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 (β = 0.271, P = 0.024) and triglyceride levels (β = 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.