Is dapagliflozin a good addition to liraglutide and insulin therapy for type 1 diabetes?

This study investigated whether adding dapagliflozin (Farxiga/Forxiga) to liraglutide (Victoza) and insulin therapy would improve blood glucose control and promote weight loss in patients with type 1 diabetes (T1D). Improved blood glucose control and weight loss was recorded, however increased ketosis (raised ketone acids in the blood) was also observed.

Many T1D patients do not have sufficient control of their blood glucose levels. Therefore, new therapy options are needed. SGLT-2 inhibitors are medications that lower blood glucose by increasing glucose in the urine. However, these drugs have been associated with diabetic ketoacidosis (DKA). DKA occurs when cells cannot use glucose for energy due to lack of insulin. Body cells break down fat, increasing acids in the blood called ketones. DKA can cause nausea, vomiting, frequent thirst, urination and eventually loss of consciousness.

Previous studies have shown that liraglutide (Victoza) does not increase the risk of DKA. It is not known whether combining an SGLT-2 inhibitor such as dapagliflozin with liraglutide would lower blood glucose without increasing the risk of DKA. 

30 patients were recruited into this 12 week study. 20 patients received dapagliflozin and 10 received a placebo (substance with no effect on the body) in combination with liraglutide and insulin.

Dapagliflozin decreased the HbA1c (average blood glucose over 3 months) by 0.66%. No significant change was noted in the placebo group. There was no significant increase in hypoglycemia (dangerously low blood glucose) in either group.

Dapagliflozin patients showed increased signs of DKA. These include a 29% increase in an enzyme which breaks down fat and a 67% and 254% increase in two different ketones. Increased ketones were also recorded in the urine. Two patients in the dapagliflozin group developed DKA.

Body weight fell by an average of 1.9 kg in the dapagliflozin group while remaining unchanged in the placebo group. 

This study concluded that adding dapagliflozin to liraglutide and insulin therapy improved blood glucose control and promoted weight loss without increasing the risk of low blood sugar. There is, however, an increased risk of ketosis and DKA. The authors recommend this treatment should only be considered by a knowledgeable patient and endocrinologist.