Inflammation and Cognition in Older Adults: Evidence from Taiwan

Inflammation has been linked to clinical cognitive impairment, including Alzheimer's disease. Less is known, however, about the relationship between inflammation and normal, age-associated cognitive decline. An understanding of the determinants of all types of cognitive decline is important for improving quality of life in an aging world. This study investigated whether biomarkers of inflammation were associated with cognitive function and decline in older Taiwanese adults. Data were from the Taiwan Longitudinal Study of Aging and the Social Environment and Biomarkers of Aging Study. Inflammation was measured in 2000 and 2006 as C-reactive protein, interleukin-6, soluble e-selectin, soluble intercellular adhesion molecule-1, and white blood cell count. Cognition was assessed by 10 cognitive and memory tasks, measured in 2006, 2007, and 2011. Growth curve models were used to examine the relationship between inflammation and cognitive score over this time period. Higher levels of inflammation were associated with lower baseline cognitive scores, but not with longitudinal change in cognitive score. This study did not support a causal link between inflammation and cognitive decline among this older cohort. The observed cross-sectional relationship could reflect a causal relationship that arises earlier in life, or confounding; additional research across the life course is warranted.