title: Diabetic retinopathy and cognitive decline in older people with type 2 diabetes: the Edinburgh Type 2 Diabetes Study.
abstract: OBJECTIVE
  Cerebral microvascular disease associated with type 2 diabetes may exacerbate the effects of aging on cognitive function. A considerable homology exists between the retinal and cerebral microcirculations; a hypothesized association between diabetic retinopathy (DR) and cognitive decline was examined in older people with type 2 diabetes.
  
  
  METHODS
  In the population-based Edinburgh Type 2 Diabetes Study, 1,046 men and women aged 60-75 years with type 2 diabetes underwent standard seven-field binocular digital retinal photography and a battery of seven cognitive function tests. A general cognitive ability score (g) was generated by principal components analysis. The Mill-Hill Vocabulary Scale was used to estimate premorbid cognitive ability. DR was graded using a modification of the Early Treatment of Diabetic Retinopathy Scale.
  
  
  RESULTS
  After age and sex adjustment, a significant relationship was observed with increasing severity of DR (none, mild, and moderate to severe) for most cognitive measures. Participants with moderate-to-severe retinopathy had the worst g and the worst performances on the individual tests. There was a significant interaction between sex and retinopathy for g. In male subjects, the associations of retinopathy with g (and with tests of verbal fluency, mental flexibility, and processing speed but not memory and nonverbal reasoning) persisted (P < 0.05) when further adjusted for vocabulary (to estimate lifetime cognitive decline), depression, sociodemographic characteristics, cardiovascular risk factors, and macrovascular disease.
  
  
  CONCLUSIONS
  DR was independently associated with estimated lifetime cognitive decline in older men with type 2 diabetes, supporting the hypothesis that cerebral microvascular disease may contribute to their observed accelerated age-related cognitive decline. A sex interaction with stronger findings in men requires further confirmation.
authors.affiliation: Centre for Population Health Sciences, University of Edinburgh,Edinburgh, UK. j.ding-2@sms.ed.ac.uk
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.forename: Mark W J
authors.initials: MW
authors.lastname: Strachan
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Reynolds
authors.forename: Brian M
authors.initials: BM
authors.lastname: Frier
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: F Gerald R
authors.initials: FG
authors.lastname: Fowkes
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Lee
authors.forename: Janet
authors.initials: J
authors.lastname: McKnight
authors.forename: Patricia
authors.initials: P
authors.lastname: Halpin
authors.forename: Ken
authors.initials: K
authors.lastname: Swa
authors.forename: Jackie F
authors.initials: JF
authors.lastname: Price
mesh_terms: D000368:Aged; D002560:Cerebrovascular Circulation; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000188:drug therapy / Q000523:psychology*; D003925:Diabetic Angiopathies / Q000453:epidemiology; D003930:Diabetic Retinopathy / Q000209:etiology*; D004522:Educational Status; D005260:Female; D006306:Health Surveys; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008568:Memory; D008875:Middle Aged; D012606:Scotland; D012727:Sex Characteristics; D015348:Vision, Binocular; D014792:Visual Acuity
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin
references.citation: Neuroepidemiology. 2006;26(2):83-92
references.pmid: 16352911
references.citation: J Clin Epidemiol. 1992 Oct;45(10):1101-9
references.pmid: 1474406
references.citation: J Psychosom Res. 2003 Feb;54(2):129-39
references.pmid: 12573734
references.citation: Neurobiol Aging. 2009 Mar;30(3):337-52
references.pmid: 17869382
references.citation: Prog Retin Eye Res. 2008 Mar;27(2):161-76
references.pmid: 18249026
references.citation: Age Ageing. 2007 Mar;36(2):164-70
references.pmid: 17350976
references.citation: Ophthalmology. 1991 May;98(5 Suppl):823-33
references.pmid: 2062515
references.citation: Br J Ophthalmol. 2008 Aug;92(8):1017-25
references.pmid: 18614569
references.citation: Stroke. 2006 Jan;37(1):82-6
references.pmid: 16306463
references.citation: N Engl J Med. 2003 Mar 27;348(13):1215-22
references.pmid: 12660385
references.citation: Diabetes. 2006 Apr;55(4):1106-13
references.pmid: 16567535
references.citation: Diabetologia. 2007 Nov;50(11):2388-97
references.pmid: 17764005
references.citation: Alcohol Res Health. 2003;27(1):18-29
references.pmid: 15301397
references.citation: JAMA. 2002 Jul 3;288(1):67-74
references.pmid: 12090864
references.citation: Ophthalmology. 1991 May;98(5 Suppl):786-806
references.pmid: 2062513
references.citation: J Psychiatr Res. 1975 Nov;12(3):189-98
references.pmid: 1202204
references.citation: Stroke. 2005 Oct;36(10):2116-20
references.pmid: 16141425
references.citation: Neurology. 2009 Sep 15;73(11):862-8
references.pmid: 19752453
references.citation: Lancet Neurol. 2006 Jan;5(1):64-74
references.pmid: 16361024
references.citation: Neurology. 2002 Nov 26;59(10):1536-40
references.pmid: 12451193
references.citation: Acta Psychiatr Scand. 1983 Jun;67(6):361-70
references.pmid: 6880820
references.citation: Nature. 2002 Aug 29;418(6901):932
references.pmid: 12198535
references.citation: Diabetologia. 2005 Dec;48(12):2460-9
references.pmid: 16283246
references.citation: Ann N Y Acad Sci. 2002 Nov;977:9-23
references.pmid: 12480729
references.citation: J Anat. 2005 Apr;206(4):319-48
references.pmid: 15817102
references.citation: Stroke. 2002 Jun;33(6):1487-92
references.pmid: 12052979
references.citation: Diabetes. 2010 Mar;59(3):710-3
references.pmid: 19959761
references.citation: J Am Geriatr Soc. 2009 Oct;57(10):1892-6
references.pmid: 19737331
references.citation: Psychol Med. 2001 Apr;31(3):451-8
references.pmid: 11305853
references.citation: Diabetes. 2003 Jan;52(1):149-56
references.pmid: 12502506
references.citation: Br J Prev Soc Med. 1977 Mar;31(1):42-8
references.pmid: 856370
references.citation: J Neurol Neurosurg Psychiatry. 2003 Jan;74(1):70-6
references.pmid: 12486269
references.citation: Brain. 2005 Sep;128(Pt 9):2034-41
references.pmid: 15947059
references.citation: Intelligence. 2004 Nov;32(6):
references.pmid: 24357886
references.citation: Neurobiol Aging. 2008 Jul;29(7):1022-6
references.pmid: 17434648
references.citation: BMC Endocr Disord. 2008 Dec 11;8:18
references.pmid: 19077235
references.citation: Stroke. 2007 Jul;38(7):2041-7
references.pmid: 17525385