Abstract
Background:
Transplant centers hesitate to transplant patients with cognitive impairment. It is unclear if pre-kidney transplant (KT) cognitive screening can predict post-KT cognitive function.
Methods:
We evaluated pre-to post-KT cognitive function with the Montreal Cognitive Assessment (MoCA) in a cohort of 108 patients. We used an adjusted logistic regression model to assess pre- to post-KT changes in cognitive status (continuous variable) and a linear mixed model to assess changes in MoCA scores (categorical variable) pre- to post- KT.
Results:
The average pre- and post-KT MoCA scores were 25.3±3.0 and 26.4±2.8 respectively. Final pre-KT score did not predict post-KT cognitive status (OR = 1.08; 95% CI: 0.92–1.26; p = 0.35). 32% of the patients with a final pre-KT score ≥26 had at least one post-KT score <26. Conversely, 61% of the patients with a final pre-KT score <26 had at least one post KT score ≥26. In the linear mixed model analysis, the final pre-KT score was associated with a small, clinically insignificant (β = 0.34; 95% CI: 0.19–0.49; p < 0.001) effect on the post-KT score.
Conclusion:
A low pre-KT MoCA score is not a strong independent predictor of post-KT cognitive function and should not preclude patients from receiving a KT.
Keywords: End stage kidney disease, kidney transplantation, cognition, MoCA, transplant eligibility
Introduction:
Cognitive impairment is common in patients with end stage kidney disease (ESKD).1–3 Cognitive impairment affects kidney transplant (KT) eligibility4 and can be a barrier to KT due to concern for persistent cognitive impairment. The high prevalence of cognitive impairment in ESKD and in KT recipients3 has raised concerns about persistent cognitive impairment after KT particularly in those patients with pre-KT cognitive impairment. Post-KT cognitive impairment, in the absence of good social support, can affect a patients’ ability to comprehend and comply with post-KT care and adherence to treatment.5 However, cognitive function and associated structural brain changes seen in ESKD improve with KT.6,7 Thus, it remains unclear whether pre-KT cognitive impairment can predict post-KT cognitive status and if pre-KT cognitive impairment should preclude KT eligibility for fear of adverse outcomes post-KT due to persistent cognitive impairment.
Since a full neuropsychological assessment in all KT candidates is burdensome and expensive, screening cognitive tests that can be performed in the transplant clinic by staff have often been recommended to screen for cognitive impairment, but their utility in predicting post-KT cognitive function is unclear. We used one such test, the Montreal Cognitive Assessment (MoCA)8 at our center during patients’ regular visits to the transplant clinic. The tests were performed by trained medical assistants and the transplant team was blinded to the MoCA results; MoCA scores were not used for medical decision making. Using these pragmatically collected MoCA scores, we examined if pre-KT cognitive impairment predicts post-KT cognitive function.
Materials and Methods:
Study Design:
We conducted a single-center longitudinal cohort study. We used MoCA to assess cognitive function in a longitudinal cohort of patients during their routine pre- KT or post-KT clinic visits at a large academic transplant center. Compared to other commonly used screening tests for assessing cognitive impairment (the Modified Mini Mental State Examination, the Trail Making Test Part B, the Mini-Cog test, and the Digit Symbol Substitution Test), MoCA is the best-performing screening test in ESKD.9 Clinic staff administered the MoCA after thorough training. In accordance with the pragmatic nature of the study, all consecutive patients were assessed, unless there was an obvious contraindication such as inability to participate due to vision, speech, or hearing impairment.
