title: Association between urine protein/creatinine ratio and cognitive dysfunction in Lewy body disorders.
abstract: BACKGROUND
  Impaired renal function and proteinuria have been associated with cognitive impairment and dementia. Chronic kidney disease is considered to be an independent risk factor for Lewy body spectrum disorders (LBD). However, few studies have mentioned an association between proteinuria and cognition in LBD. We investigated the relationship between proteinuria and cognitive dysfunction in patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB).
  
  
  METHODS
  Among 186 patients with LBD, 53 had PD-normal cognition (PD-NC), 76 had PD-mild cognitive impairment (PD-MCI), 43 had PD-dementia (PDD) and 14 had DLB. The urine protein/creatinine ratio was calculated using the spot urine test and brain magnetic resonance scans was obtained in all patients.
  
  
  RESULTS
  The urine protein/creatinine ratio was significantly higher in patients with PDD and DLB than in those with PD-MCI, PD-NC patients and healthy controls, and was correlated with white matter hyperintensities on magnetic resonance imaging. All abnormal neuropsychological test results were associated with increased urine protein/creatinine ratio. After controlling for age, education, symptom duration, diabetes mellitus, hypertension, and parkinsonian motor severity, the urine protein/creatinine ratio was significantly associated with decreased cognition.
  
  
  CONCLUSIONS
  The urine protein/creatinine ratio was associated with cognitive status in LBD. These finding suggests that increased protein excretion is associated with cognitive dysfunction in patients with LBD.
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Yoon-Sang
authors.initials: YS
authors.lastname: Oh
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: neuronet@catholic.ac.kr.
authors.forename: Joong-Seok
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Hyung-Eun
authors.initials: HE
authors.lastname: Park
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: In-Uk
authors.initials: IU
authors.lastname: Song
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jeong-Wook
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Dong-Won
authors.initials: DW
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Son
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Si-Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Kwang-Soo
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000652:urine*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012044:Regression Analysis
chemical_list: D003404:Creatinine
keywords: Cognitive dysfunction; Dementia; Lewy body disorders; Proteinuria