Time of day affects test results for asthma, researchers find
New research presented today (Friday 8th December) at the British Thoracic Society Winter Meeting shows the human body clock significantly impacts on sample results used to diagnose and treat asthma when taken at different times of the day. This may have implications for how asthma is diagnosed and treated in the future.
Dr Hannah Durrington, Senior Clinical Lecturer at The University of Manchester, who has led the research, funded by Asthma UK, will explain that test results from an asthma patient taken in the morning differ from those taken from the same patient in the afternoon.
Dr Durrington’s research team analysed blood, mucus coughed up from the lungs and the breath of ten moderately severe asthmatics and ten healthy volunteers at different times of the day.
The asthmatic volunteers, as researchers had expected, displayed greater narrowing of their airways in the early hours of the morning than in the afternoon and this corresponded with a change in inflammatory cells - or eosinophils, measured in their sputum. Sputum eosinophil levels can be used to guide treatment in severe asthma patients.
The research also showed that sputum eosinophil levels can vary considerably between the morning and afternoon. They were higher in the morning, lower in the afternoon.
The University of Manchester is home to the largest biological timing research community in Europe. Dr Durrington also provides an asthma clinic at Wythenshawe Hospital, Manchester University NHS Foundation Trust (MFT).
This research is hugely exciting because it helps us to understand how time of day impacts on our ability to accurately diagnose asthma as well as to effectively treat asthma
Dr Durrington explains:
“These research results are really exciting but at an early stage – our aim was to understand a bit more about how the body clock affects the biochemistry of a person with asthma. We are pleased because our work should help with the accurate diagnosis and treatment of asthma in the future.
“It is really important to stress that this is ongoing scientific work – and no asthma patient should make any adjustment to their treatment regime without consulting their doctor. We are now planning a large randomised clinical trial which we hope in the future will point towards an indication about the optimum time of day for asthma treatments to be taken.
“We feel it may also have important implications on other lung conditions, as well as outside respiratory medicine. It also points towards opportunities for more personalised treatment for asthma care in the future. In the same way that measuring glucose levels in diabetes allows adjustment of insulin dosing, we may see asthmatics monitoring their biomarker chemicals during the day, to help inform optimum treatment times.”
Dr Samantha Walker, Director of Research and Policy at Asthma UK, adds:
"People's body clocks are incredibly powerful. This research, which we are proud to help fund, shows that for the 5.4 million people in the UK who have asthma, the results of an asthma test could differ depending on the time of day the test took place. While this research is at a very early stage, it could have a significant impact on when people with asthma are tested at some stage in the future. We look forward to seeing the results of the next stage of the team’s research in this area."