Gastric bypass surgery is 'much more effective' than intensive exercise, healthy eating and medical treatment alone at reversing type 2 diabetes, a study published in Diabetologia has found.
The researchers say the results call into question putting cut-offs on BMI eligibility as the primary criteria for gastric bypass surgery.
It is already known that gastric bypass surgery leads to improved glycaemic control, resulting in type 2 diabetes remission in many cases.
The current trial compared patient outcomes one year after receiving a Roux-en-Y gastric bypass surgery (RYGB) with patients who spent a year on ‘the most rigorous intensive lifestyle and medical intervention yet tested against surgery in a randomised trial’.
Patients on the intervention scheme did at least 45 minutes of aerobic exercise five days a week, ate a dietician-directed weight and glucose lowering diet and received optimal diabetes treatment.
Over 30 patients aged 25-64 with a BMI between 30 and 45 were involved in the trial. Of these, 15 received gastric bypass surgery and 17 were put in the intervention group.
After one year, the researchers – from the University of Washington – found that 60% of patients in the bypass group were in diabetes remission, compared to just 6% in the intervention group. Diabetes remission was defined as HbA1c below 6%.
Observed weight loss was also higher in the gastric bypass group at 26% compared to 6% in the intervention group. Weight loss in the gastric bypass group also remained more stable over time.
The researchers said: ‘Despite these limitations, our trial and other relevant randomly-controlled trials demonstrate that commonly used bariatric and metabolic operations are all more effective than a variety of medical and/or lifestyle interventions to promote weight loss, diabetes remission, glycaemic control, and improvements in other CVD risk factors, with acceptable complications, for at least 1–3 years.
‘These results apply to patients with a BMI <35, and our study and others show that neither baseline BMI nor the amount of weight lost dependably predicts diabetes remission after RYGB, which appears to ameliorate diabetes through mechanisms beyond just weight reduction. These findings call into serious question the longstanding practice of using strict BMI cut-offs as the primary criteria for surgical selection among patients with type 2 diabetes.’