Current therapeutic strategies for type 2 diabetes mellitus

Type 2 diabetes mellitus is now regarded a worldwide epidemic with diabetes-related complications exacting a heavy toll on those with poor metabolic control. Although there is no cure currently, the therapeutic armamentarium has expanded over the last few years to five classes of oral agents - sulfonylureas, biguanides, meglitinides, thiazolidinediones and alpha-glucosidase inhibitors. Sulfonylureas continue to be the mainstay oral hypoglycaemic agents for type 2 diabetics because they are potent insulin secretagogues and cost-effective. Metformin exerts its main effect by reducing hepatic glucose output and is proven to particularly benefit obese type 2 diabetics. Meglitinides are rapid-acting insulin secretagogues targeting at postprandial hyperglycaemia and this class of drug is useful for those who are at risk of hypoglycaemia with longer-acting sulfonylurea drugs. Thiazolidinediones constitute a new class of insulin sensitizers that work predominantly in improving glucose uptake by the adipose tissues and skeletal muscles. Alpha-glucosidase inhibitors delay the digestion and absorption of polysaccharides, thus attenuating postprandial hyperglycaemia. This review article briefly examines the nature of these oral agents, including the role of combination therapy and insulin where clinically indicated.