Percentage of maximum weight lost as an optimal parameter of weight regain after bariatric surgery in Chinese patients with diabetes.

OBJECTIVE: The goal of this study was to compare measures of weight regain (WR) and their association with the glucose metabolism deterioration within 3 years following bariatric surgery among Chinese patients with obesity and type 2 diabetes mellitus (T2DM).

METHODS: Among a retrospective cohort of 249 patients with obesity and T2DM who underwent bariatric surgery and were followed up to 3 years, WR was assessed by weight changes, BMI changes, percentage of presurgery weight, percentage of nadir weight, and percentage of maximum weight lost (%MWL). Glucose metabolism deterioration was defined as a change from an absence of antidiabetic medication use to use, or absence of insulin use to use, or an increase in glycated hemoglobin by at least 0.5% to 5.7% or greater.

RESULTS: A comparison of C-index of glucose metabolism deterioration indicated %MWL had better discriminatory ability versus weight change, BMI change, percentage of presurgery weight, or percentage of nadir weight (all p < 0.01). The %MWL also had the highest prediction accuracy. The optimal %MWL cutoff point was 20%.

CONCLUSIONS: Among Chinese patients with obesity and T2DM who underwent bariatric surgery, WR quantified as %MWL predicted 3-year postoperative glucose metabolism deterioration better than the alternatives; 20% MWL was the optimal cutoff point.