The Incidence and Risk Factors of Refeeding Syndrome-like Hypophosphatemia in Inflammatory Bowel Disease: A Preliminary Study.

Background and aims: Refeeding syndrome (RFS) is defined by the presence of acute electrolyte disturbances, including hypophosphatemia. Underlying disease(s), malnutrition and hospitalisation are known risk factors for RFS. It can occur in patients with inflammatory bowel disease (IBD). We aimed to determine the frequency of hypophosphatemia and the relationship between hypophosphatemia, disease severity and nutritional status in hospitalized patients with IBD.

Methods: This study was performed prospectively in hospitalized adult patients for the treatment of IBD in a tertiary-care hospital. Disease severity was assessed using Truelove and Witts score for ulcerative colitis (UC) and Crohn's Disease Activity Index for Crohn's disease (CD). Nutritional status was determined using Subjective Global Assessment (SGA). Serum phosphate concentration was recorded for first 7 days after hospitalization, and less than 0.65 mmol/l was defined as hypophosphatemia.

Results: Fifty participants (33 with UC and 17 with CD) were included in the study. The mean age of the study sample was 43.4±14.9 years, of which 64% were male. A total of 8.8% of patients with UC and 37.5% of patients with CD had severe (>moderate) disease upon study admission. Seventeen patients (34%) were malnourished. During the 7 study days, 23 participants (46%) had at least one episode of hypophosphatemia. Serum phosphate concentration was significantly and moderately correlated with serum potassium concentration in both the patients and the hypophosphatemia group on study day 3 (p<0.05). Multivariate logistic regression analysis showed that the presence of malnutrition [odds ratio (OR) = 3.64, 95% confidence interval (CI): 1.52-5.58, p=0.008), the administration of parenteral nutrition (OR=2.91, 95%Cl: 1.37-4.63, p=0.015), and severe IBD (OR=1.74, 95%CI: 1.03-3.42, p=0.020) were associated with hypophosphatemia.

Conclusions: Approximately half of the participants exhibited at least one instance of hypophosphatemia during the study period. Hypophosphatemia was found to be associated with malnutrition, parenteral nutrition, and severe disease in patients with IBD requiring hospitalization.