Patients with chronic kidney disease are at an elevated risk of dementia: a population-based cohort study in Taiwan.

BACKGROUND

Chronic kidney disease (CKD) is more prevalent in Taiwan than in most countries. This population-based cohort study evaluated the dementia risk associated with CKD.

METHODS

Using claims data of 1,000,000 insured residents covered in the universal health insurance of Taiwan, we selected 37049 adults with CKD newly diagnosed from 2000-2006 as the CKD cohort. We also randomly selected 74098 persons free from CKD and other kidney diseases, frequency matched with age, sex and the date of CKD diagnosed. Incidence and hazard ratios (HRs) of dementia were evaluated by the end of 2009.

RESULTS

Subjects in the CKD cohort were more prevalent with comorbidities than those in the non-CKD cohort (p <0.0001). The dementia incidence was higher in the CKD cohort than in the non-CKD cohort (9.30 vs. 5.55 per 1,000 person-years), with an overall HR of 1.41 (95% confidence interval (CI), 1.32-1.50), controlling for sex, age, comorbidities and medicaitions. The risk was similar in men and women but increased sharply with age to an HR of 133 (95% CI, 68.9-256) for the elderly. However, the age-specific CKD cohort to non-CKD cohort incidence rate ratio decreased with age, with the highest ratio of 16.0 (95% CI, 2.00-128) in the youngest group. Among comorbidities and medications, alcoholism and taking benzodiazepines were also associated with dementia with elevated adjusted HRs of 3.05 (95% CI 2.17-4.28) and 1.23 (95% CI 1.14-1.32), respectively.

CONCLUSIONS

Patients with CKD could have an elevated dementia risk. CKD patients with comorbidity deserve attention to prevent dementia.