Relationships Among C-Reactive Protein, Alanine Aminotransferase, and Metabolic Syndrome in Apparently Healthy Chinese Subjects

Elevated levels of C-reactive protein (CRP) and alanine aminotransferase (ALT) are tightly associated with metabolic syndrome (MetS). However, it is unclear whether the combination of normal CRP and ALT increases probability of the presence of MetS.We enrolled 433 Chinese in health screening with both CRP and ALT in normal range. They were divided into four groups: both low (BL, both low baseline CRP and ALT), only high CRP (HCRP), only high ALT (HALT), and both high (BH, both high baseline CRP and ALT) in different genders. The receiver operating characteristic curve was used for comparing the sensitivity and assessing the cutoff point.The BH group had more numbers of MetS components than the BL group. Addition of CRP and ALT did not further increase the accuracy of predicting MetS with a sensitivity of 65.1% and a specificity of 59.1% in men, and a sensitivity of 77.8% and a specificity of 60.2% in women. The area under curve for ALT was greater than that for CRP (0.62 vs. 0.524 in men; 0.663 vs. 0.598 in women). After adjusting for age, ALT could significantly predict the incidental MetS in both genders; nevertheless, CRP failed to demonstrate prediction. The formula of probability of occurrence of MetS was established on CRP and ALT.Healthy subjects with high baseline ALT may be at risk of developing MetS, and early recognition and prevention are important for health providers. We concluded that local liver inflammation is significantly associated with the presence of MetS compared with systemic inflammation in health screening subjects.