Type 2 Diabetes Mellitus (T2DM) is highly prevalent in the United States and affects nearly 26 million people. In 2007, 1.6 million new cases were diagnosed in people aged 20 years or older. This disease accounts for nearly $174 billion in total economic costs.1 T2DM is associated with an increased risk of microvascular and macrovascular complications. Several studies have shown that tighter glycemic control is recommended for these patients to reduce the risk of complications. Insulin therapy, which includes conventional insulin and insulin analogues, has been the breakthrough for both type 1 and type 2 diabetic patients who are unable to manage the disease with diet, exercise, or oral medications. Insulin analogues include rapid acting insulins such as insulin aspart, insulin lispro, and insulin glulisine, and bolus insulins such as insulin glargine and insulin detemir. This new class of drugs has been associated with a more flexible treatment regimen and lower incidence of hypoglycemia. Two recent studies have evaluated the outcomes and cost-effectiveness of insulin analogues compared with conventional insulins.
A meta-analysis of 68 randomized controlled trials was conducted to compare the safety and efficacy of insulin analogues with conventional insulins.2 Populations included in the study were patients with type 1, type 2, and gestational diabetes. Hemoglobin A1c (Hgb A1c), complications of diabetes, including death, and adverse effects such as hypoglycemia were the main outcomes of interest in this study. Other outcomes included in the study were quality-of-life and patient satisfaction.
In trials comparing insulin lispro and regular human insulin, no significant differences in Hgb A1c, the risk for severe hypoglycemia, nocturnal glycemia, or overall hypoglycemia were observed. The pooled analysis of trials comparing insulin aspart and regular human insulin failed to show significant differences in Hgb A1c or in the risk of any type of hypoglycemia between the groups. Two studies compared insulin lispro with regular insulin to evaluate quality of life and patient satisfaction. No significant differences were found between the treatment groups. Insulin glargine was associated with significantly less nocturnal hypoglycemia when compared to other insulins and in studies allowing oral hypoglycemic agents (relative risk 0.78, 95% CI 0.62 to 0.98). Data were insufficient for comparisons between insulin analogues and conventional insulins in terms of diabetes-related complications or death.
After pooling results from studies comparing insulin lispro and regular insulin in pregnant women, no significant differences in Hgb A1c were observed (0.20%, 95% confidence interval, -1.03% to 1.43%). Furthermore, no significant differences in Hgb A1c among women with gestational diabetes were noted. Randomized controlled trials of long acting insulin analogues in pregnant women were not identified in this study.
In a companion paper, Cameron and colleagues evaluated the cost-effectiveness of insulin analogues versus conventional insulins in the management of type 1 and type 2 diabetes.3 The authors used the Center for Outcomes Research Diabetes Model to calculate the cost-effectiveness estimates. The primary outcome measure was the quality-adjusted life year which consisted of length of life ...