Lab

Glucose Tolerance Test 3 hour

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Glucose Tolerance Test 3 hour, Glucose Tolerance Test, Three Hour Glucose Tolerance Test

  • See Also
  1. Gestational Diabetes
  • Indications
  1. Diagnosis of Gestational Diabetes
  2. Failed Glucose Challenge Test
  • Protocol
  1. Fasting patient ingests 100 gram oral Glucose drink (e.g. Glucola Drink)
  2. Blood Glucose measured at 4 times
    1. Fasting baseline before oral Glucose
    2. Hour 1 after oral Glucose
    3. Hour 2 after oral Glucose
    4. Hour 3 after oral Glucose
  • Interpretation
  1. Diagnosis suggestive of Gestational Diabetes
    1. Two or more values below are abnormal
    2. Carpenter and Coustan guidelines are the standard of care now
      1. Replaces the NDDG guidelines which were 10 points higher than these
  2. Carpenter and Coustan Abnormal Value cut-offs
    1. Fasting Glucose > 95 mg/dl (5.3 mmol/L)
    2. Glucose at 1 hour > 180 mg/dl (10.0 mmol/L)
    3. Glucose at 2 hours > 155 mg/dl (8.6 mmol/L)
    4. Glucose at 3 hours > 140 mg/dl (7.8 mmol/L)
  3. References
    1. Carpenter (1982) Am J Obstet Gynecol 144:768-73 [PubMed]
  • References
  1. Moyer (2014) Ann Intern Med 160(6): 414-20 [PubMed]