Cardiac Autonomic Neuropathy and Its Impact on Progression of Diabetic Kidney Disease in Type 1 and Type 2 Diabetes.

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and kidney failure worldwide, with one-third of patients with diabetes developing kidney disease over the course of their lifetime. With no cure for DKD, its management is mainly conservative. Despite advancement in treatments, the rate of DKD progression to kidney failure is unpredictable, varying from months to years in different individuals. Therefore, researchers have been extensively investigating novel risk factors and biomarkers associated with advancement of DKD. One such emerging factor is cardiac autonomic neuropathy (CAN), which is widespread among diabetic population. It has become imperative to assess whether a causal relationship exists between CAN and DKD. This literature review aims to (1) summarize current evidence for the correlation between DKD and CAN in type 1 and type 2 diabetes mellitus, and (2) outline hypotheses for a possible causal relationship between CAN and DKD. The review covers 28 studies (of which 10 in type 1 diabetes) over the last 3 decades, including well-designed cohort and case-control analytic studies that have clearly demonstrated an association between CAN and the progression of DKD by using kidney parameters such as estimated glomerular filtration rate and urinary albuminuria.