AN EXAMINATION OF DNA STRAND BREAKAGE IN THE COMET ASSAY AND ANTIOXIDANT CAPACITY IN DIABETIC-PATIENTS

There are two forms of diabetes, insulin-dependent Diabetes mellitus ( IDDM) and non-insulin dependent Diabetes mellitus (NIDDM). There is ev idence to suggest that reactive oxygen is involved in the pathogenicit y and complications arising from IDDM, but there is little to suggest a role of oxidative stress in the pathogenesis of NIDDM. Ln order to i nvestigate this hypothesis further, peripheral blood samples were take n from control individuals and IDDM and NIDDM patients and examined fo r antioxidant capacity and in the Comet assay for DNA strand breakage. The individuals answered a questionnaire to provide information relat ing to lifestyle factors in case such factors might have a confounding effect. There were 20 controls, 22 IDDM patients and 23 NIDDM patient s. No differences could be detected in control and diabetic patient gr oups in terms of creatinine levels and antioxidant capacity. DNA damag e in the Comet assay was at a lower level than in the control in the I DDM patients and a slightly lower level in the NIDDM patients, which m ight indicate that these cells are handling more oxidative damage on a regular basis. As expected, there were differences in glycosylated ha emoglobin (HbA(1C)) levels. The confounding factors (smoking, drinking and vitamin intakes, etc.) appeared to have no effect. (C) 1998 Elsev ier Science B.V.