Background: Telomeres are repetitive, gene-poor regions that cap the ends of DNA and help to maintain chromosomal integrity. Their shortening is caused by inflammation and oxidative stress within the cellular environment and ultimately leads to cellular senescence. Shortened leukocyte telomere length (LTL) is hypothesized to be a novel biomarker for age-related diseases and may therefore be useful in the prediction of cardiometabolic outcomes above conventional risk factors.
Methods: A systematic review and meta-analysis was undertaken to summarize existing literature on the association between LTL and myocardial infarction (MI), stroke, and type 2 diabetes (T2D). MEDLINE (1966–present), and EMBASE (1980-present) were last searched on September 9th 2013. Studies were combined using the generic inverse variance method and both fixed and random effects models. Additionally, LTL was measured in 3972 MI patients and 4321 controls from an international study on risk factors for MI (INTERHEART), and 8635 participants from an epidemiological study on dysglycemia and T2D (EpiDREAM) prospectively followed (approximately 3.5 years) for incident cardiometabolic events.
Results: Based on current literature, a 1-standard deviation decrease in LTL was significantly associated with stroke (OR=1.21, 95% CI=1.06-1.37; I2=61%), myocardial infarction (OR=1.24, 95% CI=1.04-1.47; I2=68%), and type 2 diabetes (OR=1.37, 95% CI=1.10-1.72; I2=91%). Stratification by measurement technique, study design, study size, and ethnicity explained heterogeneity in certain cardiometabolic outcomes. Within INTERHEART participants, a 1 unit decrease in LTL was associated with an increased risk of MI (OR=2.17, 95% CI=1.74-2.72). Effect estimates were consistent across all ethnic groups (p=0.19). In EpiDREAM a significant association between LTL and T2D or incident cardiometabolic outcomes was not observed.
Conclusion: Telomere length appears to be a marker for MI above conventional risk factors. Further research is needed to explain existing heterogeneity in the literature with respect to LTL and T2D. / Thesis / Master of Science (MSc)
Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/15951 |
Date | 11 1900 |
Creators | D'Mello, Matthew |
Contributors | Paré, Guillaume, Health Research Methodology |
Source Sets | McMaster University |
Language | English |
Detected Language | English |
Type | Thesis |
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