Testing for Carbohydrate Disorders Flashcards
Why do we test for carbohydrate disorders?
- Diagnose diabetes/hypoglycemia
- Identify insulinomas
- Monitor glycemic control
- Screen for renal complications
Criteria for screening asymptomatic children for type 2 diabetes
- Start early, 10 years or puberty onset
- Test every 2 years w/ children who are overweight and any 2 of the following: family history of type 2, high risk population, signs of insulin resistance, maternal history of diabetes or GDM
What are the 4 possible methods for diagnosis of DM?
- Fasting (8hr) plasma gluc ≥ 7.0 (preferred method)
- OGTT w/ 2hr post-load (75g) ≥ 11.1
- HbA1C (not for type 1 diag)
- Symptoms of diabetes and R plasma gluc ≥ 11.1
When there are no symptoms (asymptomatic) how do we confirm?
1st test must be confirmed by one of the following: FPG, 2hr PG or A1C
Describe the 2hr post-postprandial test
- Not recommended for routine use
- Patient prep: normal-high carb diet 3 days prior, fasting 10-16hrs, test in AM, no exercise or smoking
- 75g gluc load for adults
- 2 specimens drawn; fasting and 2hrs post-load
Sources of error:
Meds, GI problems, endocrine dysfunction
What is the WHO criteria for interpretation of OGTT?
- Normal: 2hr PG<7.8
- Imparied gluc tolerance: 2hr PG 2.8-11
- Diabetes: ≥11.1 at 2 hrs; provisional diag for asymptomatic patients until confirmed by increased FBG, A1C or 75g OGTT
What is the criteria for testing for GDM in Canada?
- All preg women screened at 24-28 weeks (or high risk)
CDA preferred approach:
- Patient fasting 8hrs
- Start w/ 50g dose, test at 1hr; if gluc is 7.8-11.1 do 75g OGTT
(GDM if FBG ≥ 5.3, 1hrPG ≥ 10.6, 2hrPG ≥ 9.0)
- If 50g gluc is ≥ 11.1 = GDM
What is the alternate approach for GDM testing in Canada?
- 75g OGTT (measure FBG, 1hrPG, 2hrPG)
GDM if one of the following:
- FBG ≥ 5.1
- 1hrPG ≥ 10.0
- 2hrPG ≥ 8.5
