Particulate Matter and Cognitive Function / 신경정신의학

The term “particulate Matter (PM)” refers to the mixture of small-sized solid particles and liquid droplets floating in the air, and is referred to as PM₁₀ ( < 10 µm), PM(2.5) ( < 2.5 µm) and PM(1.0). Much PM is an anthropogenic substance generated by transportation or industrial activities, which is transformed into a second toxic substance by chemical reactions in the atmosphere. PM reaches the brain directly through olfactory transport, or through the blood-brain barrier during systemic circulation. PM that enters the local cerebral circulation causes neuroinflammation through microglial cells and endotoxins. According to previous studies, greater PM exposure results in lower brain volume, especially white matter. Among neurodevelopmental disorders, the correlation between the occurrence of autism spectrum disorder and exposure to PM is widely known. Other studies have found that exposure to PM was associated with low cognitive function and increased rate of cognitive aging. PM can also cause pathology of early Alzheimer's disease and increases the risk of Alzheimer's dementia and mild cognitive impairment.

Relationship between Body Composition and Cognitive Function : Using Bioelectrical Impedance Analysis

OBJECTIVE: Body composition is measured using bioelectrical impedance analysis (BIA), and correlation between the result of BIA and cognitive function is analyzed. METHODS: A total of 118 elderly (46 male, 72 female) were recruited. They were divided into three groups; normal (n=33), mild cognitive impairment (n=42), and Alzheimer's dementia (n=43) according to the diagnostic criteria. Skeletal muscle mass, body fat mass, and fat-free mass were measured using a BIA device, and were converted to the ratio of body weight. All participants underwent Korean version of Mini-Mental State Examination (MMSE-K). RESULTS: In pearson correlation analysis, skeletal muscle percentage (SMP) and fat-free mass percentage (FFMP) were positively correlated with MMSE-K score (r=0.309, p=0.001; r=0.245, p=0.008), and body fat percentage was negatively correlated (r=−0.258, p=0.005). In multiple regression analysis, SMP (β=2.012, t=4.457, p < 0.001) and FFMP (β=−1.733, t=−3.838, p < 0.001) were selected as the best predictors of changes in MMSE-K score (R2=0.198). CONCLUSION: Reduced skeletal muscle and increased body fat correlate with decreased cognitive function, suggesting the need for prevention of frailty and early diagnosis of cognitive impairment.