A Comparison of the Rates of Clock-Based Nocturnal Hypoglycemia and Hypoglycemia While Asleep Among People Living with Diabetes: Findings from the Hypo-METRICS Study

Gilberte Martine-Edith*, Patrick Divilly, Natalie Zaremba, Uffe Søholm, Melanie Broadley, Petra Martina Baumann, Zeinab Mahmoudi, Mikel Gomes, Namam Ali, Evertine J. Abbink, Bastiaan de Galan, Julie Brøsen, Ulrik Pedersen-Bjergaard, Allan A. Vaag, Rory J. McCrimmon, Eric Renard, Simon Heller, Mark Evans, Monika Cigler, Julia K. MaderJane Speight, Frans Pouwer, Stephanie A. Amiel, Pratik Choudhary

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

3 Citations (Scopus)

Abstract

Introduction: Nocturnal hypoglycemia is generally calculated between 00:00 and 06:00. However, those hours may not accurately reflect sleeping patterns and it is unknown whether this leads to bias. We therefore compared hypoglycemia rates while asleep with those of clock-based nocturnal hypoglycemia in adults with type 1 diabetes (T1D) or insulin-treated type 2 diabetes (T2D). Methods: Participants from the Hypo-METRICS study wore a blinded continuous glucose monitor and a Fitbit Charge 4 activity monitor for 10 weeks. They recorded details of episodes of hypoglycemia using a smartphone app. Sensor-detected hypoglycemia (SDH) and person-reported hypoglycemia (PRH) were categorized as nocturnal (00:00-06:00 h) versus diurnal and while asleep versus awake defined by Fitbit sleeping intervals. Paired-sample Wilcoxon tests were used to examine the differences in hypoglycemia rates. Results: A total of 574 participants [47% T1D, 45% women, 89% white, median (interquartile range) age 56 (45-66) years, and hemoglobin A1c 7.3% (6.8-8.0)] were included. Median sleep duration was 6.1 h (5.2-6.8), bedtime and waking time ∼23:30 and 07:30, respectively. There were higher median weekly rates of SDH and PRH while asleep than clock-based nocturnal SDH and PRH among people with T1D, especially for SDH <70 mg/dL (1.7 vs. 1.4, P < 0.001). Higher weekly rates of SDH while asleep than nocturnal SDH were found among people with T2D, especially for SDH <70 mg/dL (0.8 vs. 0.7, P < 0.001). Conclusion: Using 00:00 to 06:00 as a proxy for sleeping hours may underestimate hypoglycemia while asleep. Future hypoglycemia research should consider the use of sleep trackers to record sleep and reflect hypoglycemia while asleep more accurately. The trial registration number is NCT04304963.

Original languageEnglish
JournalDiabetes Technology and Therapeutics
Volume26
Issue number7
Pages (from-to)433-441
ISSN1520-9156
DOIs
Publication statusPublished - 2024

Bibliographical note

Publisher Copyright:
Copyright 2024, Mary Ann Liebert, Inc., publishers.

Keywords

  • Continuous glucose monitoring
  • Fitbit
  • Hypo-METRICS
  • Nocturnal hypoglycemia
  • Sleep tracking

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