Patients with poorly controlled type 2 diabetes who underwent bariatric surgery, in addition to medical treatment, showed a significantly greater improvement in glycaemic control and weight loss than those receiving medical therapy alone.

The trial, from the US, was a single site, open label, randomised 12-month study comparing intensive medical therapy with or without the addition of a surgical bariatric intervention (Roux-en-Y gastric bypass or sleeve gastrectomy) in 150 obese patients with poorly controlled type 2 diabetes. A single experienced surgeon performed the bariatric procedures. Mean age of the patients was 49 years, BMI 36 and average HbA1c  9.2%. Two-thirds of the patients were women.

The primary end point was the proportion of patients with an HbA1c ≤ 6% 12 months after treatment.

Surgery resulted in a significantly greater proportion of patients achieving an HbA1c  ≤ 6% at 12 months: 42% with gastric bypass and 37% with sleeve gastrectomy versus 12% with medical therapy alone.

Mean reductions in weight were: 29.4 kg with gastric bypass and 25.1 kg with sleeve gastrectomy compared with 5.4 kg in those receiving medical treatment alone.

All the gastric bypass patients who achieved the primary end point did so without antidiabetic medication, as did many of the gastrectomy patients. There was also a reduction in lipid lowering and antihypertensive therapy in both surgical groups. Clinical gains were most evident in the first 3 months following surgery and were retained throughout the 12 months of the study. The use of drugs to lower glucose, lipids and blood pressure increased in the group who received medical therapy alone.

Obesity is a worldwide epidemic that along with many other adverse health effects can lead to insulin resistance and type 2 diabetes. The potential complications of diabetes are well known and prevention of this disease by addressing the growing tide of obesity is key.

However, efforts to achieve significant weight loss are often labour intensive and many patients either fail to achieve or sustain long-term weight loss. Despite its short-term cost and invasive nature bariatric surgery offers a way to address this issue with the potential for long-term benefit.

This is certainly an encouraging study with impressive weight loss in the surgical groups which translates into an improvement in diabetic control in a previously poorly controlled and high-risk cohort. However, the period of follow-up was quite short so it is not known whether the positive findings observed translate into longer-term benefit.

Furthermore, it would have been helpful to have the results stratified according to BMI particularly as this is the primary tool used by commissioners to decide if patients are eligible for such surgery.

Dr Peter Savill