Diabetic nephropathy: is it always there? Assumptions, weaknesses and pitfalls in the diagnosis.

Diabetic nephropathy is defined as a microvascular complication of the kidneys induced by diabetes mellitus and is characterized by albuminuria and progressive loss of kidney function. However, neither albuminuria nor glomerular filtration rate decline are diabetic nephropathy-specific markers, thus the diagnosis of diabetic nephropathy greatly depends on assumptions. Several factors should be taken into account when urinary albumin levels are assessed before establishing the diagnosis of diabetic nephropathy, while newer more specific markers for diabetic nephropathy are urgently needed.