Morphometric analysis of cellular and vascular changes in gingival connective tissue in long-term insulin-dependent diabetes.

This study examined cellular and vascular changes in gingival connective tissue samples by stereologic point-counting procedures and interactive digital analyzing systems in long-term insulin-dependent diabetes mellitus patients. Gingival connective tissue capillaries representing a clinically healthy sulcus with no evidence of periodontal disease at the site of biopsy were studied in 29 patients with diabetes. Based upon their long-term medical records, 19 were identified as having poorly controlled (PIDD) and 10 as controlled insulin-dependent diabetes mellitus (CIDD). Ten nondiabetic, age- and gender-matched individuals served as controls. Thirty-nine biopsies were processed for light microscopy, and the blood vessel area was analyzed using an interactive digital analyzing system; 9 gingival biopsies, 5 diabetic and 4 controls, were processed for morphometric electron microscopic analysis. For each individual, site-specific recordings were made for the plaque index, bleeding index, probing depth, loss of attachment, and radiographic loss of interproximal alveolar bone. No evident signs of periodontitis occurred at the biopsy sites. For each PIDD patient, respective volumetric and numeric densities of cellular components including fibroblasts, neutrophilic granulocytes, monocyte/macrophages, mast cells, lymphocytes, blast cells, and plasma cells were recorded in the inflamed connective tissue (ICT). Non-cellular components such as collagen fibers and blood vessels were also recorded. PIDD patients had elevated plasma cell levels relative to controls and they appeared also to have a decreased collagen fiber density. In addition, fibroblasts occupied less volume in the ICT of PIDD patients than in controls. PIDD patients had the largest mean area of cross-section of the blood vessels, but this difference was not statistically significant (P > or = 0.211; t-test). No specific characteristics of ICT or vascular changes were detectable in adult well-controlled long-term diabetics under similar plaque conditions. Swollen and proliferated endothelial cells were frequently found in PIDD patients and the mean distance from the lumen to the outer border of basement membrane was greater in the PIDD than in the controls (P < 0.001; t-test). Overall, our findings that cellular, vascular, and connective tissue changes indicative of increased catabolism rather than anabolism detected in gingiva are especially associated with poorly controlled long-term insulin-dependent diabetes.