Certified Diabetes Care and Education Specialist
(CDCES)Comprehensive Predictor Exit Exam
with Questions & 100% Correct Answers with
Latest Actual Exam Version
,Domain 1: Assessment and Diagnosis
1. Question: A 45-year-old asymptomatic patient has a fasting plasma glucose (FPG) of 128 mg/dL on two separate
occasions. How should this be interpreted?
Answer: Diabetes.
Rationale: A diagnosis of diabetes is made when FPG is ≥126 mg/dL on two separate tests. This meets the threshold.
2. Question: What is the primary utility of measuring C-peptide levels in a patient with diabetes?
Answer: To assess residual endogenous insulin secretion.
Rationale: C-peptide is cleaved from proinsulin and secreted in equimolar amounts with insulin. It helps differentiate
between type 1 diabetes (low/absent) and type 2 diabetes (normal/high).
3. Question: A 60-year-old woman has no symptoms but a random plasma glucose of 210 mg/dL. Is this diagnostic for
diabetes?
Answer: Yes, if classic hyperglycemia symptoms are absent, a confirmatory test (FPG or A1C) is needed. But if a random
glucose is ≥200 mg/dL and symptoms (polyuria, polydipsia, weight loss) are present, it is diagnostic.
,Rationale: The ADA criteria state that classic symptoms plus a random glucose ≥200 mg/dL meet the threshold for
diagnosis, but without symptoms, a second confirmatory test is required.
4. Question: What A1C level is considered diagnostic for diabetes?
Answer: ≥6.5%.
Rationale: The ADA and WHO use an A1C of 6.5% or higher, performed in a lab using an NGSP-certified method, as a
diagnostic criterion.
5. Question: A patient with an A1C of 6.0% and a FPG of 116 mg/dL would be diagnosed with what condition?
Answer: Prediabetes.
Rationale: Prediabetes is defined by an A1C of 5.7–6.4%, IFG (FPG 100–125 mg/dL), or IGT (2-hr OGTT glucose 140–199
mg/dL).
6. Question: What is the most common cause of an A1C result that does not correlate with the patient’s blood glucose
logs and fructosamine levels?
Answer: A hemoglobin variant (e.g., HbS, HbC) or condition affecting red blood cell turnover (e.g., anemia).
Rationale: A1C relies on normal red blood cell lifespan. Hemoglobinopathies and conditions like hemolytic anemia can
falsely lower or elevate A1C, while iron-deficiency anemia can falsely elevate it.
, 7. Question: A thin 18-year-old presents with DKA, an A1C of 12%, and a family history of autoimmune disease. What is
the most critical lab test to order for definitive classification?
Answer: Autoantibody panel (GAD65, IA-2, ZnT8, IAA).
Rationale: The presence of autoantibodies confirms type 1 diabetes, distinguishing it from type 2 or MODY, and is
essential for appropriate insulin therapy.
8. Question: Which antibody is most prevalent in adult-onset type 1 diabetes (LADA)?
Answer: GAD65 (Glutamic Acid Decarboxylase) antibodies.
Rationale: GAD65 antibodies are typically the most persistent and common marker in latent autoimmune diabetes in
adults.
9. Question: A patient’s estimated glomerular filtration rate (eGFR) is 45 mL/min/1.73m². How often should they be
referred for nephrology or monitored for complications compared to someone with an eGFR >90?
Answer: More frequently (at least twice yearly) and co-managed with nephrology.
Rationale: An eGFR <60 mL/min/1.73m² indicates CKD stage 3. This requires intensified monitoring (every 6 months) and
referral to manage complications like anemia and bone mineral disease.
(CDCES)Comprehensive Predictor Exit Exam
with Questions & 100% Correct Answers with
Latest Actual Exam Version
,Domain 1: Assessment and Diagnosis
1. Question: A 45-year-old asymptomatic patient has a fasting plasma glucose (FPG) of 128 mg/dL on two separate
occasions. How should this be interpreted?
Answer: Diabetes.
Rationale: A diagnosis of diabetes is made when FPG is ≥126 mg/dL on two separate tests. This meets the threshold.
2. Question: What is the primary utility of measuring C-peptide levels in a patient with diabetes?
Answer: To assess residual endogenous insulin secretion.
Rationale: C-peptide is cleaved from proinsulin and secreted in equimolar amounts with insulin. It helps differentiate
between type 1 diabetes (low/absent) and type 2 diabetes (normal/high).
3. Question: A 60-year-old woman has no symptoms but a random plasma glucose of 210 mg/dL. Is this diagnostic for
diabetes?
Answer: Yes, if classic hyperglycemia symptoms are absent, a confirmatory test (FPG or A1C) is needed. But if a random
glucose is ≥200 mg/dL and symptoms (polyuria, polydipsia, weight loss) are present, it is diagnostic.
,Rationale: The ADA criteria state that classic symptoms plus a random glucose ≥200 mg/dL meet the threshold for
diagnosis, but without symptoms, a second confirmatory test is required.
4. Question: What A1C level is considered diagnostic for diabetes?
Answer: ≥6.5%.
Rationale: The ADA and WHO use an A1C of 6.5% or higher, performed in a lab using an NGSP-certified method, as a
diagnostic criterion.
5. Question: A patient with an A1C of 6.0% and a FPG of 116 mg/dL would be diagnosed with what condition?
Answer: Prediabetes.
Rationale: Prediabetes is defined by an A1C of 5.7–6.4%, IFG (FPG 100–125 mg/dL), or IGT (2-hr OGTT glucose 140–199
mg/dL).
6. Question: What is the most common cause of an A1C result that does not correlate with the patient’s blood glucose
logs and fructosamine levels?
Answer: A hemoglobin variant (e.g., HbS, HbC) or condition affecting red blood cell turnover (e.g., anemia).
Rationale: A1C relies on normal red blood cell lifespan. Hemoglobinopathies and conditions like hemolytic anemia can
falsely lower or elevate A1C, while iron-deficiency anemia can falsely elevate it.
, 7. Question: A thin 18-year-old presents with DKA, an A1C of 12%, and a family history of autoimmune disease. What is
the most critical lab test to order for definitive classification?
Answer: Autoantibody panel (GAD65, IA-2, ZnT8, IAA).
Rationale: The presence of autoantibodies confirms type 1 diabetes, distinguishing it from type 2 or MODY, and is
essential for appropriate insulin therapy.
8. Question: Which antibody is most prevalent in adult-onset type 1 diabetes (LADA)?
Answer: GAD65 (Glutamic Acid Decarboxylase) antibodies.
Rationale: GAD65 antibodies are typically the most persistent and common marker in latent autoimmune diabetes in
adults.
9. Question: A patient’s estimated glomerular filtration rate (eGFR) is 45 mL/min/1.73m². How often should they be
referred for nephrology or monitored for complications compared to someone with an eGFR >90?
Answer: More frequently (at least twice yearly) and co-managed with nephrology.
Rationale: An eGFR <60 mL/min/1.73m² indicates CKD stage 3. This requires intensified monitoring (every 6 months) and
referral to manage complications like anemia and bone mineral disease.
