Sources of Variation of Commonly Measured Serum Analytes in 6 Asian Cities and Consideration of Common Reference Intervals

作者：Kiyoshi Ichihara, Yoshihisa Itoh, Christopher Wai Kei Lam, Priscilla M.K. Poon, Jeong‐Ho Kim, Hiroshi Kyono, Naning Chandrawening, Dewi Muliaty · 发表于：Clinical Chemistry · 年份：2007 · DOI：10.1373/clinchem.2007.091843 · 被引用次数：90 · 研究领域：Clinical Laboratory Practices and Quality Control、Health, Environment, Cognitive Aging、Reliability and Agreement in Measurement

BACKGROUND: In a previous study to determine the feasibility of common reference intervals in Asia, we found significant differences among populations from 6 cities. In this study, we attempted to define the sources of these differences. METHODS: We enrolled 580 healthy volunteers (279 men, 301 women, 20-62 years old), after a selection process that was based on the Clinical and Laboratory Standards Institute guidelines, and used a lifestyle questionnaire. All sera were obtained at a basal state and frozen at -80 degrees C until the collective assay was done. We measured 21 basic chemical analytes and 10 serum proteins. RESULTS: We used 3-level nested ANOVA to separate the variation (SD) into between-city (SD-city), between-sex (SD-sex), between-age (SD-age), and between-individual (SD-indiv) components. SD-indiv corresponds to one-quarter of the "pure" reference interval obtained after removing variations due to city, sex, and age. The SD-sex to SD-indiv ratio was >0.8 for creatinine, urate, retinol-binding protein, and transthyretin. We observed high SD-city to SD-indiv ratios, ranging from 0.4 to 0.7, for 11 analytes including lactate dehydrogenase (LDH), electrolytes, IgG, and complement components and SD-age to SD-indiv ratios >0.4 for LDH, alkaline phosphatase, and total cholesterol. Multiple regression analysis demonstrated several other relevant sources of variation, including body mass index, alcohol consumption, and cigarette smoking, although their contributions we...