Insulin or enhanced oral anti-diabetic tablet therapy in uncontrolled type 2 diabetes?

The aim of this study was to investigate the effects of starting insulin therapy versus enhancing oral tablet therapy after failure with three oral anti-diabetic (OAD) tablets in patients with type 2 diabetes (T2D). The main finding of the study was that adding insulin after failure with three OADs was effective, however, it increased the risk of hypoglycemia (dangerously low blood glucose levels).

There are many different treatments for type 2 diabetes (T2D) that help lower blood sugar. These include both oral (tablets taken by mouth) and medications that are injected. Different combinations of medications are used in order to have good sugar control as different combinations work differently for every patient. One of the injected medications is insulin. Insulin is usually used when all of the other therapies have failed. This is because insulin can cause blood sugar to go dangerously low (hypoglycemia).

There are many complications of T2D such as cardiovascular (CV; heart and blood vessels) disease. It is important to research which therapy is more effective on these complications, adding insulin to failed triple OAD therapy or enhancing OAD therapy (either adding a fourth OAD or increasing the dose of OAD).

This study looked at the data from 3959 patients with T2D, both with and without diabetic complications over an 11-year period.  1186 of these patients received insulin after failure with three OADs. 2773 of the patients had an enhancing of the OAD therapy after failure with three OADs.

In patients without diabetic complications, there was no increased risk of CV complications (heart attack, stroke, heart failure, heart disease) associated with added insulin therapy. However, there was a significantly increased risk of hypoglycemia in those who received insulin therapy compare those who had enhanced OAD therapy.

In all patients, those who received insulin were 23% more likely to have CV complications, 59% more likely to have heart failure and 37% more likely to have heart disease than those who had enhanced OAD therapy. They also had a 49% increased risk of hypoglycemia and are 30% more likely to die than those who had enhanced OAD therapy.

The authors concluded that insulin can be used as an add-on therapy when three OADs have failed to control diabetes. However, this comes with an increased risk of hypoglycemia.

This study was done on patients in Taiwan. Further studies are required on the risk of CV complications, in more diverse populations.