Which of the following tests is most sensitive for detecting early diabetic nephropathy?

ANSWER: (C) Microalbuminuria REF: Harrison 17th ed chapter 338The first clinically detectable sign of diabetic nephropathy is microalbuminuria.The most sensitive method to detect microalbuminuria is by radioimmunoassayThe renal biopsy is the only test of the effect of diabetes on the kidney that is more sensitive than microalbuminuria.Microalbuminuria is defined as 30-300 mg/d in a 24-h collection or 30-300 mg/mg creatinine in a spot collection (preferred method). Once macroalbuminuria is present, there is a steady decline in GFR, and -50% of individuals reach ESRD in 7-10years. Once macroalbuminuria develops, blood pressure rises slightly and the pathologic changes are likely irreversible.The nephropathy that develops in type 2 DM differs from that of type 1 DM in the following respects:Microalbuminuria or macroalbuminuria may be present when type 2 DM is diagnosed, reflecting its long asymptomatic periodHypertension more commonly accompanies microalbuminuria or macroalbuminuria in type 2 DMMicroalbuminuria may be less predictive of diabetic nephropathy and progression to macroalbuminuria in type 2