INCREASED MICROVASCULAR FLUID PERMEABILITY IN YOUNG TYPE-1 (INSULIN-DEPENDENT) DIABETIC-PATIENTS

Microvascular fluid permeability was assessed by determination of the capillary filtration coefficient in the forearm of ten young Type 1 (i nsulin-dependent) diabetic patients with a short duration of diabetes, satisfactory glycaemic control and minimal evidence of microangiopath y, and ten age- and sex-matched control subjects. A strain gauge pleth ysmographic method with a computer based logging and analysis system w as used. This enabled differentiation between the volume filling and f luid filtration components of the response to venous pressure elevatio n. The median capillary filtration coefficient was found to be signifi cantly higher in the young diabetic patients in comparison with contro l subjects (9.2 x 10(-3)ml.min-1.100 g tissue-1. mmHg-1 vs 3.8 x 10(-3 )ml.min-1.100 g tissue-1.mmHg-1, p < 0.001). There were no significant correlations between capillary filtration coefficient and either plas ma glucose concentration, haemoglobin A1c or duration of diabetes. As there is no evidence from other studies to support an increase in capi llary surface area in the forearms of young Type 1 diabetic patients, these results may reflect a primary change in microvascular fluid perm eability.