STAR 3 Study

STAR 3 Study on Sensor-Augmented
Pump Therapy for A1C Reduction

The most wide-ranging clinical implications about the use of integrated insulin pump therapy comes from the STAR 3 study, published in 2010 in the New England Journal of Medicine.

Purpose

To examine the effectiveness of sensor-augmented pump (SAP) therapy in subjects transitioning from previously optimized multiple daily injections (MDI) to SAP therapy for 6 months and the glycemic benefits of sustained use of SAP for 18 months.

Conclusions
  • The continuation phase results support and extend the findings of the study phase.
  • Switching from optimized MDI to SAP therapy allows for rapid and safe A1C reductions.
  • Glycemic benefits of SAP persist for at least 18 months.
  • Maximal glycemic control is associated with more frequent wearing of the CGM sensor.
 

1Bergenstal RM, Tamborlane WV, Ahmann A, et al. Sensor-augmented pump therapy for A1C reduction (STAR 3) study: results from the 6-month
  continuation phase. Diabetes Care. 2011;34:2403-2405.
 

Sensor-Augmented Pump Therapy for A1C Reduction (STAR 3) Study:

Results from the 6-month continuation phase

Purpose
  • To examine the effectiveness of sensor-augmented pump (SAP) therapy in subjects transitioning from previously optimized multiple daily injections (MDI) to SAP therapy for 6 months and the glycemic benefits of sustained use of SAP for 18 months.
Endpoints
  • The primary endpoint was the change in A1C from 12 months to 18 months in the two treatment groups: cross-over and sustained SAP use.
  • The primary safety measure was the difference in the rates of severe hypoglycemia between the two groups.
Methods
  • Subjects aged 7-70 years of age were randomized to either SAP therapy with insulin aspart or MDI using insulin aspart and insulin glargine.
  • Other eligibility criteria included: use of MDI with a long-acting insulin analog, A1C between 7.4% and 9.5% and less than 2 severe hypoglycemic episodes over the previous year.
  • Subjects randomized to MDI were placed on individualized regimens by their respective investigator-physicians. All subjects were trained on the use of CareLink® Therapy Management Software for Diabetes.
  • Quarterly visits provided for individual therapy optimization and A1C measurements. Training and visit schedules were identical after the first 5 weeks, during which SAP patients completed device training.
  • All subjects completed blinded baseline CGM studies. CGM studies were also performed at 6 and 12 months for all subjects; the MDI group was blinded to the results.
  • Following completion of the 12-month study, there was an optional 6-month, single, crossover continuation phase. In the continuation phase, SAP subjects could continue on SAP, those on MDI could switch to SAP for the 6-month study period (crossover group).
  • The complete study design has been reported elsewhere.1
Results
  • 443 subjects completed the study phase. Of those, 420 enrolled in the continuation phase: 204 of 216 (94%) SAP subjects and 190 of 204 (93%) MDI crossover to SAP subjects, completed both phases of the study.
  • There was a significant decrease in A1C from 12 months to 15 and 18 months in the crossover group (8.0 ± 0.1% vs. 7.6 ± 0.1%, P<0.001, respectively) (Fig A).
  • The significant decrease in A1C values in the crossover group was seen in adults (n=141, Fig B) and children (n=63, Fig C).
  • Maximum glycemic improvements in the crossover group were seen in those with sensor wear times >60%.
  • In the continuation phase, mean sensor wear times were greater among adults (61 ± 24% of the time) than in children (45 ± 24% of the time) (P<0.001).
  • Improvement in A1C levels in the SAP group was maintained during the continuation phase (Fig A). There was no significant difference between the 12 month A1C value in this group and the 15 and 18 month A1C values.
  • Subjects in the SAP group that maintained their A1C values used CGM sensors >40% of the time. Subjects who used sensors less often experienced slight deteriorations in glycemic control.
  • There was no significant difference in the rates of severe hypoglycemia between the SAP and crossover groups during the continuation phase (2.8% vs. 1.0%, respectively, P>0.05).
1Bergenstal RM, Tamborlane WV, Ahmann A, et al. Sensor-augmented pump therapy for A1C reduction (STAR 3) study: results from the 6-month
  continuation phase. Diabetes Care. 2011;34:2403-2405.
 

Sensor-Augmented Pump Therapy for A1C Reduction (STAR 3) Study:

Results from the 6-month continuation phase

A. All Subjects
All Subjects

B. Ages 19-70
Ages 19-70
C. Ages 7-18
Ages 7-18

Author's Conclusions

The continuation phase results support and extend the findings of the study phase.
Switching from optimized MDI to SAP therapy allows for rapid and safe A1C reductions.
Glycemic benefits of SAP persist for at least 18 months.
Maximal glycemic control is associated with more frequent wearing of the CGM sensor.

1Davis SN, Horton ES, Battelino T, Rubin RR, Schulman KA, Tamborlane WV. STAR 3 randomized controlled trial to compare sensor-augmented insulin
  pump therapy with multiple daily injections in the treatment of diabetes: research design, methods, and baseline characteristics of enrolled subjects.
  Diabetes Technol Ther. 2010;12:249-255.
2Bergenstal RM, Tamborlane WV, Ahmann A, et al. Sensor-augmented pump therapy for A1C reduction (STAR 3) study: results from the 6-month
  continuation phase. Diabetes Care. 2011;34:2403-2405.