Long-term changes in cognitive status of patients with type 2 diabetes mellitus after coronary artery bypass graft surgery

Aim. To study long-term changes (5 to 7 years after coronary artery bypass graft (CABG) surgery) in cognitive status of patients with type 2 diabetes.
Materials and Methods. The study included 47 male patients admitted to the Research Institute for Complex Issues of Cardiovascular Diseases for the CABG surgery. Criteria of inclusion were signed informed consent, age from 40 to 75 years, male gender, planned on-pump CABG surgery, and right-handedness. Criteria of exclusion were brain pathology at multislice computed tomography, chronic cerebral ischemia grade II-IV, Beck Depression Inventory score > 16 points, the Mini-Mental State Examination (MMSE) score < 24 points and the Frontal Assessment Battery score < 11 points, arrhythmia, class IIB-IV chronic heart failure stage IIB, chronic obstructive pulmonary disease, cancer, and past medical history of brain injury or stroke. Pre-operative examination of patients classified them into two groups: with (n = 21) and without (n = 26) type 2 diabetes mellitus (DM).
Results. 5-7 years after CABG surgery, patients with type 2 DM had a cognitive decline according to MMSE scale as compared to the preoperative level (28,0 [27,0; 29,0] and 27,0 [26,0; 28,0], p = 0.04). In keeping with these findings, odds ratio (OR) of mild cognitive impairment (MCI) in patients with type 2 DM was 1.92 (95% CI = 1.09- 3.37, p = 0.02). Psychomotor and executive functions were reduced in patients with type 2 DM both at baseline and in particular 5-7 years after CABG (p ≤ 0.05). The correlation between glycated hemoglobin (HbA1c) and cognitive parameters were found only in patients with type 2 DM. Higher HbA1c level was also associated with deteriorated executive functions and short-term memory.
Conclusion. 5−7 years after CABG surgery, patients with type 2 DM suffer from a cognitive decline and reduced psychomotor and executive functions.

1. Jeong YJ, Ahn JM, Hyun J, Lee J, Kim JH, Yang Y, Choe K, Park H, Kang DY, Lee PH, Kang SJ, Lee SW, Kim YH, Lee CW, Park SW, Park SJ, Park DW. Ten-year Outcomes After Drug-Eluting Stents or Bypass Surgery for Left Main Coronary Disease in Patients With and Without Diabetes Mellitus: The PRECOMBAT Extended Follow-Up Study. J Am Heart Assoc. 2021;10(14):e019834. https://doi.org/10.1161/JAHA.120.019834

2. Feinkohl I, Winterer G, Spies CD, Pischon T. Cognitive Reserve and the Risk of Postoperative Cognitive Dysfunction. Dtsch Arztebl Int. 2017;114(7):110-117. https://doi.org/10.3238/arztebl.2017.0110

3. Tarasova IV, Trubnikova OA, Syrova ID, Akbirov RM, Barbarash OL. Long-term results of the neurophysiological examination of patients with cognitive decline underwent coronary artery bypass surgery. Nevrologicheskii Zhurnal. 2018;23(5):229-240. (In Russ)]. https://doi.org/10.18821/1560-9545-2018-23-5-229-240

4. Relander K, Hietanen M, Rantanen K, Rämö J, Vento A, Saastamoinen KP, Roine RO, Soinne L. Postoperative cognitive change after cardiac surgery predicts long-term cognitive outcome. Brain Behav. 2020;10(9):e01750. https://doi.org/10.1002/brb3.1750

5. Gorelick PB, Counts SE, Nyenhuis D. Vascular cognitive impairment and dementia. Biochim Biophys Acta. 2016;1862(5):860-868. https://doi.org/10.1016/j.bbadis.2015.12.015

6. Ostroumova OD, Surkova EV, Chikh EV, Rebrova EV, Borisov MS. Cognitive impairment in patients with type 2 diabetes mellitus: prevalence, pathogenetic mechanisms, the effect of antidiabetic drugs. Diabetes mellitus. 2018;21(4):307-318. (In Russ.) https://doi.org/10.14341/DM9660

7. Shi J, Dong B, Mao Y, Guan W, Cao J, Zhu R, Wang S. Review: Traumatic brain injury and hyperglycemia, a potentially modifiable risk factor. Oncotarget. 2016;7(43):71052-71061. https://doi.org/10.18632/oncotarget.11958

8. Padovani C, Arruda RMDC, Sampaio LMM. Does type 2 diabetes mellitus increase postoperative complications in patients submitted to cardiovascular surgeries? Braz J Cardiovasc Surg. 2020;35(3):249-253. https://doi.org/10.21470/1678-9741-2019-0027

