Introduction: The prevalence of obesity and type 2 diabetes mellitus is increasing quickly and is a major challenge to health care systems in the world. Bariatric surgery, which has been used widely for the treatment of morbidly obese patients, results not only in weight loss but also in a dramatic improvement in glucose metabolism. However, there is evidence that the improvement in glucose metabolism is present immediately after surgery before any significant weight loss occurs. This evidence, therefore, supports the role of other weight loss-independent mechanisms in mediating the anti-diabetic effect of bariatric surgery. To better understand the beneficial effects of bariatric surgery it is designed a study in which Obese and morbidly obese cases with non-diabetes or uncomplicated type-2 diabetes receiving bariatric surgery have to follow. The aim was to evaluate the role of caloric restriction and weight loss on glucose and lipid metabolism after Sleeve gastrectomy (Bariatric Surgery).
Materials and methods: Obese and morbidly obese cases with non-diabetes or uncomplicated type 2 diabetes receiving Sleeve Gastrectomy. The protocol includes two phases. The first phase lasts about 9 weeks & the second phase lasts 12 weeks and subjects are seen on an out-patient basis. Glucose and lipid metabolism were assessed before beginning caloric restriction (visit 1), and again after 9 weeks (visit 2) and 12 weeks (visit 3). The improvement in glucose metabolism was evaluated by changes in fasting blood glucose, fasting insulin, and dose of Anti-diabetic medications. The improvement in lipid metabolism was evaluated by changes in lipid parameters. Potential mechanisms mediating the improved glucose metabolism, which were evaluated in the current study, include changes of the insulin sensitivity or Resistance. Changes in insulin Resistance were evaluated by changes in fasting plasma insulin, fasting plasma glucose and estimated by HOMA-IR method.
Observations and Results: Fifty cases were included in the study (19 women, 31 men; age between 20 to 40 years; duration of diabetes <10 years). There was a significant improvement in glucose metabolism after the 9wks and the 12wks of Sleeve Gastrectomy. A significant improvement in lipid metabolism was also present at visit 2 (total cholesterol decreased significantly from 174.58 mg/dl to 166.12 mg/dl and triglyceride decreased from 167.92 mg/dl to 143.92 mg/dl and LDL-cholesterol decreased significantly from 107.42mg/dl to 95.04 mg/dl and HDL-cholesterol increased from 38.46 mg/dl to 42.30 mg/dl). The improvement in glucose metabolism after caloric restriction in the study is accompanied by an improved enhanced insulin resistance or insulin sensitivity. Enhanced HOMA-IR(Insulin resistance) was decreased at visit 2 from11.08 to 9.32 and at visit 3 from 11.08 to 5.43.
Conclusion: Caloric restriction and weight loss due to Sleeve gastrectomy leads to an improvement in glucose and lipid metabolism. Properly controlled studies with larger cohorts are necessary to elucidate the beneficial effects of bariatric surgery.