Kidney disease in Aboriginal Australians perpetuates poverty
Monday, 10 June 2013
The recent death of the lead singer of Yothu Yindi, is a high-profile example of an event all too common in Aboriginal Australia.
Older Aboriginal Australians (40 to 60 years old) are more than 15 times more likely to die of kidney disease than non-Aboriginal Australians. This is an age that's normally the prime life. But not only is it a tragedy for the individuals involved but has a much wider effect on the community.
Elders in all communities are a repository of knowledge and of accumulated wealth. Early death of key older family members deprives younger community members of the benefit of accrued knowledge of culture and both financial and social support.
The structure of the broader Australian population is like a pillar with similar numbers of people in all age groups. This means that a young non-Aboriginal child will often receive support and guidance from two mature adults with back up from four, still-living grandparents.
The population structure in Aboriginal Australia is quite different and is more like a triangle, with many more children than adults and even fewer living grandparents. This means that an Aboriginal child receives support and guidance from far fewer adults.
This pyramid like structure is generated partly by early death of Aboriginal adults from heart disease, diabetes and kidney disease.
Not a great start
Heart disease, diabetes and kidney disease are non-communicable diseases that are strongly influenced by the environment. Increasing evidence suggests that all three begin as the baby is developing in the uterus. This concept is known as fetal programming or the developmental origins of adult health.
Let us explain by using kidney disease as an example to illustrate the concept. Skin sores can become infected with the bacteria known as streptococcus, this type of infection can lead to kidney damage known as glomerulonephritis. This can happen in childhood, and, if it happens to a girl, her kidneys may already be damaged by the time she becomes pregnant.
Studies in pregnant sheep have demonstrated that if the mother's kidney function is damaged, then the kidneys of the developing fetus also become damaged. This allows kidney damage to be passed across generations.
Studies by others suggest that this is happening to many Aboriginal mothers and their babies. Aboriginal mothers often have evidence of kidney disease already present during pregnancy and Aboriginal babies are frequently born with a much smaller number of nephrons (the functional units of the kidney). Typically around 400,000 while non-Aboriginal babies have over one million.
This reduction in nephron numbers is linked to impaired growth within the uterus of many Aboriginal babies who are born too small (known as growth restriction), twice as often as non-Aboriginal babies.
A better way forward
If we are to close the gap in Aboriginal life expectancy and well-being, we need to focus on the beginning of life inside the uterus. We need to ensure high quality care and support for Aboriginal mothers and their babies.
We need to develop ways of identifying babies at risk of kidney disease early to prevent deterioration of kidney function that could be transmitted across generations into the future.
Progress is being made. In Tamworth, a research team from the University of Newcastle's department of rural health is recruiting young Aboriginal mums and their children and seeking to identify markers of kidney impairment in urine samples.
In Townsville, a neonatologist is using retinal photographs of newborn babies' eyes to identify those at risk of kidney disease (the blood vessels at the back of the eye reflect the way the blood vessels in the kidney are also developing).
If we can reduce the burden of kidney disease, we can improve not only the health of Aboriginal Australians but also their cultural and material wealth by allowing more older Aboriginal people to transmit their knowledge and resources to the next generation. Intervening early in life to optimise health is a much more effective strategy than trying to correct accumulated damage in later life.
Acknowledgement: Della Yarnold also contributed to this article.
Roger Smith receives funding from the National Health and Medical Research Council.
Kirsty Pringle does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.