Clinical implications of controlled attenuation parameter in a health check-up cohort

Evaluation of the controlled attenuation parameter (CAP) is a promising noninvasive method for assessing hepatic steatosis. Despite the increasing reliability of the CAP for assessing steatosis in subjects with chronic liver disease, few studies have evaluated the CAP in asymptomatic subjects without overt liver disease. Therefore, we aimed to evaluate the usefulness of the CAP for a health check-up population.

We enrolled subjects who underwent abdominal ultrasonography (US), FibroScan (Echosens, France) and blood sampling during medical health check-ups. The CAP was measured using FibroScan, and increased CAP was defined as CAP ≥ 222 dB/m.

A total of 1133 subjects were included; 589 subjects (52.0%) had fatty liver based on US, and 604 subjects (53.3%) had increased CAP. Increased CAP was significantly associated with metabolic abnormalities, including higher body mass index (BMI)[odds ratio (OR) = 1.33;95% confidence interval (CI),1.24-1.43; P < .001], higher alanine aminotransferase (ALT) (OR = 1.02; 95% CI, 1.01-1.04; P = .003), higher insulin (OR = 1.04; 95% CI, 1.00-1.08; P = .037), higher triglyceride (OR = 1.00; 95% CI, 1.00-1.01; P = 0.042) and older age (OR = 1.02; 95% CI, 1.00-1.03; P = .05). Furthermore, a comparison of clinical parameters among three groups (normal vs no fatty liver by US but increased CAP vs fatty liver based on US) revealed that metabolic parameters, including blood pressure, BMI, waist circumference, aspartate aminotransferase (AST), ALT, triglycerides, fasting glucose, uric acid, insulin, homeostasis model assessment-estimated insulin resistance and liver stiffness measurements, gradually increased across the three groups (all P < .001).

In conclusion, increased CAP could be an early indicator of fatty liver disease with metabolic abnormalities that manifests even before a sonographic fatty change appears.