1. Systemic and urine studies: proteins involved in diabetic nephropathy pathogenesis as vascular endothelial factor A (VEGF) and extracellular matrix protein as tenascin C (tenascin) concentration will be measured by a commercially available kits in plasma and urine (respectively). Samples will be obtained from diabetics with (n: 20) and without diabetic nephropathy (n: 20) and from non-diabetic subjects (controls) from the general population (n: 2000). Determinations of social, environmental and biological factor will be completed as in aim 1.