THE IMPACT OF CONTRALATERAL COOLING ON SKIN CAPILLARY BLOOD-CELL VELOCITY IN PATIENTS WITH DIABETES-MELLITUS

In healthy volunteers, cooling of the contralateral hand leads to a ra pid decrease in the ipsilateral capillary perfusion via a nerval refle x are. The aim of this study was to investigate whether this reflex ar e after contralateral cooling might be altered in patients with diabet es mellitus with and without peripheral neuropathy. Therefore, 12 pati ents with diabetic neuropathy (4 IDDM, diabetes duration 17.2 +/- 2.9 (SD) years, age 60.8 +/- 4.0 years, HbA(1c), 6.5 +/- 0.3%) and 12 pati ents with diabetes mellitus but without neuropathy (6 IDDM, diabetes d uration 15.1 +/- 2.7 years, age 55.9 +/- 4.5 years, HbA(1c), 5.4 +/- 0 .1%)were investigated by nailfold capillaroscopy. Twelve healthy volun teers (age 56.8 +/- 3.1 years, HbA(1c), 4.8 +/- 0.2%) served as contro ls. Contralateral skin capillary blood cell velocity was determined at rest and during the following 20 min after cooling of the hand (3 min at 15 degrees C). Blood pressure, heart rate and local skin temperatu re were examined regularly during the investigation. Resting capillary blood cell velocity did not differ between patients and controls. Whi le contralateral cooling resulted in a decrease in capillary blood cel l velocity (CBV) in controls (0.29 +/- 0.05 vs. 0.42 +/- 0.05 mm/s, p < 0.03), CBV remained unchanged or was delayed in patients. These resu lts demonstrate that in diabetic patients nerval reflex arcs are impai red. A long-term follow-up in a larger number of patients is required to evaluate whether these findings might serve as a very early diagnos tic tool for the diagnosis of developing diabetic neuropathy.