Shortened Telomere Length in White Blood Cells of Patients with Non-Insulin Dependent Diabetes Mellitus (NIDDM)

Abstract

Type 2 diabetes(TIIDM) aging-related disorder, is caused by a combination of peripheral insulin resistance and ?-cell dysfunction .Recent evidence, however, suggests that TIIDM is additionally characterized by impaired ?-cell regeneration and reduced ?-cell mass .Shortened telomeres have been previously associated with diabetes in several small-scale studies(Zhu et al.,2011). Measurement of telomere length in diabetic patients in different age and different duration of disease and compared with control. Also included the comparison telomere length between male and female for both control and diabetic groups and  between patients from genetic origin (mother origin or father origin) and patients from non genetic origin  . Genomic DNA was prepared from whole blood extraction using genaid kit and was quantified by Nanodrop .Terminal restriction fragment (TRF) lengths were measured using the Southern-blotting technique .This study was conducted between November 2010- November 2012 and, it was carried out at the diabetic Centre / Merjan Teaching Hospital in Babel Province by taking 54 diabetic patients(Type II DM) with disease duration (0-5),(>5-10 )and (>10 )years ,with age average (35-65 year)and most of them were on oral hypoglycemic drugs. While the study included 18 people apparently healthy that included 9 male and 9 female with age average (35-65 year) .The study revealed that telomere length(TL) were differences between males and females of control group. Age- adjusted telomere length were shorter in males than in females of control subjects (13,200 bp ) vs. (11,600 bp), (14,200 bp) vs. (13,000 bp) and (15,100 bp) vs. (13,800 bp) ,and this differences in TL between males and females decreased as aging increased, while this gender differences in TL was not observed among the diabetic patients .In both the controls group and diabetic subjects, the telomere length were shorter in older subjects than younger for both males and females. The result show differences in TL between control and diabetic subjects. TL were shorter in the patients with Type 2diabetes compared with the control subjects ,and TL in first duration of male diabetic patients(2,100 bp) in male(55 years) and (1,900 bp) in male (65 years) ,and second duration of female diabetic patients (3,600 bp) in female (55 years) and (2,900 bp) in female (65 years) were shorter compared with other duration. The differences in TL in patients with family history of disease shown shorter than patients without family history of disease and this differences in TL in patients with family history of disease from mother origin shorter than patients with family history of disease from father origin.

The result of telomere length (TL) show that TL were shorter in males than females of control group while this differences absent in diabetic patients .TL was shorter in first duration of disease in males diabetic patients and in second duration of females diabetic patients compared with other duration of disease. TL was shorter in older subjects than younger for both groups and for both gender ,also shorter in diabetic patients from genetic origin of disease than non-genetic origin. Positive correlation between TL and estrogen in female control group and between  TL and adiponectin in diabetic patients was found.

Keywords: Telomere, DNA, TRF