Timing of Insulin Glargine Administration During Intermittent Ramadan Fasting in patients With Type1 Diabetes: A Randomized Controlled Trial (GLARIF)

OBJECTIVE: The effect of basal insulin timing on hypoglycemia during Ramadan fasting remains uncertain despite recommendations to administer basal insulin earlier in the evening. We evaluated whether early evening compared with bedtime administration of insulin glargine reduces hypoglycemia and improves glycemic outcomes in individuals with type1 diabetes (T1D) fasting during Ramadan. METHODS: This multicenter open-label randomized controlled trial was conducted across 4 centers in Saudi Arabia. Participants with T1D intending to fast Ramadan were randomized to early evening or bedtime glargine administration. Glucose data were collected using self-monitoring of blood glucose (SMBG), intermittently scanned continuous glucose monitoring (FreeStyle Libre), and blinded continuous glucose monitoring (CGM; Medtronic iPro2). RESULTS: A total of 185 participants were analyzed (91 early evening, 94 bedtime). Baseline characteristics were similar between groups. Fasting interruption occurred in 75.9% versus 76.3% of participants (P = .94), with hypoglycemia accounting for >90% of interruptions in both groups. Hypoglycemia occurred predominantly during the morning period regardless of basal insulin timing. Severe hypoglycemia was reported in 2 versus 5 participants, and 1 diabetic ketoacidosis admission occurred in each group. Continuous glucose monitoring-derived glycemic metrics were similar between groups. Time in range (70-180 mg/dL) was 44.6% versus 46.1% (P = .70), time below range (<70 mg/dL) was 7.9% versus 6.4% (P = .35), and time above range (>180 mg/dL) was 47.5% in both groups (P = .99). Self-monitoring of blood glucose-detected hypoglycemic episodes and CGM-detected low glucose excursions were also comparable. Area under the curve below range was higher in the early evening group (P = .04). CONCLUSION: Changing insulin glargine administration from bedtime to earlier evening hours during Ramadan fasting did not significantly reduce hypoglycemia or improve overall glucose profiles in individuals with T1D. These findings suggest that routine universal shifting of basal insulin timing during Ramadan may not be necessary and support an individualized approach based on patient preference and glucose patterns. CLINICALTRIALS: gov identifier: NCT04383990.