Leukocyte telomere shortening in elderly Type2DM patients with previous myocardial infarction

Objective: We performed a cross-sectional study to examine the differences in leukocyte telomere length among three groups of subjects: patients with type 2 diabetes mellitus without history of previous myocardial infarction (Type2DM), patients with type 2 diabetes mellitus with evidence of previous myocardial infarction (Type2DM + MI), and healthy control subjects (CTR). The main objective of the present study is to investigate differences in telomere length between the studied groups of subjects, with the aim to clarify if telomere length could be a reliable marker associated with MI in Type2DM patients. Secondary end point is the identification of associations between leukocyte telomere length and selected variables related to glycemic control, pro-inflammatory status and lipidic profile. Research design and methods: A total of 272 elderly subjects, 103 Type2DM (mean age 70 +/- 4 years, 59% males), 65 Type2DM + MI (mean age 68 +/- 7 years, 68% males), and 104 CTR (mean age 69 +/- 7 years, 50% males) were studied. Telomere length, defined as T/S (Telomere-Single copy gene ratio), was determined in leukocytes by quantitative real-time polymerase chain reaction (real-time PCR)-based assay. Moreover, we assessed: (1) high sensitive C reactive protein (hsCRP), fibrinogen and plasminogen-activator inibitor-1 (PAI-1) as inflammatory markers; (2) fasting glucose, insulin, glycated haemoglobin (HbA1C) and waist-to- hip ratio as markers of glycemic control; (3) total-cholesterol, HDL-cholesterol and triglycerides as markers of lipidic profile, in all sample population. The use of statins and sulfonylurea, as well as the presence of some relevant diabetes complications (nephropathy and retinopathy) were also assessed. Conclusion: Type2DM + MI elderly patients have leukocyte telomere lengths shorter than those of Type2DM (without MI) and healthy CTR. Moreover, glucose, HbA1C and waist-to-hip ratio, variables related to glycemic control, showed a significant inverse correlation with leukocyte telomeres length. (C) 2009 Elsevier Ireland Ltd. All rights reserved.