What is the earliest sign of diabetic nephropathy?

• A. Nephrotic syndrome
• B. Microalbuminuria
• C. Elevated creatinine without proteinuria
• D. Hematuria

Answer: (B)

The earliest sign of diabetic nephropathy is microalbuminuria, a small, persistent leak of albumin into the urine that occurs with initial glomerular injury from long-term hyperglycemia. At this stage, kidney filtration is still largely intact, so the overall filtration rate (and serum creatinine) remains normal, and there is no edema. Microalbuminuria is defined by a modest but detectable amount of albumin excreted in urine (often 30–300 mg per day, or a corresponding elevated urine albumin-to-creatinine ratio). This stage signals the start of progressive kidney damage and prompts intensified glycemic control and blood pressure management to slow progression.

Nephrotic syndrome represents a much later stage with heavy proteinuria, hypoalbuminemia, edema, and often high cholesterol. An isolated rise in creatinine without proteinuria can occur later as the filtration burden increases or due to other causes, and hematuria is not the characteristic early sign of this process.