Abstract
The Effect of Infections on Telomere Dynamics: Insights from a Systematic Review
Introduction
Infections are linked to an increased risk of age-related diseases like cardiovascular disease and dementia. Accelerated immunological ageing, which can be measured by telomere length (TL), could be a potential underlying mechanism. However, the extent to which different infections influence TL or its attrition is not fully understood. Clarifying these relationships could guide preventive strategies to reduce age-related disease risk.
Method
We conducted a systematic review searching six major databases (MEDLINE, EMBASE, Web of Science, Scopus, Global Health, Cochrane Library) on 31 August 2023. Two reviewers independently screened and selected studies, extracted data, and assessed risk of bias using the ROBINS-E tool. High inter-study heterogeneity meant meta-analysis was not feasible, so we performed a narrative synthesis. Studies were categorised by infection type, telomere measurement method, cell type used for TL measurement, and statistical analysis approach.
Results
From 8,670 identified studies, 63 met inclusion criteria. Most studies (50) were cross-sectional and conducted after 2000, with the earliest from 1996. The USA was the most frequent study location (15 studies). HIV was the most studied infection (30 studies), followed by COVID-19 (8 studies), and then Cytomegalovirus and H.pylori (6 studies each). Eighty percent (20) of HIV studies (of those without overlapping samples) reported evidence of an association between HIV and shorter TL or increased telomere attrition. Findings for other infections were more variable. Differences in infection types, telomere measurement methods, cell types analysed, and statistical approaches, complicated cross-study comparisons. Furthermore, risk of bias was high in most studies, mainly due to risk of unmeasured confounding.
Conclusion(s)
There is evidence to suggest that HIV infection is linked to telomere attrition, while findings for other infections aren’t conclusive. Future research should prioritize longitudinal studies with standardized telomere measurement methods and rigorous control of confounding to better understand relationships between infections and telomere dynamics.