The study was declared a quality improvement project and was Institutional Review Board exempt. Informed consent was therefore not obtained. Data were collected on paper case report forms and then entered into electronic case report forms using REDCap (Research Electronic Data Capture), a web-based, electronic data capture tool hosted on a secure, password protected HIPAA-compliant server.10
Study Population:
Adult patients with ESKD seen in the transplant clinic between May 2015 and December 2019 were screened for cognitive impairment using the MoCA. Patients were not given the MoCA assessment if they had (i) hearing or visual impairment; (ii) if they were unable to read, write, speak, or understand English (as MoCA was only administered in English); (iii) if they had a diagnosis of dementia or mental retardation; iv) if they had stoke, concussion, or traumatic brain injury within two months of evaluation or (iv) if they had uncontrolled psychosis or active seizure disorder. As part of standard of care, all patients were maintained on a mycophenolic acid and a calcineurin inhibitor with or without prednisone. To minimize the impact of high dose steroids, anesthesia, or operative procedures on cognitive function, the post-KT MoCA assessments were performed at least one month after a KT.
Baseline demographics, medical history, and laboratory data were obtained from the patients’ electronic medical records. Education was assessed as years of education. Coronary artery disease was defined as having a history of coronary angioplasty, endarterectomy, or stenting. Cause of ESKD was classified as diabetes, glomerulonephritis, hypertension, polycystic kidney disease, other (includes interstitial nephritis, drug toxicity, nephrectomy, congenital abnormalities, and reflux disease), and unknown.
MoCA assessments:
We assessed cognitive function using MoCA.8 MoCA scores range from 0–30 (maximum score of 30), with higher scores indicating better cognitive function. The test samples from seven domains of cognition (visuospatial/executive, naming, memory (delayed recall), attention, language, abstraction, and orientation) and takes less than 10 min to complete. We used the original English version 7.1 (http://www.mocatest.org/papertests/moca-test-full/). Based on the original validation study on MoCA, we used a cut off score of ≥26 to describe normal cognition.8 As recommended, MoCA scores were adjusted for education with allocation of one additional point for ≤12 years of education.
MoCA assessments were performed during the patients’ clinic visit. MoCA was administered in a private room to minimize distraction and assure confidentiality. The test was administered by the transplant clinic medical assistants who underwent training that included a detailed review of online instructions on the MoCA and practice sessions on mock patients. The transplant team and the transplant selection committee were blinded to the MoCA scores.
Statistical analysis
Patients with only pre-KT or only post-KT evaluations were excluded from the analysis. Descriptive statistics were generated to compare the baseline characteristics of all patients with pre-KT cognitive impairment (final pre-KT MoCA score <26) and without cognitive impairment (final pre-KT MoCA score ≥26). Variables were described with mean ± standard deviation for continuous variables and frequencies for categorical variables. Total MoCA scores and scores in different domains were also compared. Unadjusted one-way ANOVA was used to determine differences in continuous variables between groups and a Chi-square test was used to determine group differences in frequencies for categorical variables.
We analyzed pre- to post-KT changes in MoCA scores. We used a logistic regression model with the final pre-KT MoCA score (last MoCA score available prior to KT) as a covariate adjusted for age, diabetes, race, years of education, and time on dialysis. To model the longitudinal changes in pre- to post-KT MoCA scores we used a linear mixed model and included all post-KT MoCA scores as the response variable and the final pre-KT score as the covariate of interest. We adjusted for age, race, diabetes, years of education and time since pre-KT score.
We performed a subgroup analysis on patients with final pre-KT MoCA score of ≤24 since these patients are most likely to be declared ineligible for KT if eligibility was based solely on pre-KT cognitive function. We constructed scatter plots of each participant’s MoCA scores over time to visualize the trajectory of MoCA scores pre- to post-KT.
Results
After excluding patients without a pre-KT or a post-KT assessments and those with graft failure at the time of post-KT assessments (n=7), 108 patients were included in the analysis (Supplementary Figure 1). Patients were 47±13.7 years old, 54% men, and 79.6% white (Table 1); 34 had cognitive impairment (final pre-KT score of <26). Patients with pre-KT cognitive impairment were older, less educated, and with a history of smoking and atrial fibrillation. There was no difference in race, cause of ESKD, dialysis vintage, history of diabetes, coronary artery disease, or living donor KT. While the total MoCA score and domain scores on naming and memory were lower for patients with pre-KT cognitive impairment, there was no difference in scores on executive function, attention, language, abstraction, and orientation between the two groups.
