Aim: The association between cognitive function and clinical parameters of chronic kidney disease (CKD) was investigated in Japanese patients without overt dementia in a cross-sectional study.
Materials and methods: A population of 497 patients whose cognitive function had been examined using the mini-mental state examination (MMSE) were screened for this study. After the exclusion of 306 subjects who showed overt dementia, the association between the MMSE score and clinical characteristics was investigated in 191 subjects (male: 55%, age: 69 ± 12 years).
Results: The mean MMSE score of the study subjects was 26.7 ± 2.0. The MMSE score was negatively correlated with the patients' age and positively with the estimated glomerular filtration rate. It was significantly associated with age and proteinuria based on a multivariate analysis. The scores of "temporal orientation", "attention and calculation", and "remote memory" subitems of MMSE were significantly lower in the subjects ≥ 70 years of age than in those < 70 years of age. The scores of "temporal orientation" (4.3 ± 0.8 vs. 4.7 ± 0.6), "attention and calculation" (2.9 ± 1.6 vs. 3.9 ± 1.5), and "stage command" (2.7 ± 0.5 vs. 2.9 ± 0.3) were significantly lower in the subjects with proteinuria than in those without.
Conclusion: Cognitive function was disturbed even in CKD patients without overt dementia. Intervention in patients with risk factors is deemed important for preventing future reductions in cognitive and renal functions in CKD patients without dementia. .