PLASMA CHOLINESTERASE ACTIVITY IN A HEALTHY POPULATION GROUP WITH NO OCCUPATIONAL EXPOSURE TO KNOWN CHOLINESTERASE-INHIBITORS - RELATIVE INFLUENCE OF SOME FACTORS RELATED TO NORMAL INTERINDIVIDUAL AND INTRAINDIVIDUAL VARIATIONS

Inter-individual variations of plasma cholinesterase were analysed in 193 apparently healthy volunteers (122 males, 71 females) with no known occupational exposure to cholinesterase inhibitors. Multiple regression analysis and analysis of variance showed statistically significant effects on the individual plasma cholinesterase activity by body weight, height, sex, and ChE-1 phenotype (but not by age or electrophoretic phenotype). Varying body weight explained one-fourth of the observed biological variance (s2total). The intra-individual variations during an 8-month period varied substantially from one individual to another (3%) to 41% of the subject's mean activity); a repeated-measures analysis of variance showed a within-person variance (s2intra)=5% of s2total - Intra-individual variation was uninfluenced by the variables that influence the inter-individual variance. A model for a 'standardized' plasma cholinesterase in which the combined effects of the four significant variables, ChE-1 phenotype, sex, body weight, and height are eliminated, is proposed for comparisons of plasma cholinesterase activities in unmatched population groups, e.g. within environmental or occupational medicine. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.