Table 1:
Comparison of demographics and clinical characteristics of all 108 patients with pre- and post-kidney transplant MoCA scores.
| All patients (N=108) |
Cognitive impairment pre-KT (N= 34) |
No cognitive impairment pre-KT (N= 74) |
P value | |
|---|---|---|---|---|
| Age (years) | 47.4 ± 13.7 | 53.8 ± 12.2 | 44.4 ± 13.4 | <0.001 |
| Sex (male) | 58 (53.7) | 21 (61.8) | 37 (50.0) | 0.30 |
| Level of Education | 0.04 | |||
| Did not complete high school | 10 (9.3) | 7 (20.6) | 3 (4.1) | |
| Completed high school, no college | 22 (20.4) | 9 (26.5) | 13 (17.6) | |
| Some college | 35 (32.4) | 8 (23.5) | 21 (28.4) | |
| Completed 4-year college degree | 29 (26.9) | 8 (23.5) | 21(28.4) | |
| Attended graduate school | 12 (11.1) | 2(5.9) | 10 (13.5) | |
| Race | 0.10 | |||
| White | 86 (79.6) | 23 (67.6) | 63 (85.1) | |
| African American | 15 (13.9) | 7 (20.6) | 3 (4.1) | |
| Other | 7 (6.5) | 4 (11.8) | 3 (4.1) | |
| BMI (kg/m2) | 29.3 ± 4.7 | 29.3 ± 4.4 | 29.3 ± 4.9 | 0.97 |
| Systolic BP (mmHg) | 132.0 ± 18.8 | 131.0 ± 20.0 | 132.0 ± 18.4 | 0.78 |
| Diastolic BP (mmHg) | 74.4 ± 12.9 | 72.5 ± 12.7 | 75.3 ± 13.0 | 0.30 |
| Primary cause of ESKD | 0.18 | |||
| Diabetes | 18 (16.7) | 4 (11.8) | 14 (18.9) | |
| Glomerulonephritis | 10 (9.3) | 6 (17.6) | 4 (5.4) | |
| Hypertension | 26 (24.1) | 10 (29.4) | 16 (21.6) | |
| Other | 33 (30.6) | 7 (20.6) | 26 (35.1) | |
| PKD | 17 (15.7) | 5 (14.7) | 12(16.2) | |
| Unknown | 4 (3.7) | 2 (5.9) | 2 (2.7) | |
| Pre-emptive KT | 73 (67.6) | 22 (64.7) | 51 (68.9) | 0.31 |
| Dialysis vintage (years) | 1.8 ± 2.6 | 1.6 ± 3.0 | 1.9 ± 2.5 | 0.64 |
| h/o CAD | 10 (9.3) | 5 (14.7) | 5 (6.8) | 0.28 |
| H/o CABG | 4 (3.7) | 2 (5.9) | 2 (2.7) | 0.59 |
| H/o atrial fibrillation | 3 (2.8) | 3 (8.8) | 0 | 0.02 |
| H/o diabetes | 23 (21.3) | 7 (20.6) | 16 (21.6) | 0.99 |
| H/o hypertension | 91 (84.3) | 29 (85.3) | 62 (83.8) | 0.99 |
| H/o dyslipidemia | 54 (50.0) | 19 (55.9) | 35 (47.3) | 0.53 |
| H/o seizures | 4 (3.7) | 1 (2.9) | 3 (4.1) | 0.99 |
| H/o transient ischemic attack | 6 (5.6) | 4 (11.8) | 2 (2.7) | 0.07 |
| H/o smoking | 29 (26.9) | 14 (41.2) | 15 (20.3) | 0.03 |
| Living donor transplants | 36(33.3) | 11 (32.4) | 25 (33.58) | 0.99 |
| Final pre-KT MoCA scores | ||||
| Total score | 25.4 ± 3.0 | 24.4 ± 3.1 | 25.9 ± 2.9 | 0.02 |
| Visuospatial/executive score | 4.2 ± 1.0 | 4.2 ± 1.0 | 4.3 ± 1.0 | 0.55 |
| Naming score | 2.9 ± 0.3 | 2.8 ± 0.5 | 3.0 ± 0.2 | 0.004 |
| Delayed recall/memory score | 2.9 ± 1.8 | 2.2 ± 1.9 | 3.3 ± 1.7 | 0.003 |
