Concurrent serum lead levels and cognitive function in older adults

Yu Deng; Xuechun Lin; Jie Zhou; Mengchi Li; Zhenmei Fu; Dan Song

doi:10.3389/fnins.2023.1180782

Concurrent serum lead levels and cognitive function in older adults

Front Neurosci. 2023 Apr 17:17:1180782. doi: 10.3389/fnins.2023.1180782. eCollection 2023.

Authors

Yu Deng¹, Xuechun Lin², Jie Zhou³, Mengchi Li⁴, Zhenmei Fu⁵, Dan Song³

Affiliations

¹ Department of Pediatric Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
² Hubei Key Laboratory of Food Nutrition and Safety, Ministry of Education Key Laboratory of Environment and Health, Department of Nutrition and Food Hygiene, Tongji Medical College, School of Public Health, Huazhong University of Science and Technology, Wuhan, China.
³ Department of Nursing, Shenzhen Qianhai Shekou Free Trade Zone Hospital, Shenzhen, Guangdong Province, China.
⁴ School of Nursing, John Hopkins University, Baltimore, MD, United States.
⁵ Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.

Abstract

Introduction: In this study, we investigated the relationship between serum lead levels and cognitive functioning in a sample of older adults in the US.

Method: Using the National Health and Nutrition Examination Survey (NHANES) 2011-2013, a total of 768 older adults aged ≥60 years were included in the analysis. Lead concentrations in the whole blood samples were assessed using mass spectrometry. We used the immediate and delayed memory portions of the Consortium to Establish a Registry for Alzheimer's Disease Word Learning Subtest (CERAD-WL), the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST) to assess the participants' cognitive performance. Using sample averages and standard deviations (SDs), we computed test-specific and global cognition z-scores. To assess the relationships between the quartiles of serum lead levels and cognitive performance, we built multiple linear regression models and adjusted for covariates, including age, sex, race/ethnicity, education, depressive symptoms, alcohol usage, and body mass index.

Results: The average age of the participants was 69.6 (SD 6.6) years. Approximately half of the participants were women (52.6%), non-Hispanic white (52.0%), and had completed at least some college education (51.8%). The average serum lead concentration was 1.8 g/dL (SD 1.6) for these participants. The results of multiple linear regression using individuals in the lowest serum lead quantile as a reference group revealed that the serum lead level was not associated with test-specific (CERAD-WL, AFT, and DSST) or global cognitive z-scores.

Conclusions: In older adults, concurrent serum lead concentration is not related to cognitive performance. Early or continuous lead exposure may exert a greater effect on the etiology of accelerated cognitive decline with old age.

Keywords: biomarker; cognition; heavy metal; lead; seniors.