Sweat Chloride Concentration in Adults with Pulmonary Diseases1–3

Abstract
In order to determine whether a high proportion of adults with pulmonary diseases have sweat chloride concentrations in the range usually considered diagnostic for cystic fibrosis (> 60 mEq/L), we performed the standard diagnostic “sweat test” of Gibson and Cooke prospectively on 187 subjects 18 to 85 yr of age who did not have cystic fibrosis (166 of them had some pulmonary or allergic disorder, and 21 were healthy). In this group, 99% had sweat chloride concentration < 70 mEq/L, and 96%, < 60 mEq/L. Those taking steroids had sweat chloride concentration slightly but significantly lower than those who did not take steroids, probably because of the mineralocorticoid effect. Six patients had pancreatitis, and 2 of those had sweat chloride concentration > 60 mEq/L, a distribution of values significantly different (p < 0.005) from the rest of the population. Our results suggest that a very small proportion of adults with pulmonary diseases have sweat chloride concentrations in the range usually considered diagnostic for cystic fibrosis, and that the sweat test is a good discriminant for cystic fibrosis even in the adult age group.

This publication has 6 references indexed in Scilit: