S1497 Prevalence and Impact of Zinc Deficiency on Clinical Outcomes in Inflammatory Bowel Disease

Introduction: Inflammatory bowel disease (IBD) can lead to trace elements deficiency such as zinc, which plays a vital role in immune function and tissue repair. The aims of this study were to investigate the prevalence, risk factors and impact of zinc deficiency on clinical outcomes in IBD. Methods: This is a retrospective, single center study that included patients aged ≥ 14 years with a confirmed diagnosis of IBD [Crohn's disease (CD), ulcerative colitis (UC), pouchitis, IBD-unclassified (IBD-U)] and documented zinc levels. Zinc deficiency was defined as a level < 10.6 umol/L as per our institution’s assay. Primary outcomes were prevalence and predictors of zinc deficiency. Secondary outcomes (assessed over 12 months following initial zinc level) included: rates of IBD-related hospitalizations, emergency room (ER) visits, surgeries, and complications (anemia, small bowel obstruction, new onset perianal disease, intra-abdominal abscess). Univariable and multivariate logistic regression analyses were performed on secondary outcomes. Results: A total of 447 patients (54.4% male; 79.2% CD) were included. Zinc deficiency was noted in 45.6% (83.8% with CD). Patients with zinc deficiency had significantly higher median levels of C-reactive protein (CRP) (p ˂ 0.001), fecal calprotectin (FCP) (p ˂ 0.001) and were more likely to be on corticosteroids (P = 0.04) (Table 1). Zinc-deficient patients had significantly higher rates of IBD-related hospitalizations (48.0% vs 17.7%), surgeries (19.6% vs 5.8%), complications (30.4% vs 12.4%), and ER visits (40.2% vs 17.3%) (all P < 0.001) (Figure 1). On multivariate analysis, zinc deficiency [odds ratio (OR) 2.42, 95% confidence interval (CI) 1.07-5.48, P = 0.03] and low albumin (OR 9.03, 95% CI 3.38-24.15, P < 0.001) were the only predictors of IBD-related hospitalization while low albumin only predicted ER visits (OR 5.37, 95% CI: 2.13-13.55, P < 0.001). On multivariate analyses, zinc deficiency was significantly associated with IBD-related surgeries (OR 5.23, 95% CI: 1.27-21.45; P = 0.02) and complications (OR 3.98, 95% CI: 1.52-10.41; P = 0.005). CRP and FCP were not significantly associated with any of the secondary outcomes on multivariable analysis. Conclusion: Zinc deficiency was highly prevalent in our cohort of patients with IBD and associated with high inflammatory burden. Zinc deficiency remained associated with unfavorable clinical outcomes after controlling for markers of active inflammation.Figure 1.: Secondary outcomes stratified by zinc level status. Table 1. - Baseline characteristics of patients with normal zinc levels and zinc deficiency Characteristics Normal Zinc Level(n=243) Zinc Deficiency(n=204) P-value Male, n (%) 143 (58.9) 100 (49.0) 0.04 Age, median (IQR) 30 (24-41) 27 (21-35.8) < 0.001 Disease duration, median (IQR) 7 (3-13) 4 (1-9) < 0.001 Smoking, n (%)* 35 (22.3) 13 (9.3) 0.002 Previous surgery, n (%) 72 (29.6) 56 (27.5) 0.61 Disease subtype, n (%) 0.14 Crohn’s disease 183 (75.3) 171 (83.8) Ulcerative colitis 55 (22.6) 31 (15.2) IBD-U 4 (1.7) 2 (1.0) Pouchitis 1 (0.4) 0 Perianal Crohn’s disease, n (%) 69 (28.4) 67 (32.8) 0.31 Extraintestinal Manifestations, n (%) 25 (10.3) 27 (13.2) 0.33 Labs Median CRP (IQR) 3.4 (0.9-10.6) 12.1 (3.8-46.8) < 0.001 Median FCP (IQR) 177 (49-750) 660 (146-1000) < 0.001 Median Albumin (IQR) 43.3 (40.4-45.7) 35.2 (28-40.5) < 0.001 Medications Immunomodulators, n (%) 113 (46.5) 98 (48.0) 0.75 Advanced Therapies, n (%) 128 (52.7) 109 (53.4) 0.87 Corticosteroids, n (%) 31 (12.8) 41 (20.1) 0.04 IQR: interquartile range; IBD-U: inflammatory bowel disease-unclassified; CRP: C-reactive protein; FCP: fecal calprotectin.*Smoking status was known in 297 of 447 patients.