title: Factors affecting the accuracy of controlled attenuation parameter (CAP) in assessing hepatic steatosis in patients with chronic liver disease.
abstract: OBJECTIVE
  Controlled attenuation parameter (CAP) can measure hepatic steatosis. However, factors affecting its accuracy have not been described yet. This study investigated predictors of discordance between liver biopsy (LB) and CAP.
  
  
  METHODS
  A total of 161 consecutive patients with chronic liver disease who underwent LB and CAP were enrolled prospectively. Histological steatosis was graded as S0 (<5%), S1 (5-33%), S2 (34-66%), and S3 (>66% of hepatocytes). Cutoff CAP values were calculated from our cohort (250, 301, and 325 dB/m for ≥ S1, ≥ S2, and S3). Discordance was defined as a discrepancy of at least two steatosis stages between LB and CAP.
  
  
  RESULTS
  The median age (102 males and 59 females) was 49 years. Repartition of histological steatosis was as follows; S0 26.1% (n = 42), S1 49.7% (n = 80), S2 20.5% (n = 33), and S3 3.7% (n = 6). In multivariate linear regression analysis, CAP value was independently associated with steatosis grade along with body mass index (BMI) and interquartile range/median of CAP value (IQR/MCAP) (all P<0.05). Discordance was identified in 13 (8.1%) patients. In multivariate analysis, histological S3 (odd ratio [OR], 9.573; 95% confidence interval [CI], 1.207-75.931; P = 0.033) and CAP value (OR, 1.020; 95% CI, 1.006-1.034; P = 0.006) were significantly associated with discordance, when adjusting for BMI, IQR/MCAP, and necroinflammation, reflected by histological activity or ALT level.
  
  
  CONCLUSIONS
  Patients with high grade steatosis or high CAP values have a higher risk of discordance between LB and CAP. Further studies are needed to improve the accuracy of CAP interpretation, especially in patients with higher CAP values.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyu Sik
authors.initials: KS
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea.
authors.forename: Beom Kyung
authors.initials: BK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea.
authors.forename: Seung Up
authors.initials: SU
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Chon
authors.forename: Kyeong Hyeon
authors.initials: KH
authors.lastname: Chun
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Cheon
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Bae
authors.initials: SB
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea.
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea.
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea; Brain Korea 21 Project of Medical Science, Seoul, Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Nyun
authors.initials: YN
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea; Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea; Liver Cirrhosis Clinical Research Center, Seoul, Korea; Brain Korea 21 Project of Medical Science, Seoul, Korea.
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001774:Blood Chemical Analysis; D054459:Elasticity Imaging Techniques; D005234:Fatty Liver / Q000150:complications / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000150:complications / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D055815:Young Adult