Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

Can the renal resistive index predict progression of diabetic kidney disease (#299)

Elif I Ekinci 1 , Matthew J Lyburn 2 , Leonid Churilov 3 , George Jerums 1 , Mariam Hachem 1 , Michele Milne 1 , Richard J MacIsaac 4
  1. Endocrine Centre, Austin Health & University of Melbourne, Heidelberg West, Victoria, Australia
  2. St Vincent's Clinical School, The University of Melbourne, Melbourne, VIC, Australia
  3. Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
  4. Endocrinology and Diabetes, St Vincent's Hospital & University of Melbourne, Fitzroy, Victoria, Australia

Background: Diabetic kidney disease (DKD) is the most common cause of renal failure. The ability to identify those at greatest risk of progression to renal failure would be a significant advance in clinical management. A promising prognostic marker is the renal resistive index (RI), a measure of intrarenal arterial stiffness obtained by renal Doppler ultrasound. This measurement may identify patients with DKD at risk of deteriorating renal function, over and above traditional risk markers.

 

Aim: to investigate whether high RI is associated with renal function decline in diabetes.

 

Methods: 276 outpatients (66 with type 1 diabetes and 210 with type 2 diabetes) participated in this prospective observational study, for a median time-period of 7.2 years (interquartile range [IQR]: 5.2-9.4 years). RI was measured by renal Doppler ultrasound (RI= [peak systolic velocity-end diastolic velocity]/peak systolic velocity). Routine clinical and biochemical measurements were made at baseline. Urinary albumin excretion rate (AER) and estimated glomerular filtration rate (eGFR) were measured at baseline and at the end of follow-up.

 

Results: Participants with elevated RI (RI≥0.70), relative to participants with RI<0.70, had lower median (IQR) eGFR at baseline (72.4 (59.7-87.7) vs. 88.8 (75.1-102.5)ml/min/1.73m2, p<0.0001). Baseline RI was not associated with albuminuria. The median (IQR) decline in eGFR over the observation period was greater for participants with RI≥0.70 compared to those with RI<0.70 (16.7 (7.2-23.4) vs. 7.2 (0.1-15.0)ml/min/1.73m2, p<0.0001). Multivariate linear regression revealed that baseline RI was independently and inversely associated with the final eGFR (p<0.001) following adjustments for age, sex, systolic blood pressure and haemoglobin A1c.

 

Conclusion: Decline in renal function over 7 years was more pronounced in patients who had a RI≥0.70 at baseline. This association was independent of traditional risk factors. Measuring the RI may help to further identify patients who are at the greatest risk for DKD progression.