Review: Pre-diabetes: clinical relevance and therapeutic approach

Abstract

Type 2 diabetes mellitus is epidemic in most developed and many developing countries. The associated morbidity, mortality and high costs of care, make type 2 diabetes an important global public health challenge and target for prevention. Patients at high risk for type 2 diabetes can be diagnosed by fasting glucose levels or responses to an oral glucose tolerance test (OGTT). Such patients are also at increased risk for cardiovascular disease (CVD). Since obesity and physical inactivity are important risk factors for type 2 diabetes, lifestyle interventions, emphasising modest weight loss and increases in physical activity, should be recommended for most patients with pre-diabetes. Such interventions are safe and effective and also reduce risk factors for CVD. Several oral antidiabetic agents have been shown to be effective at delaying onset of type 2 diabetes. Thiazolidinediones (TZDs) reduced incident diabetes by ~60%, whilst metformin, acarbose and orlistat are only about half as effective as the TZDs. Pharmacological interventions may be appropriate for patients at particular risk for developing diabetes, but the benefits of treatment need to be balanced against the safety and tolerability of the intervention. If pharmacological treatment is warranted, metformin should be considered first because of its favourable overall safety, tolerability, efficacy, and cost profile.