Cutaneous vasomotor responses in young type I diabetic patients

Abnormal skin temperature reactions have been reported in type I diabetic patients. Whether this is due to a primary vascular disturbance or autonomic neuropathy is unclear. The aim of this study was to clarify this issue by evaluating cutaneous circulatory reactions before and after provocation. Seventeen type I diabetic patients and 17 age-matched controls were studied by recording blood flow (laser Doppler technique) on the dorsum of the hand (before, during, and after arterial occlusion), blood flow and skin temperatures on the dorsum of the foot and on the toe (before and after cooling followed by indirect body heating) and autonomic nerve function (heart rate reaction to deep breathing and to tilting). The results showed that before [4.6 +/- 0.5 perfusion units (PU) versus 6.1 +/- 0.7 PU; p = 0.0356] and after arterial occlusion (17.5 +/- 1.6 PU versus 25.3 +/- 1.7 PU; p = 0.0024), hand skin blood flow was significantly lower in patients than in controls. On the dorsum of the foot, skin temperatures was significantly lower in patients than in controls before cooling (29.2 degrees C +/- 0.3 degrees C versus 30.5 degrees C +/- 0.4 degrees C; p = 0.0107) whereas toe temperature and toe blood flow were similar before and after cooling in patients and controls. After body heating, however, toe temperature (after 30 min: 25.2 degrees C +/- 1.4 degrees C versus 30.9 degrees C +/- 1.2 degrees C; p = 0.0022) and toe blood flow (after 30 min: 10.9 +/- 2.5 degrees C versus 22.9 +/- 4.9 PU; p = 0.0313) were significantly lower in patients than in controls, especially in patients with parasympathetic neuropathy (i.e., patients with abnormal heart rate reactions to deep breathing). In conclusion, type I diabetic patients demonstrated a vascular disturbance in their skin that seemed to be exaggerated by parasympathetic neuropathy.