Can sitagliptin help in latent autoimmune diabetes?

This study explored the effect of sitagliptin (Januvia) on the function of pancreas cells in patients with latent autoimmune diabetes in adults (LADA) receiving insulin therapy. The authors found that the combination of sitagliptin and insulin extends in time the ability of pancreas cells to produce insulin and improves the ability of the body to respond to insulin treatment.

Insulin is a hormone made by the pancreas that helps deliver glucose (sugar) from the blood into the cells. This delivers energy to the cells for them to work. When diabetes arises, insulin is either not able or not enough made to bring glucose into the cells, resulting in an increase in blood sugar levels. Together with insulin and in the same amount, the pancreas also makes C-peptide. C-peptide levels can show how much insulin is made. 

Latent autoimmune diabetes in adults (LADA) is a type of diabetes in which pancreas cells called islet ß cells are destroyed by the immune system and stop producing insulin faster than in other types. Thus, it is crucial to stop the destruction of islet b cells using the correct therapy. Although insulin therapy is currently used in LADA, the optimal therapy for this type of diabetes is still unclear.

Dipeptidyl peptidase-4 (DPP4) inhibitors such as sitagliptin are a type of drug used to control high blood sugar levels in adults with type 2 diabetes (T2D). It works by breaking down gut hormones called incretins after a meal. This leads to an increase in insulin production by the pancreas. Previous research has shown that DPP4 inhibitors may help preserve ß cells' function. However, the effectiveness of sitagliptin add-on to insulin therapy in patients with LADA is still unknown. 

This study enrolled 47 patients with LADA. 22 patients randomly received sitagliptin 100mg daily and insulin therapy, while 25 patients received insulin therapy alone. Patients were followed up every 6 months for 2 years. ß-cell function was measured through the C-peptide levels while fasting and 2 hours after a meal and the HOMA2-B test that evaluates how well the body responds to insulin (insulin sensitivity). 

In the sitagliptin group, there were no significant changes in ß-cell function tests. However, insulin sensitivity and secretion were reduced in the insulin alone group. After 2 years, insulin secretion improved in the sitagliptin group compared to the beginning of the study and to the insulin alone group. 

This study showed that sitagliptin combined with insulin therapy may slow down the destruction of ß-cell function and increase insulin sensitivity in patients with LADA.

This study had a small number of patients, and not all of them finished the study. Larger studies are needed to confirm these results.

Discuss with your doctor if sitagliptin is a good treatment in combination with insulin in your situation.