title: Establishment of reference intervals of clinical chemistry analytes for the adult population in Saudi Arabia: a study conducted as a part of the IFCC global study on reference values.
abstract: BACKGROUND
  This study is a part of the IFCC-global study to derive reference intervals (RIs) for 28 chemistry analytes in Saudis.
  
  
  METHODS
  Healthy individuals (n=826) aged ≥18 years were recruited using the global study protocol. All specimens were measured using an Architect analyzer. RIs were derived by both parametric and non-parametric methods for comparative purpose. The need for secondary exclusion of reference values based on latent abnormal values exclusion (LAVE) method was examined. The magnitude of variation attributable to gender, ages and regions was calculated by the standard deviation ratio (SDR). Sources of variations: age, BMI, physical exercise and smoking levels were investigated by using the multiple regression analysis.
  
  
  RESULTS
  SDRs for gender, age and regional differences were significant for 14, 8 and 2 analytes, respectively. BMI-related changes in test results were noted conspicuously for CRP. For some metabolic related parameters the ranges of RIs by non-parametric method were wider than by the parametric method and RIs derived using the LAVE method were significantly different than those without it. RIs were derived with and without gender partition (BMI, drugs and supplements were considered).
  
  
  CONCLUSIONS
  RIs applicable to Saudis were established for the majority of chemistry analytes, whereas gender, regional and age RI partitioning was required for some analytes. The elevated upper limits of metabolic analytes reflects the existence of high prevalence of metabolic syndrome in Saudi population.
authors.forename: Anwar
authors.initials: A
authors.lastname: Borai
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ichihara
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Al Masaud
authors.forename: Waleed
authors.initials: W
authors.lastname: Tamimi
authors.forename: Suhad
authors.initials: S
authors.lastname: Bahijri
authors.forename: David
authors.initials: D
authors.lastname: Armbuster
authors.forename: Ali
authors.initials: A
authors.lastname: Bawazeer
authors.forename: Mustafa
authors.initials: M
authors.lastname: Nawajha
authors.forename: Nawaf
authors.initials: N
authors.lastname: Otaibi
authors.forename: Haitham
authors.initials: H
authors.lastname: Khalil
authors.forename: Reo
authors.initials: R
authors.lastname: Kawano
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Kaddam
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelaal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001774:Blood Chemical Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012529:Saudi Arabia; D055815:Young Adult