Inflammatory Biomarkers and Cognitive Decline: The Ginkgo Evaluation of Memory Study

OBJECTIVES: To examine the association between inflammatory biomarkers and global cognitive function. DESIGN: Case-cohort. SETTING: Ginkgo Evaluation of Memory Study. PARTICIPANTS: Individuals aged 75 and older free of neurological or neurodegenerative conditions recruited from 2000 to 2002 (N = 1,315). MEASUREMENTS: Outcome was cognitive function assessed using the modified Mini-Mental State Examination (3MSE) every 6 months for up to 7 years. Exposures were 10 biomarkers measured at baseline: interleukin-2, -6, and -10 (general systemic inflammation); pentraxin 3 (PTX3) and serum amyloid P (SAP) (vascular inflammation); plasminogen activator inhibitor-1, adiponectin, and resistin (metabolic function); receptor for advanced glycation endproduct (oxidative stress); and endothelin-1 (endothelial function). Associations between biomarkers and 3MSE scores (stratified according to mild cognitive impairment (MCI) at baseline) were analyzed using Cox regression (outcome: 3MSE decline of >= 5 points) and mixed-model regression. Bonferroni correction was used to determine significance threshold (P<.0025). RESULTS: In individuals with baseline MCI, PTX3 was associated with a 20% greater hazard of cognitive decline (95% confidence interval = 1.07-1.35), although this association was no longer statistically significant after adjustment for apolipoprotein (APO)E epsilon 4 allele. Adiponectin was associated with faster rate of 3MSE decline in individuals without baseline MCI in mixed-model regression, but the association was similarly attenuated after adjustment for APOE-epsilon 4. CONCLUSION: This study did not find strong evidence of the utility of the biomarkers evaluated for identifying individuals at risk of cognitive decline. Future studies investigating the association between PTX3, SAP, and adiponectin and 3MSE scores may be useful.