Contribution of glycemic variability to hypoglycemia, and a new marker for diabetes remission after Roux-en-Y gastric bypass surgery.

Abstract

Diabetes remission after bariatric surgery was reported to be characterized by increased risk of hypoglycemia. This study aimed to examine the contribution of glycemic variability (GV) to the risk of hypoglycemia, and the suitability of time in range (TIR), an emerging glycemic marker, to define diabetes remission after Roux-en-Y gastric bypass (RYGB). A single referral center in China. This retrospective study included 175 individuals with type 2 diabetes and obesity who underwent RYGB. Subjects were classified as remission/nonremission according to the current standard. Each participant underwent continuous glucose monitoring both before and 1 year after RYGB. GV was measured by glucose coefficient of variation (CV), and hypoglycemia was assessed by time below range (TBR). Complete remission was achieved in 88 of the 175 participants following RYGB. In the remission group, significant correlations between postoperative CV and TBRs (r = .353-.442, both P ≤ .001) were found. Excess hypoglycemia (TBR<54 , ≥1%, TBR<70, ≥4%) increased with ascending CV quintiles (both P for trend <.05) and was significantly more frequent in subjects with glucose CV >32.2% (both P <.05). Compared with glycated hemoglobin A1C, TIR showed stronger correlation with glucose CV and risk of hypoglycemia. Increased glycemic variability was linked to excess risk of hypoglycemia after RYGB. Furthermore, TIR may serve as a new metric, in addition to HbA1C, for defining diabetes remission.