SKIN MICROCIRCULATION IN PATIENTS WITH TYPE-I DIABETES WITH AND WITHOUT NEUROPATHY AFTER NEUROVASCULAR STIMULATION

1. Neurovascular inflammation is impaired in patients suffering from d iabetic neuropathy. The aim of our study was to evaluate the distribut ion of nutritive and total skin blood flow in diabetic patients with a nd without neuropathy after neurovascular stimulation with acetylcholi ne. 2. Twenty patients with Type I diabetes, 10 with and 10 without ne uropathy, and 10 age-matched nondiabetic control subjects, underwent m icrovascular investigations before and after neurovascular stimulation by intracutaneous application of acetylcholine. The capillary blood c ell velocity in the nailfold of the hallux was measured by videophotom etric capillaroscopy, and the total skin microcirculation in the same area by laser Doppler flowmetry. 3. The increase in total skin blood f low was significantly impaired in the group of neuropathic diabetic pa tients compared with the non-neuropathic diabetic patients (17.5 +/- 8 .3 versus 51.0 +/- 16.2; P < 0.05) and the non-diabetic subjects (17.5 +/- 8.3 versus 67.8 +/- 19.7; P<0.01). The increase in capillary bloo d flow was not significantly impaired in Type I diabetes patients with neuropathy. 4. The ratio between capillary blood Row and total skin p erfusion decreased significantly in the control group (from 0.82 +/- 0 .15 to 0.47 +/- 0.11; P < 0.005) and in the Type I diabetes patients w ithout neuropathy (fi om 0.79 +/- 0.12 to 0.43 +/- 0.123 P<0,05), wher eas the decrease in the neuropathic group was statistically insignific ant (from 1.05 +/- 0.19 to 0.72 +/- 0.16), 5. Diminished total skin pe rfusion in the foot after intracutaneous stimulation with acetylcholin e in Type I diabetes patients is associated with diabetic neuropathy, indicating a disturbance in the neurovascular reflex are. This impaire d neurovascular response is caused by a diminished total and subpapill ary blood flow and not by a diminished nutritive capillary Row There i s no evidence of a diminished nutritive capillary blood flow during ne urogenic inflammation in Type I diabetes patients suffering from diabe tic neuropathy.