Impact of impaired awareness of hypoglycemia on glucose decline during and after exercise in T1D: The T1DEXI Study.

OBJECTIVE: To assess whether impaired awareness of hypoglycemia (IAH) affects exercise-associated hypoglycemia in adults with type 1 diabetes (T1D).

METHODS: We compared continuous glucose monitoring (CGM)-measured glucose during exercise and for 24-hours following exercise from 95 adults with T1D and IAH (Clarke score ≥4 or ≥1 severe hypoglycemic event within the past year) to 95 'Aware' adults (Clarke score ≤2 and no severe hypoglycemic event within the past year) matched on sex, age, insulin delivery modality, and HbA1c. A total of 4,236 exercise sessions, and 1,794 exercise days and 839 sedentary days, defined as 24-hours following exercise or a day without exercise, respectively, were available for analysis.

RESULTS: Participants with IAH exhibited a non-significant trend towards greater decline in glucose during exercise compared to 'Aware' (-21 ± 44 vs. -19 ± 43 mg/dL [-1.17 ± 2.44 vs. -1.05 ± 2.39 mmol/L], adjusted group difference of -4.2 [95% CI: -8.4 to 0.05] mg/dL [-0.23 95% CI: -0.47 to 0.003 mmol/L], P = 0.051). Individuals with IAH had higher proportion of days with hypoglycemic events <70 mg/dL[3.89 mmol/L] (≥15 minutes <70 mg/dL[<3.89 mmol/L]) both on exercise days (51% vs. 43%, P = 0.006) and sedentary days (48% vs. 30%, P = 0.001). The increased odds of experiencing a hypoglycemic event <70 mg/dL[<3.89 mmol/L] for individuals with IAH compared to 'Aware' did not differ significantly between exercise and sedentary days (interaction P = 0.36).

CONCLUSION: Individuals with IAH have a higher underlying risk of hypoglycemia than 'Aware' individuals. Exercise does not appear to differentially increase risk for hypoglycemia during the activity, or in the subsequent 24-hours for IAH compared to Aware individuals with T1D.