DNA-DAMAGE IN DIABETES - CORRELATION WITH A CLINICAL MARKER

Levels of DNA damage in groups of 10 patients with insulin-dependent d iabetes mellitus and 10 matched controls were compared using the comet assay; DNA strand breaks, oxidized pyrimidines (endonuclease m-sensit ive sites) and altered purines (sites sensitive to formamidopyrimidine glycosylase) were measured. Mean values of strand breaks and oxidized pyrimidines were significantly higher in diabetics. Strand breaks cor related with body mass index in the diabetic group. A strong correlati on was seen between formamidopyrimidine glycosylase-sensitive sites an d serum glucose concentrations. When three patients with normal glucos e levels were excluded from the statistical analysis, the mean value o f formamidopyrimidine glycosylase-sensitive sites was very significant ly elevated compared with normal. DNA damage ill lymphocytes is thus a useful marker of oxidative stress, and in particular formamidopyrimid ine glycosylase-sensitive sites seem to represent changes specifically related to hyperglycemia. (C) 1998 Elsevier Science Inc.