Diabetic nephropathy in type 1 diabetes: a review of early natural history, pathogenesis, and diagnosis.

Diabetic nephropathy constitutes a devastating complication in patients with type 1 diabetes mellitus, and its diagnosis is traditionally based on microalbuminuria. The aim of this review is to update through the medical literature the suggested early natural course of diabetic nephropathy, the theories behind the pathways of its pathogenesis, and its diagnosis. Poor glycemic control, dyslipidemia, smoking, advanced glycation end products, and environmental and genetic clues play an important role in the development of diabetic nephropathy. Microalbuminuria has been traditionally considered as a primary early marker of microvascular complication unraveling the risk for progress to the advanced stages of chronic kidney disease, but because of our inability to make an early diagnosis of diabetic nephropathy in young patients as well as nonalbuminuric diabetic nephropathy, recently, other additional markers of renal injury like serum and urinary neutrophil gelatinase-associated lipocalin, chitinase-3-like protein 1, cystatin C, and plasma growth differentiation factor 15 have been proposed to unmask early renal dysfunction, even before microalbuminuria supervenes.