Acute Kidney Injury can be triggered by high ambient temperatures

Apr 22
As global temperatures continue to climb, the impact of ambient heat on kidney health is becoming a critical concern in environmental health. This raises an important question: What are the temperature conditions that increase the risk of an AKI episode in England? To address this, a new study published in Lancet Planetary Health has been conducted using the UK Renal Registry's data from the nationwide electronic alert (e-alert) system in a novel way: to monitor the effects of ambient temperatures on AKI occurrences.

Methodology and study design

This epidemiological study was aimed at examining the short-term associations between ambient temperature and the occurrence of AKI. The data encompassed all instances of AKI, whether acquired in the community or in hospital settings, as recorded by the UK Renal Registry from April to September during the years 2017 to 2021. Utilizing a time-stratified case-crossover study design, each AKI episode was linked to the daily maximum temperature data specific to the patient’s postcode sector. Control days were selected to match the day of the week. An AKI episode was defined for this study as one or more AKI e-alerts occurring within a 30-day period. The analysis was conducted using conditional logistic regression to assess the impact of temperature on AKI risk.


The study identified a strong increase in the risk of acute kidney injury (AKI) episodes associated with higher temperatures. Specifically, there was a 62.3% increased risk of experiencing an AKI episode on days when the maximum temperature reached 32°C, compared to days with a maximum of 17°C. The effects of heat exposure were most pronounced the day before the AKI episode was recorded.

This elevated risk of AKI during hotter days was more substantial than those observed in previous epidemiological studies that relied on hospital data alone. This difference is likely due to the e-alert system's capability to detect milder cases of AKI that do not necessitate secondary healthcare interventions, thus providing a broader view of the impact of heat on kidney health.


The results of this study have important implications for the detection and management of acute kidney injury (AKI), especially in the community where cases might be milder and less likely to receive immediate medical attention. The findings suggest a need to refine existing AKI risk stratification tools to include factors related to heat vulnerability. This adjustment could enhance the effectiveness of these tools in predicting and preventing heat-related AKI episodes.

Integrating AKI e-alert data into syndromic surveillance systems could be a policy strategy in heat action plans. Such integration would enable the real-time monitoring of public health impacts during periods of high temperatures, ensuring timely interventions.

It is important to consider that AKI can affect individuals with or without pre-existing chronic kidney disease (CKD). However, those experiencing AKI with incomplete recovery are at a heightened risk of progressing to CKD. This underscores the importance of effective management and follow-up in patients who have experienced AKI, to prevent long-term kidney damage and the potential development of chronic conditions.


The study did not draw a distinction between hospital- and community-acquired AKI, which may have led to differential heat impacts. Heat effects may be been modified by age, sex, comorbidities, and medication use which we did not assess.

Opportunities for future research

Building on the insights gained from this study, future research could expand the scope to explore other environmental factors that may influence the incidence of acute kidney injury (AKI). Examining the effects of air pollution, colder wintertime temperatures, and other weather-related variables like relative humidity could provide a more comprehensive understanding of how various environmental conditions contribute to AKI risk.

Such studies would not only deepen our knowledge of environmental determinants of kidney health but also improve public health strategies and interventions tailored to diverse climatic challenges.


Heat-related AKI is a growing public health challenge in England and elsewhere. Since even small changes in renal function can affect patient outcomes, susceptible patients should be advised to take preventative measures whenever hot weather is forecast.

The use of an e-alert system allows impacts in milder cases that do not require secondary care to be detected, improving the ability to study the environmental determinants of AKI, improve public health policies, and identify and manage heat-related AKI incidents.

Given that nephrology practices are major contributors to global environmental degradation, could kidney health be used as a global risk indicator and therapeutic target for actions that address climate change adaptation and mitigation?

Citation and link to the publication

Hajat S, Casula A, Murage P, Omoyeni D, Gray T, Plummer Z, Steenkamp R, Nitsch D. Ambient heat and Acute Kidney Injury: case-crossover analysis of 1,354,675 automated e-alert episodes linked to high-resolution climate data. Lancet Planetary Health; 2024 Mar;8(3):e156-e162. doi: 10.1016/S2542-5196(24)00008-1.