Blood lead, blood manganese, and grip strength in older U.S. adults: NHANES 2011-2012
Environmental exposure to toxic metals is a major public health issue. Neurological impact caused by low concentrations of lead (Pb) and manganese (Mn), is still not well understood. National Health and Nutrition Examination Survey (NHANES) 2011-2012 data was used to test the hypothesis that blood Pb (BPb), blood Mn (BMn), or both, may have a significant impact on grip strength, a marker of neuromotor function. This cross-sectional analysis included 1286 individuals ≥60 years old with complete data on confounders. Blood metals, indicators of recent exposure, were analyzed using ICP-MS and natural-log transformed for statistical analysis. Grip strength was collected using a handgrip dynamometer. Analysis included appropriate survey weights and linearized standard errors. Adjusted multivariable linear regression models controlled for age, sex, race/ethnicity, education, blood cotinine and body mass index (BMI). Geometric mean BPb and BMn were 1.55µg/dL (95% Confidence Interval (C.I.): 1.44, 1.68) and 8.75µg/L (95% C.I.: 8.53, 8.98), respectively. In adjusted models, decreased grip strength was significantly associated with increasing BPb (β= -1.40; 95% C.I.: -2.54, -0.26) but not BMn (β= -1.31; 95% C.I.: -4.36, 1.73). BPb, but not BMn, was significant in a model controlling for both metals; there was no evidence of a statistical interaction. These results suggest that increasing BPb levels are associated with decreasing grip strength. However, as neurologic function may be the result of exposures occurring over a lifetime, we recommend that future studies incorporate use of cumulative exposure markers such as bone lead and manganese.
Environmental health sciences
Describe blood manganese and blood lead concentrations in older U.S. adults.
Assess the relationship between lead and manganese with grip strength in a nationally representative elderly population.
Keyword(s): Aging, Environmental Health
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Qualified on the content I am responsible for because: I am a graduate student currently conducting research on metal toxicity in various environmental and occupational populations.
Any relevant financial relationships? No
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