subcutaneous blood flow
Type 1 diabetes
Springer Online Journal Archives 1860-2000
Summary Autoregulation of blood flow in subcutaneous tissue was studied at the level of the lateral malleolus in eight long-term Type 1 (insulin-dependent) diabetic patients with clinical microangiopathy, eight short-term Type 1 diabetic patients without clinical microangiopathy and seven healthy control subjects. Blood flow was measured by the local 133Xenon washout technique. Mean arterial blood pressure was reduced by a maximum of 23 mmHg by elevating the limb above heart level and elevating to a maximum of 70 mmHg by head-up tilt; in the latter position venous pressure was kept constant and low by activation of the leg muscle vein pump (heel raising). Mean arterial blood pressure was thus varied between 60 and 160 mmHg. In normal and short-term diabetic subjects blood flow remained within 10% of control values during the changes in arterial blood pressure. In six of the eight Type 1 diabetic patients with clinical microangiopathy, autoregulation of blood flow was impaired, blood flow changing ap proximately 20% per 10 mmHg change in arterial blood pressure; the slope of the autoregulation curves was significantly higher compared with the two control groups (p〈0.02). Resting mean arterial blood pressure was significantly elevated in long-term diabetic patients (median: 107 mmHg) compared with short-term diabetic (median: 85 mmHg) and control subjects (median: 91 mmHg) (p〈0.01 and p〈0.02, respectively). No correlation was, however, demonstrated between resting mean arterial blood pressure and the degree of disturbed autoregulation, but a relationship was demonstrated between the degree of disturbed autoregulation and the amount of periodic acid Schiff positive material in the terminal arteriolar walls of the investigated area (p〈0.05).
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