The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which is part of the National Institutes of Health.
Researchers enrolled 5,047 people with type 2 diabetes who were already taking metformin.
Almost two-thirds of participants were white, one-fifth were Black and almost one-fifth identified as Hispanic or Latinx.
This “multicultural patient base … helps bring a better understanding of how different groups in our communities can be served,” said Shapiro.
Researchers randomly assigned participants to receive one of four medications alongside metformin.
Sitagliptin, liraglutide, and glimepiride act by increasing insulin levels. Insulin glargine is a long-acting insulin.
Researchers followed participants for an average of 5 years.
During this time, participants taking liraglutide or insulin glargine were able to achieve and maintain their blood glucose levels within the recommended range for the longest time, compared to those taking sitagliptin or glimepiride.
Glargine was the most effective at helping people maintain the target blood glucose levels; sitagliptin was the least effective.
Researchers found that the effect of the medications on blood glucose levels did not differ based on age, sex, race or ethnicity.
However, people who started the study with higher blood glucose levels had “progressively worse metabolic outcomes” with sitagliptin compared to the other treatments, researchers said in the paper.
The study also looked the medications’ effects on the risk of people developing diabetes-related cardiovascular disease. People taking liraglutide had a lower risk of cardiovascular disease overall, compared to those taking one of the other medications, researchers found.
Researchers also examined the side effects of the drugs, finding:
- Severe hypoglycemia — low blood glucose levels — was uncommon, but occurred more frequently in people taking glimepiride. Shapiro said this side effect is concerning enough that it needs to be “monitored and managed” by patients and their doctors.
- Gastrointestinal side effects were more common in people taking liraglutide compared to those taking one of the other medications.
In addition, people taking liraglutide or sitagliptin lost more weight (7.7 pounds and 4.4 pounds, respectively) than those taking glargine or glimepiride (less than 2 pounds).
One limitation of the study is that it did not include a type of medication used to treat type 2 diabetes called SGLT2 inhibitors, which were not approved by the Food and Drug Administration at the start of the study.
In addition, researchers said in the paper that during the trial, participants’ medications were frequently adjusted, which “may not reflect the slow rate of medication adjustments in the clinical setting.”
Still, the results of the study may help doctors and patients decide on the best medication treatments for type 2 diabetes.
“For a long time we had the ‘gold standard’ of metformin and insulin,” said Shapiro. “Now we are moving forward with a better understanding of how to help our patients with the current medications.”
In addition to prescription drugs, people can also help
“Diabetes is not just a ‘sugar problem,’ it requires a change in the way that we perceive health,” said Shapiro. So we “need to have a multidimensional approach: healthy diet, moderate-intensity movement, good sleeping habits and mental health support.”
In addition, he thinks communities can benefit from the services of
“Medications are a key part of the conversation,” he said, “but we cannot forget the complex lives that we live.”