EVALUATION OF THE LACTULOSE MANNITOL AND CR-51-ETHYLENEDIAMINETETRAACETIC ACID C-14 MANNITOL METHODS FOR INTESTINAL PERMEABILITY - INFLUENCE OF URINARY VOLUME, SEX, AGE, SMOKING, AND INTESTINAL DISEASE ON MARKER EXCRETION/

Background: We earlier compared the lactulose/mannitol and Cr-51-ethyl enediaminetetraacetic acid (EDTA)/C-14-mannitol methods for intestinal permeability We have now investigated an increased number of control subjects, with special regard to the influence of urinary volume, sex, age, and smoking on marker excretion, and patients with intestinal di sorders, with special regard to correlations between markers. Methods: The 0- to 6-h urinary excretion of orally administered markers was me asured in 65 control subjects and in 70 patients. Results: In the cont rol group excretion of mannitol and C-14-mannitol (small-pore permeabi lity markers) was strongly correlated to urinary volume, whereas such correlation was weak for lactulose and absent for Cr-51-EDTA (large-po re permeability markers). No sex difference in marker excretion was fo und, but correlation to urinary volume was more pronounced in males. T here was a slightly decreasing excretion of markers with increasing ag e, reaching significance for Cr-51-EDTA and C-14-mannitol; their excre tion ratio was unaffected. Smoking did not significantly affect marker excretion. In the patient group the excretion of large-pore markers t ended to be higher and that of small-pore markers to be lower than in the control group; correlation between the large-pore markers, between the small-pore markers, and between the large-pore/small-pore marker ratios was higher than in the control group. Conclusions: Correction f or urinary volume substantially reduces variability in small-pore mark er excretion. Excretion of both types of markers tends to decrease wit h age, the large-pore/small-pore marker ratio remaining unchanged. Smo king does not affect small-intestinal permeability. C-14-mannitol is p referred to chemically determined mannitol owing to lower test variabi lity.