The Impact of Ethnicity on Metabolic Outcomes After Bariatric Surgery

Previous studies have demonstrated that ethnic minority patients experience significant metabolic improvements after bariatric surgery but less so than non-Hispanic whites. Previous research has primarily investigated differences between non-Hispanic white and black patients. Thus, there remains a need to assess differences in diabetic outcomes among other ethnic groups, including Hispanic and Asian patient populations.

A retrospective analysis including 650 patients with type II diabetes mellitus (T2DM), who underwent either laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy (LSG) procedures, was conducted to understand ethnic disparities in diabetic metabolic outcomes, including weight loss, serum concentrations of glucose, fasting insulin, and hemoglobin A1c (HbA1c). Data were from a single academic institution in northern California. Ethnicity data were self reported. T2DM was defined as having one or more of the following criteria: a fasting glucose concentration >125 mg/dL, HbA1c >6.5%, or taking one or more diabetic oral medications. Diabetes resolution was defined as having a fasting glucose <125 mg/dL, a HbA1c <6.5%, and discontinuation of diabetic oral medications.

Within-group comparisons in all ethnic groups showed significant reductions in body mass index, body weight, fasting insulin, fasting glucose, and HbA1c by 6 mo, but Asian patients did not experience further improvement in body mass index or diabetic outcomes at the 12-mo visit. Black patients did not experience additional reductions in fasting insulin or glucose between the 6- and 12-mo visit and their HbA1c significantly increased. Nevertheless, the majority of patients had diabetes remission by the 12-mo postoperative visit (98%, 97%, 98%, and 92% in Non-Hispanic, Hispanic, black, and Asian, respectively).

The results of this study demonstrate that bariatric surgery serves as an effective treatment for normalizing glucose metabolism among patients with T2DM. However, this study suggests that additional interventions that support black and Asian patients with achieving similar metabolic outcomes as non-Hispanic white and Hispanic patients warrant further consideration.