No abstract

Clinical data suggest that thiazolidinediones--specifically, rosiglitazone and pioglitazone--may improve cardiovascular risk factors through multiple mechanisms. Low insulin sensitivity has been described as an independent risk factor for coronary artery disease and cerebrovascular disease. Patients with insulin resistance often have several known risk factors, such as obesity, dyslipidemia, and hypertension. Other emerging risk factors may be prevalent in patients with insulin resistance, such as hyperinsulinemia, elevated C-reactive protein, elevated plasminogen activator inhibitor levels, and small, dense, low-density lipoproteins. The only available drug class that primarily targets insulin resistance is the thiazolidinediones. These drugs have shown efficacy in affecting surrogate markers of cardiovascular risk in patients with diabetes mellitus. Alterations in these risk factors are likely due to their effects on improving insulin sensitivity and/or glycemic control. Trials to assess whether thiazolidinediones actually reduce cardiovascular outcomes are continuing.

The frequency of type 2 diabetes mellitus is increasing at an alarming rate. Prediabetes, also referred to as impaired glucose tolerance (IGT) and/or impaired fasting glucose, is a major risk factor for development of type 2 diabetes mellitus. In addition, IGT has been associated with an increased risk of cardiovascular disease and mortality. Several studies have measured the effects of various interventions in patients with IGT on the development of type 2 diabetes mellitus. Intensive lifestyle modifications through alterations in diet and improvement in exercise have delayed the development of type 2 diabetes mellitus by 58% in patients with IGT. Therapy with metformin, troglitazone, or acarbose also has reduced the progression of IGT to diabetes mellitus by 31%, 49% and 25%, respectively. The mechanisms by which lifestyle interventions and drugs reduce the progression may be through alterations in insulin sensitivity. The American Diabetes Association recommends screening for prediabetes in patients who are 45 years or older and those with a body mass index of 25 kg/m2 or greater who have additional diabetes mellitus risk factors. Pharmacists can promote awareness, counsel patients on intervention strategies to delay the onset of diabetes mellitus, and screen high-risk patients.