Hypoglycaemia Awareness Key to Predicting Severe Events in Type 1 Diabetes, Study Shows
UK: People with type 1 diabetes who experience impaired awareness of hypoglycaemia (IAH) face a markedly higher risk of severe low-blood-sugar episodes when their glucose levels drop frequently, according to new findings in Diabetologia.
The international SFDT1 study demonstrates that simply measuring “time below range” (TBR) on a continuous glucose monitor is insufficient to predict future severe hypoglycemia (SHE); combining TBR data with an assessment of hypoglycemia awareness yields a far more accurate risk identification.
Researchers led by Dr. Pratik Choudhary from the Diabetes Research Centre, University of Leicester, analysed data from 848 adults with type 1 diabetes who were using continuous glucose monitoring. Over a 12-month follow-up, 11.7% of participants reported at least one severe hypoglycemic event—a condition where blood glucose levels fall so low that outside assistance is required. The team examined two TBR thresholds: glucose levels below 70 mg/dl (TBR70) and below 54 mg/dl (TBR54).
The study found the following:
- Higher time below range (TBR) alone did not reliably predict severe hypoglycaemia.
- Participants with normal hypoglycaemia awareness showed a low and stable risk across all TBR levels.
- Individuals with both impaired hypoglycaemia awareness (IAH) and significant time in low-glucose ranges faced a markedly higher risk.
- Those with TBR70 greater than 6% and IAH had more than three times the odds of a severe hypoglycaemic event (odds ratio 3.32) compared with those with minimal TBR and normal awareness.
- Participants with TBR54 of at least 1% combined with IAH nearly tripled the risk of a severe event (odds ratio 2.99).
Hypoglycaemia awareness was measured using the Gold Score, which evaluates a person’s ability to recognize symptoms of falling blood sugar. When this awareness is impaired, individuals may fail to take corrective action early, allowing blood glucose to reach dangerously low levels without warning.
The researchers highlighted that current diabetes care often focuses on metrics like TBR to guide therapy adjustments. These results suggest that such measures, while important, cannot be used in isolation to flag those most likely to experience life-threatening hypoglycaemia. Instead, systematic screening for IAH should accompany continuous glucose monitoring metrics.
Despite advances in diabetes technology—including insulin pumps and real-time glucose sensors—severe hypoglycaemia remains a persistent challenge. The study highlights the need for comprehensive assessments that integrate behavioural and physiological factors. Educational and cognitive-behavioural strategies aimed at improving hypoglycaemia recognition, alongside careful glycaemic monitoring, may help reduce risk.
"The SFDT1 study demonstrates that time spent in hypoglycaemic ranges alone is an inadequate predictor of severe events. Evaluating hypoglycaemia awareness provides critical context, enabling clinicians to identify those at highest risk and tailor interventions accordingly," the authors wrote.
"This combined approach could be pivotal in preventing dangerous hypoglycaemic episodes and improving the safety of diabetes management for people with type 1 diabetes," they concluded.
Reference:
Canha, D., Choudhary, P., Cosson, E. et al. Time below range alone is insufficient to identify severe hypoglycaemia risk in type 1 diabetes—the critical role of hypoglycaemia awareness: results from the SFDT1 study. Diabetologia (2025). https://doi.org/10.1007/s00125-025-06536-x
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