You just diagnosed Mrs Bates as having metabolic syndrome. The unusual fatigue and nocturia she describes make you wonder about another potential diagnosis. How would you proceed?
Recently you performed an annual physical examination of 65-year-old Mrs Bates. At that appointment she complained of feeling more fatigued than usual and of having to get up to urinate twice a night. Based on results of a lipid panel and her BMI of 31 kg/m2 you diagnosed her as having metabolic syndrome. Her only medication is a high-potency statin which she has taken for 8 years.
Given the metabolic syndrome diagnosis and her new symptoms, you now strongly suspect new-onset type 2 diabetes.
What is the ADA-recommended diagnostic test of choice for diagnosing diabetes?