title: Effect of renal impairment on cognitive function during a 3-year follow up in elderly patients with type 2 diabetes: Association with microinflammation.
abstract: OBJECTIVE
  We investigated the effect of renal impairment on cognitive function during a 3-year follow up in elderly type 2 diabetic patients, and an association with microinflammation.
  
  
  METHODS
  Four cognitive function tests - Mini-Mental State Examination (MMSE), word recall, Digit Symbol Substitution (DSS) and Stroop Color Word - were carried out in 67 patients. Renal impairment was defined as the presence of albuminuria and a decline in estimated glomerular filtration (eGFR) <60 mL/min/1.73 m(2). Inflammatory markers, such as highly sensitive C-reactive protein (hs-CRP), tumor necrotizing factor-α (TNF-α), interleukin (IL)-1β and IL-6, were measured at baseline.
  
  
  RESULTS
  At baseline, cognitive decline was found in patients with renal impairment. The DSS test was independently associated with eGFR decline, whereas MMSE tended to be associated with albuminuria after adjusting for confounding factors. Regarding changes in cognitive function and renal impairment, changes in urinary albumin to creatinine ratios were strongly and independently associated with changes in word recall scores. In patients with persistent eGFR decline, there was a tendency toward a greater decrease in MMSE and DSS scores, whereas in those with newly detected albuminuria, there was a tendency toward a greater decrease in word recall scores. Increased baseline levels of hs-CRP, TNF-α and IL-6 were associated with renal impairment and cognitive function, especially DSS tests, respectively. However, the increased levels were not independent predictors for cognitive decline.
  
  
  CONCLUSIONS
  The present study showed a reciprocal relationship between cognitive decline and renal impairment, especially progression of albuminuria. Thus, monitoring treatment using renal biomarkers will be important for preserving both renal and cognitive function.
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan ; Center for Preventive Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Kawamura
authors.affiliation: Department of Neurology Chubu Rosai Hospital Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Umemura
authors.affiliation: Department of Geriatrics Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Umegaki
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Rui
authors.initials: R
authors.lastname: Imamine
authors.affiliation: Department of Geriatrics Nagoya University Graduate School of Medicine Nagoya Japan ; Department of Psychiatry Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Kawano
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Chiai
authors.initials: C
authors.lastname: Tanaka
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Kawai
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Minatoguchi
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Kusama
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kouchi
authors.affiliation: Diabetic Center Aichi Medical University Nagakute Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Watarai
authors.affiliation: Center for Preventive Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kanai
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Eitaro
authors.initials: E
authors.lastname: Nakashima
authors.affiliation: Department of Diabetes and Endocrine Internal Medicine Nagoya University Graduate School of Medicine Nagoya Japan.
authors.forename: Nigishi
authors.initials: N
authors.lastname: Hotta
keywords: Cognitive impairment; Microinflammation; Renal impairment