Insulin Resistance Improvement After Cardiac Surgery by Preoperative Carbohydrate Loading: A Randomized Controlled Trial

Document Type : Original Article


1 Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.

2 Cardiovascular Intervention Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.

3 Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.

4 Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.


Background: The idea of preoperative overnight fasting was challenged and verified to have no benefits compared with drinking clear liquids up until 2 hours before surgery. In this study, we explored the possible effects of preoperative oral carbohydrate loading (OCL) on insulin resistance and the clinical outcomes of patients undergoing cardiac surgery.
Methods: Totally, 260 patients were recruited and allocated randomly to intervention (n=130) and control (n=130) groups. The intervention group received 250 mL of an oral carbohydrate fluid containing 25 g of glucose, and the control group received standard care. Insulin resistance, glycemic indices, and clinical outcomes were assessed before and after surgery.
Results: Totally, 107 patients in the intervention group and 103 in the control group completed the study and were, thus, included in the final analysis. Preoperative OCL 2 hours before surgery improved postoperative fasting blood sugar and clinical outcomes after cardiac surgery including thirst, hunger, anxiety, pain, the length of stay in the hospital, and the length of stay in the ICU (all Ps<0.05).
Conclusions: OCL administered preoperatively seems to be beneficial in improving the biochemical and clinical outcomes of patients undergoing cardiac surgery. Notably, preoperative OCL as a safe, simple, and cost-benefit approach is associated with no or negligible harm and, therefore, could be recommended in the setting of cardiac surgery, with careful attention to contraindications. (Iranian Heart Journal 2022; 23(3): 49-58)


