KS TAN1,2,3, S NG1, J ZHANG1,2, Z WANG1,2, A CAMERON1,2, WE HOY1,2
1NHMRC CKD.CRE and CKD.QLD, Brisbane, Queensland; 2Faculty of Medicine, University of Queensland, Brisbane, Queensland; 3Renal unit, Logan Hospital & Metro South Health Service, Brisbane, Queensland.
Aim: Define the baseline characteristics, all-cause mortality and renal outcomes of patients with DM and CKD enrolled in the CKD.QLD registry who had undergone renal biopsy.
Background: Diabetes Mellitus (DM) is the commonest cause of end stage kidney disease and one of the commonest causes of chronic kidney disease (CKD) in Australia.
The CKD.QLD registry is a Queensland-wide registry of patients with CKD who are followed up in the state’s public hospital renal units and have provided informed consent. Enrolment commenced in 2011.
Methods: Patients with DM enrolled in the registry between 22/01/2011 and 15/11/2016 inclusive with previous renal biopsy were included. Baseline characteristics, incidence of renal replacement therapy (RRT) or death without RRT were determined. Censor date was 1/03/2017.
Results: Among 2665 CKD patients with DM, 189 patients (84 women) had undergone renal biopsy. Mean follow up at censor date was 3.1 years, giving 561 patient-years follow-up. Mean age at enrolment was 60.2y (SD 12.5). 110 (58%) patients had evidence of diabetic kidney disease on biopsy (29 had at least one additional histological diagnosis).
Mean eGFR at enrolment was 36ml/min (SD 17.7). 146 (77%) patients had macroalbuminuria at enrolment (urine ACR ≥30mg/mmol/PCR ≥50mg/mmol).
At censor date, there were 34 deaths without RRT and 42 patients had commenced RRT (all dialysis, no pre-emptive transplants).
Conclusions: This group had significant renal impairment at enrolment and commonly had significant residual proteinuria. Despite likely selection bias, diabetic kidney disease was still the commonest histological diagnosis. The finding that commencement of RRT was a more common outcome than death raises the possibility that these patients are quite a different subgroup from patients with CKD in general.