Objective: Increases in the inflammatory marker C-reactive protein (CRP) have been associated with a higher risk of incident coronary heart disease (CHD). The causes of increased CRP, however, are not completely understood. Studies suggest that oxidative stress may have pro-inflammatory effects, but data on the relationship between oxidative stress and CRP in healthy persons is sparse.
Methods and results: We conducted a cross-sectional study of oxidative stress markers and high sensitivity CRP (hsCRP) among 126 adults without CHD. Markers of oxidative stress included the free oxygen radical test (FORT), which reflects levels of organic hydroperoxides, and the redox potential of the reduced glutathione/glutathione disulfide couple, (Eh) GSH/GSSG. In a linear regression model that adjusted for age, sex, body mass index, and other potential hsCRP determinants, the FORT was positively associated with log-transformed hsCRP and explained 14% of log-transformed hsCRP variance (P < 0.001). In contrast, (Eh) GSH/GSSG showed little association with hsCRP.
Conclusions: Among adults free of CHD, oxidative stress, as measured by the FORT, is significantly associated with higher hsCRP levels, independent of BMI and other CRP determinants. This result suggests that oxidative stress may be a determinant of CRP levels and promote pro-atherosclerotic inflammatory processes at the earliest stages of CHD development.