The glomerular barrier is highly selective and an only minute amount
reaches the urine. Normally, the daily loss of albumin in urine is less than 30 mg
and microalbuminuria denotes losses between 30-300 mg per day. Overt
proteinuria means daily losses between 300- 3000 mg, whereas larger albumin
losses are in the nephrotic range. There are a wide variety of conditions that
cause microalbuminuria or proteinuria, but recently our understanding of these
phenomena has improved considerably. Microalbuminuria is one of the first
signs of diabetic nephropathy where it reflects endothelial dysfunction and
increased risk of microvascular complications. Microalbuminuria is also an
independent predictor of cardiovascular disease in non-diabetic individuals.
Insulin resistance is an interesting condition that precedes the development of
type II diabetes. Patients with severe kidney disease have insulin resistance
without developing diabetes. Insulin resistance is also associated to
microalbuminuria, hypertension and obesity. Finally, there is an association
between all these conditions and certain inflammatory vascular reactions. In this
chapter, I will try to review our current understanding of microalbuminuria and
how it is related to insulin resistance.
Keywords: Albumin, diabetes, endothelium, glomerular, glycocalyx, kidney, podocytes.
