Linking acute kidney injury to chronic kidney disease: the missing links.

Acute kidney injury (AKI) is considered to be a major public health problem around the globe, and it is associated with major adverse clinical outcomes and significant health care costs. There is growing evidence suggesting that AKI is associated with the subsequent development of chronic kidney disease (CKD). While recovery of kidney function occurs in the majority of patients surviving an AKI episode, a large number of patients do not recover completely. Similarly, CKD is a well-known risk factor for the development of AKI. Recent studies suggest that both AKI and CKD are not separate disease entities but are in fact components of a far more closely interconnected disease continuum. However, the true nature of this relationship is complex and poorly understood. This review explores potential relationships between AKI and CKD, and seeks to uncover a number of "missing links" in this tentative emerging relationship.