The following is a summary of “Acute Kidney Injury and Its Association With Dementia and Specific Dementia Types: Findings From a Population-Based Study in Sweden,” published in the August 2024 issue of Neurology by Xu et al.

Dementia is a gradual decline in cognition and functioning abilities that interferes with daily activities. Some biochemical and pathological changes in the brain that occurred due to Acute Kidney Injury (AKI) have been reported in some pre-clinical studies. 

Researchers conducted a retrospective study to evaluate the linkage between AKI and subsequent risks of developing dementia.

They conducted a study on individuals aged 65 years and older in Stockholm from 2006 to 2019 who were free from dementia diagnosis and had data on kidney function. The exposure was an episode of AKI (time-varying), ascertained by issued clinical diagnoses and creatinine elevations according to Global Outcomes criteria. The outcome was all-cause dementia and specific types of dementia, ascertained by clinically confirmed cases in the Swedish registry of cognitive/dementia disorders, the presence of 2 issued dementia diagnoses in outpatient care, or the initiation of specific anti-dementia medications. The associations with dementia through Cox proportional hazard regression by AKI, severity levels of AKI, AKI recurrence, and setting (community-acquired or hospital-acquired AKI) were also investigated. 

The results included 305,122 individuals with a median age of 75 ± 8 years (56.6% women). In a median follow-up of 12.3 (interquartile range 8.7–13.3) years, there were 79,888 individuals (26%) suffering from at least 1 episode of AKI and 47,938 incident cases (16%) of dementia. The rate of dementia cases was 37.0 per 1,000 person-years (95% CI 36.2 – 37.8) after developing AKI, which was approximately 2 times higher than the rate observed during the periods before AKI (17.3, 95% CI 17.2 – 17.5). After multivariable adjustment, developing AKI was associated with a 49% higher rate of subsequent dementia (adjusted hazard ratio hazard ratio [HR] 1.49, 95% CI 1.45–1.53). This pattern was consistent across dementia types, with HRs of 1.88 (95% CI 1.53–2.32), 1.47 (1.38–1.56), and 1.31 (1.25–1.38) for dementia with Lewy bodies and Parkinson’s disease with dementia, vascular dementia, and Alzheimer dementia, respectively. Risk associations were more robust in magnitude across more severe AKIs and in hospital-acquired vs community-acquired AKIs.

They concluded Individuals with AKI were at increased risk of dementia.

Source: neurology.org/doi/10.1212/WNL.0000000000209751#con1