title: "Normal" liver stiffness values differ between men and women: a prospective study for healthy living liver and kidney donors in a native Korean population.
abstract: OBJECTIVE
  Liver stiffness (LS) measurement can distinguish individuals with potential liver disease (LD) from the general population. However, if LS is sex-sensitive, prevalence of LD may be incorrectly estimated when the same reference LS value is applied irrespective of sex. Here, we evaluated whether normal ranges of LS differ between healthy men and women.
  
  
  METHODS
  LS was measured in a cohort of healthy living liver and kidney donors, none of whom suffered from diabetes mellitus, hypertension, hepatitis B or C virus infection, heart or liver dysfunction, or metabolic syndrome. Patients with abnormal laboratory findings related to potential LD (platelet count < 150 × 10(3) /µL; aspartate aminotransferase > 40 IU/L; alanine aminotransferase [ALT] > 40 IU/L; albumin < 3.3 g/dL; total bilirubin > 1.2 mg/dL; gamma-glutamyl transpeptidase > 54 IU/L; alkaline phosphatase > 115 IU/L) were excluded.
  
  
  RESULTS
  Among 242 patients analyzed, the mean age was 34.1 for men (n = 121) and 40.5 years for women (n = 121) (P < 0.001). Men had a higher mean LS value than women (5.2 ± 1.2 vs 4.8 ± 1.1 kPa/P < 0.001). Multivariate-linear regression analysis identified sex as the only independent factor for LS values (β = 0.361/P = 0.021). Using the 5th-95th percentiles, we determined normal LS ranges of 3.7-7.0 kPa in men and 3.3-6.8 kPa in women. In subgroups with ALT < 30 IU/L (subgroup-1, n = 216) and ALT < 20 IU/L (subgroup-2, n = 163), men had significantly higher LS values than women (5.2 ± 1.3 vs 4.7 ± 1.1 kPa/P = 0.003 and 5.1 ± 1.2 vs 4.7 ± 1.1 kPa/P = 0.030, respectively), demonstrating an independent sex effect (β = 0.483/P = 0.003 and β = 0.389/P = 0.030, respectively).
  
  
  CONCLUSIONS
  An independent sex effect on LS values was confirmed. Thus, sex-specific references should be used for effective screening based on LS measurements.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Beom Kyung
authors.initials: BK
authors.lastname: Kim
authors.forename: Seung Up
authors.initials: SU
authors.lastname: Kim
authors.forename: Gi Hong
authors.initials: GH
authors.lastname: Choi
authors.forename: Woong Kyu
authors.initials: WK
authors.lastname: Han
authors.forename: Mi Sung
authors.initials: MS
authors.lastname: Park
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Kim
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Park
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Jin Sub
authors.initials: JS
authors.lastname: Choi
authors.forename: Seung Choul
authors.initials: SC
authors.lastname: Yang
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Choi
authors.forename: Kijun
authors.initials: K
authors.lastname: Song
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Ahn
authors.forename: Kwang-Hyub
authors.initials: KH
authors.lastname: Han
authors.forename: Chae Yoon
authors.initials: CY
authors.lastname: Chon
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D016014:Linear Models; D008099:Liver / Q000502:physiology*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012016:Reference Values; D056910:Republic of Korea; D012737:Sex Factors; D055815:Young Adult
chemical_list: D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase