Screening for Diabetes Mellitus (DM)

Screening for Diabetes Mellitus (DM)

• Screening for T1D:
  • Symptomatic patients
  • Asymptomatic patients at higher risk (first-degree relatives with T1D)
  • Measure islet autoantibodies to assess risk of T1D
• Screening for T2D:
  • Age 35 or older, repeat every 3 years if normal
  • Screen regardless of age if BMI is 25 kg/m2 or greater (23 kg/m2 or greater in Asian Americans) and at least one of the following risk factors:
    • History of cardiovascular disease
    • A1C is 5.7% or greater, impaired glucose tolerance, or impaired fasting glucose in previous testing
    • History of PCOS
    • HDL less than 35 mg/dL or TG greater than 250 mg/dL
    • Hypertension
    • High-risk ethnicity: African American, Latino, Native American, Asian American, Pacific Islander
    • First-degree relative with T2D
    • Physical inactivity
    • Insulin resistance conditions (e.g., severe obesity, acanthosis nigricans)
• Screening for Gestational DM:
  • Screen at first prenatal visit for undiagnosed T2D in all patients with T2D risk factors present
  • Screen at 24–28 weeks’ gestation using OGTT
  • If a diagnosis of gestational DM is made, screen for diabetes 4–12 weeks after delivery
  • Continue to screen patients who have had gestational DM every 3 years for T2D for life

DM Diagnosis

• Glycemic values in nonpregnant patients:
  • FPG ≥ 126 mg/dL
  • OGTT ≥ 200 mg/dL
• Gestational diabetes diagnosis:
  • Glycemic values in pregnancy:
    • One-step approach: 75-g OGTT at 24–28 weeks’ gestation Fasting: ≥ 92 mg/dL 1 hour after OGTT: ≥ 180 mg/dL 2 hours after OGTT: ≥ 153 mg/dL
    • Two-step approach: 50-g OGTT (nonfasting) at 24–28 weeks’ gestation If 1 hour after 50-g OGTT is < 140 mg/dL, no further workup If ≥ 140 mg/dL, do additional fasting OGTT using 100 g

Goals of Diabetes Management in Nonpregnant Adults

• Primary goal: Prevent the onset of acute or chronic complications
• Acute complications:
  • Hypoglycemia
  • Diabetic ketoacidosis (DKA)
  • Hyperglycemic hyperosmolar non-ketotic syndrome
• Chronic complications:
  • Mechanism of action: Increases urinary glucose excretion by blocking normal reabsorption in the proximal convoluted tubule; has some effect on delaying GI glucose absorption
  • Dosing:
    • Canagliflozin: 100 mg once daily before the first meal of the day, max 300 mg
    • Dapagliflozin: 5 mg once daily in the morning (with or without food), max 10 mg
    • Empagliflozin: 10 mg once daily in the morning (with or without food), max 25 mg
    • Ertugliflozin: 5 mg once daily in the morning (with or without food), max 15 mg

GLP-1 Analogs

• Mechanism of action: Synthetic analog of human GLP-1 that binds to GLP-1 receptors, resulting in glucose-dependent insulin secretion, reduction in glucagon secretion, and reduced gastric emptying; promotes satiety
• Approved agents: Exenatide, liraglutide, dulaglutide, lixisenatide, and semaglutide
• Dosing:
  • Exenatide:
    • Twice-daily formulation (pen): 5 mcg subcutaneously twice daily, max 10 mcg twice daily
    • Once-weekly formulation (single-dose tray or pen): 2 mg subcutaneously once weekly
  • Liraglutide (pen):
    • 0.6 mg subcutaneously once daily for 1 week, max 1.8 mg/day
  • Lixisenatide (pen):
    • Initial dose: 10 mcg once daily for 14 days, maintenance dose: 20 mcg once daily