Background
Evidence comparing premixed insulin analogues with other antidiabetic agents is urgently required to guide appropriate therapy.
Purpose
To summarize the English-language literature on the effectiveness and safety of premixed insulin analogues as compared with other antidiabetic agents in adults with type 2 diabetes.
Data Sources
We searched MEDLINE®, EMBASE®, CINAHL, and the Cochrane Central Register of Controlled Trials from inception to February 2008, and unpublished data from U.S. Food and Drug Administration, European Medicines Agency, and industry.
Study Selection
Studies with control arms that compared premixed insulin analogues to another antidiabetic medication in adults with type 2 diabetes
Data Extraction
Serial abstraction by 2 reviewers using standardized protocols
Data Synthesis
Evidence from clinical trials was inconclusive for clinical outcomes, such as mortality. Therefore, the review focused on intermediate outcomes. Premixed analogues were similar to premixed human insulin in lowering fasting glucose, hemoglobin A1c, and the incidence of hypoglycemia but were more effective in lowering postprandial glucose (mean difference = -1.1 mmol/L; 95% CI = -1.4 to -0.7 mmol/L [-19.2 mg/dL; 95% CI=-25.9 to -12.5 mg/dL]). As compared to long-acting insulin analogues, premixed analogues were superior in lowering postprandial glucose (mean difference= -1.5 mmol/L; 95%CI = -1.9 to -1.2 mmol/L [-27.9 mg/dL; 95% CI=-34.3 to -21.5 mg/dL]) and hemoglobin A1c (mean difference=-0.39%; 95% CI=-0.50% to -0.28%) but inferior in lowering fasting glucose (mean difference=0.7 mmol/L; 95%CI = 0.3 to 1.0 mmol/L [12.0 mg/dL; 95% CI=6.0 to 18.1 mg/dL]) and had higher incidence of hypoglycemia. When compared to noninsulin antidiabetic agents, premixed analogues were more effective in lowering fasting glucose (mean difference= -1.1mmol/L; 95%CI = -1.7 to 0.6 mmol/L [-20.5 mg/dL; 95% CI=-29.9 to -11.2 mg/dL]), postprandial glucose (mean difference= -2.1 mmol/L; 95%CI = -3.4 to -0.8 mmol/L [-37.4 mg/dL; 95% CI=-61.0 to -13.7 mg/dL]), and hemoglobin A1c (mean difference=-0.49%; 95% CI=-0.86% to -0.12%) but had higher incidence of hypoglycemia.
Limitations
Searching was restricted to studies published in English. Data on clinical outcomes was limited. The small number of studies for each comparison limited assessment of between-study heterogeneity.
Conclusions
Premixed insulin analogues provide glycemic control similar to premixed human insulin and may provide tighter glycemic control than long-acting insulin analogues and noninsulin antidiabetic agents.