IMPROVED METABOLIC CONTROL IN PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS IS ASSOCIATED WITH A SLOWER ACCUMULATION OF GLYCATION PRODUCTS IN COLLAGEN

Twenty-one patients with non-insulin-dependent diabetes in poor metabo lic control were subjected to intensified therapy, in most cases with insulin, to investigate whether it is possible to slow down the accumu lation of advanced glycosylation end products of collagen by improving glycaemic control. Fasting and mean daily blood glucose, serum fructo samine and glycohaemoglobin levels, as well as glycation of collagen w ere measured before and after 1.5 years of intensified therapy. All th ese parameters except for fructosamine correlated significantly with f asting blood glucose and glycohaemoglobin when measured before the ins ulin therapy was started, when the patients had had poor but stable me tabolic control for a long period of time. After 1.5 years of intensif ied therapy the level of glycation of collagen did not significantly c orrelate with the fasting blood glucose or glycohaemoglobin levels, su ggesting that the non-enzymatic glycosylation of collagen reflects a l onger period of metabolic control of diabetes than the glycohaemoglobi n level. Intensified treatment improved previously poor metabolic cont rol in patients with non-insulin-dependent diabetes, and this improvem ent was reflected in a decrease in fasting and mean daily blood glucos e levels, serum fructosamine and glycohaemoglobin concentrations, and in the level of early products of glycation of collagen. The average c ontent of advanced glycosylation end products of collagen, assayed in terms of collagen-linked fluorescence did not decrease. However, they accumulated more slowly in the patient tercile with the greatest decre ase in the level of fasting blood glucose than in the tercile with the smallest decrease, and even a decrease in fluorescence was observed i n the patients with the greatest improvement in the metabolic control. Our findings suggest that the improvement of metabolic control in non -insulin-dependent diabetes is reflected in a slower accumulation of a dvanced glycosylation end products in collagen. If the slower accumula tion of advanced glycosylation end products in collagen is translated into a slower development of the long-term complications of diabetes r emains to be studied.