Aim:
To investigate the association of serum homocysteine levels with cognitive function in elderly patients with chronic kidney disease (CKD).

Methods:
A case-control study on 200 elderlies >60 years who were distributed into two groups: group 1 (cases): 100 patients with CKD and group 2 (controls): 100 subjects who do not have CKD. All subjects undergo comprehensive geriatric assessment, cognitive assessment, and biochemical investigations including serum homocysteine.

Results:
The odds ratio of having impaired clinical dementia rating scores is 3.1 for CKD cases compared to controls. CKD patients have almost 3 times the risk of having cognitive impairment [OR=3.1; 95% CI (1.6-6.0)]. The mean serum homocysteine (18.2 μmol/L) among CKD showed a highly statistically significance compared to controls (10.1 μmol/L). Performance of multiple cognitive domains was reduced in association with elevated homocysteine levels. By using linear regression model for the factors independently related to cognitive performance among studied CKD cases, it was found that diabetes mellitus, educational level, age, and serum homocysteine level were strongly associated with consortium to establish a registry for Alzheimer’s disease neuropsychological battery total scores. Respecting the percentage variance explained by each significant variable (R2), serum homocysteine level is an independent significant variable predictor with the total scores.

Conclusion:
The main features of cognitive impairment in CKD patients are executive dysfunction and memory impairment. Poor cognitive function in CKD patients was related with a higher homocysteine level independently.