AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisMedium
A 48-year-old male presents with a 2-week history of nocturnal polyuria (waking up multiple times to urinate), polydipsia, and fatigue. He also reports recent unintentional weight loss despite increased appetite. His past medical history is unremarkable. A random plasma glucose is 280 mg/dL. Which additional diagnostic test is most essential to confirm the diagnosis and guide initial management?
- AUrine culture and sensitivity
- BSerum creatinine and BUN
- CThyroid-stimulating hormone (TSH)
- DHemoglobin A1c (HbA1c)
Show answer & explanationAnswer & explanation
Correct answer: D. Hemoglobin A1c (HbA1c)
The patient's symptoms (polyuria, polydipsia, weight loss, fatigue) and a random plasma glucose of 280 mg/dL are highly suggestive of Type 2 Diabetes Mellitus. HbA1c is essential to confirm the diagnosis and provide an average glucose level over the past 2-3 months, which is crucial for guiding initial management.
Why the other options are wrong
- A. A urine culture would be for urinary tract infection, which might cause polyuria but not the other systemic symptoms or the elevated blood glucose.
- B. Serum creatinine and BUN assess kidney function, which is important for long-term diabetes management but not the primary diagnostic test for diabetes itself.
- C. TSH would screen for thyroid dysfunction, which can cause fatigue and weight changes, but does not explain the classic polyuria/polydipsia or the elevated glucose.
Type 2 Diabetes Mellitus Diagnosis
A chronic metabolic disorder characterized by high blood glucose levels due to insulin resistance and/or relative insulin deficiency.
- Common symptoms include polyuria, polydipsia, polyphagia, and fatigue.
- Diagnosis involves blood glucose tests (fasting plasma glucose, random plasma glucose, oral glucose tolerance test) and HbA1c.
- Early diagnosis and management are crucial to prevent complications.
Memory trick: Diabetes: A1c Confirms A Long-term Picture.