  1. Tran S, Wolever TM, Errett LE, Ahn H, Mazer CD, Keith M. Preoperative carbohydrate loading in patients undergoing coronary artery bypass or spinal surgery. Anesthesia & Analgesia. 2013; 117(2):305-13.
  2. Svanfeldt M, Thorell A, Hausel J, Soop M, Rooyackers O, Nygren J, et al. Randomized clinical trial of the effect of preoperative oral carbohydrate treatment on postoperative whole‐body protein and glucose kinetics. British Journal of Surgery: Incorporating European Journal of Surgery and Swiss Surgery. 2007; 94(11):1342-50.
  3. Rapp-Kesek D, Stridsberg M, Andersson L-G, Berne C, Karlsson T. Insulin resistance after cardiopulmonary bypass in the elderly patient. Scandinavian Cardiovascular Journal. 2007; 41(2):102-8.
  4. Ljungqvist O, Nygren J, Soop M, Thorell A. Metabolic perioperative management: novel concepts. Current opinion in critical care. 2005; 11(4):295-9.
  5. Van den Berghe G, Wouters P, Weekers F, Verwaest C, Bruyninckx F, Schetz M, et al. Intensive insulin therapy in critically ill patients. New England journal of medicine. 2001; 345(19):1359-67.
  6. Qi C, Pekala PH. Tumor Necrosis Factor‐α–Induced Insulin Resistance in Adipocytes. Proceedings of the Society for Experimental Biology and Medicine: Minireviews. 2000; 223(2):128-35.
  7. Thorell A, Loftenius A, Andersson B, Ljungqvist O. Postoperative insulin resistance and circulating concentrations of stress hormones and cytokines. Clinical Nutrition. 1996; 15(2):75-9.
  8. Singh P, Zeng I, Srinivasa S, Lemanu D, Connolly A, Hill A. Systematic review and meta‐analysis of use of serum C‐reactive protein levels to predict anastomotic leak after colorectal surgery. British Journal of Surgery. 2014; 101(4):339-46.
  9. Straatman J, Cuesta MA, Gisbertz SS, van der Peet DL. Value of a step-up diagnosis plan: CRP and CT-scan to diagnose and manage postoperative complications after major abdominal surgery. Rev Esp Enferm Dig. 2014; 106(8):515-21.
  10. Ljungqvist O. Jonathan E. Rhoads lecture 2011: insulin resistance and enhanced recovery after surgery. Journal of Parenteral and Enteral Nutrition. 2012;36(4):389-98.
  11. Mizock BA. Blood glucose management during critical illness. Reviews in Endocrine and Metabolic Disorders. 2003; 4(2):187-94.
  12. Soop M, Nygren J, Thorell A, Weidenhielm L, Lundberg M, Hammarqvist F, et al. Preoperative oral carbohydrate treatment attenuates endogenous glucose release 3 days after surgery. Clinical Nutrition. 2004; 23(4):733-41.
  13. Yuill K, Richardson RA, Davidson H, Garden O, Parks R. The administration of an oral carbohydrate-containing fluid prior to major elective upper-gastrointestinal surgery preserves skeletal muscle mass postoperatively—a randomised clinical trial. Clinical Nutrition. 2005; 24(1):32-7.
  14. Thorell A, Nygren J, Ljungqvist O. Insulin resistance: a marker of surgical stress. Current Opinion in Clinical Nutrition & Metabolic Care. 1999; 2(1):69-78.
  15. Guyatt GH, Townsend M, Berman LB, Keller JL. A comparison of Likert and visual analogue scales for measuring change in function. Journal of chronic diseases. 1987; 40(12):1129-33.
  16. Li M, Zhang J, Gan TJ, Qin G, Wang L, Zhu M, et al. Enhanced recovery after surgery pathway for patients undergoing cardiac surgery: a randomized clinical trial. European Journal of Cardio-Thoracic Surgery. 2018; 54(3):491-7.
  17. Feguri GR, Lima PRLd, Franco AC, Cruz FRHDL, Borges DC, Toledo LR, et al. Benefits of fasting abbreviation with carbohydrates and omega-3 infusion during CABG: a double-blind controlled randomized trial. Brazilian journal of cardiovascular surgery. 2019; 34(2):125-35.
  18. Feguri G, Lima P, Lopes A, Roledo A, Marchese M, Trevisan M, et al. Clinical and metabolic results of fasting abbreviation with carbohydrates in coronary artery bypass graft surgery. Brazilian journal of cardiovascular surgery. 2012; 27(1):7-17.
  19. Järvelä K, Maaranen P, Sisto T. Pre‐operative oral carbohydrate treatment before coronary artery bypass surgery. Acta anaesthesiologica scandinavica. 2008; 52(6):793-7.
  20. Kotfis K, Jamioł-Milc D, Skonieczna-Żydecka K, Folwarski M, Stachowska E. The Effect of Preoperative Carbohydrate Loading on Clinical and Biochemical Outcomes after Cardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Trials. Nutrients. 2020; 12(10):3105.
  21. Awad S, Varadhan KK, Ljungqvist O, Lobo DN. A meta-analysis of randomised controlled trials on preoperative oral carbohydrate treatment in elective surgery. Clinical Nutrition. 2013; 32(1):34-44.
  22. Li L, Wang Z, Ying X, Tian J, Sun T, Yi K, et al. Preoperative carbohydrate loading for elective surgery: a systematic review and meta-analysis. Surgery today. 2012; 42(7):613-24.
  23. Engelman DT, Ali WB, Williams JB, Perrault LP, Reddy VS, Arora RC, et al. Guidelines for perioperative care in cardiac surgery: enhanced recovery after surgery society recommendations. JAMA surgery. 2019; 154(8):755-66.
  24. Kehlet H, Wilmore DW. Multimodal strategies to improve surgical outcome. The American journal of surgery. 2002; 183(6):630-41.
  25. de-Aguilar-Nascimento JE, Salomão AB, Waitzberg DL, Dock-Nascimento DB, Correa MIT, Campos ACL, et al. ACERTO guidelines of perioperative nutritional interventions in elective general surgery. Revista do Colégio Brasileiro de Cirurgiões. 2017; 44(6):633-48.
  26. Weimann A, Braga M, Carli F, Higashiguchi T, Hübner M, Klek S, et al. ESPEN guideline: clinical nutrition in surgery. Clinical nutrition. 2017; 36(3):623-50.
  27. Ghanbari B, Khaleghparast S, Ghadrdoost B, Bakhshandeh H. Nutritional status and coronary artery disease: a cross sectional study. Iranian Red Crescent Medical Journal. 2014; 16(3).
  28. Bilku D, Dennison A, Hall T, Metcalfe M, Garcea G. Role of preoperative carbohydrate loading: a systematic review. The Annals of The Royal College of Surgeons of England. 2014; 96(1):15-22.
  29. Thorell A, Alston-Smith J, Ljungqvist O. The effect of preoperative carbohydrate loading on hormonal changes, hepatic glycogen, and glucoregulatory enzymes during abdominal surgery. Nutrition (Burbank, Los Angeles County, Calif). 1996; 12(10):v-695.
  30. Madsen M, Brosnan J, Nagy VT. Perioperative thirst: a patient perspective. Journal of PeriAnesthesia Nursing. 1998; 13(4):225-8.
  31. Morrison RS, Magaziner J, McLaughlin MA, Orosz G, Silberzweig SB, Koval KJ, et al. The impact of post-operative pain on outcomes following hip fracture. Pain. 2003; 103(3):303-11.