Climate change will lead to increase in kidney stones, study says
will lead to an increase in kidney stones due to more sweating and dehydration, a new study says. More hot days in the future will likely due to greater water losses through sweat, resulting in more concentrated urine and increased formation of kidney stones, researchers in claim. Kidney stones are hard deposits made of minerals and salts that form inside your kidneys. They form when your urine contains more crystal-forming substances such as calcium, oxalate and uric acid than the fluid in your urine can dilute. Previous research has already shown that high ambient temperatures increase the risk of developing these kidney stones. Not drinking enough water contributes to their formation because more water in the kidneys helps prevent stone-forming crystals from sticking together. Higher temperatures are therefore more likely to cause dehydration, which in turn leads to the painful condition, which can often require surgery. The new study was conducted by researchers at Children's Hospital of Philadelphia (CHOP) in Pennsylvania, led by urologist Dr Gregory E. Tasian. 'It is impossible to predict with certainty how future policies will slow or hasten greenhouse gas emission and anthropogenic climate change, and to know exactly what future daily temperatures will be,' Dr Tasian said. '[But] our analysis suggests that a warming planet will likely cause an increased burden of kidney stone disease on healthcare systems.' Kidney stone disease is a painful condition caused by hard deposits of minerals that develop in concentrated urine and cause pain when passing through the urinary tract. The incidence of the condition has increased in the last 20 years, particularly among women and adolescents. In the US, there is an increase in the incidence of kidney stones from North to South, and there is a rapid increase in risk of kidney stone presentations following hot days. However, previous studies have not precisely projected how climate change will impact the burden of kidney stone disease in the future. To learn more, Dr Tasian and colleagues created a computer model to estimate the impact of heat on future kidney stone presentations in South Carolina. The researchers chose to use South Carolina as a model state because it lies within the 'kidney stone belt' a region in the southeastern US with a higher incidence of kidney stone disease. The researchers first determined the relationship between historic daily statewide mean temperatures and kidney stone presentations in South Carolina from 1997 to 2014. The researchers used wet-bulb temperatures (WBT), a moist heat metric that accounts for both ambient heat and humidity, and a more accurate temperature metric for predicting kidney stones. They then used that data to forecast the heat-related number of kidney stones and associated costs to 2089 based on projected daily WBT under two climate change scenarios. The researchers took into account the different climate eventualities as outlined in the UN Intergovernmental Panel on Climate Change's 'RCP' system. The RCP trajectory ranges from RCP1.9 where global warming is limited below 2.7F (1.5C) as per the to the dreaded RCP8.5, where emissions continue to rise throughout the 21st century in a worst-case scenario. 'Our analysis is a model to conceptualise how the burden of kidney stone disease is expected to progress with climate change, and also how mitigations to greenhouse gas emissions can offset some of this burden,' said first author Jason Kaufman at the University of Pennsylvania Perelman School of Medicine. The first climate change scenario the researchers used RCP 4.5 represents an 'intermediate' future, with shifts to lower-emissions sources of energy, the use of carbon capture technology, prices on carbon dioxide (CO2) emissions, and an expansion of forest lands from the present day to 2100. The second scenario (the dreaded RCP 8.5) represents a future with mostly uninhibited greenhouse gas emissions. RCP 4.5 projects a 4.1F (2.3C) increase in mean temperature per five-year period from 2010-2014 to 2085-2089, while RCP 8.5 projects a 6.5F (3.6C) increase in the same time frame. Using their model, the researchers found that by 2089, kidney stones due to heat would increase statewide by 2.2 per cent from baseline in the 'intermediate' future of RCP 4.5 and by 3.9 per cent in RCP 8.5. From 2025 to 2089, the total cost attributable to these excess kidney stones would be $56.6 million (41.7 million) for RCP 4.5 and $99.4 million (73.4 million) for RCP 8.5. These figures are based on a baseline average cost per patient of more than $9,000 (6,650), the researchers say, 'With climate change, we don't often talk about the impact on human health, particularly when it comes to children, but a warming planet will have significant effects on human health,' Dr Tasian said. 'As pediatric researchers, we have a duty to explore the burden of climate change on human health, as the children of today will be living this reality in the future.' The study has been published today in .