Background: High-sensitivity C-reactive protein (hsCRP) has emerged as an independent predictor of coronary heart disease (CHD) in Western countries. However, it is still uncertain regarding whether hsCRP is associated with the risk of CHD in Japan.
Methods: The serum hsCRP levels were measured in 687 middle-aged Japanese male workers (age range; 40-59 years) during an annual health examination at a company in Kanagawa, Japan, in 2005. All participants were free from any cardiovascular diseases and any medications for hypertension, hyperlipidemia, or diabetes. The Framingham Risk Score (FRS) was calculated as an individual's risk level of future development of CHD. Associations between hsCRP and the FRS were then evaluated.
Results: The distribution of hsCRP was skewed to the left with a median value (interquartile range) of 0.3 (0.2, 0.6) mg/L. Log-transformed hsCRP significantly correlated with all components of the FRS except for age. The FRS gradually and significantly increased (p=0.001 for trend) with an increase in the quartiles of hsCRP after adjusting for multiple potential confounders such as triglycerides, the body mass index, alcohol intake, and a family history of cardiovascular disease. For the highest quartile of hsCRP, crude and above-listed confounders-adjusted odds ratios of the high-risk for CHD (FRS>/=6 point) compared to the lowest quartile were 6.97 (95% CI: 3.20-15.17, p<0.001) and 3.85 (95% CI: 1.69-8.77, p=0.001), respectively.
Conclusions: These results suggest that hsCRP is associated with the risk of CHD, as estimated by the FRS, in middle-aged Japanese men.