Safety and effectiveness of non-insulin glucose-lowering agents in the treatment of people with type 2 diabetes who observe Ramadan: a systematic review and meta-analysis

Aim: To determine which non-insulin glucose-lowering treatment regimens are most appropriate in people with type 2 diabetes who choose to fast during Ramadan. Methods: Electronic databases were searched for randomized controlled trials (RCTs) and observational studies that compared non-insulin glucose-lowering agents in people with type 2 diabetes fasting during Ramadan. Those studies which reported hypoglycaemia, weight and glycated haemoglobin (HbA1c) change were included. Data were pooled using random effects models. Results: A total of 16 studies were included: 9 RCTs and 7 observational studies. There was evidence that dipeptidyl peptidase-4 (DPP-4) inhibitors led to fewer hypoglycaemic events compared with sulphonylureas. Sitagliptin significantly reduced the number of patients with ≥1 hypoglycaemic episodes during Ramadan [risk ratio (RR) 0.48, 95% confidence interval (CI) 0.36, 0.64; p > 0.0001]. This was not replicated in the RCTs of vildagliptin, but a significant reduction was found in the observational studies (RR 0.28, 95% CI 0.10, 0.75; p = 0.01) with high heterogeneity (I[superscript: 2] = 86.7%). Significant reductions in HbA1c and weight were seen in the observational studies of vildagliptin versus sulphonylureas. The use of liraglutide led to significant weight loss (−1.81 kg, 95% CI −2.91, −0.71; p = 0.001) compared with sulphonylureas. Pioglitazone significantly increased weight compared with placebo (3.48 kg, 95% CI 2.82, 4.14; p < 0.0001). Conclusions: The analysis supports the use of DPP-4 inhibitors during Ramadan rather than sulphonylureas for reduction in hypoglycaemia without a cost to diabetes control and weight. The glucagon-like peptide (GLP)-1 agonist liraglutide provides clinical benefits, but more studies are required. RCTs of DPP-4 inhibitors compared with GLP-1 agonists and novel therapies including the sodium-glucose co-transporter 2 and α-glucosidase inhibitors are needed to inform evidence-based guidelines.