Association of peripheral inflammatory factors with cognitive performance in mild cognitive impairment

Objective To explore the association between peripheral inflammatory factor levels and cognitive performance in the older people with mild cognitive impairment population (MCI). Methods A case-control study was performed, consisting of 150 MCI patients and 101 healthy controls.The Wechsler Adult Intelligence Scale was revised in China (WAIS-RC) was used to assess the cognitive function. Serum interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and amyloid β-protein (Aβ) levels were measured by ELISA and Milliplex Map Cytokine Kit. Results The levels of serum IL-6 and Aβ42 in MCI group were both higher than those in control group (all P<0.05). Multiple linear regression showed there was significant correlation between the increase of Aβ42 level and the decrease of verbal intelligen quotient (VIQ) (β=-0.285, P<0.001). Elevated IL-6 and TNF-α levels were associated with the decrease of performative in telligence quotient (PIQ) and full intelligence quotient (FIQ) (all P<0.05). Conclusions Serum IL-6 and Aβ42 levels are increased in MCI patients. Serum levels of IL-6 and TNF-α could evaluate the performative and general intellectual impairment of MCI, and the level of Aβ42 could be used as an assessment factor of verbal intellectual impairment in MCI.