Blood-based Lead Biomarkers And Sarcopenia Indicators In Older Adults

Abstract

Background: Chronic exposure to low levels of lead (Pb) remains a widespread public health issue, especially among older adults. While its neurotoxic and cardiovascular effects are well recognized, its potential role in accelerating age-related musculoskeletal decline is less understood. Emerging evidence suggests Pb may contribute to sarcopenia, but epidemiological data, especially regarding the most informative biomarkers of exposure, are limited. Methods: We analyzed data from 11,842 participants aged ≥60 years across four population-based studies (NHANES III, NHANES 1999-2006, NHANES 2011-2012 and Seniors-ENRICA-2). Sarcopenia indicators included muscle strength (grip strength and chair stand test), muscle mass (Dual energy X-ray Absorptiometry, calf circumference and arm circumference), and muscle function (gait speed and Short Physical Performance Battery scores). Sarcopenia was defined in the Seniors-ENRICA-2 using the European Working Group on Sarcopenia in Older People 2 criteria. Associations between Pb exposure (serum and whole blood) and sarcopenia indicators were estimated using multivariable regression and meta-analyses. Results: Pb levels were associated with residential environmental exposures such as traffic proximity, industrial emissions, and soil contamination, explaining approximately 11% of variability in whole blood Pb and 9% in serum Pb. Both whole blood and serum Pb showed dose-dependent inverse associations with muscle sarcopenia indicators, including measures of strength, mass, and function. Associations with lower-limb outcomes were generally stronger for serum Pb comparted to whole blood Pb. An interquartile range increase in serum Pb was associated with a 1.33-fold increase in the odds of confirmed or severe sarcopenia (95% CI: 1.02, 1.70), compared to a 1.20-fold increase for whole blood Pb (95% CI: 1.06, 1.36). Conclusions: Environmental Pb exposure is associated with detrimental effects on musculoskeletal health and contributes to sarcopenia in older adults. Serum Pb may be a more sensitive biomarker of musculoskeletal aging than whole blood Pb and should be considered in future research and surveillance strategies.