CKD not independently tied to pre- or post-event dementia in those with TIA, stroke

Researchers observed no independent association between chronic kidney disease and pre- or post-event dementia among patients with transient ischemic attack and stroke, according to results of a population-based cohort study.

“In one previous study, CKD was predictive of all-cause dementia independent of both previous symptomatic cerebrovascular disease and small vessel disease on brain imaging,” Dearbhla M. Kelly, MB, BCh, BAO, MSc, MRCPI, of the Wolfson Center for Prevention of Stroke and Dementia at the University of Oxford in the U.K., and colleagues wrote in Neurology. “We therefore aimed to determine the associations between CKD and all-cause dementia before and after transient ischemic attack (TIA) or stroke, with adjustment for measures of severity of the initial event, vascular risk factors and other determinants of susceptibility in a large, longitudinal population-based study with standardized assessment of dementia to 5-years follow-up.”

The investigators examined data of 2,305 patients with TIA/stroke (median age, 77 years; 49% men; 30% TIA), of whom 1,174 (50.9%) had CKD. They noted an association between CKD with both pre-event (OR = 2.04; 95% CI, 1.52-2.72) and post-event dementia (HR = 2.01; 95% CI, 1.65-2.44); however, adjustment for covariates attenuated these associations. Upon using a competing risk model, the researchers observed similar results. They reported a stronger association between CKD and late (greater than 1 year) post-event dementia, especially following TIA and minor stroke; however, the association was no longer significant after adjustment.

“Dementia is more common in patients with CKD than in the general population but pre-dialysis CKD itself appears not to be independently associated with either pre- or post-stroke dementia, except possibly with late-onset dementia in those with minor stroke events,” Kelly and colleagues wrote. “Patients with CKD appear to have a clustering of risk factors associated with dementia including pre-stroke factors (advanced age, diabetes and atrial fibrillation), stroke factors (greater event severity, dysphasia and disability), and lower brain reserve (low education, pre-morbid dependency and leukoareosis) that likely mediate much of the unadjusted relationship between CKD and dementia.

“Further studies are needed to determine if there are additional unique mechanisms or pathways leading to late-onset dementia in those with CKD and minor stroke events,” they added.