Objective: Recent studies have identified a set of serological markers for telomere dysfunction and DNA damage. In the present study, the levels of 2 serological markers of telomere dysfunction namely chitinase and N-acetylglucosaminidase (NAG) were studied in type 2 diabetes mellitus (T2DM) patients. The possibility that genomic damage, accumulation of reactive oxygen species and shorter telomeres may be linked to the onset and progression of diabetes and it is complications.
Patients and Methods: A total of 38 patients with T2DM together with 15 healthy persons comparable in age and sex with patients were included, serum samples were used for determination of chitinase, NAG and lipid peroxide (LPER) by colorimetric methods, and homocysteine by ELISA. Methylene tetrahydofolate reductase (MTHFR) C677T gene polymorphism was determined by polymerase chain reaction (PCR).
Results: Serological levels of chitinase and NAG were significantly increased in T2DM compared with controls and correlated significantly with age. The levels of LPER and homocysteine were also increased in patients compared with controls. These 2 indices also correlated with age as well as chitinase and NAG. The levels of the 2 indices of telomere dysfunction reflected diabetic complications. Moreover, examination of MTHFR C677T gene polymorphism, in T2DM showed that the genotype frequencies were CC (36.48%), CT (39.47%) and TT (23.68%). Patients with mutant gene, namely CT, TT showed significantly elevated chitinase, NAG, homocysteine and LPER compared to those with the CC type. Diabetic patients with mutated gene had significantly advanced age. Moreover analysis of Odds ratio showed that CT and TT mutations compared to the wild type CC conferred increased T2DM risk.
Conclusion: Serological chitinase, NAG, LPER and homocysteine were significantly increased in T2DM compared with controls and correlated significantly with age. Moreover, in T2DM the genotype frequencies were CC (36.48%), CT (39.47%) and TT (23.68%). Patients with mutant gene, CT, TT showed significantly elevated indices compared to CC type. Serological chitinase and NAG which are recent markers of telomere dysfunction and DNA damage were found to be markedly increased in T2DM.