Review Question - QID 215044

A 47-year-old woman presents to the clinic with 3 weeks of increased thirst and urination. She has a history of obesity, hypertension, and depression for which she takes losartan and sertraline. She has smoked 1 pack of cigarettes per day for 30 years. Her temperature is 99.5°F (37.5°C), blood pressure is 148/90 mmHg, pulse is 84/min, and respirations are 15/min. Physical exam is unremarkable, including no costovertebral or suprapubic tenderness to palpation. Laboratory studies are performed and show:

Serum:
Na+: 140 mEq/L
K+: 4.4 mEq/L
HCO3-: 21 mEq/L
Blood urea nitrogen (BUN): 38 mg/dL
Creatinine: 1.1 mg/dL
Glucose: 215 mg/dL

Which of the following is the most appropriate screening test for nephropathy in this patient?