Normal Controlled Attenuation Parameter Values: A Prospective Study of Healthy Subjects Undergoing Health Checkups and Liver Donors in Korea

Background/Aims The controlled attenuation parameter (CAP) is a noninvasive method of assessing hepatic steatosis. We defined the normal range of CAP values in healthy subjects and evaluated the associated factors. Methods CAP values were measured in a cohort of healthy subjects who were screened as living liver transplantation donors and those who underwent health checkups. Subjects with current or a history of chronic liver disease, abnormalities on liver-related laboratory tests, or fatty liver on ultrasonography or biopsy were excluded. Results The mean age of the 264 recruited subjects (131 males and 133 females; 76 potential liver donors and 188 subjects who had undergone health checkups) was 49.2 years. The mean CAP value was 224.8 +/- 38.7 dB/m (range 100.0-308.0 dB/m), and the range of normal CAP values (5th-95th percentiles) was 156.0-287.8 dB/m. The mean CAP value was significantly higher in the health checkup than in the potential liver donor group (227.5 +/- 42.0 vs. 218.2 +/- 28.3 dB/m, P = 0.040). CAP values did not differ significantly according to gender or age in either group (all P > 0.05). In a multivariate linear regression analysis, body mass index (beta = 0.271, P = 0.024) and triglyceride levels (beta = 0.348, P = 0.008) were found to be independently associated with CAP values. Conclusion We determined the normal range of CAP values and found that body mass index and triglyceride levels were associated with the CAP values of healthy subjects.