Type 2 Diabetes: Diagnostic Criteria

Type 2 Diabetes Diagnosis

Diagnostic Thresholds for Non-Pregnant Adults

• A diagnosis can be made if any ONE of the following conditions are met:
  • HbA1c ≥ 6.5% (≥ 48 mmol/mol)
  • Fasting Plasma Glucose (FPG) ≥ 7.0 mmol/L (126 mg/dL)
  • 2-hour Plasma Glucose (2hPG) ≥ 11.1 mmol/L (200 mg/dL) during an Oral Glucose Tolerance Test (OGTT)

Testing for Prediabetes

• Testing should be considered for adults of any age who are overweight or obese (BMI ≥ 25 kg/m2 or ≥ 23 kg/m2 in Asian Americans) and have at least one additional risk factor.
• Risk factors include:
  • First-degree relative with diabetes
  • High-risk race/ethnicity (African American, Latino, Native American, Asian American, Pacific Islander)
  • CVD history
  • Hypertension (≥ 140/90 mmHg or on therapy for hypertension)
  • HDL cholesterol < 35 mg/dL (0.90 mmol/L)
  • Triglyceride level > 250 mg/dL (2.82 mmol/L)
  • Women with polycystic ovary syndrome
  • Physical inactivity
  • Other clinical conditions associated with insulin resistance (severe obesity, acanthosis nigricans)

Prediabetes Thresholds

• Prediabetes is identified by:
  • A1C 5.7–6.4% (39–46 mmol/mol)
  • Fasting plasma glucose 5.6–6.9 mmol/L (100–125 mg/dL)
  • 2-h plasma glucose in the 7.8–11.0 mmol/L (140–199 mg/dL) range during an OGTT

Recommendations for Testing

• Test overweight or obese adults (BMI ≥ 25 kg/m2 or ≥ 23 kg/m2 in Asian Americans) with one or more risk factors:
  • First-degree relative with diabetes
  • High-risk race/ethnicity
  • History of CVD
  • Hypertension (≥ 140/90 mmHg or on therapy)
  • HDL cholesterol < 35 mg/dL (0.90 mmol/L) and/or triglyceride level > 250 mg/dL (2.82 mmol/L)
  • Women with polycystic ovary syndrome
  • Physical inactivity
  • Clinical conditions associated with insulin resistance
• Patients with prediabetes (A1C ≥ 5.7% [39 mmol/mol], IGT, or IFG) should be tested yearly
• Women planning pregnancy or with GDM should have lifelong testing at least every 3 years
• For all other patients, start testing at age 35 years
• If results are normal, repeat testing at least every 3 years, considering more frequent testing based on initial results and risk

Pharmacologic Approaches to Glycemic Treatment

Recommendations

• Metformin should be initiated at, or soon after, diagnosis unless contraindicated
• Lifestyle intervention is a must in any diabetes management plan, and should include:
  • Medical nutrition therapy
  • Physical activity
  • Sleep
• After metformin, consider the use of GLP-1 RA or SGLT2i based on compelling indications: -ASCVD
  • Heart failure
  • CKD
• In patients without compelling indications, agent choice should be individualized based on:
  • Efficacy
  • Cost
  • Hypoglycemia risk
  • Effect on weight
  • Risk for side effects
  • Patient preference