Sustained reduction in severe hypoglycemia in adults with type 1 diabetes complicated by impaired awareness of hypoglycemia: Two-year follow-up in the HypoCOMPaSS randomized clinical Trial

OBJECTIVE Severe hypoglycemia is a feared complication of type 1 diabetes; yet, few trials have targeted prevention using optimized self-management (educational, therapeutic, and technological support). We aimed to investigate whether improved awareness and reduced severe hypoglycemia, achieved during an intensive randomized clinical trial (RCT), were sustained after return to routine care. RESEARCH DESIGN AND METHODS Ninety-six adults with type 1 diabetes (29 ± 12 years’ duration) and impaired awareness of hypoglycemia at five U.K. tertiary referral diabetes centers were recruited into a 24-week 2 × 2 factorial RCT (HypoCOMPaSS). Participants were randomized to pump (continuous subcutaneous insulin infusion [CSII]) or multiple daily injections (MDIs) and real-time continuous glucose monitoring (RT-CGM) or self-monitoring of blood glucose (SMBG), with equal education/attention to all groups. At 24 weeks, participants returned to routine care with follow-up until 24 months, including free choice of MDI/CSII; RT-CGM vs. SMBG comparison continued to 24 months. Primary outcome was mean difference (baseline to 24 months [between groups]) in hypoglycemia awareness. RESULTS Improvement in hypoglycemia awareness was sustained (Gold score at baseline 5.1 ± 1.1 vs. 24 months 3.7 ± 1.9; P < 0.0001). Severe hypoglycemia rate was reduced from 8.9 ± 12.8 episodes/person-year over the 12 months prestudy to 0.4 ± 0.8 over 24 months (P < 0.0001). HbA1c improved (baseline 8.2 ± 3.2% [66 ± 12 mmol/mol] vs. 24 months 7.7 ± 3.1% [61 ± 10 mmol/mol]; P = 0.003). Improvement in treatment satisfaction and reduced fear of hypoglycemia were sustained. There were no significant differences between interventions at 24 months. CONCLUSIONS Optimized insulin replacement and glucose monitoring underpinned by hypoglycemia-focused structured education should be provided to all with type 1 diabetes complicated by impaired awareness of hypoglycemia.