SPP1 and type 2 diabetes mellitus: In light of the evidence available from these studies, it is safe to conclude that age of <60 years, duration of T2DM of <5 years, BMI >40 kg/m2, HbA1c <7%, fasting C-peptide levels of >3, osteopontin level >46.57 mg/mL, no preoperative insulin treatment, and a DiaRem score of <5 indicate good prognosis after bariatric surgery.