Q. A 45-year-old male is admitted to the hospital with a complaint of uncontrolled hypertension. The patient has a history of poorly controlled hypertension for the past 3 years and has been taking multiple antihypertensive medications without much improvement. He also describes gradual progressive enlargement of his hands, feet, and facial features over the past decade, and reports joint pain, excessive sweating, and a deepening of his voice. On physical examination, the patient is found to have a thickened tongue, widely spaced dentition (see image), and coarse facial features. Which of the following laboratory assessments is indicated to confirm the most likely diagnosis?