Relationship between diabetic retinopathy and cognitive impairment in patients with type 2 diabetes mellitus

Zherdiova N.N., Cand. Sc. (Med.)

Medvedovskaya N.V., Dr. Sc. (Med.)

Mankovsky B.N., NAMS corr.-member, Prof., Dr. Sc. (Med.)

Shupik National Medical Academy of Postgraduate Education

Kyiv, Ukraine

E-mail: zherdeva@bk.ru

 

Background. Retinal microcirculation disorders can be diagnosed at the early stage of complication development while cerebral circulation disorders and cognitive impairment are diagnosed at a rather late stage, when structural changes develop in the brain of the patients. Most authors have investigated the cognitive function by studying memory, information and operation processing speed not taking into consideration the sensitivity of tests in this group of patients.  The relationship between diabetic retinopathy and cognitive impairments has not investigated.

The purpose of the present study was to investigate the state of cognitive function in type 2 diabetes patients with diabetic retinopathy and to determine the most sensitive cognitive tests.

Material and Methods. The study included 93 patients with type 2 diabetes, aged 50 to 80. The patients were divided into two groups: DR-group and non-DR group. Cognitive function was studied using tests as follow: a “five words” test, Mini-mental State Examination (MMSE); Frontal Assessment Battery (FAB), a clock drawing test, a “fifteen words” test, the Brixton test, the Trail making test (TMT), Digit span forward and backforward (DSFB), the Verbal fluency test, the Тest symbol and the Stroop color test.

Results. The TMT test showed significantly better performance in regard of working memory, memory flexibility, and executive functions in the group of patients without DR as compared to those with retinopathy. Statistically significant impairment of the executive function in patients with DR was confirmed by the Brixton test in comparison with that parameter in non-DR-group. According to the TMT and the Brixton test, patients without DR had better performance of working memory and memory flexibility as well as executive functioning compared to DR patients, which indicates lesions of frontal and prefrontal areas of the brain in those patients with DR. The Brixton test seems to be more sensitive and easy to use for screening the cognitive impairments in patients with diabetes mellitus and DR.

Key words: diabetes mellitus, mild cognitive impairment, dementia, diabetic retinopathy               

 

References

1.   Rury R Holman, Sanjoy K Paul, M Angelyn Bethel, David R Matthews and H. Andrew W Neil. 10-Year Follow-up of Intensive Glucose Control in Type 2 Diabetes. Engl J Med 2008; 359:1577-89
Crossref   Pubmed

2.   Cukierman-Yaffe T, Gerstein HC, Williamson JD, Lazar RM, Lovato L, Miller ME, Coker LH, Murray A, Sullivan MD, Marcovina SM, Launer L J. Relationship between baseline glycemic control and cognitive function in individuals with type 2 diabetes and other cardiovascular risk factors: the action to control cardiovascular risk indiabetes-memory in diabetes (ACCORD-MIND) trial. Diabetes Care. 2009;Feb32(2):221-6.
Crossref   Pubmed

3.   Ryan CM, Geckle MO, Orchard TJ. Cognitive efficiency declines over time in adults with type 1 diabetes: effects of micro- and macrovascular complications. Diabetologia 2003;46:940–8
Crossref   Pubmed

4.   Crosby-Nwaobi RR, Sivaprasad S, Amiel S. The relationship between diabetic retinopathy and cognitive impairment. Diabetes Care. 2013;36:3177–3186
Crossref   Pubmed

5.   Nguyen TT, Wang JJ, Sharrett AR et al. Relationship of retinal vascular caliber with diabetes and retinopathy: the MultiEthnic Study of Atherosclerosis (MESA). Diabetes Care. 2008;31:544–9.
Crossref   Pubmed

6.   Roberts RO, Geda YE, Knopman DS et al. Association of duration and severity of diabetes mellitus with mild cognitive impairment. Arch Neurol. 2008;65:1066– 73.
Crossref   Pubmed

7.   Ding J, Patton N, Deary IJ et al. Retinal microvascular abnormalities and cognitive dysfunction: a systematic review. Br J Ophthalmol. 2008;92:1017–25.
Crossref   Pubmed

8.   Crosby-Nwaobi R, Sivaprasad S, Forbes A. A systematic review of the association of diabetic retinopathy and cognitive impairment in people with type 2 diabetes. Diabetes Res Clin Pract. 2012;96:101–10.
Crossref   Pubmed

9.   Jie Ding, Mark WJ Strachan, Rebecca M Reynolds, Brian M Frier et al.  Diabetic Retinopathy and Cognitive Decline in Older People With Type 2 Diabete. The Edinburgh Type 2 Diabetes Study. Diabetes. 2010;Nov 59(11): 2883-9.

10. Strauss E, Sherman EM, Spreen O. A Compendium of Neuropsychological Test: Administration, Norms and Commentary. Oxford: Oxford University Press. Retrieved 14 July 2013. 1240 p.
Crossref   Pubmed

11.Gaudino EA, Geisler MW, Squires NK. Construct validity in the Trail Making Test: What makes Part B harder?  J Cli  n Exp Neuropsychol.1995;17 (4):529-35.
Crossref   Pubmed

12.Reitan RM. The relationship of the Trail Making Test to organic brain damage. Journal of Consulting Psychology.1955;19:393-4.
Crossref   Pubmed

13.S?nchez-Cubillo, Peri??ez JA, Adrover-Roig D, Rodr?guez-S?nchez JM, R?os-Lago M, Tirapu J, Barcel? F. Construct validity of the Trail Making Test: role of task-switching, working memory, inhibition/interference control and visuo-motor abilities Journal of International Neuropsychological Society. J Int Neuropsychol Soc. 2009;May 15(3):438-50.

14.Allison AM Bielak, Laura Mansueti, Esther Strauss, Roger A. Dixon. Performance on the Hayling and Brixton tests in older adults: Norms and correlates. Archives of Clinical Neuropsychology. 2006;21:141–9.
Crossref   Pubmed