Potential benefits of hybrid closed-loop systems for managing moderate- to high-risk individuals with type 1 diabetes...

We evaluated whether using hybrid closed-loop systems (HCL) provides a safer, more effective fasting experience compared with multiple daily injections with continuous glucose monitoring (MDI + CGM) for people with T1D at moderate-to-high risk in a real-world setting.

In this multicentre prospective study, 178 adults with T1D [HCL n = 98 (39 males 59 females); MDI + CGM n = 80 (30 males 50 females)] who chose to fast in Ramadan of 2024 were assessed for clinical and glycaemic profiles and risk stratified according to the International Diabetes Federation-Diabetes and Ramadan (IDF-DAR) criteria. The composite endpoint was completing >15 days of fasting and achieving time in range (TIR) ≥70%, with time below range (TBR) <4%.

At baseline, the MDI + CGM group was older than the HCL group (mean ± standard deviation, 29.2 ± 9.6 vs. 26.3 ± 9.4 years) (p = 0.049). Half of the HCL participants met the composite endpoint versus only 8% of MDI + CGM users (p < 0.001). Similarly, participants in the HCL group were able to complete all possible fasting days more frequently than the MDI + CGM group (p < 0.05). The use of HCL was associated with nine-fold higher odds ratio (OR) (9.4 [95% confidence intervals 3.1-28.4]) of achieving the composite endpoint.

For moderate-to-high risk individuals with T1D, HCL substantially improves the safety and feasibility of prolonged daytime fasting during Ramadan, outperforming MDI + CGM in achieving glycaemic and fasting targets. While the results favour HCL, causal inference is still limited, given the lack of randomization and cross-over design. Concurrently, there is a need to update current recommendations for high-risk populations and underscore the central role of advanced diabetes technology in Ramadan.