Glycemic Dynamics and Management Strategies in Individuals With Type 1 Diabetes During Ramadan: A Continuous Glucose Monitoring-Based Narrative Review

Ramadan is the ninth month of the Islamic lunar calendar, during which healthy adult Muslims fast daily from sunrise to sunset. Fasting during Ramadan presents unique physiological and behavioral challenges for individuals with type 1 diabetes mellitus (T1DM), who are generally classified as high- to very-high-risk for fasting. Because traditional markers such as hemoglobin A1C (HbA1c) and self-monitored blood glucose fail to capture short-term glycemic excursions, continuous glucose monitoring has become essential for evaluating real-world glycemic dynamics during this period. This review examines recent continuous glucose monitoring-based studies to characterize the direction, magnitude, and determinants of glycemic changes during Ramadan. Across the literature, findings demonstrate considerable heterogeneity, ranging from glycemic deterioration to temporary improvement or stability, influenced heavily by baseline glycemic control, age, insulin delivery modalities, and whether participants received structured pre-Ramadan education. Notably, exposure to hypoglycemia does not appear to increase during Ramadan fasting; instead, postprandial hyperglycemia clustered around the evening and pre-dawn meals emerges as the predominant and most variable challenge. Structured pre-Ramadan education, individualized insulin adjustments, and continuous glucose monitoring-guided management are critical levers for supporting safer fasting in this population.