Diabetic nephropathy develops in only a subgroup of patients affected by
type 1 diabetes. Once established, this complication is quite difficult to control, and consequently its prevention is presently considered the first target to achieve. As
hyperglycemia has immediate effects on renal function and structure, it is reasonable to say that, in predisposed individuals, the pathogenesis of
diabetic nephropathy also begins with the onset of diabetes. Two major hypotheses have been put forward to explain how the renal abnormalities that characterize the first years of diabetes - i.e., hyperfiltration and
hypertrophy - will later lead to the appearance of microalbuminuria and
end-stage renal disease. The first hypothesis considers hyperfiltration as the driving dysfunction and
hypertrophy as the consequence. Conversely, the second points to proximal tubule
hypertrophy as the starting point and hyperfiltration as the result. Whatever the case, tight
glucose control from the very first days of disease seems to be the only established
therapy to prevent future complications in
type 1 diabetes.