Key Message
Five relevant systematic reviews (four with meta-analysis and one with network meta-analysis), two randomized controlled trials, and six non-randomized studies were identified regarding the safety of pioglitazone for patients with pre-diabetes or type 2 diabetes.In patients with pre-diabetes, evidence from one non-randomized study suggested that pioglitazone was associated with an increased likelihood of weight gain and edema when compared to placebo, while studies evaluating other safety outcomes generally found no significant differences between pioglitazone and comparators. Results in patients with type 2 diabetes were mixed, though there were often no significant differences from systematic reviews regarding several safety outcomes when comparing pioglitazone to other treatments for type 2 diabetes. However, the body of evidence was largely of low to moderate quality. As such, there remains some uncertainty around the overall safety profile of pioglitazone.The limitations of the included studies (e.g., heterogeneity of the literature, and lack of blinding to treatment), should be considered when interpreting the results.