Prognostic value of telomere length in acute coronary syndrome

Physical activity and telomere length: Impact of aging and potential mechanisms of action

Telomeres protect the integrity of information-carrying DNA by serving as caps on the terminal portions of chromosomes. Telomere length decreases with aging, and this contributes to cell senescence. Recent evidence supports that telomere length of leukocytes and skeletal muscle cells may be positively associated with healthy living and inversely correlated with the risk of several age-related diseases, including cancer, cardiovascular disease, obesity, diabetes, chronic pain, and stress. In observational studies, higher levels of physical activity or exercise are related to longer telomere lengths in various populations, and athletes tend to have longer telomere lengths than non-athletes. This relationship is particularly evident in older individuals, suggesting a role of physical activity in combating the typical age-induced decrements in telomere length. To date, a small number of exercise interventions have been executed to examine the potential influence of chronic exercise on telomere length, but these studies have not fully established such relationship. Several potential mechanisms through which physical activity or exercise could affect telomere length are discussed, including changes in telomerase activity, oxidative stress, inflammation, and decreased skeletal muscle satellite cell content. Future research is needed to mechanistically examine the effects of various modalities of exercise on telomere length in middle-aged and older adults, as well as in specific clinical populations.

Study to Improve Cardiovascular Outcomes in high-risk older patieNts (ICON1) with acute coronary syndrome: study design and protocol of a prospective observational study

INTRODUCTION

The ICON1 study (a study to Improve Cardiovascular Outcomes in high-risk older patieNts with acute coronary syndrome) is a prospective observational study of older patients (≥75 years old) with non-ST-elevation acute coronary syndrome managed by contemporary treatment (pharmacological and invasive). The aim of the study was to determine the predictors of poor cardiovascular outcomes in this age group and to generate a risk prediction tool.

METHODS AND ANALYSIS

Participants are recruited from 2 tertiary hospitals in the UK. Baseline evaluation includes frailty, comorbidity, cognition and quality-of-life measures, inflammatory status assessed by a biomarker panel, including microRNAs, senescence assessed by telomere length and telomerase activity, cardiovascular status assessed by arterial stiffness, endothelial function, carotid intima media thickness and left ventricular systolic and diastolic function, and coronary plaque assessed by virtual histology intravascular ultrasound and optical coherence tomography. The patients are followed-up at 30 days and at 1 year for primary outcome measures of death, myocardial infarction, stroke, unplanned revascularisation, bleeding and rehospitalisation.

ETHICS AND DISSEMINATION

The study has been approved by the regional ethics committee (REC 12/NE/016). Findings of the study will be presented in scientific sessions and will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT01933581: Pre-results.

Telomere mean length in patients with diabetic retinopathy

Telomere regression has been shown to be associated with several complex disorders like diabetes mellitus, cancer, cataract etc. Diabetic retinopathy develops as a complication of chronic hyperglycemia leading to increased oxidative stress that may potentially lead to shortening of telomeres. We sought to determine whether there is any association between telomere mean length (TML) of peripheral blood monocytes with the presence and severity of diabetic retinopathy. The study involved 120 subjects, comprising 27 non-insulin dependent diabetes mellitus (NIDDM) without any diabetic retinopathy (NDR), 45 NIDDM subjects with non-proliferative diabetic retinopathy (NPDR), 12 NIDDM subjects with proliferative diabetic retinopathy (PDR) and 36 healthy controls. Determination of TML of the study subjects was performed by Southern hybridization using telomere probe. Among the biochemical parameters, HBA1c showed a negative correlation with shortened telomeres in the PDR subjects. However, telomere length was positively correlated with high density lipo protein (HDL) in the control subjects. The control group had significantly greater TML as compared to the rest of the groups and the NDR subjects with NPDR and PDR had substantially decreased TML than the NIDDM subjects without retinopathy.

Effect of telomere length on prognosis in men with acute coronary syndrome

Telomere length is related to cellular aging and cardiovascular disease. Nevertheless, the specific role of cellular aging in this process is still unclear. The aim of this report was to analyze the prognostic value of telomere length in men admitted for acute coronary syndrome. Telomere length was measured by quantitative polymerase chain reaction in peripheral blood leukocytes of 203 men classified into 2 groups: those aged 50 to 75 years and those >75 years. Clinical follow-up had been done for >600 days, and a prognostic combined event was defined. In men aged 50 to 75 years, we found a statistically significant worse prognosis in patients with short telomeres (log-rank: 5.22, p <0.05) but not in men >75 years (log-rank: 0.01, p = 0.91). Cox analysis confirmed short telomeres in men aged 50 to 75 years as an independent prognostic risk factor. In conclusion, telomere length is a good predictor of cardiovascular prognosis in men admitted for acute coronary syndrome, but this relation depends on the chronological age of the population studied.

Telomeres and cardiovascular disease risk: an update 2013

Leukocyte telomere length (LTL) has been regarded as a potential marker of biologic aging because it usually shortens in a predictable way with age. Recently, a growing interest in cardiovascular aging has led to a number of new epidemiologic studies investigating LTL in various disease conditions. Some methodological problems exist because there are different methods available to determine LTL, and standardization is much needed. For example, in the majority of studies, patients with early-onset coronary heart disease have been shown to have shorter LTL. In addition, patients with diabetes mellitus complications tend to have shorter LTL than control subjects. On the other hand, increased left ventricular hypertrophy or mass is associated with longer LTL, and studies investigating hypertension have reported both shorter and longer LTL than found in normotensive control subjects. There is, therefore, a need for longitudinal studies to elucidate these complicated relationships further, to provide estimations of telomere attrition rates, and to overcome analytical problems when only cross-sectional studies are used. The understanding of cardiovascular aging and telomere biology may open up new avenues for interventions, such as stem cell therapy or agents that could retard this aging process over and beyond conventional risk factor control.