A 21-year-old man comes to the office due to recent weight loss and fatigue. The patient is a college athlete and states, "My coach wants me to put on more weight, but I can't seem to do it. It doesn't matter how much I eat, I keep losing weight. I've been really thirsty and drinking lots of water lately too, and it's causing me to use the bathroom frequently during practice. I'm worried that I'm going to get dropped from the team if I don't get myself together." He is sexually active and has 1 lifetime partner. The patient's father was diagnosed with colon cancer at age 64. Which of the following studies would be the best next step to establish the diagnosis in this patient?

Question

A 21-year-old man comes to the office due to recent weight loss and fatigue.  The patient is a college athlete and states, "My coach wants me to put on more weight, but I can't seem to do it.  It doesn't matter how much I eat, I keep losing weight.  I've been really thirsty and drinking lots of water lately too, and it's causing me to use the bathroom frequently during practice.  I'm worried that I'm going to get dropped from the team if I don't get myself together."  He is sexually active and has 1 lifetime partner.  The patient's father was diagnosed with colon cancer at age 64.  Which of the following studies would be the best next step to establish the diagnosis in this patient?

Quizplus · Accepted Answer

11ec160b_3ab5_d935_9249_75e41bfdb047_MD0001_00 This patient's polyuria, polydipsia, fatigue, and weight loss despite increased food intake are suggestive of type 1 diabetes mellitus. Patients often develop these characteristic symptoms over an acute to subacute time frame and may occasionally present with diabetic ketoacidosis (nausea/vomiting, abdominal pain, decreased mental status, fruity odor to breath). Although most patients with type 1 diabetes mellitus are diagnosed before age 10, onset in adolescence and adulthood is not uncommon. Appropriate initial tests and related diagnostic criteria for diabetes include: Fasting plasma glucose ≥126 mg/dL Hemoglobin A1c ≥6.5% Random (nonfasting) glucose ≥200 mg/dL in a patient with symptoms of hyperglycemia (eg, polyuria, polydipsia) Oral glucose tolerance test with plasma glucose ≥200 mg/dL 2 hours after glucose ingestion (preferred for diagnosis of gestational diabetes) (Choice A) Colon cancer in a first-degree relative increases an individual's risk for this disease. However, because this patient's father was at an advanced age at diagnosis, the patient's risk is not significantly elevated. (Choice C) Acute HIV presents as an acute viral syndrome with nonspecific symptoms and signs (eg, weight loss, fatigue). However, polyuria and polydipsia suggest diabetes rather than acute HIV. (Choice D) It is possible that weight loss and polyuria are due to thyrotoxicosis, but the absence of other symptoms of thyroid disease (eg, palpitations, heat intolerance, excessive sweating) makes this less likely. (Choice E) Acute cystitis can cause frequent urination but the total urine volume is not increased, and polydipsia and weight loss are more suggestive of diabetes mellitus. Although urinalysis can detect glucosuria, it has low sensitivity for diabetes and should not be used to confirm the diagnosis. (Choice F) Although surreptitious drug abuse can be considered in patients with weight loss or other unexplained symptoms, a hemoglobin A1c test is more likely to be diagnostic in light of this patient's polyuria and polydipsia. Educational objective: Type 1 diabetes mellitus typically presents subacutely with polyuria and polydipsia accompanied by fatigue and weight loss. The diagnosis can be confirmed with a fasting blood glucose or hemoglobin A1c measurement. __________ References: Type 1 diabetes. (http://www.ncbi.nlm.nih.gov/pubmed/23890997)

A 21-Year-Old Man Comes to the Office Due to Recent