Research Information System
Thesis Type: Expertise In Medicine
Institution Of The Thesis: Gazi Üniversitesi, Tıp Fakültesi, Turkey
Approval Date: 2020
Thesis Language: Turkish
Student: NAZMİ GÖKHAN ÜNVER
Co-Supervisor: ALEV EROĞLU ALTINOVA, MÜJDE YAŞIM AKTÜRK
Abstract:Introduction: In humans, telomeres shorten throughout life span with each cell division, thus reflecting an individual's complete cellular cycle. Telomere length is thought to be a marker of biological aging. In recent studies, it has been suggested that diabetes mellitus (DM) and its complications may be associated with shortening of leukocyte telomere length (LTL). Silent Information Regulator 1 (SIRT1), which is a regulator of energy metabolism, may contribute to the development of DM and obesity via its effects on oxidative stress, inflammation and mitochondrial functions. Also, SIRT1 has been shown to be associated with cellular aging. In our study, we aimed to compare leukocyte telomere length and serum SIRT1 levels in patients with type 2 DM with a heathy control group. In addition, we planned to examine the relationship between telomere length and SIRT1 level, glycemic control, complications of diabetes, body fat distribution as well as nutrition and exercise habits. Material and Method: Eighty four patients aged between 40-65 with type 2 DM diagnosis who referred to Gazi University Medical Faculty Hospital Endocrinology and Metabolism Department Diabetes and Obesity Outpatient clinic between February 2020- July 2020 were selected and fourty healthy volunteers who were similar with patients in terms of age, body mass index (BMI) and gender were taken as a control group. LTL was studied in all participants by quantitative PCR method and relative T/S ratio was calculated. Serum SIRT1 level was studied by ELISA method in 44 patients and 40 controls. The measurements of body fat distribution of the patients and the control group were performed by bioelectrical impedance analysis. Evaluation of nutrition and exercise habits with two questionnaires, which was planned to made face to face, could not be done because of Covid-19 pandemic. 68 Findings: Median LTL was found to be lower in patients with type 2 diabetes compared to control group (1.03 vs 1.25, p=0.064) but it is not statistically significant, however, the percentage of having a short telomere length (T/S <1) in diabetic patients was higher compared to the control group(47.6% vs 27.5%, p=0.035). There was no significant LTL difference between patients with and without diabetic complications (p>0.05). The percentage of having low telomere length was found to be significantly higher in obese diabetics than in non-obese diabetics (60% vs 35.7%, p=0.029). In diabetic patients, T/S correlated negatively with body weight (r=-0.248 p=0.025) and trunk fat mass (r=-0.250, p=0.028). No relationship was found between duration of diabetes, fasting blood glucose, HbA1c and LTU (p>0.05). Serum SIRT1 level was found to be significantly lower in diabetic patients (95.48±29.9 vs 138.40±42.66, p<0,001). SIRT1 level was found to be similar between patients with complications and patients without complications (p=0.05). There was no correlation between T/S ratio and SIRT1 in diabetic patients (r=0,100 p=0,507), however, a statistically significant negative correlation was observed in the control group (r=-0.368, p=0.019). Conclusion: In our study, it was found that LTL was shorter and serum SIRT1 level was lower in patients with type 2 diabetes than healthy volunteers. In addition, it was demonstrated that visceral obesity has a negative effect on LTL shortening. No relationship was observed between LTL, SIRT1 and diabetic complications. Our findings show that the cellular aging process is faster in patients with diabetes and is associated with obesity.