| Attention score | 5.1 ± 1.2 | 4.8 ± 1.3 | 5.2 ± 1.1 | 0.09 |
| Language score | 2.3 ± 0.8 | 2.2 ± 0.9 | 2.4 ± 0.8 | 0.73 |
| Abstraction score | 1.7 ± 0.6 | 1.7 ± 0.6 | 1.7 ± 0.6 | 0.79 |
| Orientation score | 5.9 ± 0.4 | 6.0 ± 0.0 | 5.9 ± 0.5 | 0.34 |
MoCA; Montreal cognitive assessment. BMI; body mass index, BP; blood pressure, ESKD; end stage kidney disease; KT; kidney transplant, h/o; history of, CAD; coronary artery disease, CABG; coronary artery bypass grafting. The “other” causes of ESKD include interstitial nephritis, drug toxicity (including lithium toxicity), nephrectomy, congenital abnormalities, and reflux disease. CAD included history of angioplasty, endarterectomy, or coronary stenting.
Continuous variables are presented as mean ± standard deviation, and categorical variables are presented as number, percentage.
The average pre-KT MoCA score was 25.3±3.0 and the average post-KT score was 26.4±2.8. Mean change in MoCA scores (final post-KT – final pre-KT) was 0.9±3.0. Mean follow up time was 1.8±1.0 year; mean time between the first MoCA assessment and KT was 0.8±0.6 years and that between KT and the final MoCA assessment was 0.9±0.9 years. The mean number of post-KT MoCA assessments per patient was 1.4±0.5; most patients had a single post-KT score (n=66), some had 2 post-KT scores (n=41), and one patient had 3 post-KT scores. Although the mean MoCA score increased post-KT, 32.2% (n=19) of the patients with a final pre-score ≥26 had at least one post score <26. Conversely, 61.2% (n=30) of the patients with a final pre-KT score <26 had at least one post KT score ≥26. The trajectory of pre-to post-KT MoCA scores in all 108 patients are shown in Figure 1a.
Figure 1:
Pre- to post-kidney transplant Montreal cognitive assessment (MoCA) scores for a) all 108 participants and b) patients with final pre-transplant MoCA score of ≤24.
Older age, non-white race, and lower education were associated with post-KT cognitive impairment in the logistic regression analysis (Table 2). There was no association between the pre-KT MOCA score and post-KT cognitive status (OR = 1.08; 95% CI: 0.92–1.26; p = 0.34). In our sensitivity analysis using the linear mixed model, older age and lower education were associated with a lower post-KT score. There was a clinically insignificant association with the final pre-KT score; a ~3-point higher final pre-KT score resulted in a 1- point higher post-KT score (β =0.31; 95% CI: 0.19–0.49; p <0.001) (Table 3).
