Predictors of Recurrent Severe Hypoglycemia in Adults With Type 1 Diabetes and Impaired Awareness of Hypoglycemia During the HypoCOMPaSS Study.

OBJECTIVE: The HypoCOMPaSS study was designed to test the hypothesis that successful avoidance of biochemical hypoglycemia without compromising overall glycemic control would restore sufficient hypoglycemia awareness to prevent recurrent severe hypoglycemia in the majority of participants with established type 1 diabetes. Before starting the study, we planned to investigate associations between baseline characteristics and recurrent severe hypoglycemia over 2 years' follow-up. RESEARCH DESIGN AND METHODS: A total of 96 adults with type 1 diabetes and impaired awareness of hypoglycemia participated in a 24-week 2 × 2 factorial randomized controlled trial comparing insulin delivery and glucose monitoring modalities, with the goal of rigorous biochemical hypoglycemia avoidance. The analysis included 71 participants who had experienced severe hypoglycemia in the 12-month prestudy with confirmed absence (complete responder) or presence (incomplete responder) of severe hypoglycemia over 24 months' follow-up. RESULTS: There were 43 (61%) complete responders and 28 (39%) incomplete responders experiencing mean ± SD 1.5 ± 1.0 severe hypoglycemia events/person-year. At 24 months, incomplete responders spent no more time with glucose ≤3 mmol/L (1.4 ± 2.1% vs. 3.0 ± 4.8% for complete responders; P = 0.26), with lower total daily insulin dose (0.45 vs. 0.58 units/24 h; P = 0.01) and greater impairment of hypoglycemia awareness (Clarke score: 3.8 ± 2.2 vs. 2.0 ± 1.9; P = 0.01). Baseline severe hypoglycemia rate (16.9 ± 16.3 vs. 6.4 ± 10.8 events/person-year; P = 0.002) and fear of hypoglycemia were higher in incomplete responders. Peripheral neuropathy was more prevalent in incomplete responders (11 [39%] vs. 2 [4.7%]; P < 0.001) with a trend toward increased autonomic neuropathy. CONCLUSIONS: Recurrent severe hypoglycemia was associated with higher preintervention severe hypoglycemia rate, fear of hypoglycemia, and concomitant neuropathy.

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.

Recovery of hypoglycemia awareness in long-standing type 1 diabetes: a multicenter 2 × 2 factorial randomized controlled trial comparing insulin pump with multiple daily injections and continuous with conventional glucose self-monitoring (HypoCOMPaSS).

OBJECTIVE: To determine whether impaired awareness of hypoglycemia (IAH) can be improved and severe hypoglycemia (SH) prevented in type 1 diabetes, we compared an insulin pump (continuous subcutaneous insulin infusion [CSII]) with multiple daily injections (MDIs) and adjuvant real-time continuous glucose monitoring (RT) with conventional self-monitoring of blood glucose (SMBG). RESEARCH DESIGN AND METHODS: A 24-week 2 × 2 factorial randomized controlled trial in adults with type 1 diabetes and IAH was conducted. All received comparable education, support, and congruent therapeutic targets aimed at rigorous avoidance of biochemical hypoglycemia without relaxing overall control. Primary end point was between-intervention difference in 24-week hypoglycemia awareness (Gold score). RESULTS: A total of 96 participants (mean diabetes duration 29 years) were randomized. Overall, biochemical hypoglycemia (≤3.0 mmol/L) decreased (53 ± 63 to 24 ± 56 min/24 h; P = 0.004 [t test]) without deterioration in HbA1c. Hypoglycemia awareness improved (5.1 ± 1.1 to 4.1 ± 1.6; P = 0.0001 [t test]) with decreased SH (8.9 ± 13.4 to 0.8 ± 1.8 episodes/patient-year; P = 0.0001 [t test]). At 24 weeks, there was no significant difference in awareness comparing CSII with MDI (4.1 ± 1.6 vs. 4.2 ± 1.7; difference 0.1; 95% CI -0.6 to 0.8) and RT with SMBG (4.3 ± 1.6 vs. 4.0 ± 1.7; difference -0.3; 95% CI -1.0 to 0.4). Between-group analyses demonstrated comparable reductions in SH, fear of hypoglycemia, and insulin doses with equivalent HbA1c. Treatment satisfaction was higher with CSII than MDI (32 ± 3 vs. 29 ± 6; P = 0.0003 [t test]), but comparable with SMBG and RT (30 ± 5 vs. 30 ± 5; P = 0.79 [t test]). CONCLUSIONS: Hypoglycemia awareness can be improved and recurrent SH prevented in long-standing type 1 diabetes without relaxing HbA1c. Similar biomedical outcomes can be attained with conventional MDI and SMBG regimens compared with CSII/RT, although satisfaction was higher with CSII.

Restoration of self-awareness of hypoglycemia in adults with long-standing type 1 diabetes: hyperinsulinemic-hypoglycemic clamp substudy results from the HypoCOMPaSS trial.

OBJECTIVE: Impaired awareness of hypoglycemia (IAH) and defective counterregulation significantly increase severe hypoglycemia risk in type 1 diabetes (T1D). We evaluated restoration of IAH/defective counterregulation by a treatment strategy targeted at hypoglycemia avoidance in adults with T1D with IAH (Gold score ≥4) participating in the U.K.-based multicenter HypoCOMPaSS randomized controlled trial. RESEARCH DESIGN AND METHODS: Eighteen subjects with T1D and IAH (mean ± SD age 50 ± 9 years, T1D duration 35 ± 10 years, HbA1c 8.1 ± 1.0% [65 ± 10.9 mmol/mol]) underwent stepped hyperinsulinemic-hypoglycemic clamp studies before and after a 6-month intervention. The intervention comprised the HypoCOMPaSS education tool in all and randomized allocation, in a 2 × 2 factorial study design, to multiple daily insulin analog injections or continuous subcutaneous insulin infusion therapy and conventional glucose monitoring or real-time continuous glucose monitoring. Symptoms, cognitive function, and counterregulatory hormones were measured at each glucose plateau (5.0, 3.8, 3.4, 2.8, and 2.4 mmol/L), with each step lasting 40 min with subjects kept blinded to their actual glucose value throughout clamp studies. RESULTS: After intervention, glucose concentrations at which subjects first felt hypoglycemic increased (mean ± SE from 2.6 ± 0.1 to 3.1 ± 0.2 mmol/L, P = 0.02), and symptom and plasma metanephrine responses to hypoglycemia were higher (median area under curve for symptoms, 580 [interquartile range {IQR} 420-780] vs. 710 [460-1,260], P = 0.02; metanephrine, 2,412 [-3,026 to 7,279] vs. 5,180 [-771 to 11,513], P = 0.01). Glycemic threshold for deterioration of cognitive function measured by four-choice reaction time was unchanged, while the color-word Stroop test showed a degree of adaptation. CONCLUSIONS: Even in long-standing T1D, IAH and defective counterregulation may be improved by a clinical strategy aimed at hypoglycemia avoidance.