Final answer:
The earliest sign of diabetic renal disease is urine microalbumin, signifying a slight increase in albumin in the urine. This is an earlier indication than proteinuria, which is the presence of larger amounts of protein and usually appears later in the disease progression.
Step-by-step explanation:
The earliest sign of diabetic renal disease is urine microalbumin. This condition, also known as microalbuminuria, refers to a slight increase in the levels of albumin in the urine, which is not usually detected with standard urine dipstick testing used for protein. A urine albumin-to-creatine ratio is a subsequent measure that quantifies the urine albumin in relation to urine creatinine to provide a more accurate assessment of proteinuria. Detectable proteinuria, which means having larger amounts of protein in the urine, is a later sign of diabetic renal disease. While ketones present in urine are a sign of inadequately managed diabetes, it is not specific to diabetic renal disease.