Indigenous people suffer substantially more end-stage kidney disease (ESKD), especially Australian Aboriginals. Previous work suggests causal pathways beginning early in life. No studies have shown the prevalence of early markers of chronic kidney disease (CKD) in both Indigenous and non-Indigenous children or the association with environmental health determinants--geographic remoteness and socioeconomic disadvantage. Height, weight, blood pressure, and urinary abnormalities were measured in age- and gender-matched Aboriginal and non-Aboriginal children from elementary schools across diverse areas of New South Wales, Australia. Hematuria was defined as>or=25 red blood cells/microl (>or=1+), proteinuria>or=0.30 g/l (>or=1+), and albuminuria (by albumin:creatinine)>or=3.4 mg/mmol. Remoteness and socioeconomic status were assigned using the Accessibility and Remoteness Index of Australia and Socio-Economic Indexes For Areas. From 2002 to 2004, 2266 children (55% Aboriginal, mean age 8.9 years) were enrolled from 37 elementary schools. Overall prevalence of hematuria was 5.5%, proteinuria 7.3%, and albuminuria 7.3%. Only baseline hematuria was more common in Aboriginal children (7.1 versus 3.6%; P=0.002). At 2-year follow-up, 1.2% of Aboriginal children had persistent hematuria that was no different from non-Aboriginal children (P=0.60). Socioeconomic disadvantage and geographical isolation were neither significant nor consistent risk factors for any marker of CKD. Aboriginal children have no increase in albuminuria, proteinuria, or persistent hematuria, which are more important markers for CKD. This suggests ESKD in Aboriginal people may be preventable during early adult life.

Objective: To describe the natural history and risk of early chronic kidney disease (CKD) in Indigenous Australian populations. Design, setting and participants: A prospective cohort of 2266 Aboriginal and non‐Aboriginal children enrolled from primary schools throughout New South Wales from February 2002 to June 2004 and followed for 4 years. Main outcome measures: Urinalysis, height, weight, blood pressure, birthweight and sociodemographic status at baseline and 2‐ and 4‐year follow‐up; CKD risk factors: haematuria, albuminuria, obesity, and systolic and diastolic hypertension. Results: 2266 children (55% Aboriginal; 51% male; mean age, 8.9 years [SD, 2.0 years]) were enrolled at baseline. 1432 children (63%) were retested at 2‐year follow‐up, and 1506 children (67%) at 4‐year follow‐up. Prevalence of baseline CKD risk factors was frequent (2%–7%), but most abnormalities were transient. Besides persistent obesity (5.0%), persistence of CKD risk factors at final follow‐up was low: haematuria (1.9%), albuminuria (2.4%), systolic hypertension (1.5%) and diastolic hypertension (0.2%). There was no difference in prevalence of persistent CKD risk factors between Aboriginal and non‐Aboriginal children. Conclusions: Over 4 years of follow‐up, Indigenous Australian children had no increased risk for early evidence of CKD. More than 70% of baseline risk factors were transient, and persistent risk factors were uncommon. Our findings suggest the increased risk for end‐stage kidney disease seen in Indigenous adults is not yet manifest in these schoolchildren, and may be potentially preventable.

Socio-economic status and birth weight have differential effects on BMI among Aboriginal boys, and Aboriginal girls had a higher mean BMI than non-Aboriginal girls through childhood and adolescence. Intervention programs need to recognise the differential risk for obesity for Aboriginal and non-Aboriginal boys and girls to maximise their impact.

No abstract

Compared with non-Aboriginal children, Aboriginal children are of higher risk of albuminuria when overweight or obese. We hypothesise that overweight and obesity are key contributors to the development of adult onset CKD among Aboriginal Australians, which needs further exploration in future studies.