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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #231908
Title: Albuminuria, Cognitive Functioning and White Matter Hyperintensities in Homebound Elders

Author
item WEINER, DANIEL - TUFTS MEDICAL CENTER
item BARTOLOMEI, KEITH - TUFTS MEDICAL CENTER
item PRICE, LORI LYN - TUFTS MEDICAL CENTER
item SCOTT, TAMMY - TUFTS MEDICAL CENTER
item GRIFFITH, JOHN - TUFTS MEDICAL CENTER
item Rosenberg, Irwin
item LEVEY, ANDREW - TUFTS MEDICAL CENTER
item FOLSTEIN, MARSHAL - TUFTS MEDICAL CENTER
item SARNAK, MARK - TUFTS MEDICAL CENTER

Submitted to: American Journal of Kidney Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2008
Publication Date: 3/1/2009
Citation: Weiner, D., Bartolomei, K., Price, L., Scott, T., Griffith, J., Rosenberg, I., Levey, A., Folstein, M., Sarnak, M. 2009. Albuminuria, Cognitive Functioning and White Matter Hyperintensities in Homebound Elders. American Journal of Kidney Diseases. 53(3):438-447.

Interpretive Summary: Cognitive impairment is common in individuals with end stage renal disease, likely reflecting small vessel cerebrovascular disease. There is little data about cognitive functioning in earlier stages of chronic kidney disease. Albuminuria, a marker of microvascular disease of the kidney, may herald microvascular disease elsewhere in the body, including in the brain. Homebound elderly participants in the Nutrition and Memory in the Elderly Study who consented to brain magnetic resonance imaging were studied. Of 335 participants, mean age was 73.4 +/- 8.1 years, 74% were women and 31% had diabetes; 123 participants had levels of albumin in the urine consistent with micro- or macroalbuminuria while the remaining 212 participants had minimal albumin in the urine. Each doubling of the amount of albumin in urine was associated with poorer performance on a battery of tests designed to assess executive functioning (the ability to perform complex mental tasks like following an insulin regimen for diabetes that changes depending on what an individual eats) but was not associated with worse performance on memory tests. The presence of albuminuria is significantly associated with worse cognitive performance, particularly in executive functioning. Albuminuria likely indicates brain microvascular disease burden.

Technical Abstract: Background: Albuminuria, a kidney marker of microvascular disease, may herald microvascular disease elsewhere, including in the brain. Study Design: Cross sectional. Setting and Participants: Boston, MA (USA) elders receiving home health services to maintain independent living who consented to brain magnetic resonance imaging. Predictor: Urine albumin to creatinine ratio (ACR). Outcome: Performance on a cognitive battery assessing executive function and memory using principal components analysis and white matter hyperintensity volume on brain imaging, evaluated in logistic and linear regression models. Results: Of 335 participants, mean age was 73.4 +/- 8.1 years; 123 participants had microalbuminuria or macroalbuminuria. Each doubling of ACR was associated with worse executive function [beta=-0.05 (p=0.005) in univariate and beta=-0.07 (p=0.004) in multivariable analyses controlling for age, sex, race, education, diabetes, cardiovascular disease, hypertension, medications, and estimated glomerular filtration rate] but not with worse memory or working memory. Individuals with microalbuminuria or macroalbuminuria were more likely to be in the lower versus the highest tertile of executive functioning [Odds ratio =1.18 (1.06 to 1.32) and 1.19 (1.05 to 1.35) per doubling of ACR in univariate and multivariable analyses, respectively]. Albuminuria was associated with qualitative white matter hyperintensity grade [Odds ratio =1.13 (1.02 to 1.25) and 1.15 (1.02 to 1.29) per doubling of ACR] in univariate and multivariable analyses, and with quantitative white matter hyperintensity volume [beta=0.11 (p=0.007) and beta=0.10 (p=0.01)] in univariate and multivariable analyses of log-transformed data, respectively. Results were similar when excluding individuals with macroalbuminuria. Limitations: Single measurement of ACR, indirect creatinine calibration and reliance on participant recall for elements of medical history. Conclusions: Albuminuria is associated with worse cognitive performance, particularly in executive functioning, as well as increased white matter hyperintensity volume. Albuminuria likely identifies greater brain microvascular disease burden.