Combination Therapy with Insulin and Oral Antidiabetic Drugs in Patients with Type 2 Diabetes Mellitus: A Systematic Review
DOI: 10.3238/zfa.2010.0006german translation / full article
Background: During the course of type 2 diabetes mellitus, treatment with insulin is often needed either as monotherapy or in combination with oral antidiabetic drugs (OAD).
Method: Systematic review of randomised controlled trials that investigated insulin monotherapy vs. combination therapy of insulin and OAD in insulin-naïve patients with diabetes mellitus type 2. Minimal study duration was longer than three months.
Results: We identified 22 studies for 25 comparisons. None investigated mortality or morbidity. The combination of insulin and metformin (MET) appears favourable compared to insulin monotherapy regarding HbA1c level and weight gain. While once-daily insulin monotherapy appears inferior to once-daily insulin-sulfonylurea (SU) regarding HbA1c control, it is superior regarding weight gain. For other insulin schemes and their combination with SU no statistically significant effects were found. The findings for other OAD (MET-SH, acarbose, pioglitazone, MET-rosigliatzone and MET-repaglinide) are described.
Discussion: It is disappointing not to find studies that investigated the patient-relevant outcomes mortality and morbidity. Therefore, the benefits of the investigated treatments are not known. Thus, it is of special importance to avoid any harm resulting from treatment. Known benefits of specific compounds may be useful for the selection of combination therapies.