Collagen remodelling in myocardia of patients with diabetes.

AIMS To investigate collagen remodelling in the interstitium of the heart in patients with diabetes. METHODS Immunohistochemical study of the biopsied myocardium using type specific anticollagen antibodies (I, III, IV, V, VI) was performed in 12 patients with non-insulin dependent diabetes mellitus and six non-diabetic patients. There was no history of hypertension or coronary artery stenosis in any of the patients. RESULTS Noticeable accumulations of collagen types I, III, and VI in the myocardial interstitium were recognised in both groups, but little accumulation of types IV or V was found. Types I and III mainly stained in the perimysium and perivascular region, while type VI predominantly stained in the endomysium. There was no disease specific accumulation of collagen in diabetes mellitus. The percentage of total interstitial fibrosis in the myocardium was significantly higher in the diabetic group than in the control group (p < 0.05). Although the percentages of collagen types I and VI did not differ between the two groups, the percentage type of III was significantly higher in the diabetic group than in the controls (p < 0.01). CONCLUSIONS Collagen remodelling mainly as a result of an increase in collagen type III in the perimysium and perivascular region, occurs in the hearts of patients with diabetes.