Current and Emerging Pharmacotherapies for Weight Management in Prediabetes and Diabetes

Type 2 diabetes is a serious chronic disease that is associated with increased morbidity and premature mortality. It has become the tsunami of noncommunicable diseases, with more than 400 million people worldwide currently living with diabetes. The global diabetes epidemic is driven by rising obesity rates. Excess body fat increases the risk for insulin resistance and prediabetes; obese men and women, respectively, have a 7-fold and 12-fold higher risk for developing type 2 diabetes. Obesity also predisposes to the development of a myriad of medical complications leading to increased morbidity and mortality. Each increase in body mass index of 5 kg/m(2) or higher is, on average, associated with about a 30% higher overall mortality rate. Modest weight loss through health-behaviour modification can significantly prevent or delay the onset of type 2 diabetes in people at risk. Each kg of body weight loss is associated with a 16% relative reduction in diabetes risk. Intentional weight loss is also associated with a 15% reduction in all-cause mortality. Unfortunately, health-behaviour modification alone seldom sustains adequate weight loss to achieve the desired health outcomes, especially in people with diabetes who already have greater difficulty losing weight. Pharmacotherapy is a realistic treatment option as an adjunct to diet and exercise. In addition to orlistat, the glucagon-like peptide-1 receptor agonist liraglutide has recently been approved in Canada for the treatment of obesity in doses of up to 3.0 mg daily. This review is focused on current and emerging pharmacotherapies for obesity in people with prediabetes or diabetes.