Kidney function deteriorates with age, study shows

Reviewed by Emily Henderson, B.Sc.Jun 9 2020

An international study that has been carried out on nearly 3000 people in Norway, Germany, and Iceland, shows that our kidney function deteriorates with age, even if we do not have any other diseases. The results from the study have recently been published in the reputable journal for kidney diseases, Journal of the American Society of Nephrology (JASN). In the study, the researchers have examined the kidney function of a group of people between the ages of 50 and 70, and two groups of people between the ages of 70 to 95, to discover how the kidney function develops.

What we see is that what happens in our kidneys when we age is representative of all the other things that happen in our bodies. The kidney function deteriorates, not because we get ill, but as part of aging."

Bjørn Odvar Eriksen, Professor at the Department of Clinical Medicine at UiT and leader of the Metabolic and Renal Research Group

Eriksen is the lead author of the article that has been published in JASN.

- Loss of kidney function is something that happens to all humans and is thus a way to determine ageing in general. There is still variation as to how quickly this happens, and we still do not have good answers as to why this variation occurs. We have examined many factors that can play a part as to why some of us experience larger loss of kidney function than others, he adds.

One of the groups that have participated in the study consists of over 1600 people and stems from The Tromsø Study, which is Norway's most comprehensive and best participated population study throughout 40 years. This group has been through the different examinations three times; between 2007 to 2009, 2013 to 2015, and 2018 to 2020. The last iteration of the study is still ongoing at The University Hospital of North Norway (UNN) and is lead by Associate Professor Toralf Melsom.

- No other study has done these kinds of examinations on a part of the normal population. That is why this study is so unique, Eriksen says.

The researchers use a precise method of measuring kidney function. They inject a substance into the blood veins that only separates into the kidneys, and let a few hours pass before they measure how much of the substance remains in the blood. This gives a measure of the kidney's ability to remove toxins and waste products. Eriksen explains that more people may experience loss of kidney function as it becomes more common to survive diseases like cancer and heart and vascular diseases.

- For those who experience loss of kidney function at a high age, this is a considerable burden. That is why this is an area that needs further research to find more answers. We are still looking for the fountain of youth, Eriksen says.