Capillary basement membrane width in diabetic children.

The effect of juvenile onset diabetes mellitus on quadriceps muscle capillary basement membrane (QCBM) width has been examined by the electron microscopic morphometric method previously developed in this laboratory. The results demonstrate that in this age group QCBM thickening is strongly related to the age of the diabetic subject. As a result, in contrast to the almost constant thickening of QCBM that has consistently been documented in diabetic adults, QCBM hypertrophy is present in only 40 per cent of children with diabetes mellitus. As was previously shown to be the case in adults, in children, too, QCBM thickening is unrelated to the duration of the diabetes. Finally, the finding that QCBM hypertrophy is present at the time of acute onset of juvenile diabetes mellitus in 30 per cent of children, coupled with the fact that this lesion is not affected by duration of hyperglycemia, strongly supports our previous conclusion that diabetic microangiopathy is independent of the hyperglycemia of this disease. On the other hand, barring the possibility that microangiopathy in the pancreas precedes that in muscle, these results represent evidence against the suggestion that basement membrane hypertrophy represents the primary lesion of the diabetic syndrome.