Cumulative inflammatory load is associated with short leukocyte telomere length in the Health, Aging and Body Composition Study

Background

Leukocyte telomere length (LTL) is an emerging marker of biological age.Chronic inflammatory activity is commonly proposed as a promoter ofbiological aging in general, and of leukocyte telomere shortening inparticular. In addition, senescent cells with critically short telomeresproduce pro-inflammatory factors. However, in spite of the proposed causallinks between inflammatory activity and LTL, there is little clinicalevidence in support of their covariation and interaction.

Methodology/Principal Findings

To address this issue, we examined if individuals with high levels of thesystemic inflammatory markers interleukin-6 (IL-6), tumor necrosisfactor-α (TNF-α) and C-reactive protein (CRP) had increased odds forshort LTL. Our sample included 1,962 high-functioning adults whoparticipated in the Health, Aging and Body Composition Study (age range:70–79 years). Logistic regression analyses indicated that individualswith high levels of either IL-6 or TNF-α had significantly higher oddsfor short LTL. Furthermore, individuals with high levels of both IL-6 andTNF-α had significantly higher odds for short LTL compared with thosewho had neither high (OR = 0.52,CI = 0.37–0.72), only IL-6 high(OR = 0.57, CI = 0.39–0.83)or only TNF-α high (OR = 0.67,CI = 0.46–0.99), adjusting for a wide variety ofestablished risk factors and potential confounds. In contrast, CRP was notassociated with LTL.

Conclusions/Significance

Results suggest that cumulative inflammatory load, as indexed by thecombination of high levels of IL-6 and TNF-α, is associated withincreased odds for short LTL. In contrast, high levels of CRP were notaccompanied by short LTL in this cohort of older adults. These data providethe first large-scale demonstration of links between inflammatory markersand LTL in an older population.