GLYCOSAMINOGLYCAN EXCRETION IN DIABETES-MELLITUS - RELATION WITH ATHEROSCLEROSIS AND GLOMERULOSCLEROSIS

The prevalence of nephropathy and atherosclerosis is elevated in diabe tes. Both complications could result from a common alteration in the c omposition of extracellular matrix including some derangement in glyco saminoglycan metabolism. In order to gain further insight into the mec hanism leading to athero and glomerulosclerosis in the course of diabe tes, we measured serum cholesterol, microalbuminuria and three urinary markers of the extracellular matrix catabolism (total glycosaminoglyc ans, chondroitin sulfates, hydroxyproline) in 71 diabetic patients. Pa tients were stratified for known type of diabetes (Type I, n=43 - Type II, n=28) or for presence of the following risk factors: albuminuria >30 mg/d (subset 1, n=12); poor metabolic control (subset 2, n=21); di abetes duration >20 yr (subset 3, n=9) and cholesterolemia >6.15 mmol/ l (subset 4, n=21). Normalized to creatininuria, glycosaminoglycan and chondroitin sulfate excretion rates were similar in all groups of dia betics. Strong correlations were observed between chondroitin sulfate excretion rates and cholesterolemia in patients of subsets 1 (r=0.71, p<0.02), and 4 (r=0.77, p<0.001). In this latter group, the proportion of urinary CSs (CSs/total GAGs) was also strongly correlated with cho lesterolemia (r=0.79, p<0.001) and to a smaller extend with the diabet es duration (r=0.51, p<0.02). It is concluded that glomerulosclerosis and atherosclerosis development in diabetes could be accompanied by a modified pattern of glycosaminoglycan synthesis with increase of chond roitin sulfate synthesis.