Leucocyte telomere length and paroxysmal atrial fibrillation: A prospective cohort study and systematic review with meta-analysis

Background: Telomere length is a surrogate marker of biological aging. Whether telomere length predicts the risk of atrial fibrillation (AF) independently of biological aging is controversial. We conducted a cohort study to examine the relationship between telomere length and paroxysmal AF (PAF), followed by a systematic review and meta-analysis of the published literature, incorporating our own data. Methods: DNA was extracted from peripheral blood. Leucocyte telomere length was measured by a real-time polymerase chain reaction-based method, normalized to a single copy gene, and presented as telomere/single gene ratio (t/s). Results: A total of 100 non-AF patients and 50 PAF patients (mean age: 61.0 ± 9.4 and 64.0 ± 10.7 years, respectively) were included. T/s for subjects without AF tended to be shorter than for those with AF (0.21 [0.06-0.36] vs 0.28 [0.11-0.71], P =.077). T/s was associated with a 1.60-fold increase in the risk of AF but this was not significant (95% CI: 0.988-2.597, P =.056). Our meta-analysis confirms no difference in telomere length between AF and non-AF patients and t/s was not associated with higher risk of AF in multivariate analysis. Conclusions: Our prospective data showed that leucocyte telomere length was similar between AF and non-AF patients but was significantly longer in male patients with PAF than those without AF in our subgroup analysis. Our meta-analysis found that t/s did not predict AF. These findings support the notion that chronological aging, but not markers of biological aging, predicts the risk of AF.