Association among plasma lactate, systemic inflammation, and mild cognitive impairment: a community-based study

The level of lactate in the blood is associated with obesity, blood pressure, and type 2 diabetes. In addition, lactate is a pro-inflammatory cytokine, which plays an important role in the pathogenesis of cognitive impairment. However, the association between blood lactate, systemic inflammation, and mild cognitive impairment (MCI) has not been investigated. The aim of the study is to explore this association in a Chinese population. This community-based cross-sectional study included 2523 Chinese participants aged 18-88 years. Cognitive function was assessed using the Chinese version of the Mini-Mental State Examination. MCI was defined using education-based cutoffs. The concentration of plasma lactate and serum high-sensitivity C-reactive protein (hs-CRP) was measured using the lactate oxidase method and latex enhanced immunoturbidimetric assay, respectively. Compared with participants without a cognitive impairment, participants with a MCI had an increased concentration of plasma lactate and serum hs-CRP (P < 0.001). As blood lactate increased, the concentration of serum hs-CRP and prevalence of MCI also increased (P < 0.001). Logistic regression analysis showed that plasma lactate (odds ratio (OR) 2.76, 95% confidence interval (CI) 2.21-3.45, P < 0.001) and serum hs-CRP (OR 1.15, 95% CI 1.08-1.24, P < 0.001) were significant risk factors for MCI. The adjusted OR for MCI in participants in the fourth lactate quartile was 3.44 (95% CI 2.02-5.88, P < 0.001) compared with the first quartile. Our results showed that plasma lactate is associated with systemic inflammation and MCI.