Association of Ubiquitin C-Terminal Hydrolase-L1 (Uch-L1) serum levels with cognition and brain energy metabolism.

In recent years, many researchers have taken serum ubiquitin c-terminal hydrolase (Uch-L1) as an indicator of post-traumatic brain injury and associated it with cognitive impairment. Alzheimer's disease is characterized by cognitive impairment and energy metabolism disorders. The purpose of this study was to detect whether serum Uch-L1 is related to cognition and brain energy metabolism in healthy people, and to explore whether it can be used as an early blood marker of Alzheimer's disease.In this prospective cohort study, adult outpatients from a Grade 3A hospital were recruited. They completed the 18F-FDG-PET/CT examination in the nuclear medicine department and were screened by the Mini Mental State scale (MMSE) and the Montreal Cognitive Assessment scale (MoCA). Blood samples were collected from all outpatients to detect the concentration of serum Uch-L1, and the mean standard uptake value (SUVmean) of energy metabolism in the hippocampus during PET/CT examination was collected.A total of 37 participants, 14 participants with cognitive impairment (MMSE score < 27) and 23 controls (MMSE score 27-30) were included. There was a significant difference in the SUVmean of the hippocampus between the cognitive impairment group and the normal control group (p < 0.05). There was a significant correlation between the SUVmean of the hippocampus and the total score of MMSE in all participants [r = 0.439, 95% CI: (0.139-0.668), p = 0.007]. There were also significant correlations between serum Uch-L1 and MMSE. Based on the significant differences of demographic variables between groups, we conducted a multivariate linear regression analysis of MMSE cognitive scores based on age (X1), length of education (X2) and SUVmean of hippocampus (X3). The regression equation is as follows: Y = 25.709-0.072 X1 + 0.422 X2 + 0.232 X3.Brain cognitive ability is closely related to energy metabolism and serum Uch-L1 concentration, so serum Uch-L1 may become a blood marker for extensive screening of dementia in the future. We look forward to the introduction of a more accurate and low-cost method for detecting serum Uch-L1 concentration.