Table 2:
Logistic regression analysis predicting post-transplant cognitive impairment adjusted for age, diabetes, race, years of education, time on dialysis and final pre-transplant MoCA score.
| Variable | Coefficient | Standard Error | p-value |
|---|---|---|---|
| Age | −0.0645 | 0.0208 | 0.002 |
| Race (Ref: White) | −1.0862 | 0.6233 | 0.08 |
| Years of Education | 0.2601 | 0.1117 | 0.02 |
| Diabetes (Ref: no diabetes) | 1.1560 | 0.6400 | 0.07 |
| Dialysis vintage | 0.0003 | 0.0003 | 0.29 |
| Final pre-KT score | 0.0744 | 0.0797 | 0.35 |
KT; kidney transplant
Table 3:
Linear mixed model analysis predicting post-transplant MoCA score adjusted for age, diabetes, race, years of education, time on dialysis and final pre-transplant MoCA score.
| Variable | Coefficient | Standard Error | p-value |
|---|---|---|---|
| Age | −0.0043 | 0.0017 | 0.01 |
| Race (Ref: White) | 0.6970 | 0.5830 | 0.23 |
| Years of Education | 0.2701 | 0.0993 | 0.01 |
| Diabetes (Ref: no diabetes) | −0.2580 | 0.566 | 0.65 |
| Dialysis vintage | −0.2000 | 0.0002 | 0.93 |
| Final pre-KT score | 0.3115 | 0.0075 | <0.001 |
| Time between final pre-KT and first post-KT assessment | −0.0010 | 0.0005 | 0.02 |
KT; kidney transplant
In the subgroup analysis of patients with a final pre-KT score of ≤24 (n=34) (Supplementary Table 1), the average pre-KT MoCA score was 21.8±2.19 and the average post-KT score was 24.6±2.63. The mean change in MoCA scores (final post-KT – final pre-KT) was 2.57±2.68, higher than that in the entire cohort, indicating that the change in MoCA score in the entire cohort was limited by the ceiling effect of the test. Most patients had improvement in at least one post-KT score; 19 (56%) had at least one post-KT score ≥26 and 22 (65%) had at least one post-KT score of >24 (Figure 1b).
Discussion
We assessed pre- to post-KT cognitive function using MoCA, a practical screening tool easily available to trained transplant clinic staff. MoCA scores improved pre-KT to post-KT. Pre-KT cognitive status did not predict post-KT cognitive status. After KT, cognitive status changed in both directions; most patients with pre-KT cognitive impairment had no cognitive impairment post-KT while some with no cognitive impairment pre-KT had cognitive impairment post-KT. While pre-KT scores predicted post-KT scores in the linear mixed model analysis, the effect size was small and clinically insignificant. For two individuals who are otherwise similar but have a difference of 3 points in their pre-KT MoCA scores, the post-KT score will only differ by 1 point. In a sub-group analysis of patients with pre-KT score of ≤24, 65% had improvement in post-KT MoCA scores to >24. These patients who would be at the highest risk for being deemed ineligible for KT if MoCA scores were used to determine transplant eligibility. However, most had an improvement in MoCA scores post-KT.
Pre-KT cognitive impairment was not predictive of post-KT cognitive impairment. Cognitive impairment in ESKD is complex and multifactorial. Emerging data indicates that mild-moderately low estimated glomerular filtration rate, especially in older patients may not contribute to cognitive impairment or structural brain changes.11–14 In addition, ESKD associated cognitive impairment, alterations in cerebral blood flow, white matter integrity, and brain metabolites normalize with KT.6,7. Given these improvements, pre-KT cognitive impairment may not be predictive of post-KT cognitive status. Cognitive function in KT recipients is also dependent on transplant associated factors such as immunosuppression and perioperative factors such as delirium, post-KT recovery, and infectious complications,15 independent of pre-KT cognitive status. Age is a known risk factor for cognitive impairment and dementia in the general population as well as in KT recipients.3 In our analysis, older age remained predictive of post-KT cognitive status.
Cognitive impairment in KT recipients can affect adherence to medical treatment. Our results show that pre-KT cognitive function does not predict post-KT cognitive function in patients who have been through the KT evaluation process and waitlisted for KT. It is possible that patients with cognitive impairment due to disease processes such as stroke or Alzheimer’s dementia were determined ineligible for KT and thus not included in this analysis. Indeed, pre-KT cognitive status affects transplant eligibility even if transplant selection committee is blinded to the results of cognitive assessment.4 Age, diabetes, and vascular disease are strongly associated with cognitive impairment; it is possible that patients with severe cognitive impairment were not selected for KT due to other confounding medical issues. Screening of patients for cognitive impairment after they have passed the rigorous selection process may not provide additional benefit.
