Overweight, obese diabetic Asians benefit from metabolic surgery

Metabolic surgery is an effective method to improve body weight and metabolic health among overweight and obese Asians with type 2 diabetes mellitus (T2DM), according to a new study.

However, there seems to be a large variation in terms of the specific surgical procedures performed across different centres, which in turn leads to substantial variation in outcomes and efficacies.

“Laparoscopic adjustable gastric banding (LAGB) was the least effective treatment for these metabolic disorders, whereas single-anastomosis gastric bypass (SAGB) was the most effective. The substantive variation in efficacy should be considered during treatment planning,” the researchers said.

The study included 1,999 obese/overweight T2DM patients, most of whom were from Taiwan; participants were also enrolled from Korea, Hong Kong, Japan, Singapore, and India. SAGB was the most common procedure (32.6 percent), followed by Roux-en-Y gastric bypass (RYGB; 22.1 percent) and laparoscopic sleeve gastrectomy (SG; 16.5 percent). The other procedures saw use in <10 percent of patients. [Diabetes Obes Metab 2020;doi:10.1111/dom.14279]

The researchers observed significant variations in the types of metabolic procedures performed between centres (p<0.001) and over the years (p<0.001). In general, bypass procedures were predominant and SGs saw increasing use over time.

In terms of outcomes, metabolic surgery led to significant reductions in body weight and body mass index (BMI) after 1 year relative to baseline (p<0.001 for both). There were gradual increases thereafter, but both measures remained significantly lower at 5 years than at baseline (p<0.001).

The average body weight loss at 1 and 5 years was 25.8 percent and 20.6 percent, respectively. At the same time points, the mean BMI loss was 23.9 percent and 20.6 percent.

The same was true for fasting blood sugar and HbA1c, both of which were significantly lower after 1 year and, despite seeing slight increases, remained so at 5 years (p<0.001 for all). The proportion of patients on antidiabetic drugs was likewise lowered at 1 (p<0.001) and 5 (p=0.034) years, though the number of such medications taken was significantly reduced only at the 1-year mark (p<0.001).

The efficacy of metabolic surgery remained significant across many other outcome measures, including insulin, insulin resistance, C-peptide levels, blood pressure, and lipid and liver function biomarkers.

Notably, differences in efficacy were seen among the surgical procedures. Those who underwent SAGB and other bypass procedures, for example, saw greater body weight and BMI reductions relative to SG counterparts; LAGB, in contrast, led to the weakest results.

Similarly, SAGB was most effective in terms of blood sugar and HbA1c levels, as well as insulin resistance, for both of which LAGB had the lowest impact.

“Our results may complement randomized trials for optimizing the management of obesity and related metabolic derangements,” the researchers said.

“[T]he results for DM control were inconsistent between the major procedures. Complementary medical treatment should be tailored to meet the derangement in individual patients,” they added.