[Effect of insulin by local injection on the level of systemic blood glucose and granulation tissue formation of wound in patients with diabetic foot ulcer].

OBJECTIVE

To investigate the effects of local injection of insulin on the level of systemic blood glucose and granulation tissue formation of wound in patients with diabetic foot ulcer.

METHODS

Thirty-two patients with diabetic foot ulcer hospitalized in our wards from June 2009 to June 2010 were divided into insulin (I, n = 16) and control (C, n = 16) groups according to the random number table. For patients in I group, after debridement, one half of calculated dose of insulin diluted with equal amount of normal saline was injected diffusely into the base of the ulcer, and another half dose of insulin was subcutaneously injected into abdominal wall for 7 days, two times a day. For patients in C group, after debridement, primary insulin was subcutaneously injected into abdominal wall, 1 mL saline was subcutaneously injected into basal layer of ulcer for 7 days, two times a day. Before injection and 0.5, 1.0, 2.0, and 4.0 hours after injection (PIH), level of fasting blood glucose was determined. Before injection and on post injection day (PID) 3, 5, and 7, the growth of granulation tissue was assessed, and wound specimens were harvested for observation of CD34 expression and calculation of microvessel density (MVD). Data were processed with t test.

RESULTS

The levels of fasting blood glucose in both groups during observational time points ranged from 6.6 mmol/L to 12.8 mmol/L with a mean of (10.0 ± 2.2) mmol/L, and there was no statistical difference (with t values from 0.000 to 2.209, P values all above 0.05). Growth of granulation tissue in I group was more exuberant from PID 5, especially on PID 7 [(59.06 ± 1.58)%], which was significantly richer than that in C group [(23.61 ± 1.57)%, t = 17.420, P = 0.000]. New vessels were observed in I group from PID 3 as indicated by CD34 expression. There was no obvious difference in the number of MVD between I group and C group on PID 3 (t = 0.247, P > 0.05). The number of MVD per 200 times visual field in I group was respectively 8.34 ± 0.48, 11.22 ± 0.97 on PID 5 and 7, which was respectively higher than that in C group (4.42 ± 0.14, 5.44 ± 1.13, with t value respectively 16.568, 27.664, P values all below 0.01).

CONCLUSIONS

Local injection of insulin has a significant effect on systemic blood glucose in patients with diabetic foot ulcer, and it can promote the growth of granulation tissue and wound healing.