Methods: Non-diabetic consecutive adult patients undergoing spine surgery are going to be prospectively included during a 6 months period. BG capillary measures are collected from the preoperative fasting period to the end of postoperative day 3, six times a day. Three main glycemic parameters are calculated: Delta Day 0 (DD0), Day 2 mean (D2), and Hyperglycemic Index (HGI). In the peri operative period, no change in oral intake nor in intravenous fluids is prescribed. Patients are followed-up for three months postoperatively for any early adverse event, requiring or not surgical revision.