Factors affecting inter-individual variation in human plasma cholinesterase activity: body weight, height, sex, genetic polymorphism and age.
The influence of body weight, height, age and sex on plasma cholinesterase activity (ChE) in 650 males and 437 females with ChE-1 phenotype U (genotype ChEuChEu or ChEuChEs) or UA (genotype ChEuChEa) was studied in a multiple regression model. ChE was not influenced by age (p > 0.01), but, like other liver synthesized plasma enzymes, highly (p < 0.001) influenced by body weight and height. In a logarithmic scale ChE followed a linear model (R = 0.535, p < 0.001) with randomly distributed residuals, InChE = 3.286-0.308 x ChE-1 phenotype-0.104 x sex + 0.00765 x weight - 0.00723 x height (U = 1, UA = 2; male = 1, female = 2; kg; cm). A simplified model based on body-mass index (BMI = weight divided by squared height, kg/m2), InCHE = 2.016-0.308 x ChE-1 phenotype - 0.091 x sex + 0.0230 x BMI, showed the same goodness-of-fit (R = 0.533). In a non-logarithmic scale both multiple regression models failed to fit cases with high ChE activity. A model for a 'standardized' plasma ChE in which the effects of ChE-1 phenotype, sex, body weight and height are eliminated, is proposed to compare ChE in unmatched population groups when using this enzyme activity as a biomarker in environmental or occupational medicine.
Brock
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University of Aarhus, Department of Clinical Chemistry, Randers Central Hospital, Denmark.
Brock
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D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001827:Body Height; D001835:Body Weight; D002802:Cholinesterases / Q000097:blood*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010641:Phenotype; D011110:Polymorphism, Genetic; D012044:Regression Analysis; D012727:Sex Characteristics
D002802:Cholinesterases