9. Shimobayashi M, Albert V, Woelnerhanssen B, Frei IC, Weissenberger D, Meyer-Gerspach AC, Clement N, Moes S, Colombi M, Meier JA, Swierczynska MM, Jenö P, Beglinger C, Peterli R, Hall MN. Insulin resistance causes inflammation in adipose tissue. J Clin Invest. 2018;128(4):1538-1550. https://doi.org/10.1172/JCI96139

10. Cai D, Khor S. Hypothalamic microinflammation. Handb Clin Neurol. 2021;181:311-322. https://doi.org/10.1016/B978-0-12-820683-6.00023-3

11. Trubnikova OA, Mamontova AS, Syrova ID, Kukhareva IN, Maleva OV, Barbarash OL. The cognitive status of patients with type 2 diabetes mellitus after coronary bypass surgery. Clinical medicine (Russian Jornal) 2015;93(8):39-44. (In Russ).

12. Kotfis K, Szylińska A, Listewnik M, Brykczyński M, Ely EW, Rotter I. Diabetes and elevated preoperative HbA1c level as risk factors for postoperative delirium after cardiac surgery: an observational cohort study. Neuropsychiatr Dis Treat. 2019;15:511-521. https://doi.org/10.2147/NDT.S196973

13. Trubnikova O, Tarasova I, Kukhareva I, Barbarash O. Long-term postoperative cognitive dysfunction predictors in patients with type 2 diabe-tes after coronary artery bypass grafting. In: Psikhologicheskoe zdorov'e cheloveka: zhiznennyy resurs i zhiznennyy potentsial: materialy V Mezhdunar. nauch.-prakt. konf. Loginovoy IO, edit. Krasnoyarsk: Verso; 2018:176-186. (In Russ).

14. Tarasova IV, Trubnikova OA, Syrova ID, Barbarash OL. Long-term neurophysiological outcomes in patients undergoing coronary artery bypass grafting. Braz J Cardiovasc Surg. 2021;36(5):629-638. (In Russ). https://doi.org/10.21470/1678-9741-2020-0390

15. Florido-Santiago M, Pérez-Belmonte LM, Osuna-Sánchez J, Barbancho MA, Ricci M, Millán-Gómez M, Bernal-López MR, Gómez-Huelgas R, Lara JP. Assessment of long-term cognitive dysfunction in older patients who undergo heart surgery. Neurologia (Engl Ed). 2021:S0213-4853(20)30443-6. https://doi.org/10.1016/j.nrl.2020.12.002

16. Gao S, Chen Y, Sang F, Yang Y, Xia J, Li X, Zhang J, Chen K, Zhang Z. White Matter Microstructural Change Contributes to Worse Cognitive Function in Patients With Type 2 Diabetes. Diabetes. 2019;68(11):2085-2094. https://doi.org/10.2337/db19-0233

17. Huang L, Zhang Q, Tang T, Yang M, Chen C, Tao J, Liang S. Abnormalities of Brain White Matter in Type 2 Diabetes Mellitus: A Meta-Analysis of Diffusion Tensor Imaging. Front Aging Neurosci. 2021;13:693890. https://doi.org/10.3389/fnagi.2021.693890

18. Alotaibi A, Tench C, Stevenson R, Felmban G, Altokhis A, Aldhebaib A, Dineen RA, Constantinescu CS. Investigating Brain Microstructural Alterations in Type 1 and Type 2 Diabetes Using Diffusion Tensor Imaging: A Systematic Review. Brain Sci. 2021 Jan 22;11(2):140. https:// doi.org/10.3390/brainsci11020140.

19. Redondo MT, Beltrán-Brotóns JL, Reales JM, Ballesteros S. Executive functions in patients with Alzheimer's disease, type 2 diabetes mellitus patients and cognitively healthy older adults. Exp Gerontol. 2016;83:47-55. https://doi.org/10.1016/j.exger.2016.07.013

20. Choi SE, Roy B, Freeby M, Mullur R, Woo MA, Kumar R. Prefrontal cortex brain damage and glycemic control in patients with type 2 diabetes. J Diabetes. 2020;12(6):465-473.https://doi.org/10.1111/1753-0407.13019

21. Cukierman-Yaffe T, McClure LA, Risoli T, Bosch J, Sharma M, Gerstein HC, Benavente O. The relationship between glucose control and cognitive function in people with diabetes after a lacunar stroke. J Clin Endocrinol Metab. 2021;106(4):e1521-e1528. https://doi.org/10.1210/clinem/dgab022