Pioglitazone for Type 2 Diabetes Mellitus and Pre-Diabetes: A Review of Safety [Internet]

Excerpt

Diabetes mellitus is a group of metabolic disorders that result from deficiencies in insulin secretion, sensitivity, or both. Type 2 diabetes mellitus ranges from predominant insulin resistance with relative insulin secretory deficiency, to insulin resistance with a predominant insulin secretory deficiency as the disease progresses.^– There are several risk factors for type 2 diabetes, including a history of pre-diabetes, usually defined as having impaired fasting glucose (6.1 to 6.9 mmol/L), impaired glucose tolerance (noted by an oral glucose tolerance test results of 7.8 to 11 mmol/L), or an elevated glycated hemoglobin A_1c level (6% to 6.4%).

In 2017, it was estimated there were 123,085 Canadians (95% confidence interval [CI], 109,119 to 137,118) newly diagnosed with type 2 diabetes, raising the national burden of disease to an estimated 2,553,158 (95% CI, 2,295,152 to 2,857,046) prevalent cases. Furthermore, it was estimated that 2.12% of total Canadian deaths (95% CI, 2.0% to 2.25%) in 2017 were attributable to type 2 diabetes. This translates to an estimated 83,603 years of life lost (95% CI, 76,847 to 90,036) for 2017.

The goals of therapy in type 2 diabetes are aimed at achieving stringent glycemic control within the normal range as early as possible. In addition to diet and lifestyle measures, several classes of antidiabetic agents are approved in Canada: insulins, sulphonylureas (SUs), α-glucosidase inhibitors, biguanides, glucagon-like peptide-1 (GLP-1) receptor agonists, meglitinides (MEGs), thiazolidinediones (TZDs), sodium-glucose cotransporter 2 inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, and a combination of these may often be necessary for optimal treatment.^–, This report will focus on a particular drug of the TZD class, pioglitazone (PIO), which is often considered as a therapeutic option when glycemic targets are not achieved with first-line drugs, such as metformin. PIO works by binding to the peroxisome proliferator-activated receptor-γ, which is primarily located on adipose and vascular cells, increasing their insulin sensitivity.

In addition to its hypoglycemic effect, PIO has been shown to have favourable effects on reducing major adverse cardiovascular events (e.g., all-cause mortality, non-fatal myocardial infarction [MI], stroke).^, Nevertheless, and as is the case with any drug therapy, the benefits associated with PIO ought to be weighed against possible risks to the patient. Because of previously reported concerns about adverse events (AEs) such as bladder cancer,^– heart failure (HF),^,, edema,^,, fractures,^, weight gain, and ovulation in anovulatory women, there remains uncertainty around the overall safety profile of PIO.

Previous CADTH reports on this topic include a 2010 comparison of the safety of PIO and rosiglitazone (ROS) for patients with type 2 diabetes. The objective of the present report is to investigate the clinical evidence regarding the safety of PIO for patients with pre-diabetes or type 2 diabetes.