title: Establishing reference values for blood urea nitrogen and serum creatinine in Chinese Han ethnic adult men.
abstract: BACKGROUND
  The aim was to calculate the two-sided 95th percentile reference values for blood urea nitrogen (BUN) and serum creatinine (SCr) in Chinese Han ethnic adult men.
  
  
  METHODS
  Serum samples were collected from Chinese Han ethnic adult men aged 20 - 69 years. After screening based on the inclusion and exclusion criteria, a total of 1575 individuals were enrolled in our study. BUN and SCr values were measured on an automatic analyzer (Dade Behring, USA). The data was analyzed and calculated using nonparametric statistical methods.
  
  
  RESULTS
  BUN and SCr values were not normally distributed. The reference values were in the range 3.3 - 7.5 mmol/L for BUN and 64 - 113 micromol/L for SCr. BUN levels were significantly lower in the smoking group than the non-smoking group (Z = -4.52, p < 10(-5)). An increase with age was observed in BUN levels (r(s) = 0.172, p < 0(-5)) and lower SCr levels were weakly associated with the older subjects (r(s) = -0.071, p = 0.005). Moreover, it was found that higher Body Mass Index (BMI) tended toward higher levels of SCr (r(s) = 0.118, p < 10(-5)).
  
  
  CONCLUSIONS
  The reference values established for BUN and SCr exhibit a slight deviation compared to those developed in previous studies. We propose reference values of BUN for smokers and non-smokers be constructed, and age- and BMI-specific reference values be applied in clinical laboratories.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Huang
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Yang
authors.forename: Qiliu
authors.initials: Q
authors.lastname: Peng
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Cuiju
authors.initials: C
authors.lastname: Mo
authors.forename: Junrong
authors.initials: J
authors.lastname: Wu
authors.forename: Jingzhe
authors.initials: J
authors.lastname: Sui
authors.forename: Yanqiong
authors.initials: Y
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Deng
authors.forename: Li
authors.initials: L
authors.lastname: Xie
authors.forename: Taijie
authors.initials: T
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: He
authors.forename: Yong
authors.initials: Y
authors.lastname: Gao
authors.forename: Zengnan
authors.initials: Z
authors.lastname: Mo
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Yang
authors.forename: Xue
authors.initials: X
authors.lastname: Qin
mesh_terms: D000328:Adult; D001806:Blood Urea Nitrogen; D002681:China; D003404:Creatinine / Q000097:blood*; D005006:Ethnicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D012015:Reference Standards
chemical_list: D003404:Creatinine