Rates of CKD3 Development in Type 1 and Type 2 Diabetes with and without Glomerular Hyperfiltration — ASN Events
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  3. Rates of CKD3 Development in Type 1 and Type 2 Diabetes with and without Glomerular Hyperfiltration

Rates of CKD3 Development in Type 1 and Type 2 Diabetes with and without Glomerular Hyperfiltration (#199)

Nicholas Radcliffe 1 2 , Hilary J Thomson 1 2 , Anna Wood 3 , Leonid Churilov 4 5 , Jas-mine Seah 3 , Erosha Premaratne 3 , Scott Baker 3 , Sara Baqar 3 , Thuy Vu 3 , Michele Clarke 3 , Richard J MacIsaac 1 6 , George Jerums 1 3 , Elif I Ekinci 1 3
  1. Department of Medicine, The University of Melbourne, Parkville (Melbourne), Victoria,, Australia
  2. Austin Clinical School, Austin Health, Heidelberg (Melbourne), Victoria, , Australia
  3. Austin Health Endocrine Centre, Austin Health, Heidelberg (Melbourne), Victoria,, Australia
  4. Florey Institute of Neuroscience and Mental Health, Heidelberg (Melbourne), Victoria,, Australia
  5. RMIT University, , Melbourne, , Victoria, , Australia
  6. Department of Endocrinology & Diabetes, St Vincent’s Hospital, Melbourne, Victoria, Australia

INTRODUCTION: Glomerular hyperfiltration, though controversial, is traditionally considered an initial event in the development of Diabetic Kidney Disease. Some, but not all, studies have reported a faster rate of renal function decline in patients with diabetes experiencing baseline hyperfiltration[1].

OBJECTIVE: Risk of Chronic Kidney Disease Stage 3 (CKD3) development was assessed using multiple measurements of Glomerular Filtration Rate (mGFR) in patients with type 1 and type 2 diabetes (T1DM, T2DM, respectively), undergoing follow up at a university teaching hospital.

METHODS: mGFR was calculated from plasma clearance of diethylene-triamine-penta-acetic acid (DTPA; corrected using the Brochner-Mortensen equation). Patients were classified as experiencing hyperfiltration if baseline mGFR was above the age-adjusted threshold (125ml/min/1.73m2, minus 1ml/min/1.73m2 for every year in patient age above 40). The comparison group consisted of patients experiencing normal baseline mGFR (90ml/min/1.73m2 to age-adjusted threshold). Time-to-event analysis for hyperfilterers vs. normofilterers was performed for the risk developing CKD3 (mGFR <60ml/min/1.73m2) in the follow up period. Comparison was made using the Log-rank test for equality of survivor functions. Hazard ratios using Cox propotional hazards regression were derived from unadjusted, and adjusted (for baseline duration of diagnosis, age, sex, HbA1c and diabetes type) modelling.

RESULTS: 461 diabetic patients (309 T2DM, 152 T1DM) with ≥2 mGFR measurements were identified. 281 (n=156, T2DM and n=125, T1DM) patients fulfilled the inclusion criteria of baseline hyperfilterer or normofilterer. Median follow-up in this group of patients was 11.4 years (15.4 years in T1DM and 10.4 years in T2DM). 130 (44 with T1DM and 86 with T2DM) patients were classified with baseline hyperfiltration. Survival analysis (Figure 1) revealed that normofilterers were significantly more likely to develop CKD3 compared to those with baseline hyperfiltration (Log-rank p=0.013; Hazard Ratio (HR) 0.49 (95% CI 0.28-0.87; p=0.015) unadjusted; HR 0.36 (95% CI 0.19-0.68; p=0.002; 95% CI 0.19-0.68) adjusted).

CONCLUSION: These results suggest that diabetic hyperfiltration-associated rapid GFR decline, observed by some investigators, does not confer an increased risk of CKD3. In type 1 and type 2 diabetes, presence of age-adjusted hyperfiltration was associated with a lower rate of CKD3 attainment, independent of duration of diagnosis, age, sex, HbA1c and diabetes type.

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  1. [1] Premaratne E, Verma S, Ekinci EI, Theverkalam G, Jerums G, MacIsaac RJ (2015) The impact of hyperfiltration on the diabetic kidney. Diabetes Metab 41: 5-17