title: Association of N-terminal pro-brain natriuretic peptide with cognitive function and depression in elderly people with type 2 diabetes.
abstract: BACKGROUND
  Type 2 diabetes mellitus is associated with risk of congestive heart failure (CHF), cognitive dysfunction and depression. CHF itself is linked both to poor cognition and depression. The ventricular N-terminal pro-brain natriuretic peptide (NT-proBNP) is a marker of CHF, suggesting potential as a marker for cognitive impairment and/or depression. This was tested in the Edinburgh Type 2 Diabetes Study (ET2DS).
  
  
  RESULTS
  Cross-sectional analysis of 1066 men and women aged 60-75 with type 2 diabetes. Results from seven neuropsychological tests were combined in a standardised general cognitive ability factor, 'g'. A vocabulary-based test estimated pre-morbid cognitive ability. The Hospital Anxiety and Depression Scale (HADS) assessed possible depression. After adjustment for age and sex, raised plasma NT-proBNP was weakly associated with lower 'g' and higher depression scores (ß -0.09, 95% CI -0.13 to -0.03, p = 0.004 and ß 0.08, 95% CI 0.04 to 0.12, p<0.001, respectively). Comparing extreme quintiles of NT-proBNP, subjects in the highest quintile were more likely to have reduced cognitive ability (within the lowest tertile of 'g') and 'possible' depression (HADS depression ≥8) (OR 1.80; 95% CI: 1.20, 2.70; p = 0.005 and OR 2.18; 95% CI: 1.28, 3.71; p = 0.004, respectively). Associations persisted when pre-morbid ability was adjusted for, but as expected were no longer statistically significant following the adjustment for diabetes-related and vascular co-variates (β -0.02, 95% CI -0.07 to 0.03, p>0.05 for 'g'; β 0.03, 95% CI -0.02 to 0.07, p>0.05 for depression scores).
  
  
  CONCLUSIONS
  Raised plasma NT-proBNP was weakly but statistically significantly associated with poorer cognitive function and depression. The prospective phases of the ET2DS will help determine whether or not NT-proBNP can be considered a risk marker for subsequent cognitive impairment and incident depression and whether it provides additional information over and above traditional risk factors for these conditions.
authors.affiliation: German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Duesseldorf, Germany. I.Feinkohl@sms.ed.ac.uk
authors.forename: Insa
authors.initials: I
authors.lastname: Feinkohl
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: Paul
authors.initials: P
authors.lastname: Welsh
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Reynolds
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Mark W J
authors.initials: MW
authors.lastname: Strachan
authors.forename: Jackie F
authors.initials: JF
authors.lastname: Price
mesh_terms: D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000150:complications / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000097:blood*
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002784:Cholesterol