Visualizing Beta Cells in Patients With T2D Before and After Bariatric Surgery

The prevalence of Type 2 Diabetes Mellitus (T2D) in the Netherlands is 600.000-800.000 and each year ~70.000 new patients are diagnosed. This increasing number of patients with T2D is closely correlated with the obesity epidemic.

Obese patients with T2D are also at risk to develop dyslipidemia and hypertension. This clustering of cardiovascular risk factors leads to an increased risk of micro-and macrovascular long-term complications. In fact, patients with T2D have a 2-4 times increased risk for cardiovascular disease. These complications seriously decrease the quality of life and life expectancy of T2D patients. The burden of this disease affects our society as well. Health care costs with respect to diabetes amounted 814 million euro in 2005 in the Netherlands and indirect costs because of absence of work are unknown but thought to be substantial.

Weight loss is perhaps the most important therapeutic intervention in obese patients with T2D. Weight loss intervenes in the underlying pathophysiology and restores insulin sensitivity and sometimes even insulin secretion. In addition, it improves dyslipidemia and hypertension. In contrast, most pharmacological interventions only relieve the symptoms of the complex disease process underlying T2D whilst the disease process itself is not addressed and even progresses in the course of time. Unfortunately, the effect of weight loss interventions such as diet and lifestyle or even drugs (orlistat, sibutramine) is often modest (3-5 kg) and short-lived.

Bariatric surgery and T2D remission Weight reducing surgery, i.e. bariatric surgery, is the only intervention that leads to persistent weight loss and is superior above conventional (non-surgical) treatment. Bariatric surgery can be divided into restrictive (gastric band or sleeve) and malabsorptive (biliopancreatic diversion, BD) procedures or a combination of both (Roux-en-Y gastric bypass, RYGB). Currently, RYGB is the most performed bariatric procedure. The international indications for bariatric surgery are BMI > 40kg/m2 or BMI > 35 kg/m2 with co-morbidities (e.g. T2D).

Besides weight loss, spectacular metabolic improvements after bariatric surgery are seen. In patients with T2D, normalization of fasting plasma glucose and/or HbA1c without medication (referred as "resolution of T2D") was observed in 48% and 83% after gastric banding and RYGB, respectively. Recently, randomized controlled trials showed the superiority of bariatric surgery in glycemic control above conventional medical treatment. Furthermore, the improvement in glycemic control is higher in RYGB compared to purely restrictive bariatric procedures.