Objective: To provide an overview of type 1 and type 2 diabetes mellitus and review newer insulin therapies used to manage patients with diabetes.
Data sources: A MEDLINE search covering articles published from 1985 to March 2003 was conducted to identify English-language literature available on the management of diabetes, specifically focusing on the newer insulin products insulin glargine and insulin aspart, and any other novel insulin therapies (Medical Subject Headings [MeSH] search terms used were: diabetes, insulin, insulin aspart, insulin glargine, inhaled insulin, intranasal insulin, oral insulin). These articles, abstracts, and data provided by the pharmaceutical manufacturers were reviewed to collect pertinent data. Additional references were obtained from the bibliographies of those publications.
Study selection: Human studies presenting safety or efficacy information on newer insulin formulations.
Data extraction: Specific insulin formulations were reviewed with regard to background information, pharmacokinetic data, relevant clinical studies, U.S. Food and Drug Administration-approved indications, dosing and administration, adverse effects, storage, cost, and role in therapy.
Data synthesis: Insulin therapy is essential in the management of patients with type 1 diabetes, as well as in many patients with type 2 diabetes. No single insulin product currently on the U.S. market mimics natural endogenous insulin secretion. Problems encountered with traditional insulin products include variable absorption, peaks leading to hypoglycemic events, troughs leading to inadequate duration of response, and difficulty accurately timing injections in relation to meals. Insulin analogs such as insulin glargine and insulin aspart have been synthesized in an effort to overcome those difficulties. Novel insulin formulations (oral, intranasal, and inhaled) are also in various stages of investigation.
Conclusion: Insulin glargine and insulin aspart are two of the newest insulin products approved for managing diabetes mellitus. Clinical trials have shown that these agents may offer certain clinical benefits and conveniences for patients. These advantages, however, must be weighed against the increased cost of insulin glargine and insulin aspart relative to traditional insulins.