Meta-analysis of short-acting insulin analogues in adult patients with type 1 diabetes: continuous subcutaneous insulin infusion versus injection therapy

AIMS/HYPOTHESIS: This study aimed to compare the effect of treatment with short-acting insulin (SAI) analogues versus structurally unchanged short-acting insulin (regular insulin) on glycaemic control and on the risk of hypoglycaemic episodes in type 1 diabetic patients using different insulin treatment strategies. METHODS: We performed a meta-analysis of 27 randomised controlled trials that compared the effect of SAI analogues with regular insulin in patients with type 1 diabetes mellitus. The treatments were administered either via continuous subcutaneous insulin infusion (CSII) or by conventional intensified insulin therapy (IIT) with short-acting insulin injections before meals and basal insulin administered once or twice daily in most cases. RESULTS: HbA(1)c levels were reported for 20 studies. For studies using CSII, the weighted mean difference between values obtained using SAI analogues and regular insulin was -0.19% (95% CI: -0.27 to -0.12), whereas the corresponding value for injection studies was -0.08% (95% CI: -0.15 to -0.02). For the analysis of overall hypoglycaemia, we used the results from nine studies that reported the mean frequency of hypoglycaemic episodes per patient per month. For studies using CSII, the standardised mean difference between SAI analogues and regular insulin was -0.07 (95% CI: -0.43 to 0.28), whereas for IIT studies the corresponding value was -0.04 (95% CI: -0.24 to 0.16). CONCLUSIONS/INTERPRETATION: Taking into consideration the low quality of the trials included, we can conclude that use of a short-acting insulin analogue in CSII therapy provides a small, but statistically significant improvement in glycaemic control compared with regular insulin. An even smaller effect was obtained with the use of ITT. The rate of overall hypoglycaemic episodes was not significantly reduced with short-acting insulin analogues in either injection regimen.