The multideterminant model of renal disease in a remote Australian Aboriginal population in the context of early life risk factors: lower birth weight, childhood post-streptococcal glomerulonephritis, and current body mass index influence levels of albuminuria in young Aboriginal adults.

Background: Australian Aborigines in remote areas have very high rates of kidney disease, which is marked by albuminuria. We describe a "multihit" model of albuminuria in young adults in one remote Aboriginal community. Methods: Urinary albumin/creatinine ratios (ACR) were measured in all subjects who volunteered to participate in a community-wide health screen. Subjects for this study were young adults who had birth weights recorded and whose medical records were inspected for a history of post-streptococcal glomerulonephritis (PSGN). Urine ACR levels were evaluated in the context of birth weights, PSGN history and current BMI. Results: 580 subjects (335 males and 245 females) who were aged 18 - 39 years at time of screening and qualified for inclusion. 26% of subjects had birth weights of < 2.5 kg, and the median birth weight was 2.8 kg. 23% of subjects had a remote history of PSGN, all 3 or more years earlier. Median BMI for the group was 21 kg/m2. Urine ACR levels exceeded the microalbuminuria threshold of 3.4 g/mol in 35.5% of subjects. Birth weight (inversely), remote PSGN, and current BMI were all independent predictors of ACR levels. Median levels of ACR were lowest in those with birth weights ≥2.5 kg, and no history of PSGN, intermediate in those with either birth weights < 2.5 kg or a history of PSGN, and highest in those with both low birth weights and a PSGN history. ACR levels were higher in those with BMIs above the median values, most notably in those with lower birth weights or a PSGN history or both. Interpretation: Much of the great excess of disease in this population is explained by high rates of the early life risk factors, low birth weight and PSGN. Their effects are expressed through amplification of ACR in the context of increasing age, and are further moderated by levels of current body size. Both early life risk factors are potentially modifiable.