A prior study associated pre-KT cognitive impairment with increased graft loss.16 However, baseline differences in the groups with and without cognitive impairment and presence of confounding variables, such as older recipient and donor age, lower education, history of diabetes, higher Estimated Post Transplant Survival score, and lower serum albumin in the patients with cognitive impairment preclude firm conclusions. We have previously demonstrated that multiple co-morbidities seen in patients with ESKD can confound assessment of cognitive function.17 Thus the higher graft failure rate in patients with cognitive impairment may be attributable to these confounding variables. Indeed, living donor recipients with severe cognitive impairment had a lower hazard ratio of graft loss when compared with those with any degree of cognitive impairment, questioning a causal association.16
Our study also highlights some unintended consequences of using pre-KT cognitive function for KT eligibility. Patients with a MoCA score ≤26 were older and more likely to be Black. Using pre-KT MoCA scores for determining KT eligibility can increase disparities in access to KT for these vulnerable populations.
Our study is innovative and pragmatic. MoCA was administered by trained clinic staff during patient’s clinic visits. This study depicted the real-world application of MoCA; all pre-KT patients were included if they could perform a MoCA which mimics the general transplant clinic population.
Our study has limitations. Due to small numbers, we could have missed a small effect. However, a small effect may be clinically irrelevant in making decisions about transplant eligibility. We assessed cognition with a screening test. The performance of MoCA has been evaluated in research settings in ESKD 18 and of the commonly used screening tests, MoCA has the best performance in ESKD.9 Despite this, like most good screening tests, the MoCA can have high false positive results. Using a full neuropsychological work up may be more predictive of post-KT outcomes but this will need additional resources in an already busy transplant clinic. Also, since our analysis only included patients who were already selected for KT our data is not generalizable to all ESKD patients.
In conclusion, cognitive function improves post-KT and pre-KT cognitive impairment assessed by a screening test does not predict post-KT cognitive impairment. Transplant eligibility should not be precluded based solely on a low performance on a screening test. In addition to lack of benefit of this strategy, this practice may increase disparities in access to KT for older and underrepresented minorities with a higher prevalence of ESKD but lower access to KT. Post-KT cognitive function is multifactorial. Future research should focus on identifying risk factors for persistent cognitive impairment post-KT to prevent adverse transplant outcomes.
Supplementary Material
Acknowledgements:
We would like to thank our medical assistants who trained in MoCA and administered the test to the patients. We would also like to thank our patients who took the test.
