Zinc clearance correlates with clinical severity of Crohn's disease. A kinetic study.

After peroral and intravenous loading of zinc in 10 patients with Crohn's disease, a kinetic analysis of serum zinc was carried out. The patients were divided into two groups depending on the clinical activity indices (group A:five with active form and group B:five with inactive form). The mean level of serum zinc was significantly reduced in group A patients, but not in group B, when compared to findings in control subjects. A significant reduction in AUCpo (area under the concentration vs time curve by peroral administration), accompanied by increased zinc clearance (ClZn) was also found in group A but not in group B. The ClZn significantly correlated with clinical activity indices. Absorption efficiency, the ratio of AUCpo/AUCiv (area under the concentration vs time curve by intravenous administration), was similar in group A, group B, and the control. Therefore, the absorption of zinc in patients with the disease seems to be intact, regardless of whether they have the active or inactive form of Crohn's disease. The hypozincemia seen in patients with Crohn's disease is presumably related to an accelerated turnover rather than to a malabsorption of zinc.