Factors Affecting Initial Cholinesterase Levels from a Pilot Study of Central Wisconsin Farmers

Abstract

Measurement of cholinesterase levels can serve as an indirect estimate of exposureto organophosphate or carbamate insecticides. In addition to individual variability,there are potential predictable confounding factors that may affect the result. In aconvenience sample of producers that were being evaluated for general healthconcerns, we performed a pilot study to evaluate parameters that might affect thegroup cholinesterase levels. Cholinesterase levels were found to be related to the typeof grower, even though all claimed not to be exposed at the time of the tests. Theplasma and red cell cholinesterase levels did not vary in the same direction betweencommodity groups. Plasma cholinesterase levels were higher for males than females,but red cell cholinesterase levels were not affected by gender. The plasmacholinesterase levels correlated positively with several tests of liver function whereasthe red cell cholinesterase results were negatively correlated with albumin butpositively correlated with age. This study underscores the fact that several parameterssystematically affect cholinesterase levels. These parameters do not affect both the redcell and plasma cholinesterase similarly. These factors need to be considered whencholinesterase levels are used to compare groups of potentially exposed persons.