Increased frequency of sister chromatid exchanges in patients with type II diabetes

Sister chromatid exchange (SCE) is the exchange of homologous stretches of DNA sequence between two chromatids. Though SCE per se is not known to have any harmful medical effects, the higher frequency is associated with certain pathological conditions. Since patients with diabetes mellitus (DM) are at an increased risk for various vascular and other complications, it is likely that the extent of DNA damage is much higher in DM as compared to healthy controls. The present study is aimed to know the frequency of SCE in type II DM as compared to controls. A study of SCE, chromosomal aberrations and cell cycle proliferative index (CCPI) has been carried out in 35 individuals (20 type II DM patients and 15 normal healthy controls) from their peripheral blood cultures. Significant increase in SCE has been observed in DM patients as compared to the normal controls (P < 0.0001). No chromosomal aberrations or CCPI changes have been observed in any of the studied subjects. These results indicate that increased frequency of SCE in diabetic patients could be an early marker of DNA damage and a predisposing factor for some diabetes-related complications. There is a need to study other markers of DNA damage in DM, in larger sample size.