Higher cut-off values of non-invasive methods might be needed to detect moderate-to-severe steatosis in morbid obese patients: a pilot study

To evaluate the diagnostic value of described thresholds of controlled attenuation parameter (CAP) and biomarker scores for liver steatosis and to evaluate new cut-offs to detect moderate-to-severe steatosis (S2–3) in patients with morbid obesity. In this prospective study, 32 patients with morbid obesity with indications for bariatric surgery (15 women and 17 men, mean age = 36 years, median BMI = 40.2 kg/m(2)) underwent CAP, magnetic resonance spectroscopy (MRS), three biomarker scores (Steato-ELSA, Fatty Liver Index (FLI), and Hepatic Steatosis Index (HSI)), and liver biopsy. Subjects were divided into an exploratory cohort (reliable CAP and liver biopsy) and a confirmatory cohort (reliable CAP and MRS) to evaluate new thresholds for CAP and biomarker scores to detect S2–3. Receiver operator characteristic (ROC) curves analyses were performed and the optimal cut-off points were identified using the maximal Youden index. A total of 22 patients had CAP measure and liver biopsy (exploratory cohort) and 24 patients had CAP measure with MRS (confirmatory cohort). New cut-offs were identified for detection of S2–3 by the non-invasive tests using liver biopsy as the reference standard (exploratory cohort). Considering the new proposed cut-offs for detection of S2–3 for CAP (≥ 314 dB/m), Steato-ELSA (≥ 0.832), FLI (≥ 96), and HSI (≥ 53), for the exploratory and confirmatory cohorts sensitivities were: 71–75%, 86–81%, 85–81%, and 71–69% and specificities were: 94–89%, 75–63%, 63–63%, and 75–88%, respectively. Higher cut-offs for CAP and biomarker scores may be better to diagnose moderate-to-severe steatosis in patients with morbid obesity.