Association of Occupational Factors and Dementia or Cognitive Impairment: A Systematic Review and Meta-Analysis.

Abstract

Several existing studies have reported that occupational factors might play an important part in cognitive function with aging. We aim to explore the associations between modifiable occupational factors and risk of dementia or mild cognitive impairment (MCI). Adopting random-effect models, this study conducted primary analyses for all occupational factors and subgroup analyses for the effect of occupation type based on prospective cohort and case-control studies searched from PubMed and EMBASE databases up to March 2020. Among the 38,111 identified literatures, 9 studies on occupation type, 4 studies on work complexity, and 30 studies on occupational exposure were included. In terms of occupation type, mental work conferred a 44% reduced risk (95% CI = 0.34-0.94, I² = 85.00%, p < 0.01) for MCI. In terms of work complexity, higher work complexity conferred a 5% reduced risk (95% CI = 0.91-1.00, I² = 57.00%, p < 0.01) for dementia. In terms of occupational exposure, high strain and passive job in the longest-held job conferred a 1.21- and 1.15-fold excess risk (95% CI = 1.05-1.39 I² = 62.00%, p < 0.05; 95% CI = 1.05-1.26 I² = 31.00%, p = 0.23; respectively) of cognitive decline. Besides, magnetic field exposure conferred a 1.26-fold excess risk (95% CI = 1.01-1.57, I² = 69.00%, p < 0.01) for dementia. Novel prevention strategies based on occupational factors may hold promise against dementia and MCI.