April 18 (UPI) -- In comparing three classes of medication for type 2 diabetes, researchers found one class, which includes the drugs Onglyza, Janumet and Januvia, did not reduce the risk of death.
Scientists from Imperial College London found that dipeptidyl peptidase inhibitors were not as effective as two others types when compared with a placebo: sodium-glucose cotransporter inhibitors, which include Jardiance and Invokana, and glucagon-like peptide agonists, which include Victoza, Byettea, Saxenda, Bydureon and Trulicity, and are used as injectables.
Their findings were published Tuesday in the Journal of the American Medical Association.
The researchers analyzed 236 trials involving 176,310 participatns, comparing all the drugs against each other, a placebo or no treatment at all. The three groups of drugs are among the top sellers for diabetes, according to FirePharma in 2016, including $2.3 billion in sales of Januvia, $984 million of Janumet, $2.1 billion of Victoza, $738 million of Trulicity and $1.3 billion of Inkokana.
The researchers found all of the drug classes lowered blood sugar levels, but only two types reduced the risk of death when compared with a placebo. The SGLT-2 inhibitor drugs were associated with a 20 percent reduction in risk of death, compared with a placebo pill or no medication, GLP-1 agonist drugs reduced the death risk by 18 percent and the DPP-4 inhibitor drugs weren't associated with a reduced risk of mortality.
"Type 2 diabetes has become a global epidemic, with more cases than ever before," leader author Dr Sean Zheng, a researcher at the National Heart and Lung Institute at Imperial, said in a press release. "The three drug classes assessed here are being increasingly prescribed, yet until now there have been no clinical trials studying how these drugs compare to each other, and which type of drug could be the best option for patients."
In type 2 diabetes, levels of sugar in the blood to become too high, usually because of a lack of insulin.
Aside from changes to diet and exercise, most people need medication to control blood sugar.
Metformi is the most commonly prescribed drug type 2 diabetes and first on the market for the condition, but the drug sometimes doesn't work or triggers side effects.
GLT-2 inhibitors increase the amount of sugar excreted by the body, and GLP-1 agonists and DPP-4 inhibitors increase natural insulin levels.
In the study, SGLT-2 inhibitor drugs were associated with a 21 percent reduction in risk of dying from a cardiovascular event such as a heart attack or stroke and GLP-1 agonist medication was associated with a 15 percent drop. There was no reduction in risk of death from a cardiovascular event for the drugs DPP-4 inhibitors.
The SGLT-2 inhibitor drugs were associated with significant reductions in risk of heart failure compared compared with the two other.
Zheng said further work is now needed to confirm these findings and there was no evidence that any of the treatments caused harm. In addition, he said because these drugs are relatively new, they only tracked participants for a few years.
"Our hope is that in the crowded market that is diabetes medications, patients and their doctors have the necessary information to allow them to make informed decisions about long-term treatment strategies," Zheng said.