Continuous glucose monitoring detected hypoglycaemia in the Treating to Target in Type 2 Diabetes Trial (4-T)

for the 4-T Study Group

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Aims Hypoglycaemia is a significant risk in insulin treated type 2 diabetes and has been associated with future risk of cardiovascular events. We compared the frequency of low-glucose events using continuous glucose monitoring (CGM) with that of self-reported hypoglycemic events at the end of the first and third years of the Treating to Target in Type 2 Diabetes Trial (4-T), which compared biphasic, prandial and basal insulin regimens added to sulfonylurea and metformin. Methods CGM using a Medtronic Gold system was performed in a subgroup of 4-T participants. CGM detected low-glucose events were defined at thresholds of ≤3.0 (CGM3.0) and ≤2.2 (CGM2.2) mmol/l. Results Of the 110 participants, 106 and 70 had CGM analysable data at the end of years 1 and 3 respectively. In both years, the frequency of CGM detected low glucose events was several fold higher than that of self-reported hypoglycaemia (symptoms with blood glucose less than 3.1 mmol/l [<56 mg/dl]). At the end of the first year, CGM3.0 and CGM2.2 mean (95%CI) event frequencies, expressed at events per participant per year, were 120 (85, 155) and 41 (21, 61) compared with 17 (8, 29) self-reported events during CGM, each p = 0.001. The disparity at the end of the third year was similar. Conclusions These data demonstrate the likely under-reporting of hypoglycaemia and of potential hypoglycaemia unawareness in clinical trials. The clinical implications of these findings need to be explored further (ISRCTN No ISRCTN51125379).

Original languageEnglish
Pages (from-to)161-168
Number of pages8
JournalDiabetes Research and Clinical Practice
StatePublished - Sep 2017
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2017


Dr. Levy has acted on advisory boards for Lilly, Novo Nordisk and Novartis. Professor Melanie Davies has acted as consultant, advisory board member and speaker for Novo Nordisk, Sanofi-Aventis, Lilly, Merck Sharp & Dohme, Boehringer Ingelheim, AstraZeneca and Janssen and as a speaker for Mitsubishi Tanabe Pharma Corporation. She has received grants in support of investigator and investigator initiated trials from Novo Nordisk, Sanofi-Aventis and Lilly. Professor Holman reports receiving grant support from Bayer, AstraZeneca, MSD and consulting fees from Amgen, Elcelyx, MSD, Novartis, Novo Nordisk.

FundersFunder number
Boehringer Ingelheim
Novo Nordisk


    • Clinical trials
    • Continuous glucose monitoring
    • Hypoglycaemia
    • Insulin therapy
    • Type 2 diabetes


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