Diabetic kidney disease: Is there a non-albuminuric phenotype in type 2 diabetic patients?

Background: Albuminuria was widely considered as the first clinical sign of diabetic kidney disease (DKD), which is why it has traditionally been used as a screening test for DKD. However, increasing evidence has shown that a significant number of type 2 diabetes mellitus (DM) patients have a decreased glomerular filtration rate (GFR) without significant albuminuria, known as non-albuminuric DKD (NA-DKD). The aim of this study was to determine the prevalence and the demographic and clinical characteristics of patients with NA-DKD. Methods: This was a 1-year retrospective study that included 146 type 2 diabetic patients with GFR<75 mL/min followed-up in a diabetes outpatient department. Patients were divided into two groups according to their ACR status - NA-DKD and albuminuric DKD (A-DKD). Results: Of the 146 patients included in the study, 53.4% had A-DKD and 46.6% had NA-DKD. According to the multivariable analysis performed, patients with NA-DKD tended to be older (p = 0.021), female (p = 0.045) and with a lower GFR (p = 0.004) than A-DKD patients. There was no difference between the groups in terms of body mass index, metabolic control of DM, duration of DM diagnosis and prevalence of metabolic syndrome. Conclusions: The majority of patients with DKD had albuminuria, but a significant proportion had a non-albuminuric phenotype (46.6% in this population). These patients exhibit distinct clinical features that could have screening, therapeutic and prognosis implications. (C) 2016 Sociedad Espanola de Nefrologia. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license