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

Predictors of albumin to creatinine ratio (ACR) among Indigenous Australian participants in the eGFR follow up study (#152)

Elif I. Ekinci 1 2 , Federica Barzi 3 , Jaqui Hughes 3 4 , Elizabeth Barr 3 5 , Paul D Lawton 3 , Graham R Jones 6 , Wendy Hoy 7 , Alan Cass 3 , Mark Thomas 8 , George Jerums 1 2 , Kerin O'Dea 9 , Richard MacIsaac 10 11 , Louise Maple-Brown 3 4
  1. Austin Health, Heidelberg West, VIC, Australia
  2. Department of Medicine Austin Health, University of Melbourne, Melbourne, VIC, Australia
  3. Menzies School of Health Research, Darwin, Northern Territory, Australia
  4. Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
  5. Baker Heart and Diabetes Institute, Melbourne
  6. SydPath, St Vincents Hospital, Sydney, NSW, Australia
  7. University of Queensland, Brisbane, Queensland, Australia
  8. Royal Perth Hospital , Perth
  9. University of South Australia, Adelaide, South Australia, Australia
  10. Department of Endocrinology and Diabetes, St Vincents Hospital, Melbourne, Melbourne, Victoria, Australia
  11. University of Melbourne, Melbourne, Australia

Background

Macroalbuminuria is associated with kidney function loss in Indigenous Australians, however, no studies have examined the association of albuminuria at follow up with the presence of hyperfiltration at baseline, based on direct measurements of glomerular filtration rate (GFR) in this population.

Aims

To determine the risk factors (including glomerular hyperfiltration) contributing to an increase of ACR after 3 years follow-up in Indigenous Australians. 

Methods

Study participants were grouped into baseline mGFR < 90 mL/min/1.73m2, mGFR 90-125 mL/min/1.73m2, mGFR > 125 mL/min/1.73m2 (hyperfiltering group) categories. Multivariable regression models were used to assess the association between the log of follow-up ACR (FuACR), mGFR levels and other factors after adjusting for age, gender and baseline log ACR. Results were expressed in terms of percent change of ACR from baseline to follow-up.

Results

This analysis included 407 individuals (32.5% male, mean age 47 years) followed-up after a median of  3 years. At baseline, 77 individuals had hyperfiltration, 191 had normofiltration (mGFR 90-125ml/min/1.73m2) and 139 had chronic kidney disease (CKD) stage 2 or below  (mGFR<90/min/1.73m2).  Each 10% higher baseline ACR was associated with a 8.5% (95% CI: 7.9-9.1%) increase in FuACR and each 1% increase in HbA1c was associated with a 13% (95% CI; 6-20%) increase in FuACR, whereas presence of hyperfiltration at baseline was not associated with higher FuACR. There was a weak association with DBP showing a 6.7% (p=0.02) increase in FuACR for each 5mmHg lower DBP, this association was not seen on a sensitivity analyses restricted to those not on antihypertensive medications.

Conclusions

Higher baseline ACR, higher baseline HbA1c and lower baseline diastolic blood pressure predicted and baseline hyperfiltration did not predict higher ACR levels in Indigenous Australians after a 3 year follow-up. Longer follow-up is necessary to determine the prognostic value of hyperfiltration in this population.