Funding:
NIH K23-AG055666 (funded to AG)
List of abbreviations:
- KT
kidney transplantation
- MoCA
Montreal Cognitive Assessment
- ESKD
end stage kidney disease
- REDCap
Research Electronic Data Capture
Footnotes
Conflict of Interest Statement: none declared
References:
- 1.Murray AM, Tupper DE, Knopman DS, et al. Cognitive impairment in hemodialysis patients is common. Neurology 2006;67(2):216–223. doi: 10.1212/01.wnl.0000225182.15532.40 [DOI] [PubMed] [Google Scholar]
- 2.Drew DA, Weiner DE, Tighiouart H, et al. Cognitive Decline and Its Risk Factors in Prevalent Hemodialysis Patients. American journal of kidney diseases : the official journal of the National Kidney Foundation Jun 2017;69(6):780–787. doi: 10.1053/j.ajkd.2016.11.015 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Gupta A, Mahnken JD, Johnson DK, et al. Prevalence and correlates of cognitive impairment in kidney transplant recipients. BMC Nephrol May 12 2017;18(1):158. doi: 10.1186/s12882-017-0570-1 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Gupta A, Montgomery RN, Bedros V, et al. Subclinical Cognitive Impairment and Listing for Kidney Transplantation. Clin J Am Soc Nephrol Apr 5 2019;14(4):567–575. doi: 10.2215/cjn.11010918 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Butler JA, Roderick P, Mullee M, Mason JC, Peveler RC. Frequency and impact of nonadherence to immunosuppressants after renal transplantation: a systematic review. Transplantation Mar 15 2004;77(5):769–76. [DOI] [PubMed] [Google Scholar]
- 6.Lepping RJ, Montgomery RN, Sharma P, et al. Normalization of Cerebral Blood Flow, Neurochemicals, and White Matter Integrity after Kidney Transplantation. Journal of the American Society of Nephrology 2021;32(1):177. doi: 10.1681/ASN.2020050584 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Gupta A, Lepping RJ, Yu AS, et al. Cognitive Function and White Matter Changes Associated with Renal Transplantation. Am J Nephrol 2016;43(1):50–7. doi: 10.1159/000444334 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Nasreddine ZS, Phillips NA, Bédirian V, et al. The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. Journal of the American Geriatrics Society Apr 2005;53(4):695–9. doi: 10.1111/j.1532-5415.2005.53221.x [DOI] [PubMed] [Google Scholar]
- 9.Drew DA, Tighiouart H, Rollins J, et al. Evaluation of Screening Tests for Cognitive Impairment in Patients Receiving Maintenance Hemodialysis. Journal of the American Society of Nephrology 2020;31(4):855. doi: 10.1681/ASN.2019100988 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap)--a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform Apr 2009;42(2):377–81. doi: 10.1016/j.jbi.2008.08.010 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Grasing M, Kenned K, Sarnak MJ, Burns JM, Gupta A. Mild to moderate decrease in eGFR and cognitive decline in older adults. Nephrol Dial Transplant Jul 20 2021;doi: 10.1093/ndt/gfab226 [DOI] [PMC free article] [PubMed]
- 12.Gupta A, Burns JM. A Single Point-in-Time eGFR Is Not Associated with Increased Risk of Dementia in the Elderly. J Am Soc Nephrol Dec 2020;31(12):2965. doi: 10.1681/asn.2020081119 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Gupta A, Kennedy K, Perales-Puchalt J, et al. Mild-moderate CKD is not associated with cognitive impairment in older adults in the Alzheimer’s Disease Neuroimaging Initiative cohort. PLoS One 2020;15(10):e0239871. doi: 10.1371/journal.pone.0239871 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Grasing M, Sharma P, Lepping RJ, et al. Association between the Estimated Glomerular Filtration Rate and Brain Atrophy in Older Adults. American Journal of Nephrology 2022;doi: 10.1159/000521892 [DOI] [PMC free article] [PubMed]
- 15.Jurgensen A, Qannus AA, Gupta A. Cognitive Function in Kidney Transplantation. Curr Transplant Rep Sep 2020;7:145–153. doi: 10.1007/s40472-020-00284-0 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Thomas AG, Ruck JM, Shaffer AA, et al. Kidney Transplant Outcomes in Recipients With Cognitive Impairment: A National Registry and Prospective Cohort Study. Transplantation Jul 2019;103(7):1504–1513. doi: 10.1097/tp.0000000000002431 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Gupta A, Burns JM. A Single Point-in-Time eGFR Is Not Associated with Increased Risk of Dementia in the Elderly. Journal of the American Society of Nephrology 2020;31(12):2965–2965. doi: 10.1681/asn.2020081119 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Tiffin-Richards FE, Costa AS, Holschbach B, et al. The Montreal Cognitive Assessment (MoCA) - a sensitive screening instrument for detecting cognitive impairment in chronic hemodialysis patients. PloS one 2014;9(10):e106700. doi: 10.1371/journal.pone.0106700 [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.