Changing the rhythm of asthma care

Professor Hannah Durrington leads research into how the body’s internal clock shapes asthma, challenging how the condition is traditionally diagnosed and treated. Her work shows that symptoms, lung function and treatment response change throughout the day, and that timing care to match these rhythms could significantly improve outcomes for patients. Through this work, she is redefining how asthma is understood and managed.

A pattern in the early hours

“One of the earliest challenges I noticed as a junior doctor was the pattern of patients arriving overnight with breathing difficulties or asthma attacks.

The wards would be busy until midnight, followed by a short period of calm, but then around 3am or 4am, patients would arrive in crisis, with severe asthma attacks frequent at this time, alongside other acute breathing and respiratory conditions.

Although this pattern was recognised, we didn’t understand why it was happening. In research I led, we studied how asthma symptoms, lung function and inflammation change across a 24-hour period, and found that they follow a clear biological rhythm driven by the body’s internal clock.

A rhythmic disease

Asthma has traditionally been treated as a condition that behaves consistently throughout the day. However, our research showed that asthma is shaped by the body’s internal clock, a pattern we were able to detect in patients in real-world settings.

Airways are naturally narrower at night and wider during the day, even in healthy individuals. In people with asthma, this pattern is more pronounced, meaning symptoms worsen overnight. 

Levels of inflammation in the lungs also peak in the early hours of the morning. This helps explain why symptoms often worsen overnight and why many severe attacks occur during this period. In relation to this, it means the same patient can appear to have different disease severity depending on when they are tested.

Why timing matters in asthma

A key finding from this work is that the timing of measurements and treatment can change what we see. In clinical practice, tests are often carried out during the day, and treatments are typically taken in the morning and evening. These decisions are based on routine clinical schedules rather than the body’s biological rhythms.

Our research shows that this approach can miss important signals. Biomarkers used in asthma diagnosis vary depending on when they are taken, making it difficult to interpret results without considering time of day.

We have also shown that treatment effectiveness can change depending on timing, for example a recent study showed how taking an inhaler in the afternoon was more effective, than taking it in the morning or evening. 

This suggests we may be able to improve patient outcomes without developing new drugs, but by simply by using existing treatments differently.”

Changing habits and healthcare systems

Translating these findings into practice is not straightforward. Healthcare systems are not designed around biological rhythms, and most treatment schedules are built around routine rather than underlying biology.

Studies in this area can also be challenging, often requiring overnight monitoring. For many patients, taking medication at a specific time outside their usual routine can be difficult.

However, the potential benefits are significant. The field of chronotherapy, aligning treatment with the body’s internal clock, is gaining momentum particularly in cancer. Asthma research is now beginning to follow that lead.

Tackling respiratory health inequality

Asthma is strongly linked to health inequality. Rates of disease are higher in more deprived communities, where factors such as poor housing, pollution and limited access to healthcare contribute to worse outcomes.

Circadian disruption adds another layer to this. The circadian rhythm, the body’s natural 24-hour clock that controls sleep, hormones and how our organs function, can be disrupted in shift and night workers.

Those whose internal clocks are repeatedly disrupted are more likely to develop asthma and have poorer symptom control than those working regular daytime hours. These roles are more common in lower socioeconomic groups, meaning biological and social factors combine to increase risk.

Looking ahead

“If we can incorporate timing into routine care, we have an opportunity to improve diagnosis and treatment without increasing complexity- by aligning care more closely with how the body actually works.

This includes identifying new biological targets and understanding how the lung’s internal clock controls airway function and inflammation.

By spanning both clinical and laboratory studies, I am aiming to improve our understanding of the mechanisms behind these daily rhythms and how they can be used to improve care for all patients”.