Kidney disease linked to modest risk of dementia

Patients with kidney disease appear to have a slightly elevated risk of dementia, which is driven by vascular dementia, a study suggests.

Using data from the nationwide historical registry of Denmark, the study included 82,690 patients with kidney disease and 413,405 matched individuals from the general population without kidney disease (controls).

The median age of the entire cohort was 69 years, with women comprising 41 percent. More patients in the kidney disease cohort than the control cohort had diagnoses of cardiovascular disease (CVD) and CVD risk factors. Patients with kidney disease were also more likely to have lower income, higher unemployment rate, and lower education.

During the study period, 466,071 (94 percent) deaths were recorded, of which 78,555 were in the kidney disease cohort and 387,516 in the control cohort (95 percent vs 94 percent). The 5- and 10-year mortality rates were twice as high among patients with kidney disease than the general population.

The 5-year risk for all-cause dementia was 2.90 percent in the kidney disease cohort as opposed to 2.98 percent in the control cohort. Multivariable Cox analysis showed that kidney disease was associated with a 6-percent risk increase over the 5-year follow-up (hazard ratio [HR], 1.06, 95 percent confidence interval [CI], 1.00–1.12) and an 8-percent risk increase during the entire study period (HR, 1.08, 95 percent CI, 1.03–1.12).

There were substantial differences noted for the risk estimates of dementia subtypes associated with kidney disease, with lower Alzheimer’s disease and higher vascular dementia risk.