Rationale: Fulminant type 1 diabetes mellitus (FT1DM) is a new subtype of type 1 diabetes mellitus that was first proposed by the Japanese scholar Imagawa in 2000. In the 2 patient cases described in this study, gastrointestinal symptoms were the first symptoms reported, and the initial blood glucose levels were very high. However, the glycosylated hemoglobin (HbA1c) levels were not very high, the islet β-cell function was almost completely lost in a short time, and the metabolic disorder was severe; the patients' islet β cells demonstrated complete and irreversible functional damage, and the prognosis was poor.
Patient concerns: We report a 37-year-old and 48-year-old male patients. The first patient was addmited with emesis and diarrhea for 2 days and the second patient had stomachache for 8 days, emesis and dyspnea for half an hour before admission. Both patients had no history of hypertension, coronary heart disease, or hyperglycemia.
Diagnosis: Two patients had same scenario: acute onset, hyperglycemia, ketoacidosis, β cell function deficiency, and HbA1c <8.5%.
Interventions: After admission, the administration of adequate liquid infusion, the intravenous injection of regular insulin to reduce the blood glucose levels, and the correction of electrolyte disturbance and acid-base imbalance were conducted.
Outcomes: Subsequently, the blood glucose level of the patients was gradually reduced, the acidosis was corrected, and the disease conditions gradually stabilized. For both patients, the long-term insulin replacement therapy of "insulin aspart plus insulin glargine" was selected.
Lessons: FT1DM is a new subtype of type 1 diabetes mellitus. The onset of this disease is rapid, and the function of islet β cells is almost completely lost in a short time period. This metabolic disorder is severe, and the clinical manifestations are nonspecific. Unless a timely and accurate diagnosis is made, and patients receive prompt treatment, it is difficult to control the disease and the risk of death is high.