Baseline Hypozincemia Predicts Clinical Relapse in Patients with Ulcerative Colitis in Remission

Objective Ulcerative colitis (UC) follows a relapsing-remitting course. Identifying modifiable clinical relapse prognostic factors remains challenging. Patients with inflammatory bowel disease commonly exhibit zinc deficiencies. In this study, we aimed to determine whether hypozincemia is independently associated with the risk of relapse. Methods Baseline serum zinc levels were measured in patients with UC in clinical remission (i.e., partial Mayo score <3) from a single center between April 2015 and March 2025. Patients were classified as having hypozincemia (serum zinc <80 μg/dL) or normozincemia (serum zinc ≥80 μg/dL). The primary outcome was clinical relapse within one year. Relapse-free survival was assessed using a Kaplan-Meier survival analysis. Independent predictors of relapse were evaluated using multivariable Cox proportional hazards models adjusted for inflammatory markers, serum albumin levels, and previous biologic therapy. Results Overall, 102 patients were included (50 with hypozincemia and 52 with normozincemia). The hypozincemia group experienced clinical relapse more frequently than the normozincemia group (74.0% vs. 34.6%, P<0.001). Relapse-free survival was significantly shorter in patients with hypozincemia (log-rank: P<0.001). A multivariable Cox regression analysis showed that normozincemia was independently associated with a reduced relapse risk (adjusted hazard ratio, 0.42; 95% confidence interval, 0.24-0.74; P=0.003). C-reactive protein and serum albumin were not significant predictors. Serum zinc levels were weakly correlated with the inflammatory biomarkers. Conclusion Hypozincemia was independently associated with an increased clinical relapse risk in patients with UC in remission. Baseline assessment of serum zinc levels may provide additional prognostic information beyond that of conventional inflammatory and nutritional markers.