Hotter temperatures linked to more kidney disease

Renal diseases were declared a global health issue in 2017 by The Lancet, which estimated 2.6 million deaths were caused by poor kidney function.

Chris Arnold 3 minute read November 1, 2021
global warming illustration

For every one degree Celsius the temperature rises, there is a one per cent increase in renal disease. GETTY

An increase in outdoor temperature contributed to more than 200,000 cases of kidney disease in Brazil, according to a new study

The study from the Planetary Health department at Australia’s Monash University says for every one degree Celsius (C) the temperature rises, there is a one per cent increase in renal (kidney) disease. It also says that 7.4 per cent of all hospitalizations for renal disease can be attributed to warmer weather.

Data was collected from more than 1,800 cities from 2000 to 2015, when a total of 2,726,886 people were admitted to hospital for renal diseases. Hospitals experienced the largest increase in patients on days with significant spikes in outdoor temperature, although patients still could still come in up to two days later. 

Women were hospitalized more often than men, the researchers found, while children less than four years old and people more than 80 years old were also more prone to hospitalization. 

In 2017, renal diseases were declared a global public health issue by peer-reviewed medical  journal The Lancet, which estimated that 2.6 million deaths were caused by poor kidney function that year alone, an increase of 26.6 per cent from the decade prior, which this study partially attributes to climate change. 

“In the context of global warming, more strategies and policies should be developed to prevent heat-related hospitalizations and address climate change as soon as possible,” the study’s authors say. 

The authors also argue that government policies regarding climate change should be developed to protect vulnerable people who may be more susceptible to the effects of heat and kidney disease.

“Moreover, attention should be paid to low- and middle-income countries like Brazil, where reliable heat warning systems and preventive measures are still in need,” said professor Yuming Guo.

Brazil’s average temperature ranges from 22 C to 26 C, though hotter areas can regularly hit temperatures around 38 C. Daily minimum and maximum temperatures were recorded in each city and used with information from 735 weather stations across Brazil, with the average temperature being calculated from the minimum and maximum each day. 

Jose Marengo of Brazil’s National Institute for Space Research says that studies show the only area of South America that is cooling is the coast of Chile, while all other areas of the continent are getting warmer. 

Marengo says deforestation, specifically in the Amazon rainforest, is contributing to the rising temperatures because it is a carbon sink. The forest essentially takes the carbon chemicals from the atmosphere and stores them for a period of time, which lowers CO2 levels. The Amazon is also essential for producing rain and humidity in South America, with as much as 50 per cent of all rain in the Amazon basin originating from the forest’s evaporation.

Kidney disease can result in a decrease of the organ’s function, resulting in uremia, a condition in which the kidneys are not able to filter toxins out of your body through urine. Treatments require medication, dialysis, and even kidney transplants. If left untreated, uremia can cause death. 

As many as four million people in Canada have kidney disease, according to a 2020 release from The Kidney Foundation of Canada, with 50,000 of those being treated for kidney failure. 

The number of Canadians receiving dialysis treatment essentially doubled between 2000 and 2019, going from 11,601 to 23,125 in 2019, according to the Canadian Institute for Health Information