Six-Year Complete Remission of Type-1 Diabetes Mellitus in an Adult Treated With Sitagliptin

A “honeymoon” phase is a transient period of type 1 diabetes (T1D) remission, characterized by a significant reduction in insulin requirements and good glycemic control due to a temporary restoration of pancreatic β-cell function. This phenomenon occurs in about 60% of adults with this disease, is usually partial, and lasts for up to 1 year. We present a case of a 6-year complete remission of T1D in a 33-year-old man, the longest remission ever described in the literature to our knowledge. He was referred for presenting a 6-month history of polydipsia, polyuria, and weight loss of 5 kg. Laboratory studies confirmed the diagnosis of T1D (fasting blood glucose of 270 mg/dL; HbA1c of 10.6%, and positive antiglutamic acid decarboxylase), and the patient started intensive insulin therapy. After 3 months, a complete remission of the disease was assumed, he suspended insulin administration and since then, he has been under treatment with sitagliptin 100 mg daily, a low-carbohydrate diet, and regular aerobic physical activity. This work aims to highlight the potential role of these factors in delaying disease progression and preserving pancreatic β-cells when introduced at the time of presentation. More robust, prospective, and randomized studies will be needed to confirm its protective effect on the natural course of the disease and support its indication in adults with newly diagnosed T1D.