Telomere Length Associated with Insulin Resistance and Arterial Stiffness in Absence of Cardiovascular Disease

by | Jul 16, 2018 | 2015, Cardiovascular Health, Circulatory Health

Written by Halima Phelps, Staff Writer. This study found that decreased telomere length was associated with increased arterial stiffness, increased aging, and impaired glucose metabolism.

cardiovascular healthStudies have determined that changes occur within the immune system with age, and these changes are particularly evident within the body’s leukocyte populations.1 In particular, the leucocyte telomere length which is controlled by the enzyme telomerase, and has been implicated in CVD, tends to shorten with the aging process.2 The length of telomeres found in leukocytes can be measured to help predict advancements in age, because “LTL (Leukocyte telomere length) reflects both an individual’s telomere length at birth and the telomere attrition during the life course, demonstrating replicative history and cumulative oxidative burden.”3

Aging, as reflected in LTL, is said to be the chief component that increases the risk of developing cardiovascular disease.3 Furthermore, cardiovascular disease may be exacerbated by the aggravating factor of insulin resistance. 3 This study aimed to examine the hypothesis of the associations between insulin resistance, arterial stiffness and telomere length in the absence of cardiovascular disease to determine whether insulin resistance, as a factor independent of heart disease, could cause changes in LTL as well as decrease the plasticity of the arteries.3

To test the hypothesis, the following cross-sectional study of 303 participating Caucasian subjects (104 male and 199 female from 23-91 years of age), who were not previously diagnosed with a cardiovascular condition nor were on prescription medications, was designed. Participants underwent the following tests: mean systolic and diastolic blood pressures, body mass index (BMI, kg/m2), serum fasting glucose, glycosylated hemoglobin (HbA1c), serum insulin, and impaired fasting glucose levels. Arterial stiffness was also measured using carotid-femoral pulse wave velocity (c-f PWV), and a measurement of LTL was performed via q polymerase chain reaction (PCR) analyses 4. Finally, telomerase activity (TA) was assessed via monocytic cellular extraction and PCR testing 5.

Results indicated three main findings in support of the hypothesis. The study discovered that factors determining the efficiency of proper glucose metabolism all have a link to arterial stiffness; and this stiffness precedes the onset of type II diabetes mellitus. These factors include glycosylated hemoglobin, 2 hour oral glucose tolerance test, and homeostasis model assessment of insulin resistance (HOMA-IR). Furthermore, insulin resistance (IR) appears to be one of the primary determining factors in the development of arterial stiffness. HOMA-IR (p=0.0001) also appeared to weigh in as an even greater independent causative factor in developing arterial rigidity than did systolic blood pressure (p=0.1260).

Secondly, this study also found that arterial stiffness (c-f PWV) decreased with increased LTL (p=0.0001). This finding supports the fact that there is a correlation between the aging of the larger blood vessels, and the cell components that comprise the wall of the vessels.

Lastly, this study found as age increased, LTL was found to decrease (p=0.0001). This is perhaps due to the fact that insulin resistance can exacerbate oxidation, which can cause single-strand breaks in telomeres as well as prevent their repair; thereby causing the shortened LTL as seen in aging.3

Although further research is needed to determine the mechanism of action of these relationships between c-f PWV, telomeres, glucose regulation and blood pressure, this study was able to determine that there is a relationship between arterial stiffness, shorter telomere length and impaired glucose metabolism.3

Source: Strazhesko, Irina, et al. “Association of Insulin Resistance, Arterial Stiffness and Telomere Length in Adults Free of Cardiovascular Diseases.” PLOS Medicine, Public Library of Science, journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0136676.

© 2015 Strazhesko et al. Open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Click here to read the full text study.

Posted July 16, 2018.

Halima Phelps, BA, AA, PBT, is a graduate of the University of Wisconsin Parkside. She graduated in 2014 with a bachelor of arts in Spanish and a biology minor. She is currently a student staff member in the department of postgraduate education and completing a medical degree at the National University of Health Sciences in Lombard, IL.

References:

  1. Stervbo U, Meier S, Mälzer JN, et al. Effects of aging on human leukocytes (part I): immunophenotyping of innate immune cells. Age. 2015;37(5):92.
  2. Desai A, Grolleau‐Julius A, Yung R. Leukocyte function in the aging immune system. Journal of leukocyte biology. 2010;87(6):1001-1009.
  3. Strazhesko I, Tkacheva O, Boytsov S, et al. Association of insulin resistance, arterial stiffness and telomere length in adults free of cardiovascular diseases. PloS one. 2015;10(8):e0136676.
  4. Cawthon RM. Telomere measurement by quantitative PCR. Nucleic acids research. 2002;30(10):e47-e47.
  5. Kim NW, Piatyszek MA, Prowse KR, et al. Specific association of human telomerase activity with immortal cells and cancer. Science. 1994;266(5193):2011-2015.