Earliest marker of renal damage in a known case of diabetes mellitus is:

 # Earliest marker of renal damage in a known case of diabetes mellitus is:

A. Microalbuminuria

B. Glycosuria

C. Increased serum creatinine

D. Increased serum urea

The correct answer is A. Microalbuminuria. 

Microalbuminuria refers to the urinary excretion of small amounts of albumin. The consistent presence

of albumin in the urine is abnormal and is clinically important in identifying the very early stages of glomerular disease, as occurs in conditions like diabetic nephropathy. Because significant renal damage

has already taken place before standard dipstick tests become positive, patients with diabetes mellitus should be screened regularly for microalbuminuria. Persistent microalbuminuria has also been associated with an increased risk of atherosclerosis and cardiovascular  mortality but neither the mechanism of proteinuria nor an explanation for this association has been established.