People with higher levels of harmful fats or cholesterol commonly linked to heart diseases are more likely to experience ongoing symptoms from both COVID-19 and non-COVID disease, according to a study not peer-reviewed yet.

The findings are based on data from the ZOE Health Study app by King's College London. The scientists analysed blood markers from 4,787 people and compared them with those living in the community, where the majority of people with COVID have been treated.

The blood markers in asymptomatic people had a healthier pattern that is associated with a lower risk of heart attacks and diabetes. The people with long-lasting symptoms showed higher levels of 'bad cholesterol, and unhealthy fatty acids, the team said

The analysis also showed that those with COVID symptoms for more than 28 days could not be clearly distinguished from those with non-COVID illnesses of prolonged duration. Both had a set of compounds in their blood commonly seen in patients who are at risk of heart disease and diabetes.

Experts said this association could mean that research looking at ways to treat other diseases might also play a role in COVID. "We saw a clear difference in blood fats of people who had had asymptomatic COVID-19 compared to those with long-lasting symptoms," said Dr Marc Osterdahl, clinical fellow and lead author at King's.

"We were able to look at whether changes we saw were specific to COVID or whether they reflected something more general about prolonged symptoms. What is interesting is that we saw the same pattern of harmful fats in people with long symptoms in COVID and non-COVID disease," added Dr Claire Steves, co-author and lead researcher in the ZOE Health Study.

"We think this might shed light on the experience of long COVID, and other conditions, where people take time to recover from illness," Steves said.