Diabetic kidney disease with and without albuminuria

Historically, for people at risk of developing diabetic chronic kidney disease (CKD), an initial increase in albumin excretion rate (AER) has been linked to a subsequent decline in glomerular filtration rate (GFR). We review recent findings that suggest that in some people with diabetic CKD there is an uncoupling of progressive increases in AER and declining GFR.

Approximately 20% of people with type 2 diabetes develop at least stage 3 CKD, defined as an estimated GFR (eGFR) less than 60 ml/min/1.73 m, after accounting for the use of renin-angiotensin system blockers, while remaining normoalbuminuric. A recent analysis from the Diabetes Control and Complications Trial and Epidemiology of Diabetes Interventions and Complications study has shown that 24% of people with type 1 diabetes reached an eGFR threshold of less than 60 ml/min/1.73 m that was not associated with a rise in albuminuria to the microalbuminuria or macroalbuminuria range. This discordance between changes in GFR and AER has resulted in a search for new markers that identify people with diabetes who are at risk of declining GFR independent of progressive increases in AER.

The conventional paradigm of kidney disease in people with diabetes has been challenged. Changes in AER and GFR are being increasingly recognized as complementary rather than obligatory manifestations of diabetic CKD.