Gastric banding and 2 years of treatment with metformin resulted in similar improvements in insulin sensitivity in moderately obese adults with impaired glucose tolerance or mild type 2 diabetes (T2D), according to findings published in Diabetes Care.
T2D is often the result of a progressive loss of β-cell compensation for chronic insulin resistance. In the Beta Cell Restoration Through Fat Mitigation study, laparoscopic gastric banding was compared with treatment with metformin to evaluate the ability to preserve or restore β-cell function in a cohort of 88 patients age 21 to 65 years who had a body mass index of 30 to 40 kg/m2 and either impaired glucose tolerance or known diabetes for <1 year. Participants were randomly assigned to receive either gastric banding with nutritional management or metformin for 2 years. To assess for different aspects of β-cell compensation, steady-state C-peptide and acute C-peptide response to argenine at maximum glycemic potentiation were measured at 12 and 24 months.
At the 2-year follow-up, patients with gastric banding lost 10.7 kg vs 1.7 kg in the metformin group (P <.01), and insulin sensitivity increased 45% from baseline for the gastric banding group vs 25% from baseline in the metformin group (P =.30 between groups). Steady-state C-peptide adjusted for insulin sensitivity decreased slightly in both groups but did not reach significance (P =.34 between groups).
Acute C-peptide response to argenine at maximum glycemic potentiation, also adjusted for insulin sensitivity, declined significantly in the metformin group (P =.002) but not in the gastric banding group (P =.25 between groups). Patients in both groups achieved a slight but significant drop in hemoglobin A1c levels at 12 months, but the decrease was sustained at 24 months only in the gastric band group. At 24 months, normoglycemia was observed in 22% of the gastric banding group and 15% of the metformin group (P =.66 between groups).
“Whether these changes, which resulted in mild reductions in β-cell secretory demands, will result in any long-term preservation of β-cell function remains to be determined,” wrote the researchers.
Xiang AH, Trigo E, Martinez M, et al. Impact of gastric banding versus metformin on β-cell function in adults with impaired glucose tolerance or mild type 2 diabetes [published online October 3, 2018]. Diabetes Care. doi:10.2337/dc18-1662