Correlación y conversión entre los valores de actividad de la colinesterasa plasmática medida por tres técnicas diferentes / Correlation and conversion of plasma cholinesterase activity values using three techniques

RESUMEN

OBJETIVO: Determinar las relaciones matemáticas entre tres técnicas cuantitativas empleadas para medir la actividad de la colinesterasa plasmática, a partir de los valores de referencia ya establecidos para dos poblaciones de Antioquia, Colombia. MÉTODOS:Diseño descriptivo, transversal y prospectivo. Se conformaron dos muestras independientes representativas de la población laboral adulta (18-65 años), no expuesta a plaguicidas inhibidores de la colinesterasa y vinculada al Seguro Social, del valle de Aburrá (415 personas) y del cercano oriente antioqueño (412 personas), del departamento de Antioquia, Colombia. La colinesterasa plasmática (EC 3.1.1.8) se midió mediante tres técnicas cuantitativas Michel, EQM® y Monotest®. Se elaboraron ecuaciones de regresión que relacionaran entre sí los resultados de las tres técnicas estudiadas. RESULTADOS: Se definieron seis ecuaciones de regresión lineal simple que permitieron relacionar los resultados de las tres técnicas de medición de colinesterasa plasmática analizadas. La correlación entre las técnicas fue moderada (r de 0,686 a 0,771), pero aumentó (r de 0,744 a 0,811) al eliminar 12 (1,5 por ciento) valores extremos. Las asociaciones entre las técnicas fueron altamente significativas (P < 0,001). Las ecuaciones Y = a + bX ajustadas son EQM (U/mL) = 0,40773 + 1,8757 (Michel [delta pH/hora]); Michel (delta pH/hora) = 0,25799 + 0,33871 (EQM [U/mL]); Monotest (U/L) = 462,0 + 4 565,0 (Michel [delta pH/hora]); Michel (delta pH/hora) = 0,42956 + 0,00012125 (Monotest [U/L]); EQM (U/mL) = 0,75333 + 0,00031056 (Monotest [U/L]); y Monotest (U/L) = 262,0 + 2 118,0 (EQM [U/mL]). CONCLUSIONES: Los modelos propuestos permiten convertir los valores de actividad de la colinesterasa medida con las tres técnicas estudiadas.

ABSTRACT

OBJECTIVES: To determine mathematical correlations of three quantitative techniques to measure plasma cholinesterase, using reference values already established for two populations in the department of Antioquia, Colombia. METHODS: In this descriptive, cross-sectional, prospective study, two independent, representative samples of working adults (18 to 65 years old) were examined. In both samples the adults worked for businesses associated with ColombiaÆs Social Security system. Adults in the two samples had not been exposed to cholinesterase-inhibiting pesticides. The samples were from two neighboring regions of the department of Antioquia one sample (415 adults) was from the Aburrá Valley, and the other (412 adults) was from Oriente Antioqueño (Eastern Antioquia). Plasma cholinesterase (EC 3.1.1.8) was measured using three quantitative methods: Michel, EQM, and Monotest. Linear regression equations were developed to correlate results of these three techniques. RESULTS: Six simple linear regression equations were defined to show the relationship of three measurement techniques for plasma cholinesterase. There was a moderate correlation of the three techniques (r = 0.686 to 0.771), but it increased (r = 0.744 to 0.811) when 12 (1.5 percent) outliers were eliminated. Associations among the three techniques were highly significant (P < 0.001). The adjusted equations for Y = a + bX are EQM (U/mL) = 0.40773 + 1.8757 (Michel [delta pH/h]); Michel (delta pH/h) = 0.25799 + 0.33871 (EQM [U/mL]); Monotest (U/L) = 462.0 + 4 565.0 (Michel [delta pH/h]); Michel (delta pH/h) = 0.42956 + 0.00012125 (Monotest [U/L]); EQM (U/mL) = 0.75333 + 0.00031056 (Monotest [U/L]); and Monotest (U/L) = 262.0 + 2 118.0 (EQM [U/mL]). CONCLUSIONS: The proposed mathematical models allow conversion of cholinesterase activity values using the Michel, EQM, and Monotest techniques. These models can be of assistance in Colombia and other countries where a variety of measurement...