Influence of manganese exposure on cognitive function, plasma APP and Aβ levels in older men.

Abstract

BACKGROUND:

Elevated manganese (Mn) exposure impairs cognition in adults and children, but the association between Mn and cognitive function in elderly people is unclear. Previous studies have linked Mn neurotoxicity in AD to Aβ-dependent mechanisms. However, the association between Mn and plasma APP and Aβ in the general elderly population remains unknown. This study aimed to investigate the association between Mn exposure and cognitive function, plasma APP and plasma Aβ in older adults.

METHODS:

Cognitive abilities in 375 men aged 60 and older in Guangxi, China were assessed using the Mini-Mental State Examination (MMSE) and cognitive impairment were identified using education-stratified cut-off points of MMSE scores. Urinary Mn levels and plasma APP, and Aβ levels were measured using ICP-MS and ELISA, respectively.

RESULTS:

A total of 109 (29.07 %) older men were identified as having cognitive impairment. The median urinary Mn level was 0.22 μg/g creatinine. Urinary Mn levels were negatively correlated with MMSE scores (β = -1.35, 95 % CI: -2.65 to -0.06; p = 0.041). In addition, higher concentrations of urinary manganese were associated with a greater risk of cognitive impairment (OR = 2.03, 95 % CI: 1.14-3.59; comparing the highest and lowest manganese; p = 0.025). Moreover, plasma APP levels were inversely associated with urinary Mn levels (r = -0.123, p = 0.020), and positively associated with MMSE scores (r = 0.158, p = 0.002). Surprisingly, no correlations were observed between plasma Aβ42, Aβ40, Aβ40/Aβ42, or Aβ42/Aβ40 and urinary Mn levels and MMSE scores.

CONCLUSION:

These results suggested that Mn exposure is negatively associated with older men's cognition and plasma APP levels, but not plasma Aβ levels.

• Authors: Jie Zhang, Yiping Yang, Xiaobo Yang, Jian Qin, Xiao Wei, Yang Peng, Zhiying Li, Li'e Zhang, Zhiyong Zhang, Yunfeng Zou
• Journal: Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) (J Trace Elem Med Biol) Vol. 67 Pg. 126788 (Sep 2021) ISSN: 1878-3252 [Electronic] Germany
• PMID: 34015662 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 Elsevier GmbH. All rights reserved.

Chemical References

• Amyloid beta-Peptides
• Manganese

Topics

• Aged
• Amyloid beta-Peptides
• China
• Cognition
• Cognitive Dysfunction (chemically induced)
• Humans
• Male
• Manganese (toxicity)
• Middle Aged