Exp Clin Endocrinol Diabetes 2012; 120(06): 329-334
DOI: 10.1055/s-0031-1298016
Article
© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Increased DNA-Glycation in Type 2 Diabetic Patients: The Effect of Thiamine and Pyridoxine Therapy

F. C. Polizzi
1   İstanbul University, Cerrahpaşa Medical Faculty, Department of Biochemistry
,
G. Andican
1   İstanbul University, Cerrahpaşa Medical Faculty, Department of Biochemistry
,
E. Çetin
1   İstanbul University, Cerrahpaşa Medical Faculty, Department of Biochemistry
,
S. Civelek
1   İstanbul University, Cerrahpaşa Medical Faculty, Department of Biochemistry
,
V. Yumuk
2   Department of Internal Medicine
,
G. Burçak
1   İstanbul University, Cerrahpaşa Medical Faculty, Department of Biochemistry
› Author Affiliations
Further Information

Publication History

received 06 September 2011
first decision 25 November 2011

accepted 02 December 2011

Publication Date:
09 January 2012 (online)

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Abstract

Background:

It is well known that advanced glycation plays an important role in the progression of diabetic complications. Although several studies have been done on protein glycation, studies related to DNA glycation is limited. The aim of this study is primarily to investigate DNA glycation in diabetes mellitus and secondarily to observe the effects of vitamins B1 and B6.

Materials and Methods:

Patients with diabetes (n=31) were divided into 2 groups as patients with nephropathy (n=17) and without nephro­pathy (n=14). The control group was recruited from age and sex matched healthy individuals (n=30). In the experimental groups, DNA glycation was measured in DNA isolated from leukocytes. HbA1c, thiamine pyrophosphate (TPP) and pyridoxal 5-phosphate (PLP) levels were determined in whole blood; glucose and insulin levels in plasma. Patients with nephropathy were further divided into 2 groups and were administered either vitamins B1 + B6 (n=6) or B6 (n=11), for 5 months. All the measurements were performed both before and after the vitamin administration period.

Results:

AGE-DNA levels were found significantly higher in diabetic patients (p<0.05) than the healthy controls. AGE-DNA and PLP levels were negatively correlated in control patients (r= − 0.361, p<0.05). The combined administration of B1 and B6 caused a significant decrease in AGE-DNA values (p<0.05).

Conclusion:

This study shows that the combined administration of vitamins B1 and B6 to diabetic nephropathy patients causes a decrease in DNA glycation in leukocytes. Importantly the administration of vitamin B6 alone did not have such an effect. To our knowledge, these are the first reported findings related to glycation of leukocyte nuclear DNA in diabetic nephropathy.