Abstract / Summary
Abstract Background Ramadan fasting poses significant challenges for individuals with type 2 diabetes mellitus (T2DM), particularly those treated with insulin. This systematic review and meta-analysis evaluates the impact of insulin-based therapy on glycemic control and hypoglycemia in adults with T2DM during Ramadan. Methods Following PRISMA guidelines, we searched PubMed, Embase, and the Cochrane Library from inception to January 2025 for studies reporting on pre- and post-Ramadan HbA 1c and hypoglycemia in insulin-treated patients with T2DM. Both observational and interventional studies were included in this meta-analysis. Pooled analysis of HbA 1c change was conducted using the random-effects model. Results Twenty studies ( n = 2024 pre-Ramadan, n = 1979 post-Ramadan) were included. Insulin regimens varied, including basal, premixed, basal-bolus, and combinations with oral injectable hypoglycemic agents. When analyzed by study design, randomized controlled trials (RCTs) showed a significant reduction in HbA 1c (mean difference (MD) = -0.38; 95% CI: -0.49 to -0.27, p < 0.00001; I² = 35%), while observational studies also demonstrated a smaller but significant reduction (-0.33; 95% CI -0.59 to -0.06, p = 0.02; I² = 82%). Sensitivity analyses using fixed-effect models confirmed the robustness of these findings, with persistent statistical significance and reduced heterogeneity. The incidence of hypoglycemia was stable or reduced in most studies, though definitions and reporting methods were inconsistent. A pooled analysis of studies reporting the number of hypoglycemic events ( n = 5; mixed randomized and observational designs) showed no significant difference before and during Ramadan (SMD − 0.06; 95% CI: −0.25 to 0.13; p = 0.52; I² = 0%), and subgroup analysis by study design was not feasible. Conclusions In adults with T2DM, insulin-containing regimens during Ramadan were associated with a modest reduction in HbA 1c ; however, the clinical significance of this reduction remains uncertain. The available evidence did not demonstrate an increase in hypoglycaemia, but this finding should be interpreted cautiously given the small number of studies and variability in hypoglycaemia definitions and reporting. Individualized insulin management and structured pre-Ramadan education remain essential to optimize safety during fasting. Clinical trial number Not applicable.