A new study has found no clear survival benefits or significant differences among type 2 diabetes patients taking any of nine available antidiabetic drugs (single or in combination) and their all-cause and cardiovascular mortality.
A group of researchers have analyzed several glucose-lowering drugs, which include insulin, to estimate their levels of safety and efficacy. The team also identified 301 clinical trials that were eligible for the systematic review and meta-analysis.
Among the clinical trials reviewed, 177 involved diabetes drugs that were given as monotherapy to 56,598 patients; 109 trials involved dual therapy, which means other diabetes drugs were added to metformin, given to 53,030 patients; and 29 trials involved triple therapy where 10,598 patients were given sulfonylurea, metformin and another diabetes drug.
Across all types of therapy, the research team did not find any significant difference in the relationship between diabetes drugs and therapy type with the risk of serious health events including stroke and heart attacks, as well as in the link to cardiovascular and all-cause mortality.
The main finding is that despite reviewing over 300 clinical trials that involved almost 120,000 adult diabetes patients, they found little evidence that diabetes drugs prevented the development of cardiovascular disease or prolonged the patients' life expectancy.
"Considerable uncertainty about the association of drug treatment with cardiovascular mortality existed within trial evidence, largely because of few events in most available studies," wrote the researchers.
The new findings were consistent with the recommendation from the American Diabetes Association in which metformin is given as an initial treatment among type 2 diabetes patients. The recommendation also states that additional treatment selection is based on considerations specific to the patient's case.
"Our study shows that metformin is as good as most other treatments for lowering blood glucose, and when patients particularly wish to avoid weight gain, GLP-1 receptor agonists as single treatment are a good start," said University of Otago's Suetonia C. Palmer Ph.D., the study's lead author, and University of Sydney's Giovanni FM Strippoli Ph.D.
The antidiabetic drugs involved in the study were basal insulin, metformin, thiazolidinediones, sulfonylureas, sodium-glucose linked transporter 2 (SGLT2) inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, meglitinides, α-glucosidase inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists. The research was published in the Journal of the American Medical Association on July 19.
The recent study did not include clinical trials that do not specifically measure antidiabetic drugs as a monotherapy or as a dual therapy when taken in conjunction with metformin, or as a triple therapy when taken with sulfonylurea and metformin.
