Glycemic Control During Continuous Subcutaneous Insulin Infusion Versus Multiple Daily Insulin Injections in Type 2 Diabetes: Individual Patient Data Meta-analysis and Meta-regression of Randomized Controlled Trials.

OBJECTIVE

To compare glycemic control during continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injections (MDI) in people with type 2 diabetes to identify patient characteristics that determine those best treated by CSII.

RESEARCH DESIGN AND METHODS

Randomized controlled trials were selected comparing HbA during CSII versus MDI in people with type 2 diabetes. Data sources included Cochrane database and Ovid Medline. We explored patient-level determinants of final HbA level and insulin dose using Bayesian meta-regression models of individual patient data and summary effects using two-step meta-analysis. Hypoglycemia data were unavailable.

RESULTS

Five trials were identified, with 287 patients randomized to receive MDI and 303 to receive CSII. Baseline HbA was the best determinant of final HbA: HbA difference (%) = 1.575 - (0.216 [95% credible interval 0.371-0.043] × baseline HbA) for all trials, but with largest effect in the trial with prerandomization optimization of control. Baseline insulin dose was best predictor of final insulin dose: insulin dose difference (units/kg) = 0.1245 - (0.382 [0.510-0.254] × baseline insulin dose). Overall HbA difference was -0.40% (-0.86 to 0.05 [-4.4 mmol/mol (-9.4 to 0.6)]). Overall insulin dose was reduced by -0.25 units/kg (-0.31 to -0.19) (26% reduction on CSII), and by -24.0 units/day (-30.6 to -17.5). Mean weight did not differ between treatments (0.08 kg [-0.33 to 0.48]).

CONCLUSIONS

CSII achieves better glycemic control than MDI in people with poorly controlled type 2 diabetes, with ∼26% reduction in insulin requirements and no weight change. The best effect is in those worst controlled and with the highest insulin dose at baseline.