Association with elevated level of inflammatory biomarkers and attention deficit in Korean farmers

Abstract

Inflammation plays an important role in cognitive impairments. This study examined the association of elevated biomarkers, such as C-reactive protein (CRP) and interleukin-6 (IL-6) concentrations, with attentional deficit in Korean farmers. A total of 504 healthy Korean farmers (255 male, mean age 60 years) were enrolled from the Farmers' cohort for Agricultural work-Related Musculoskeletal disorders (FARM) study. Attention was evaluated by measuring the accuracy/error rate and speed when using a computerized Go/No-Go test. Serum level of CRP and IL-6 were measured in specimens. Higher CRP and IL-6 levels were associated with decreased accuracy rate (p < .001). The increased error rate in the Go test was related to an elevated CRP level (p < .001), while the increased error rate of the No-Go test was related to an elevated IL-6 level (p < .001). The correct response time was associated with an increased CRP level in simple and NSAID-adjusted analysis. In the age-adjusted partial correlation analysis, higher CRP and IL-6 levels were associated with a decreased accuracy rate (CRP: Partial r [pr] = −0.171, p < .001; IL-6: pr = −0.196, p < .001). The increased error rate in the Go-test was related to the elevated CRP level (pr = 0.321, p < .001), while increased error rate in the No-Go test was related to the elevated IL-6 level (pr = 0.256, p < .001). Elevated serum CRP and IL-6 were associated with attentional decline, thus suggesting the involvement of inflammation in cognitive impairments in healthy individuals.