Transcapillary escape rate of albumin and plasma volume in short- and long-term juvenile diabetics.

Abstract

Transcapillary escape rate of albumin (fraction of intravascular mass of albumin that passes to the extravascular space per unit time) was determined from the disappearance of intravenously injected 131I-human serum albumin during the first 60 min after injection in 14 non-diabetics, 12 short-term diabetics (mean duration of diabetes 2.6 years), and 21 long-term diabetics with microangiopathy (mean duration of diabetes 20 years). Transcapillary escape rate of albumin was found significantly increased in the long-term diabetics with microangiopathy, average 7.8 (S.D. 0.9) per cent/hour, compared to the short-term diabetic and the non-diabetic groups, average 5.5 (S.D. 1.0) and 5.9 (S.D. 1.0) per cent/hour, respectively. Similar results were obtained for the outflux of albumin (mass of intravascular albumin that passes to the extravascular space per unit time). It is assumed that the increased transcapillary escape rate and the outflux of albumin reflect an increased microvascular permeability to albumin, due to the presence of diabetic microangiopathy. Finally, a significant reduction in plasma volume and intravascular mass of albumin was found in the long-term diabetic group, compared to the two other groups (p < 0.05).