Lower limb venous compliance and transcapillary escape rate of transferrin were 
measured in eight normotensive, insulin-dependent male diabetic patients and 
eight control subjects using a dual isotope technique. Technetium-99m labelled 
autologous erythrocytes were used to measure venous compliance and to correct 
for local changes in blood volume, whilst Indium-113m labelled transferrin was 
used to measure transcapillary escape of protein. The diabetic patients were 
found to have reduced venous compliance 1.5 (0.7 to 3.4) x 10(-2) mmHg-1 
compared with controls 3.2 (2.4 to 4.1) x 10(-2) mmHg-1 (p less than 0.01). The 
diabetic patients were also found to have greater transcapillary escape of 
transferrin -2.7 (-1.5 to -5.3) x 10(-3), compared with control subjects -5.2 
(-4.1 to -8.1) x 10(-3) (p less than 0.02) in response to increasing hydrostatic 
pressure. These results show reduced venous compliance in patients with a mean 
duration of diabetes of 15 years and with only at most, early complications of 
diabetes, and confirm previous observations showing increased transcapillary 
escape of protein.