Association of telomere shortening with low back pain and the potential mediating role of smoking: A cross-sectional study

Chronic pain, particularly low back pain (LBP), is common among older adults and may be influenced by cellular aging. Telomere length (TL) has been suggested as a marker for age-related susceptibility to musculoskeletal pain, but evidence in elderly populations is limited. This study examined the association between TL and chronic pain, including LBP, and explored the potential mediating role of smoking. We conducted a cross-sectional analysis of 2070 participants aged ≥ 60 years from National Health and Nutrition Examination Survey 1999 to 2002. TL was measured using quantitative polymerase chain reaction, and pain outcomes were self-reported via questionnaires. Weighted multivariable logistic regression models assessed associations between TL and chronic pain. Mediation analysis was performed to evaluate the potential role of smoking in the TL-LBP relationship. Shorter TL was significantly associated with higher odds of LBP (odds ratios = 0.77, 95% confidence interval: 0.63-0.95), while no significant associations were observed for neck or joint pain. TL was inversely associated with smoking, which in turn was related to higher odds of LBP. Mediation analysis suggested that smoking may partially mediate the association between TL and LBP, explaining approximately 60.9% of the total effect. Shorter TL is associated with LBP in older adults, with smoking potentially acting as a partial mediator. These findings highlight TL as a potential biomarker for lumbar spine-related pain and support smoking cessation as a possible intervention target. Longitudinal studies are needed to further clarify causal pathways and site-specific mechanisms.