A 25-year-old Hispanic woman with a 5-year history of type 2 diabetes presents for a routine follow-up visit. Despite education, she has had difficulty in making diet and lifestyle modifications and currently has a BMI of 45 kg/m2.
Her treatment advanced from monotherapy with metformin(Drug information on metformin) at initial diagnosis, to her current regimen of metformin 2000 mg, glimepiride(Drug information on glimepiride) 8 mg, and sitagliptin(Drug information on sitagliptin) 100 mg daily. She performs home blood glucose monitoring, and her fasting blood glucose levels range between 120 and 150 mg/dL. She experiences symptoms of hypoglycemia very rarely, only once every few months. Her A1C level is 7.8% and a recent fasting C-peptide level was 6 ng/mL (normal range, 0.78-1.89 ng/dL). The patient is concerned that her medication is not working as well as it should. Although her mother has type 2 diabetes, a nephew has type 1 diabetes, and she is wondering whether she could have type 1 diabetes instead of type 2.
The patient’s glycemic control remains unacceptable (A1C >7%) with triple oral antihyperglycemic medication therapy just 5 years after diagnosis of diabetes. It is important to identify which type of diabetes this patient is experiencing, to optimize her treatment. Favoring type 1 diabetes (in the slow-to-develop form known as latent autoimmune diabetes in adults or LADA) is the relatively early failure of oral therapies and the presence of type 1 diabetes in her family history. Favoring type 2 diabetes is her very high BMI and the presence of type 2 diabetes in a close relative. It is possible to have true type 1 diabetes together with features of type 2 diabetes (eg, obesity and insulin resistance). When this occurs, the presence of a high C-peptide level may not exclude type 1 diabetes, with autoimmune injury to the beta cells, and a need for insulin treatment. The high C-peptide level, however, does suggest quite significant resistance to the action of insulin.
Anti-GAD testing was performed and in this case was found to be negative.
What is your recommendation for the next step?
1. Refer to dietitian for a weight loss program
2. Start on Lantus therapy
3. Start on a TZD
4. Reduce the glimepiride and begin liraglutide
Would you please leave us your thoughts on treatment, below, first?