A new study has found that C-reactive protein may actually not have a role in causing heart disease. However, it has been an enticing target for scientists working on new treatments for coronary heart disease.
Coronary heart disease is the leading cause of death worldwide. The progression of the disease from early to later, sometimes fatal, stages involves inflammation.
There is strong interest in measuring levels of C-reactive protein in a patient's blood, because it is a marker of inflammation.
Although previous studies have shown that it is a risk indicator, scientists are still not clear whether C-reactive protein causes coronary heart disease.
During the study, the team led by Imperial College London looked at the genes that control C-reactive protein levels in blood and their effect on the risk of coronary heart disease.
Variations in the gene that codes for C-reactive protein were not associated with risk of coronary heart disease.
The authors say that the study has identified genetic variations in three other genes associated with C-reactive protein, which may also be associated with a person's risk of coronary heart disease.
"Some researchers thought C-reactive protein would be a good molecule to target, as raised levels of this protein in the blood are associated with increased risk of coronary heart disease," said Professor Paul Elliott, lead author of the paper, from the Department of Epidemiology and Public Health at Imperial College London.
"However our research suggests that the association may not be causal, so attempts to target this protein to reduce the risk of the disease are unlikely to be fruitful.
"We have also discovered new genetic variations that are associated with coronary heart disease.
If confirmed in other studies, these might give clues to identify new targets to treat the disease," added Elliott.
The study appears in the Journal of the American Medical Association (JAMA).