Effect of Modified Laparoscopic Roux-en-Y Gastric Bypass Surgery on Type 2 Diabetics With Lower Body Mass Index in China

Type 2 diabetes mellitus (T2DM) is well known as a chronic metabolic disease. As the main manifestation of T2DM , the disorder of glucose metabolism which is due to the gradual dysfunction of pancreatic islet and significant insulin resistance results in many problems and complications associated with T2DM such as hypertension, cardiovascular diseases(CVD), lipid disorders and other complications. Currently, there are more than 346 million people suffered from T2DM worldwide, among which T2DM accounts for about 90%. A report published by Chinese diabetes and metabolic syndrome research group in 2010 showed that overall prevalence of diabetes is 9.7% over the age of 20 and the total number of diabetes mellitus has reached 92.4 million in Chinese population and what's worse, more than 15.5 percent of adults are in the pre-diabetic state. Through traditional diet therapy, exercise, changing lifestyle, and standardized medical treatment have a certain effect on diabetes and its complications, T2DM can't be cured so far. How to cure diabetes mellitus and improve the quality of life of diabetic patients is a common problem faced by doctors in all countries. In 1984, Pories et al have found that glucose metabolism indicators significantly improved when he analyzed a report of three-year progress results of obesity patients with T2DM after laparoscopic Roux-en-Y gastric bypass surgery(LRYGB) , thus opening a door to the surgical treatment for diabetes. Now LRYGB is often performed in Europe and United State, and has been written into the diabetes treatment guidelines by American Diabetes Association in 2009. The surgical treatment for diabetes is an extension from the surgical treatment for morbid obesity. So diabetes treatment guidelines in 2014 show that bariatric surgery may be considered for T2DM with a body mass index （BMI） >35 kg/m2, especially if diabetes or associated comorbidities are difficult to control with lifestyle and pharmacological therapy. However, it also mentioned that small trials have shown benefit in patients with type 2 diabetes mellitus and BMI 30-35 kg/m2 after bariatric surgery. But it still lacks sufficient evidence for patients with BMI below 30kg/m2. A survey conducted in Shanghai, China, showed that the prevalence of type 2 diabetes was 9.8%, while the prevalence of obesity was 4.3%.But in the United States, the incidence of type 2 diabetes was 10.9% and the obesity population defined by a BMI ≥30 kg/m2 may account for one third of the total population in 2009-2010. In addition, patients in Asian countries are mostly abdominal obesity compared with that of patients in the United States and Europe where have different type of obesity. Taking into account the differences of body size and diet between the United States & Europe and Asian countries, diabetic situation has its special features in different regions, especially in Asia China. Asian Chinese have a high incidence of T2DM and a relatively low BMI levels. Evaluating the benefits from LRYGB for T2DM in Asian Chinese diabetes subjects with a body mass index of less than 35kg/m2 and looking for sufficient evidence to this operation become necessary.