Time-in-range: a promising glycemic control metric for bariatric surgery

As a complication of obesity, type 2 diabetes (T2D) is a chronic disease that is difficult to manage. However, bariatric surgery makes it possible to alleviate T2D. While the existing generic index glycosylated hemoglobin (HbA1c) is a powerful tool for examining overall blood glucose levels, it still has some limitations as a daily measure of blood glucose levels and as a judge of the effectiveness of bariatric surgery. Using the time-in-range (TIR) measurement and its derivatives is a better way to evaluate short-term blood glucose fluctuations and can be used as a supplement to HbA1c. In this article, we discuss the utility and limitations of HbA1c and other indicators used during surgery. In addition, we mentioned TIR as a novel metric that can act as an accurate predictor of the risk of T2D complications and an index of preoperative risk assessment in bariatric surgery. In contrast to previous indicators, TIR has the advantage that it cannot be affected by caloric restriction to better reflect the patient's glucose level and the level of pancreatic islet function. On this basis, TIR is a promising indicator for both the diagnosis of diabetes and the preoperative and postoperative prediction and evaluation.