Higher BMI was inversely associated with leukocyte telomere length (-3.532 bp per 1-unit increase; 95% CI -6.225 to -1.178), an association significantly mediated by serum total bilirubin (13.2%).
Cross-Sectional (n=6,717)
Total bilirubin acts as a significant mediator in the association between obesity and leukocyte telomere shortening, explaining approximately 13.2% of the effect.
Mean Difference: -3.532 (95% CI -6.225–-1.178)
p-value: p=0.002
Abstract Background Both obesity and oxidative stress are closely linked to leukocyte telomere length (LTL) shortening, yet the specific mediating role of total bilirubin in this association remains insufficiently explored. This study aimed to quantify the extent to which total bilirubin, a potent endogenous antioxidant, mediates the association between obesity and LTL. Methods We analyzed data from 6,717 adults participating in the National Health and Nutrition Examination Survey 1999–2002. Causal mediation analysis with 1,000 bootstrap iterations was employed to investigate the mediating effect of serum total bilirubin on the association between body mass index (BMI) and LTL. Results In the fully adjusted model, BMI was significantly and inversely associated with LTL, with a total effect of -3.532 base pairs (bp) per 1-unit increase in BMI (95% confidence interval CI: -6.225 to -1.178; P = 0.002). Serum total bilirubin significantly mediated this association (average causal mediation effect = -0.446 bp; 95% CI: -0.726 to -0.237; P < 0.001). The estimated proportion of the association explained by bilirubin was 13.2% (95% CI: 5.5% to 41.2%; P = 0.002). A series of sensitivity analyses confirmed the robustness and stability of these mediation findings. Conclusions Total bilirubin serves as a significant statistical mediator in the relationship between obesity and LTL shortening. However, given the cross-sectional design of this study, further longitudinal investigations are required to confirm these associations and establish causality.
Zhou et al. (Thu,) conducted a cross-sectional in Obesity and telomere shortening (n=6,717). Body mass index (BMI) was evaluated on Leukocyte telomere length (LTL) (Total effect -3.532 bp, 95% CI -6.225 to -1.178, p=0.002). Higher BMI was inversely associated with leukocyte telomere length (-3.532 bp per 1-unit increase; 95% CI -6.225 to -1.178), an association significantly mediated by serum total bilirubin (13.2%).