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Published on: October 2, 2020
Assessment of cognitive impairment and related risk factors in hemodialysis patients
Hristos Karakizlis1,2, Katharina Bohl3, Jannis Ziemek4
1Department of Nephrology, Philipps-University of Marburg, Marburg, Germany. hristos.karakizlis@innere.med.uni-giessen.de.
Insights
Cognitive impairment is highly prevalent in hemodialysis patients, affecting most domains and linked to depression. Early depression identification is crucial for potentially improving cognitive function in these patients.
Area of Science:
- Nephrology
- Neuropsychology
- Geriatrics
Background:
- Cognitive impairment is common in hemodialysis patients, with up to 80% affected.
- Common contributing factors include older age, cardiovascular risks (stroke, TIA), uremia, and metabolic disturbances.
Purpose of the Study:
- To assess the cognitive profile and prevalence of cognitive impairment in hemodialysis patients.
- To analyze changes in cognitive performance over a one-year period.
- To identify factors associated with cognitive impairment in this population.
Main Methods:
- Prospective cohort study involving 408 hemodialysis patients across 10 centers.
- Neuropsychological testing battery including five tests and a phonemic fluency test.
- Classification of cognitive function into no, mild, moderate, or severe impairment based on test results.
Main Results:
- Only 25% of patients had no cognitive impairment; 75% exhibited mild, moderate, or severe impairment.
- All cognitive domains were affected in impaired patients, with immediate memory recall being the most affected.
- Cognitive impairment was significantly associated with depression and lower education levels. No significant change in cognitive performance was observed after one year.
Conclusions:
- The high prevalence of cognitive impairment in hemodialysis patients underscores the need for attention.
- Depression and education significantly influence cognitive test results and overall cognitive function.
- Early identification and treatment of depression are essential to potentially improve cognitive performance in hemodialysis patients.
Background:
Cognitive impairment in hemodialysis patients has been acknowledged over the last years and has been reported in up to 80% of patients. Older age, high prevalence of cardiovascular risk factors, such as stroke and transient ischemic attack, uremia, and multiple metabolic disturbances represent the most common factors for cognitive impairment in hemodialysis patients.
Methods:
We conducted a prospective cohort study on 408 patients from 10 hemodialysis centers in the regional government district of Middle Hesse (Germany). Patients underwent a neuropsychological test battery consisting of five tests, in addition to a phonemic fluency test, to assess cognitive profile. The patients were classified as no cognitive impairment or mildly-, moderately- or severely-impaired cognitive function, depending on the degree of impairment and number of domains where the deficit was determined. We analyzed the cognitive profile and the change in performance over time in hemodialysis patients based on their cognitive status at baseline vs. 1-year follow-up.
Results:
Of 479 eligible patients, 408 completed all tests at baseline. Only 25% (n = 102) of the patients had no cognitive impairment. Fourteen per cent (n = 57), 36.5% (n = 149), and 24.5% (n = 100) of patients showed mild, moderate, and severe impairment, respectively. In patients with cognitive impairment, all cognitive domains were affected, and impairment was significantly associated with depression and education. The most impaired cognitive performance was immediate memory recall, and the best performance was found in naming ability. No significant change was observed after 1-year follow up in any domain.
Conclusion:
Our study shows that the prevalence of cognitive impairment in hemodialysis patients is high and that it is affected by the presence of depression. Furthermore, education has an effect on cognitive test results. As depression has a significant influence on cognitive impairment, its early identification is essential in order to initiate treatment at an early stage, hoping to positively influence cognitive performance.
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