Microcirculation in diabetes mellitus: a study of gingival biopsies.

Gingival biopsy specimens from 24 diabetic patients, six obese persons, and six controls were studied statistically and morphologically to detect vascular basement membrane changes using a proposed classification of microvessels. Statistically significant basement membrane thickening is seen in all diabetic groups in most true capillaries and vessels proximal to them, especially in terminal arterioles and metarterioles, although the degree and extent of the changes vary among different clinical groups and vessel types. The basement membrane thickening is characterized by increased amorphous, granular, and fibrillary material with occasional scattered collagenous fibrils. Although nonspecific, basement membrane thickening in microvessels at, and especially proximal to, the level of true capillaries is intimately related to diabetes. Gingival biopsy may possibly be used as an adjunct in the diagnosis of diabetes.