Associations of Early Kidney Disease With Brain Magnetic Resonance Imaging and Cognitive Function in African Americans With Type 2 Diabetes Mellitus

Am J Kidney Dis. 2017 Nov;70(5):627-637. doi: 10.1053/j.ajkd.2017.05.006. Epub 2017 Jun 23.

Abstract

Background: Relationships between early kidney disease, neurocognitive function, and brain anatomy are poorly defined in African Americans with type 2 diabetes mellitus (T2DM).

Study design: Cross-sectional associations were assessed between cerebral anatomy and cognitive performance with estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio (UACR) in African Americans with T2DM.

Setting & participants: African Americans with cognitive testing and cerebral magnetic resonance imaging (MRI) in the African American-Diabetes Heart Study Memory in Diabetes (AA-DHS MIND; n=512; 480 with MRI) and Action to Control Cardiovascular Risk in Diabetes (ACCORD) MIND (n=484; 104 with MRI) studies.

Predictors: eGFR (CKD-EPI creatinine equation), spot UACR.

Measurements: MRI-based cerebral white matter volume (WMV), gray matter volume (GMV), and white matter lesion volume; cognitive performance (Mini-Mental State Examination, Digit Symbol Coding, Stroop Test, and Rey Auditory Verbal Learning Test). Multivariable models adjusted for age, sex, body mass index, scanner, intracranial volume, education, diabetes duration, hemoglobin A1c concentration, low-density lipoprotein cholesterol concentration, smoking, hypertension, and cardiovascular disease were used to test for associations between kidney phenotypes and the brain in each study; a meta-analysis was performed.

Results: Mean participant age was 60.1±7.9 (SD) years; diabetes duration, 12.1±7.7 years; hemoglobin A1c concentration, 8.3%±1.7%; eGFR, 88.7±21.6mL/min/1.73m2; and UACR, 119.2±336.4mg/g. In the fully adjusted meta-analysis, higher GMV associated with lower UACR (P<0.05), with a trend toward association with higher eGFR. Higher white matter lesion volume was associated with higher UACR (P<0.05) and lower eGFR (P<0.001). WMV was not associated with either kidney parameter. Higher UACR was associated with lower Digit Symbol Coding performance (P<0.001) and a trend toward association with higher Stroop interference; eGFR was not associated with cognitive tests.

Limitations: Cross-sectional; single UACR measurement.

Conclusions: In African Americans with T2DM, mildly high UACR and mildly low eGFR were associated with smaller GMV and increased white matter lesion volume. UACR was associated with poorer processing speed and working memory.

Keywords: African American; albuminuria; brain; chronic kidney disease (CKD); cognitive performance; estimated glomerular filtration rate (eGFR); magnetic resonance imaging (MRI); neurocognitive function; type 2 diabetes mellitus (T2DM); urine albumin-creatinine ratio (UACR).

MeSH terms

  • African Americans / psychology
  • African Americans / statistics & numerical data*
  • Aged
  • Albuminuria
  • Brain / diagnostic imaging*
  • Brain / pathology
  • Cardiovascular Diseases / epidemiology
  • Cholesterol, LDL / metabolism
  • Cognition*
  • Cognitive Dysfunction / epidemiology*
  • Cognitive Dysfunction / psychology
  • Creatinine / urine
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / psychology
  • Female
  • Glomerular Filtration Rate
  • Glycated Hemoglobin A / metabolism
  • Gray Matter / diagnostic imaging
  • Gray Matter / pathology
  • Humans
  • Hypertension / epidemiology
  • Linear Models
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Neuropsychological Tests
  • Organ Size
  • Renal Insufficiency, Chronic / epidemiology*
  • Renal Insufficiency, Chronic / metabolism
  • Smoking / epidemiology
  • United States / epidemiology
  • White Matter / diagnostic imaging
  • White Matter / pathology

Substances

  • Cholesterol, LDL
  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human
  • Creatinine