Background: Chronic gastrointestinal ischemia (CGI) is still a difficult diagnosis to make. Currently, the only diagnostic with an acceptable sensitivity for actual mucosal ischemia is gastrointestinal tonometry. However, tonometry is a cumbersome and invasive diagnostic test. We are in need of a more simple, noninvasive test for diagnosing mucosal ischemia. A sensitive and early serum marker could be of great use in this setting. The aim of this study was to evaluate the use of promising serum markers for mucosal ischemia [intestinal fatty acid binding protein (I-FABP), D-lactate, and lipopolysaccharide] and compared findings with corresponding gastrointestinal tonometry measurements.
Methods: Patients referred for evaluation of CGI were included. All patients had visualization of abdominal arteries and gastrointestinal tonometry. Before, during, and after tonometry blood samples were drawn for measurements of serum markers.
Results: Forty-nine patients were eligible for evaluation. CGI was diagnosed in 24 (49%) patients. The baseline measurements showed a significant increase in I-FABP before exercise tonometry in the abnormal-response groups compared with the normal-response group, respectively, 0.45 and 1.3 microg/l (P=0.04). An abnormal response on meal tonometry was associated with increased I-FABP levels, 1, 2, and 4 h after tonometry, compared with the patients with a normal response, respectively, 1.26, 1.11, and 0.58 microg/l (P=0.048, 0.01, and 0.03). The measurements of D-lactate and lipopolysaccharide were undetectable, or low, at all different points of time.
Conclusion: Transient postprandial mucosal ischemia, as detected with gastrointestinal tonometry, is associated with increased I-FABP levels, indicating epithelial damage. Late markers for mucosal ischemia remained negative.