1. Diabetes screening and diagnosis
Jennifer R Marks, MD

2. Diabetes screening and diagnosis
WHO?
WHEN?

3. Per USPSTF guidelines

5. For all people, testing should begin at age 45 years. B
Recommendations
Testing for prediabetes and type 2 diabetes in asymptomatic people should be considered in adults of any age who are overweight or obese (BMI ≥25 kg/m2 or ≥23 kg/m2 in Asian Americans) and who have one or more additional risk factors for diabetes. B
For all people, testing should begin at age 45 years. B
If tests are normal, repeat testing carried out at a minimum of 3-year intervals is reasonable. C
Per American Diabetes Association Guidelines

6. Per American Diabetes Association Guidelines

7. Per American Diabetes Association Guidelines

8. Diabetes screening and diagnosis
HOW?

9. Per American Diabetes Association Guidelines

10. “There is incomplete concordance between A1C, FPG, and 2-h PG, and the 2-h PG value diagnoses more people with prediabetes and diabetes than the FPG or A1C cut points. Marked discrepancies between measured A1C and plasma glucose levels should prompt consideration that the A1C assay may not be reliable for that individual, since a relatively small percentage of patients have conditions such as sickle cell trait or hemoglobinopathies that skew A1C results.”
Per American Diabetes Association Guidelines

11. Diabetes screening and diagnosis
Pitfalls?

12. Diabetes screening and diagnosis
Falsely lowers A1c
Falsely raises a1c
Any process that shortens the lifespan of the RBC
Any process that lengthens the lifespan of the RBC

13. Pregnancy (less so 3rd trimester)
Falsely lowers A1c
Falsely raises a1c
Anemia from blood loss
Hemolytic anemia
Splenomegaly
Pregnancy (less so 3rd trimester)
Vitamin E ingestion (reduced glycation)
Ribavirin & interferon- alpha (possible hemolytic anemia)
Iron, B12, & folate- deficiency anemia (reduced turnover)
Asplenia
Uremia
Chronic ETOH
Chronic salicylate use
Chronic opioid use
Lead poisoning

14. Per American Diabetes Association Guidelines

15. Diabetes screening and diagnosis Take-Home points
Screen anyone with risk factors anytime
Screen all at age 45
Use combination of HgbA1c, FPG, RPG, OGTT
Beware pitfall in using HgbA1c

16. Diabetes screening and diagnosis ABIM-style question
66 yo M with NIDDM, CAD, htn, and BPH returns to clinic for routine 6-month follow-up. He has taken MTF 1,000mg BID & glipizide 2.5 mg BID for many years with good control (A1c ~ 6.8 historically). He carefully watches his diet, walks his dog 45 minutes daily, and fastidiously charts his BGs which he brings to you in graphic format. All results are <150, and most are about 110 with no hypoglycemia or hypoglycemic symptoms.

17. You review with him the labs he had drawn several days ago prior to the office visit:
HgbA1c 7.3
Sodium 138
Potassium 4.3
Chloride 105
CO2 24
Glucose 88
Calcium 9.8
BUN 12
Creatinine 0.76
LFTs nl
WBC 7.6
RBC 3
Hgb 13
Hct 36
MCV 102
RDW 14
Platelets 299
TSH 2.43

18. The patient is quite upset by the change in his HgbA1c
The patient is quite upset by the change in his HgbA1c. You advise the following:
A) Continue current regimen including meds, diet & exercise
B) Have additional labs drawn
C) Consider a vitamin supplement to make him feel better
D) All of the above
E) None of the above

19. The patient is quite upset by the change in his HgbA1c
The patient is quite upset by the change in his HgbA1c. You advise the following:
A) Continue current regimen including meds, diet & exercise
B) Have additional labs drawn
C) Consider a vitamin supplement to make him feel better
D) All of the above
E) None of the above

20. The patient is quite upset by the change in his HgbA1c
The patient is quite upset by the change in his HgbA1c. You advise the following:
A) Continue current regimen including meds, diet & exercise (avoid overtreatment/hypoglycemia…see below)
B) Have additional labs drawn (test for deficiencies underlying his anemia)
C) Consider a vitamin supplement to make him feel better (Cyanocobalamin, IF actually deficient)
This patient has a macrocytic anemia which may indicate Vitamin B12 deficiency, which is relatively common and can be associated with metformin use. Also this patient is very reliable yet cannot explain this unexpected change in glycemic control.