Progression of cognitive dysfunction in elderly chronic kidney disease patients in a veteran's institution in central Taiwan: a 3-year longitudinal study

A strong positive correlation between estimated glomerular filtration rate (eGFR) multiplied by follow-up time and memory function has been demonstrated previously. The purpose of this study was to investigate the factors affecting progression of cognitive dysfunction in the elderly with different levels of kidney function.

In April 2002, a prospective study on progression of cognitive function was conducted on 356 elderly people. All participants received a comprehensive geriatric assessment, serum biochemical test, homeostasis model assessment (HOMA), and a genetic polymorphism study, including polymorphism of apolipoprotein E (APOE), Cystatin, C-reactive protein (CRP) and tumor necrosis factor (TNF). Lean body mass-adjusted eGFR was used to evaluate severity of chronic kidney disease (CKD), and a clinical dementia rating scale was used to assess cognitive dysfunction. Patients were stratified according to eGFR (≥49 mL/min and <49 mL/min).

Using multivariate logistic regression models, older age (OR=1.27, 95% CI=1.00-1.61) was associated with a high risk for progression of cognitive function in patients with a relatively low eGFR. In patients with lower eGFR, higher mini-mental state examination (MMSE) scores (OR=0.23, 95% CI=0.10-0.54) were correlated with a low risk for progression of cognition, while in patients with higher eGFR, higher MMSE scores (OR=0.39, 95% CI=0.23-0.65) were less correlated with cognitive dysfunction. However, elevated serum plasminogen activator inhibitor-1 (PA1-1) was associated with a high risk for cognitive dysfunction (OR=1.06, 95% CI=1.01-1.11) in patients with a better eGFR.

Age, MMSE score and serum PAI-1 were found to be factors that predicted cognitive dysfunction at different functional levels of CKD.