Characterising impaired awareness of hypoglycaemia and associated risks through HypoA-Q: findings from a T1D Exchange cohort

Aims/hypothesis: We aimed to: (1) externally validate the five-item Hypoglycaemia Awareness Questionnaire (HypoA-Q) impaired awareness subscale (HypoA-Q IA); (2) examine how impaired awareness of hypoglycaemia (IAH) relates to the risk of severe hypoglycaemia and level 2 hypoglycaemia; and (3) identify factors associated with IAH.

Methods: Nationwide survey of T1D Exchange registrants was conducted to collect data on demographics, 6 month severe-hypoglycaemia history, hypoglycaemia awareness status (via HypoA-Q IA, the Gold instrument and the Clarke instrument) and continuous glucose monitor (CGM) measures. The Clarke hypoglycaemia awareness factor (Clarke-HAF) was calculated to exclude severe-hypoglycaemia history items. Analyses included Cronbach's α, Spearman correlations and logistic regression.

Results: Valid survey responses were collected from N=1580 adults with type 1 diabetes (median age, 44 years; 52% female participants; median HbA_1c, 48 mmol/mol [6.5%]). Of these, 94% of participants were using CGMs and 69% were using hybrid closed-loop (HCL) systems; 30% had at least one severe-hypoglycaemia episode in the past 6 months. The HypoA-Q IA had satisfactory internal reliability (α=0.79) and construct validity. Higher HypoA-Q IA scores were independently associated with greater risk of severe hypoglycaemia (p<0.001), performing comparably to the Gold instrument and the Clarke-HAF instrument. HypoA-Q IA-determined IAH was independently associated with 88% higher odds of developing severe hypoglycaemia (p<0.001) and twofold higher odds for spending ≥1% of time in level 2 hypoglycaemia (p=0.011). Higher age and longer diabetes duration were associated with higher IAH risk (p<0.001). CGM and HCL use was associated with lower IAH risk (p<0.001).

Conclusions/interpretation: The HypoA-Q IA is a brief, valid and reliable tool for assessing IAH in today's technology-oriented era. IAH was independently associated with severe hypoglycaemia and level 2 hypoglycaemia in a cohort with high prevalence of advanced diabetes technology use and HbA_1c within the recommended range. CGM and HCL use was related to lower IAH risk.