Association between plasma alkaline phosphatase and C-reactive protein in Hong Kong Chinese

Background: Alkaline phosphatase (ALP) is a biomarker for hepatobiliary and skeletal diseases. It is also raised in sepsis. In atherosclerotic plaques, ALP is expressed. Similar to C-reactive protein (CRP), it may be another marker of systemic inflammation. Therefore, we investigated their association in a Hong Kong Chinese population. Methods: Plasma ALP and CRP were measured in 205 subjects (1110 men, 95 women; age 55.2 +/- 11.6 years) in the Hong Kong Cardiovascular Risk Factor Prevalence Study-2 cohort. Results: The blood levels of ALP and CRP were significantly correlated (r=0.30, p<0.001), which was due to a significant correlation in women (r=0.43, p<0.001). In a multivariate model, CRP level was related to ALP (beta=0.18, p=0.008). After adjusting for confounding factors and other liver enzymes, the relationship between ALP and CRP remained significant in women (beta=0.28, p=0.019), but in men, ALP was not an independent determinant of CRP levels. Conclusions: ALP may be another marker of systemic inflammation, especially in women. Whether it provides clinical information additional to CRP requires further study.