title: Subclinical albuminuria is linked to gray matter atrophy in type 2 diabetes mellitus.
abstract: OBJECTIVE
  Microalbuminuria (MA), a marker of renal microvascular disease, is associated with brain atrophy and neurovascular changes in older adults with type 2 diabetes mellitus (DM). We evaluated the relationship between urine albumin-to-creatinine ratio (UACR) and regional brain volumes to determine whether subclinical albuminuria may indicate early structural brain changes in type 2 DM.
  
  
  METHODS
  We studied UACR and brain volumes in 85 type 2 DM patients (64.8±8.3years) and 40 age-matched controls using 3D magnetization prepared rapid acquisition with gradient echo (MP-RAGE) MRI (magnetic resonance imaging) at 3 Tesla. The relationship between UACR and brain volumes was analyzed using the least square models.
  
  
  RESULTS
  In DM patients, UACR ≥5mg/g, UACR ≥10mg/g and clinically significant MA (UACR ≥17mg/g [males] and 25mg/g [females]) were associated with lower gray matter (GM) volume in the frontal lobe (r(2)adj=0.2-0.4, P=0.01-0.05) and UACR ≥5mg/g was also related to global GM atrophy (r(2)adj=0.1, P=0.04), independent of DM duration, glucose levels, HbA1c and hypertension. For UACR ≥5mg/g, a lower global GM volume was related to worse executive function (P=0.04) in the DM group. No associations were found for UACR (<5mg/g) and controls.
  
  
  CONCLUSIONS
  Subclinical albuminuria (UACR ≥5mg/g) is associated with lower GM volume that has clinical impact on cognitive function in older diabetic patients, and these relationships are independent of DM control and hypertension. Therefore, UACR levels may serve as an additional marker of DM-related brain structural changes.
authors.affiliation: Division of Gerontology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 117, Boston, MA 02215, USA.
authors.forename: Disha
authors.initials: D
authors.lastname: Mehta
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 127, Boston, MA 02215, USA.
authors.forename: Daniela A
authors.initials: DA
authors.lastname: Pimentel
authors.affiliation: Centro de Investigaciones Biomédicas y Clínicas (CINBIOCLI), Hospital José María Cabral y Báez, Av. 27 de Febrero, Santiago, Dominican Republic.
authors.forename: Maria-Zunilda
authors.initials: MZ
authors.lastname: Núñez
authors.affiliation: Department of Radiology, Ohio State University, 395W. 12th Avenue, Columbus, OH, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Abduljalil
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 127, Boston, MA 02215, USA.
authors.forename: Vera
authors.initials: V
authors.lastname: Novak
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000150:complications*; D016022:Case-Control Studies; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
keywords: Brain atrophy; Diabetes complications; Microalbuminuria; Microvascular disease