title: A prospective analysis of elevated fasting glucose levels and cognitive function in older people: results from PROSPER and the Rotterdam Study.
abstract: OBJECTIVE
  To investigate the relationship between fasting glucose levels, insulin resistance, and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated fasting glucose levels and insulin resistance in nondiabetic individuals, and the risk of cognitive impairment is unclear.
  
  
  METHODS
  We analyzed data from, in total, 8,447 participants in two independent prospective studies: the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5,019 participants, aged 69-84 years, and the Rotterdam Study, 3,428 participants, aged 61-97 years. Fasting glucose levels were assessed at baseline in both studies; fasting insulin levels were assessed in the Rotterdam Study only. Cognitive function was assessed in both studies at baseline and during follow-up.
  
  
  RESULTS
  Subjects with diabetes had impaired cognitive function at baseline. In contrast, in people without a history of diabetes, there was no clear association between baseline fasting glucose levels and executive function and memory, nor was there a consistent relationship between elevated baseline fasting glucose levels and the rate of cognitive decline in either cohort. Insulin resistance (homeostasis model assessment index) was also unrelated to cognitive function and decline.
  
  
  CONCLUSIONS
  Elevated fasting glucose levels and insulin resistance are not associated with worse cognitive function in older people without a history of diabetes. These data suggest either that there is a threshold for effects of dysglycemia on cognitive function or that factors other than hyperglycemia contribute to cognitive impairment in individuals with frank diabetes.
authors.affiliation: Department of Epidemiology, Erasmus MC, Rotterdam, the Netherlands.
authors.forename: Sjoerd M
authors.initials: SM
authors.lastname: Euser
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.forename: Jacqueline C M
authors.initials: JC
authors.lastname: Witteman
authors.forename: Eduard L E M
authors.initials: EL
authors.lastname: Bollen
authors.forename: Eric J G
authors.initials: EJ
authors.lastname: Sijbrands
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.forename: Ivan J
authors.initials: IJ
authors.lastname: Perry
authors.forename: Monique M B
authors.initials: MM
authors.lastname: Breteler
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis; D003071:Cognition / Q000502:physiology*; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment
chemical_list: D001786:Blood Glucose
references.citation: Diabetes Care. 2000 Jan;23(1):57-63
references.pmid: 10857969
references.citation: J Psychiatr Res. 1975 Nov;12(3):189-98
references.pmid: 1202204
references.citation: Lancet. 2008 Jun 7;371(9628):1927-35
references.pmid: 18501419
references.citation: Am J Cardiol. 1999 Nov 15;84(10):1192-7
references.pmid: 10569329
references.citation: Arterioscler Thromb Vasc Biol. 2000 Oct;20(10):2255-60
references.pmid: 11031212
references.citation: Neurology. 2006 Sep 12;67(5):843-7
references.pmid: 16966548
references.citation: Lancet. 2002 Nov 23;360(9346):1623-30
references.pmid: 12457784
references.citation: Diabetes Care. 2003 Jan;26 Suppl 1:S5-20
references.pmid: 12502614
references.citation: Diabetes Care. 2009 Feb;32(2):221-6
references.pmid: 19171735
references.citation: Neurology. 1994 Apr;44(4):609-14
references.pmid: 8164812
references.citation: Diabetes Care. 2001 Feb;24(2):366-70
references.pmid: 11213894
references.citation: JAMA. 2004 Nov 10;292(18):2237-42
references.pmid: 15536110
references.citation: Neuroepidemiology. 2008;30(3):174-9
references.pmid: 18421217
references.citation: J Am Geriatr Soc. 2004 Oct;52(10):1713-8
references.pmid: 15450050
references.citation: Curr Alzheimer Res. 2007 Apr;4(2):147-52
references.pmid: 17430239
references.citation: Eur J Epidemiol. 2009;24(9):553-72
references.pmid: 19728115
references.citation: Diabetes Care. 1999 Dec;22(12):1988-92
references.pmid: 10587831
references.citation: Arch Intern Med. 2004 Jun 28;164(12):1327-33
references.pmid: 15226167
references.citation: Diabet Med. 2007 Jul;24(7):788-91
references.pmid: 17403114
references.citation: Neurobiol Aging. 2005 Dec;26 Suppl 1:65-9
references.pmid: 16266773
references.citation: Lancet Neurol. 2006 Jan;5(1):64-74
references.pmid: 16361024
references.citation: J Neural Transm (Vienna). 1998;105(4-5):439-61
references.pmid: 9720973
references.citation: Neurology. 1999 Dec 10;53(9):1937-42
references.pmid: 10599761
references.citation: J Neurol Neurosurg Psychiatry. 2002 Oct;73(4):385-9
references.pmid: 12235304
references.citation: J Clin Psychol. 1976 Jul;32(3):654-8
references.pmid: 956433
references.citation: Diabetes Care. 2005 Jan;28 Suppl 1:S37-42
references.pmid: 15618111
references.citation: Diabetologia. 1985 Jul;28(7):412-9
references.pmid: 3899825