In Brazil - where the study was focused - this equated to more than 202,000 cases of kidney disease from 2000-2015. The study, led by Professor Yuming Guo and Dr Shanshan Li, from Planetary Health at Monash University, for the first time, quantifies the risk and attributable burden for hospitalisations of renal diseases related to ambient temperature using daily hospital admission data from 1816 cities in Brazil.
The study comes as the world focuses on the impact of climate change at the COP26 conference in Glasgow from October 31. In 2017, a landmark article in 'The Lancet' declared renal diseases a global public health concern, estimating that almost 2.6 million deaths were attributable to impaired kidney function that year. Importantly the incidence of death from kidney disease had risen 26.6 per cent compared to a decade previously, an increase that this study may indicate was, in part, caused by climate change.
The study looked at a total of 2,726,886 hospitalisations for renal diseases recorded during the study period. According to Professor Guo, for every 1 degree Celsius increase in daily mean temperature, there is an almost 1 per cent increase in renal disease, with those most impacted being women, children under 4 years of age and those 80+ years of age. The associations between temperature and renal diseases were largest on the day of the exposure to extreme temperatures but remained for 1-2 days post-exposure.
In the paper, the authors - who are also from the University of Sao Paulo - argue that the study "provides robust evidence that more policies should be developed to prevent heat-related hospitalisations and mitigate climate change. In the context of global warming, more strategies and policies should be developed to prevent heat-related hospitalisations." The authors advise interventions should be urgently incorporated into government policy on climate change, including particularly targeting specific individuals, including females, children, adolescents, and the elderly, as they are more vulnerable to heat with regard to renal diseases.
"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," Professor Guo added.