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CC BY 4.0 · Journal of Diabetes and Endocrine Practice
DOI: 10.1055/s-0045-1812070
Original Article

Timing of the Final Nocturnal Meal and Hypoglycemia Risk in Fasting Individuals with Type 1 Diabetes: A Randomized Crossover Trial

Authors

  • Reem Alamoudi 

    1   Medicine Department, King Abdulaziz Medical City, Ministry of National Guard Health, Saudi Arabia
    2   King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
    3   King Abdullah International Medical Research Center, Jeddah, Saudi Arabia

  • Mishary Alassiri

    2   King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia

  • Abdulrhman Aljawhrji

    1   Medicine Department, King Abdulaziz Medical City, Ministry of National Guard Health, Saudi Arabia

  • Mazin Almaghrabi

    1   Medicine Department, King Abdulaziz Medical City, Ministry of National Guard Health, Saudi Arabia
    2   King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia

  • Dalia Basulayman

    1   Medicine Department, King Abdulaziz Medical City, Ministry of National Guard Health, Saudi Arabia

  • Majed Ramadan

    3   King Abdullah International Medical Research Center, Jeddah, Saudi Arabia

Funding and Sponsorship None.
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Abstract

Background

Despite known risks, many individuals with type 1 diabetes (T1D) fast during Ramadan. Local studies have shown that breaking the fast due to hypoglycemia is common during the morning hours; however, the optimal timing of Suhoor (the predawn meal) has not been thoroughly investigated. Current guidelines recommend late Suhoor; however, this does not provide sufficient time for correction in case of insulin overdosing and can lead to breaking the fast in the early hours.

Objective

To compare the risk of hypoglycemia in individuals with T1D fasting during Ramadan between an early Suhoor (90–120 minutes before dawn plus a predawn snack) and a late Suhoor (30 minutes before dawn).

Methods

In this randomized crossover trial, participants with T1D were assigned to either an early or late Suhoor regimen for 1 week, then switched to the other regimen for the second week. Data were collected via questionnaires and flash continuous glucose monitoring (FCGM).

Results

Forty-four patients were enrolled (73.5% female, mean age 25 ± 5.9 years). During early versus late Suhoor, the proportion of individuals who broke their fast due to hypoglycemia was 64.5% versus 58.1% (p = 0.18). Most hypoglycemia episodes occurred during early fasting hours. Mean fast-breaking days were similar (2.5 vs. 2.05; p = 0.7). FCGM-detected hypoglycemia rates were comparable (5.5 vs. 5.4 events/week; p = 0.65), but hypoglycemia was significantly more frequent in the morning/noon than pre-sunset (1.9 vs. 0.43 events; p < 0.001). The ambulatory glucose profiles of the early versus late regimens were glucose management indicator: 7.58 ± 1.01 versus 7.49 ± 0.9 (p = 0.36), time in range (70–180 mg/dL) of 46.9 ± 17.3% versus 47.9 ± 17.3% (p = 0.99), time below range (<70 mg/dL) of 8.6 ± 14.3% versus 7.8 ± 7.6% (p = 0.15), time above range (>180 mg/dL) of 45.8 ± 22.03% versus 44.5 ± 20.1% (p = 0.6), and glucose variability of 39.3 ± 10.5% versus 40.6 ± 6.5% (p = 0.005).

Conclusion

Adjusting Suhoor timing was well tolerated and offered flexibility. Further research is needed to optimize fasting strategies for individuals with T1D.

Keywords

Ramadan - fasting - early Suhoor - late Suhoor - type 1 diabetes

Author Contribution

All named authors participated in the conception, planning, and conduct of the study; drafting and revision of the manuscript; and approval of its final version.


Compliance with Ethical Principles

The trial protocol was approved by the Research Office of King Abdulaziz International Medical Research Center (IRBC/0517/21). All participants provided written informed consent. ClinicalTrials.gov: NCT04864483.




Publication History

Article published online:
17 October 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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