Diabetic nephropathy

Diabetic kidney disease (DKD) affects around 1 in 3 patients with type 1 or type 2 diabetes and is more prevalent in non-Caucasians. Diagnosis and staging of DKD uses two dimensions: albumin excretion rate (AER Stages 1–3 (normo-, micro-, macroalbuminuria)) and glomerular filtration rate (GFR (ml/min/1.73m2) Stage 1, >90; Stage 2, 90–60; Stage 3, 59–30; Stage 4, 29–15; and Stage 5, <15). Although increases in AER usually precede decreases in GFR, early GFR decline occurs independently of AER in about 1 in 4 subjects. Intervention trials have shown that glycemic control (HbA1c ˜ 7.0%, 53 mmol/mol) can reduce onset of DKD, while in later stages of DKD blood pressure control based on RAS inhibition (BP < 140/90 mmHg), can defer onset of ESRD by up to 1 year. However, rapid lowering of glucose or BP levels beyond these values in patients at high CV risk can lead to serious side effects. Individualization of targets for glucose, BP, and lipid control is therefore necessary. Several new markers of DKD, such as elevated circulating TNF-α receptors, have been identified recently. Intervention studies are awaited to determine if they are linked to progression of DKD.