The impact of continuous glucose monitoring on glycemic control, health outcomes, and safety during Ramadan fasting: A systematic review and meta-analysis

Ramadan fasting imposes unique metabolic demands on individuals with diabetes mellitus (DM), creating increased risks of hypoglycemia and hyperglycemia. Continuous Glucose Monitoring (CGM) technology offers real-time glucose data that may mitigate these risks; however, no systematic quantitative synthesis has previously evaluated CGM's role specifically during Ramadan fasting. This study aims to systematically evaluate the impact of CGM on glycemic control outcomes - including Time in Range (TIR), Time Above Range (TAR), Time Below Range (TBR), Mean Amplitude of Glycemic Excursions (MAGE), and HbA1c - and safety outcomes among adults and adolescents with DM during Ramadan fasting. A systematic review and meta-analysis was conducted in accordance with PRISMA 2020 guidelines. PubMed, Scopus, and the Cochrane Library were searched from January 2014 through December 2024. Risk of bias was assessed using ROBINS-I for non-randomized studies and RoB2 for randomized controlled trials. Random-effects meta-analyses were performed using Comprehensive Meta-Analysis (CMA) version 3, with heterogeneity quantified using the I² statistic. Seven studies encompassing 485 participants (DM I: 4 studies; DM II: 3 studies) across six countries were included. CGM use was associated with improved TIR in most studies, with one study achieving significance [15]. Pooled meta-analytic results for TBR showed a non-significant reduction during Ramadan (standardized mean difference: - 0.138; 95% CI: - 0.650 to 0.375; p = 0.599). Substantial heterogeneity was observed across outcomes (I² range: moderate to high). HbA1c data showed inconsistencies across studies, partly attributable to unit-reporting discrepancies identified during data extraction. Safety outcomes trended toward improvement with CGM use. CGM appears to enhance glycemic control and patient safety during Ramadan fasting, particularly by improving TIR and supporting timely detection of hypoglycemic events, given the small number of included studies and substantial heterogeneity.