Snížená hladina magnezia v moči po ileokolické resekci u pacientů s Crohnovou chorobou

Abstract

Summary: Introduction: Urinary excretion of magnesium is an important preventive factor against nephrolithiasis by inhibiting several key processes in its pathogenesis. Patients with Crohn’s disease (CD) have an approximately 2-fold higher risk of lithiasis, especially those after ileocolic (IC) resection. The aim is to determine the magnesuria level in these patients and compare it with patients with CD and IC involvement without resection and then both groups with healthy controls. The secondary objective was to assess calciuria and other modifying factors. Methods: CD patients aged 18 years or older with IC resection (group 1) and terminal ileal involvement without resection (group 2) were enrolled in the study, with subjects without known bowel disease as controls (group 3). Exclusion criteria were citrate therapy, severe renal insufficiency (GFR < 30 ml/ min/ 1.73 m2), more than two bowel resections, ileostomy, colectomy, short bowel syndrome, acute urinary tract infection and evidence of CD relapse. Anamnestic data were collected by questionnaire, blood and fresh urine samples were collected, renal and gallbladder ultrasound was performed for the presence of lithiasis, and patients underwent 24-hour urine collection to determine oxaluria, citraturia, magnesuria and calciuria. Results: 107 subjects were included in the study, including 34 patients with IC resection, 42 with CD without resection and 31 healthy controls. 43% were women, mean age was 38 ± 11.5 years. There was a significant difference in magnesuria values between the resection and non-resection group (median 2.28 vs. 3.97 mmol/ l; P = 0.047) and especially between the resection group and healthy controls (median 2.28 vs. 4.31 mmol/ l; P = 0.0003). The group without resection vs. healthy controls did not reach a significant difference (median 3.97 vs. 4.31 mmol/ l; P = 0.455). Calciuria values did not differ significantly between groups (median 3.75 vs. 4.6 vs. 4.3 mmol/ l; P = 0.293). Conclusion: Magnesuria values of CD patients after IC resection were significantly lower compared to the group of CD patients with IC involvement without resection and healthy controls. The group without resection achieved results comparable to controls. Calciuria values were not significantly different between groups in our study. We hypothesize that patients with CD after IC resection at higher risk of urolithiasis might benefit from Mg supplementation to prevent concretion formation. However, confirmation of this thesis will require verification by further research. Key words: inflammatory bowel disease – Crohn’s disease – urolithiasis – magnesium – calcium oxalate