Women who have mild inflammation in the acute stages of COVID-19 infection may be more likely to experience a particular set of long COVID symptoms, according to new research.

Researchers at the Universities of York and Hull in the US showed that women who survived severe COVID in the first wave of infection in 2019 were more likely to experience the muscle ache, low mood and anxiety that characterises long COVID if their blood showed signs of inflammation while they battled the disease.

"These findings show how long COVID can be a mixed condition with physical and mental health symptoms, and how inflammation in the acute phase may play a role in that," said Dominic Sykes, respiratory physician and Academic Clinical Fellow at the University of Hull.

"We need further research into the role of serum biomarkers to be able to predict the long-term prognosis in patients who had COVID-19 infection," he added.

The team examined the cases of 144 COVID survivors, to explore possible pathways for further research into potential drivers of persisting symptoms in long COVID. 

A significant number of the survivors were experiencing lingering symptoms, including fatigue (54.2 per cent), breathlessness (52.8 per cent), and sleep disturbance (37.5 per cent) three months post-recovery.

Blood samples taken from the patients at the peak of their COVID-19 infection showed that for many of the patients with lingering symptoms, and particularly the women, the samples showed elevated biomarkers indicating inflammation activity in the body, including Interleukin-6, C-reactive protein, troponin-T, and ferritin.

Scientists have been working to unravel the complexities of long COVID since the first reports of the condition began to emerge shortly after the initial wave of the pandemic in early 2020. 

This observation sheds new light on the long-term effects of the virus by suggesting a potential link between inflammation and persistent symptoms in women, the researchers said 

"The findings of this explorative study align with other research showing elevated inflammatory biomarkers in mood disorders, anxiety disorders and fibromyalgia," they noted.