ABSTRACT
BACKGROUND: Prospective studies suggest that C-reactive protein (CRP) is a novel and indepen-dent risk factor of coronary heart disease. High-sensitivity methods for CRP (hs-CRP) measurement are needed for this purpose. In this study, we evaluated the performance of Cobas Integra 700 (Roche Diagnostics, Basel, Switzerland) and aimed to establish the distribution of serum CRP concentrations in healthy Koreans with the hs-CRP method. METHODS: The subjects of this study were 853 males (age; 45.9 +/- 9.8 years) and 546 females (age; 45.7 +/- 10.8 years) who visited the Health Promotion Center of the Asan Medical Center for routine health checks. Hs-CRP was measured with the Cobas Integra 700. The within-day precision, the between-day precision, the degree of correlation, the linearity, and the detection limit of hs-CRP were also analyzed with the Cobas Integra 700. RESULTS: The within-day coefficients of variation (CVs) were 0% and 1.3%. The between-day CVs were 4.0% and 3.0%. The percentage of relative nonlinearity was 0.78%. The correlation coefficient of the Cobas Integra 700 with the Behring Nephelometer was 0.994. The lower detection limit was 0.064 mg/L and the functional detection limit was 0.472 mg/L. The geometric mean concentration of CRP in Koreans was 0.69 mg/L. The mean CRP of the male population was 0.79 mg/L, which was higher than that of Korean females (0.54 mg/L) (P<0.0001). There was a significant trend to higher CRP values with increasing age (P<0.05). CONCLUSIONS: The linearity, the precision, the correlation, the detection limit of the Cobas Integra 700 were satisfactory. The age and sex-specific guidelines for hs-CRP would make the early intervention for coronary heart disease possible.