Gastric banding has little effect on beta-cell decline in early type 2 diabetes
medwireNews: The results of the adult surgery study from the RISE consortium show that gastric banding has only a small effect on the deterioration of beta-cell function relative to metformin, despite causing markedly greater weight loss.
In this clinical trial, known as the BetaFat Study, the 36 patients randomly assigned to undergo gastric banding lost an average of 10.7 kg, compared with just 1.7 kg in the 34 who took metformin for 24 months.
The patients assigned to the gastric banding and metformin groups were aged an average of 47 and 52 years, respectively, had average BMIs of 35.7 and 34.8 kg/m2, and all had been diagnosed with impaired glucose tolerance or type 2 diabetes less than a year previously.
Outlining the study design for delegates at the 54th EASD Annual Meeting in Berlin, Germany, Anny Xiang (Kaiser Permanente Southern California, Pasadena, USA) noted that weight gain is one of the most important contributors to diabetes risk, implying that reversing it might halt the declining beta-cell function underlying the progression to diabetes.
However, the weight loss associated with gastric banding in the BetaFat Study had only a small effect on changes in beta-cell function, reported co-investigator Thomas Buchanan (University of Southern California, Los Angeles, USA).
Specifically, the acute C-peptide response at maximal glycemia, (ie, the beta-cell secretory capacity) fell by a nonsignificant 7% in the gastric banding group over the 24 months of follow-up versus a significant 18% reduction in the metformin group. But there was no significant change in steady-state C-peptide in either treatment group, which decreased by a corresponding 11% and 13%.
Both these measures were adjusted for insulin sensitivity, which itself increased significantly in both groups during follow-up. The improvement was numerically but not significantly larger in the gastric banding than in the metformin group.
During follow-up, four patients had their gastric band removed: two for symptomatic slippage, one by choice, and one due to lack of weight loss. Patients in the metformin group were around 88% adherent to treatment after accounting for dose reductions because of gastrointestinal symptoms, and remained so for the duration of follow-up.
Measures of glucose control improved in both groups, but for most there were no significant differences between the gastric banding and metformin groups; initial differences in 2-hour glucose levels did not persist at 24 months. In all, 22% of patients in the surgery group regained normoglycemia, as did 15% of the metformin group – again, there was no significant difference.
However, the gastric banding group did have significantly larger reductions in very-low-density-lipoprotein cholesterol, triglycerides, and liver enzymes than the metformin group, a point that Roy Taylor (Newcastle University, UK) picked up on during his commentary, noting that these changes in patients in the DiRECT study were associated with remission of diabetes.
The BetaFat Study results were simultaneously published in Diabetes Care.
medwireNews is an independent medical news service provided by Springer Healthcare. © 2018 Springer Healthcare part of the Springer Nature group