Research into the health effects of climate change on the endocrine system

In a new study, endocrinologists and researchers from the Nuffield Department of Women’s & Reproductive Health (NDWRH) at the University of Oxford, the London School of Hygiene & Tropical Medicine, the William Harvey Research Institute (WHRI) at Queen Mary University of London and the National University of Singapore has highlighted the critical need for further research into the effects of heat exposure on the endocrine system.

The study, “Endocrine effects of heat exposure and relevance to climate change”, was published in Nature Reviews Endocrinology.

As climate change increases seasonal temperatures and causes heat waves to become more common, understanding these effects has become more important than ever.

Hormones play a role in almost all biological functions, but the influence of environmental factors on the release and action of hormones has not yet been well characterized. Researchers from the University of Oxford, the London School of Hygiene & Tropical Medicine, the William Harvey Research Institute at Queen Mary University of London and the National University of Singapore have highlighted the urgent need for more research into the effects of heat exposure, particularly in the context of climate change, rising seasonal temperatures and causing more heat waves.

Hormones influence how we adapt to changes in environmental temperature by controlling processes such as body water conservation, sweating, and heat generation through cell metabolism. A review of studies published since the 1940s indicates that heat exposure affects hormones involved in processes ranging from the stress response, blood glucose control, fertility and breast milk production. However, many of these studies involved short-term heat exposure in non-human animal models or in healthy human volunteers such as military recruits.

Our research highlights the gap in the evidence regarding the impact of sustained heat exposure on the endocrine system, which is particularly relevant to the increasing number of people with endocrine disorders such as diabetes mellitus or thyroid disorders, who may have limited tolerance to higher temperatures . Heat waves increase the risk of hospitalization for these patients, which also increases the pressure of the heat on the healthcare system.

Lead author, Professor Fadil Hannan from the Nuffield Department of Women’s & Reproductive Health at the University of Oxford, said: “We know very little about whether increased heat exposure due to climate change can affect endocrine health. We need research where both the endocrine and global health research communities to assess the impact of rising temperatures and heat waves on endocrine patients.

“This is especially important for patients living in warm climates, who may not have adequate access to cooled environments. Better understanding these effects will allow interventions to be developed for endocrine patients most at risk from extreme heat.”

Certain hormonal disorders can disrupt the body’s ability to regulate temperature, making it harder to cool down and increasing the risk of heat-related illness. Co-author, Professor Jason Lee, from the National University of Singapore, added: “As the world grapples with the escalating threats of climate change, unraveling the complex relationships between heat exposure, endocrine function and human health is only a scientific necessity. but a moral obligation to protect the vulnerable and ensure the well-being of generations to come.”

Managing heat risks is becoming increasingly important and this review highlights the need to educate health professionals about environmental hazards. Co-author, Associate Professor Sari Kovats at the NIHR Health Protection Research Unit in Environmental Change and Health at LSHTM, added: “We need to better manage heat risk in patients with diabetes and other endocrine disorders.”

Heat waves are increasing in frequency and intensity, with major health consequences. Co-author, Professor Rajesh Thakker from the University of Oxford and the William Harvey Research Institute of Queen Mary said: “Climate change with increasing heat exposure are major global challenges we face, but we know little about their effects on health, and identifying these gaps in our knowledge is important for planning strategies and future research for the benefit of humanity.”