ADA Free DM Class Flashcards
ADA Criteria for DM Diagnosis
Fasting Plasma Glucose= > 126; no caloric intake for 8 hours
2 hour plasma glucose, with >200 mg/dL during OGTT; should be performed per WHO, with 75 grams of anhydrous glucose dissolved in water
A1C; A1C> 6.5%
classic sxs of hyperglycemia crises with random plasma glucose > 200
Limitations to A1C testing?
cost
limited availability
potential to be affected by factors such as hemoglobinopathies, anemia, CKD, pregnancy, race and ethnicity
Factors that can affect A1C
Change in Red Blood Cell Lifespan
> Iron deficiency (increased RBC survival, may result in high A1C)
> Acute blood loss within 3 months (too low A1C)
Thalessemia (too low A1C)
Spherocytosis (Too low A1C(
Assay Related Artifacts
> Aspirin induced - too high
> cigarrette- too high
- sickle cell anemia (too low)
- hypertriglyceredemia: too high
- Hyperbilirubuinemia (too high)
Change in normal glycation
- vitamin A supplementaton or C supplementation ( too low)
- transfuson within 3 months (too high)
Miscellaneous- African Origin (too high),. HIV on ART (too low), chornic liver disease (too low)
what are some conditions that are associated with increased red blood cell turnover? What DM test would u use to diagnose?
sickle cell, pregnancy in 2nd and third trimester, G6PD, Hemodialysis, recent blood loss or transfusion or EPO therapy
U would want to use a test that doesn’t involve RBC glycation, so think more 2 hour OGTT (75g0, or fasting plasma (8 hours) or rapid plasma
Is A1C more or less reliable than blood glucose measurement in conditions such as the postpartum state, HIV on retroviral therapy, and iron-deficient anemia?
A1C is less reliable
Who needs which test for DM screening?
68 yo on HD for ESRD; initially diagnosed 15 years ago with TDM, has been managing DM with insulin only for past 5 years
Not A1C
use plasma blood glucose instead of A1C
HD can cause RBCs to turnover at increased rate;
Need to do plasma glucose levels
Who needs which test for DM screening?
5 yo patient with T1DM managed on insulin pump; Diagnosed 2 years ago with T1DM and has no complications
A1C
Who needs which test for DM screening?
49 yo with history of polysubstance abuse and IV drug use Diagnosed with HIV 14 years ago, and has been well controlled on antiretroviral therapy
Not A1C
use plasma blood glucose instead of A1C
Understimates glycemia!!!!; Test with fasting plasma glucose
Who needs which test for DM screening?
52 yo with T2DM for 10 yrs; Diagnosed with stage 1A CKD last year and is currently taking metformin and lisinopril
A1C
Who needs which test for DM screening?
37 yo with sickle cell anemia diagnosed with 8 yo, the patient has experienced sickle cell crises twice in his life
Not A1C
use plasma blood glucose instead of A1C
Who needs which test for DM screening?
45 yo patient with a BMI of 39, underwent blood transfusion after a car accident 8 months ago; patient is here for routine physical exam
A1C
Why is alternative test (other than A1C) better for: HIV patient on retrovirals
- ART can increase risk (NRTI (messes with fat distribution which can influence insulin resistance, and PI (apoptosis of beta cell dysfunction) of DM
Understimates glycemia!!!!; Test with fasting plasma glucose
Why is alternative test (other than A1C) better for: ESRD patient
On HD? then u need an alternative test
HD can cause RBCs to turnover at increased rate;
Need to do plasma glucose levels
Why is alternative test (other than A1C) better for: sickle cell patient
HbS (sickle cell_) can cause A1C to be lower by 0.3%
Falsely low A1C
use plasma blood glucose instead of A1C
Why is alternative test (other than A1C) better for: x linked G6PD deficiency
is associated with a decrease in A1C by 0.8% in men and 0.7% in women
Falsely low A1C
use plasma blood glucose instead of A1C
