Methods: The eGFR Follow‐up study is a longitudinal cohort of 520 Indigenous Australians. Linear mixed regression was used to estimate associations between baseline cardio‐metabolic risk factors and annual Chronic Kidney Disease Epidemiology Collaboration (CKD‐EPI) eGFR change (ml/min/1.73 m2/year), among those classified with baseline normoalbuminuria (uACR <3 mg/mmol; n = 297), microalbuminuria (uACR 3‐30 mg/mmol; n = 114) and macroalbuminuria (uACR ≥30 mg/mmol; n = 109).
Results: After a median of 3.0 years of follow‐up, progressive declines of the age‐ and sex‐adjusted mean eGFR was observed across albuminuria categories (‐2.0 [‐2.6 to‐1.4], ‐2.5 [‐3.7 to ‐1.3] and ‐6.3 [‐7.8 to ‐4.9] ml/min/1.72 m2/year). Although a borderline association was observed between greater baseline HbA1c and eGFR decline in those with macroalbuminuria (p = 0.059), relationships were not significant in those with microalbuminuria (p = 0.187) or normoalbuminuria (p = 0.23). Greater baseline blood pressure, C‐reactive protein, waist‐to‐hip ratio and lower HDL cholesterol showed non‐significant trends with greater eGFR decline in the presence of albuminuria.
Conclusion: This study demonstrated that in a three year period marked eGFR decline was observed with greater baseline albuminuria. Cardio‐metabolic risk factors were not strong predictors for eGFR decline in Indigenous Australians without albuminuria. Longer follow‐up may elucidate the role of these predictors and other mechanisms in CKD progression in this population.