Path analysis of trace elements and physiological and biochemical indices associated to mild cognitive impairment in...

The intricate relationships between cognitive function and a broad spectrum of trace elements and physiological and biochemical indices remain unclear. This study aimed to employ a path analysis model to investigate the effects of multiple trace elements and physiological and biochemical factors on mild cognitive impairment (MCI) among elderly Chinese. A total of 5768 residents aged 60 years and older were recruited in Shenzhen, China. Cognitive function was evaluated using the Mini-Mental State Examination and the Mini-Cognitive Assessment. Concentrations of 18 trace elements in urine were quantified with adjustments for urinary creatinine levels. Physiological and biochemical indices were acquired at community health centers. Based on the multiple logistic regression analysis, only selenium exhibited significant negative correlations with MCI (p-trend = 0.035). Serum albumin (ALB), triglyceride (TG), bone mineral density (BMD) and mitochondrial DNA copy number (mtDNAcn) exhibited negative correlations with high risk of MCI, whereas serum uric acid (SUA) and fasting blood glucose (FBG) were positively correlated with a higher risk of MCI. In addition, the path analysis model demonstrated that cobalt had direct effect on cognitive function, whereas iron, manganese, selenium, zinc, and copper affected it indirectly. Furthermore, the model identified that mtDNAcn directly affected cognitive function, while the other four physiological and biochemical indicators, including ALB, TG, BMD and SUA, had both direct and interactive indirect effects on it. Trace elements and physiological and biochemical indices exerted both direct and indirect effects on MCI. Specifically, trace elements might indirectly affect cognitive function through physiological and biochemical indices, which interact with each other.