The 'biological clock' inside the human body influences inflammation in the immune system. Patients with plantar fasciitis experience more discomfort in the morning, while those with toothache or gout are more troubled at night. Although it varies from person to person, there are specific times when pain is particularly severe depending on the type of inflammatory disease.

The time of day when immune cells, such as macrophages, act on the human body varies, and as a result, patients may experience different intensities of pain depending on the inflammatory disease. A research team from the Royal College of Surgeons in Ireland (RCSI) announced that their findings show this correlation after exploring the relationship between the immune system and biological rhythms.

 

Patients with ankylosing spondylitis, which causes lower back pain, and plantar fasciitis, which causes pain due to inflammation of the plantar fascia, tend to experience more severe pain in the morning. Additionally, patients with gout, which causes intense pain in the big toe, and frozen shoulder (adhesive capsulitis) experience more severe pain at night, leading to insomnia that disrupts restful sleep.

Professor Annie Curtis, the corresponding author of the study (School of Pharmacy and Biomedical Sciences), said, "This research is expected to open the way for 'timed targeted therapy' for inflammatory diseases, where the timing of pain varies depending on the action of macrophages." According to the research team, macrophages, immune cells that detect harmful substances in the body and respond to them, can cause inflammation as a defense mechanism by assembling large complexes known as inflammatory substances. These inflammatory substances are similar to alarms (smoke detectors) that alert the immune system to danger.

 

According to research findings, the activation of a specific inflammasome (NLRP3) is not maintained consistently throughout the day but is regulated by the 24-hour circadian clock. This daily rhythm determines the most efficient time for macrophages to detect threats and the peak energy levels at which they respond. It was also found that mitochondria, the cell's energy producers, play a crucial role in driving the daily changes in immune activity.

 

Professor Curtis explained, "When macrophages 'think' it's morning, their inflammasome activation becomes faster and more intense." He added, "This means that our immune response is heightened during the early morning hours when we are awake. This time period is when we are alert and more likely to face environmental issues such as injuries or infections." The research team stated that these findings could help better understand and treat inflammatory diseases like arthritis, where 'hyperactivation' of inflammatory proteins plays a significant role.

Immune response is strengthened during waking hours.

It seems my body automatically switches to protection mode.