Table 1.

Diagnostic criteria for type 1 diabetes mellitus in adults recommended by the American Diabetes Association

Diagnostics	Diagnostic criteria [8]
Diagnostic tests	• FPG ≥ 126 mg/dL (7.0 mmol/L), with no caloric intake for at least 8 ha   or • 2-h PG ≥ 200 mg/dL (11.1 mmol/L) during OGTT, using a glucose load with the equivalent of 75 g of anhydrous glucose dissolved in watera   or • HbA1c ≥ 6.5% (48 mmol/mol) performed using an NGSP-certified method standardized to the DCCT assaya   or Random PG ≥ 200 mg/dL (11.1 mmol/L) in patients with classic symptoms of hyperglycemia or hyperglycemic crisis
Other diagnostic criteria	• Multiple autoantibodies (islet cell, GAD65, ZnT8, IA-2, anti-insulin) • Undetectable or low C-peptide • Family history/co-existence of other autoimmune diseases
Clinical symptoms	• Hyperglycemia • Polyuria/polydipsia • Unexplained weight loss • Diabetic ketoacidosis
Pathophysiology	• Beta cell destruction (occasionally dysfunction of remnant beta cells)

DCCT Diabetes Control and Complications Trial, FPG fasting plasma glucose, GAD65 glutamic acid decarboxylase, HbA1c glycated hemoglobin, IA-2 islet antigen-2, NGSP National Glycohemoglobin Standardization Program, OGTT oral glucose tolerance test, PG plasma glucose, ZnT8 zinc transporter 8

^aResults should be confirmed by repeat testing in the absence of unequivocal hyperglycemia