The contribution of cardio-metabolic risk factors to estimated glomerular filtration rate (eGFR) decline in Indigenous Australians with and without albuminuria- the eGFR follow-up study

Abstract

Aim: We assessed associations between cardiometabolic risk factors and estimated glomerular filtration rate (eGFR) decline according to baseline albuminuria to identify potential treatment targets in Indigenous Australians. Methods: The eGFR Follow‐up Study is a longitudinal cohort of 520 Indigenous Australians. Linear regression was used to estimate associations between baseline cardiometabolic risk factors and annual Chronic Kidney Disease Epidemiology Collaboration eGFR change (mL/min per 1.73m2/year), among those classified with baseline normoalbuminuria (urine albumin‐to‐creatinine ratio (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 years follow‐up, progressive declines of the age‐ and sex‐adjusted mean eGFR were 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 per 1.72m2/year). Although a borderline association was observed between greater baseline haemoglobin A1c 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 high‐density lipoprotein cholesterol showed non‐significant trends with greater eGFR decline in the presence of albuminuria. Conclusion: Over a 3 year period, marked eGFR decline was observed with greater baseline albuminuria. Cardiometabolic 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 chronic kidney disease progression in this population.