INTRODUCTION
Obesity is a key risk factor in the development of Type 2 diabetes mellitus (T2DM). Bariatric surgery causes a large amount of durable weight loss in those with clinically severe obesity. We reported the effect of weight loss via bariatric surgery on DM prevention in those at high risk of developing DM.


METHODS
This was a retrospective cohort study of 44 patients with obesity (mean body mass index 43.8 kg/m2) and pre-DM who underwent bariatric surgery and were followed up for up to three years. We also reviewed a non-surgical cohort of patients with obesity and pre-DM seen at the weight management clinic.


RESULTS
91% of patients attained normal glycaemic status at one year after bariatric surgery. At the three-year followup, 87.5% of the patients maintained normoglycaemia. None of the patients developed T2DM after surgery. 26.9% of patients achieved absolute weight loss at one year after bariatric surgery and maintained this at two and three years post surgery (p < 0.001 vs. baseline). The homeostatic model assessment-insulin resistance index in patients also decreased from 5.50 at baseline to 1.20, 1.14 and 1.44 at one, two and three years, respectively (p < 0.001).


CONCLUSION
Bariatric surgery produces significant weight loss, and leads to reversion from the pre-diabetic state to normal glycaemic status and reduction of the incident DM rate in those with pre-DM and morbid obesity.