Factor VIII coagulant activity (VIM C) and factor Vlllrelated antigen (VIII R:Ag) were studied in 86 insulindependent diabetic children. All children were without signs of vascular disease based on a negative funduscopy, negative fluorescein angiography, normal serum creatinine levels, and absence of proteinuria. Age ranged from 4 to 17 yr; duration of clinical diabetes ranged from 1 to 12 yr. The children were grouped according to their urinary sugar excretion, the HbA1 levels, and the duration of clinical diabetes. The group with high urinary sugar excretion and the group withhigh HbA1 levels had a significantly higher VIII C than the group with low urinary sugar excretion and the group with low HbA1 levels. VIII C levels did not differ significantly in the groups with a different duration of clinical diabetes, but VIII R:Ag was significantly higher in the group with the longest duration of diabetes as compared with the group with the shortest duration. VIII R:Ag levels did not differ significantly in the groups with different degrees of urinary sugar excretion or different HbA1 levels.
The results show that in children without vascular disease, and even in children with a short duration of diabetes, alterations of the factor VIII complex can be demonstrated.