Effect of Preoperative Oral Carbohydrates on Insulin Resistance in Older Adults Who Underwent Total Hip or Knee Arthroplasty: A Prospective Randomized Trial.

INTRODUCTION: Preoperative carbohydrate drinks are recommended to reduce fasting time before surgery. Older adults are at risk of pulmonary aspiration and hyperglycemia after consuming carbohydrate drinks because of increased insulin resistance and delayed gastric emptying. We investigated the effects of oral carbohydrate drinks on perioperative insulin resistance, metabolic responses, and gastric volume in older adults. METHODS: Fifty-six patients (aged more than 65 years) were randomly assigned to the control or carbohydrate (CHO) group. The CHO group received 400 mL of a carbohydrate drink 2 to 3 hours before anesthesia. The control group was allowed clear fluid intake 2 hours before anesthesia. Blood glucose and insulin levels were measured before intake of the carbohydrate drink and 1 hour postoperatively. Gastric volume was measured before spinal anesthesia. Insulin resistance was calculated using the homeostasis model assessment for insulin resistance. RESULTS: Homeostasis model assessment for insulin resistance was not different between the control and CHO groups preoperatively (2.5 versus 3.3, P = 0.156) or postoperatively (2.6 versus 2.4, P = 0.817). Preoperative gastric volume was comparable between the control and CHO groups (35.5 versus 30.8 mL, P = 0.696). DISCUSSION: Preoperative oral consumption of carbohydrates did not affect insulin resistance or gastric volume in older adults undergoing total knee or hip arthroplasty. Preoperative carbohydrate loading is safe in older adults undergoing total knee or hip arthroplasty. DATA AVAILABILITY: The data that support the findings of this study are available from the corresponding author on reasonable request. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (No. NCT04206189).