Bariatric surgery led to greater weight loss and better glycemic control than nonsurgical treatment among patients with diabetes who were mildly obese, but the evidence for long-term efficacy and safety remains limited, a systematic review found.
In one of the three randomized studies included in the review, patients who had gastric bypass lost 29.4 kg (64.8 lb) and those who had sleeve gastrectomy lost 25.1 kg (55.3 lbs) over the course of a year, whereas patients on medical therapy lost only 5.4 kg (11.9 lb, P<0.001), according to Melinda Maggard-Gibbons, MD, of the University of California Los Angeles, and colleagues.
In addition, mean hemoglobin (Hb)A1c at 12 months was 6.4% in the gastric bypass group and 6.6% in the sleeve gastrectomy group, compared with 7.5% in the medical therapy group (P<0.003), the researchers reported in the June 5 Journal of the American Medical Association.
"Current evidence suggests that bariatric surgery is associated with more short-term weight loss and better intermediate glucose outcomes than nonsurgical therapy in patients with diabetes and a [body mass index] of 30 to 35," they wrote.
However, "it is unknown whether the benefits observed are durable long term and if these findings might translate into reductions in the microvascular and macrovascular complications of diabetes," they cautioned.
Bariatric surgery has demonstrated success for weight loss and comorbidities in morbidly obese patients whose body mass index (BMI) is 35 kg/m2 and higher, but whether individuals with less severe obesity and diabetes could also benefit has been controversial.
To examine the evidence for this, and to see if outcomes differed with the various procedures, Maggard-Gibbons and colleagues reviewed the literature and identified more than 50 studies with either direct or indirect comparisons.