=-0.446,P<0.01).Conclusions(1) Cutaneous microangiopathy gets worse with the duration in type 2 diabetes.(2) Aging, raised postprandial blood glucose, insulin resistant make the microvascular function aggravated.(3) LDF can be used to evaluate the microcirculation function characterized by no pain, convenience, and real-time.