Prevalence and Symptoms of Disaccharidase Enzyme Deficiency in Adult Patients With Unexplained Gastrointestinal Symptoms

Introduction: Disaccharidases produced by the small intestinal brush border facilitate digestion of dietary carbohydrates. If deficient, they cause carbohydrate malabsorption resulting in several abdominal symptoms. Our aim was to examine the prevalence of disaccharidase deficiency and correlate this with symptoms in adult patients with chronic abdominal symptoms. Methods: Patients with unexplained abdominal symptoms ( >1 year) and normal upper endoscopy and CAT scan had 2 biopsies taken from the third portion of duodenum between 2015-2022, placed in Eppendorf tube. These biopsies were assessed for lactase, sucrase, maltase, palatinase and glucoamylase activity (Dalqvist method). Nine common symptoms such as pain, cramping, constipation, belching, bloating, fullness, indigestion, nausea, diarrhea, vomiting, and gas were assessed for their frequency, intensity and duration using a validated scale and a total symptom index (1-10) was calculated for each symptom and compared between the groups using ANOVA. K-means cluster analysis was performed on lactase deficient and patients deficient in 3 or more enzymes (pandeficient). Results: Four hundred patients (79.3% female) were enrolled of whom, 169 (42.3%) patients had at least 1 enzyme deficiency and 44 (11%) where pandeficient, Figure 1. Mean symptom prevalence and its severity were not significantly different between those with or without disaccharidase deficiency (Table 1). Patients with pandeficiency did not have significantly worse symptoms than those with single enzyme deficiency (Table 1). No single symptom was more prevalent in patients with confirmed enzyme deficiency than those without. One of 3 clusters identified in cluster analysis of pandeficient patients had lower symptoms of cramping, indigestion and nausea. Conclusion: Disaccharidase deficiency is common in adults presenting with unexplained gastrointestinal complaints, especially gas, bloating, distention and pain, with a high prevalence of 43% for single enzyme; 11% were pandeficient. However, symptoms are poor predictors of the underlying deficiency, with patients who are deficient in any 1 enzyme presenting with several symptoms and a lack of classic symptoms in a subset of pandeficient patients. Because these deficiencies are treatable with enzyme supplements and/or dietary exclusion, a high index of clinical suspicion together with duodenal biopsy for disaccharidases enzyme assay should be routinely considered in the evaluation of patients with chronic gastrointestinal complaints.Figure 1.: Prevalence of Normal and Abnormal Disaccharidase Activity. Table 1. - One-Way ANOVA Comparing Average Symptom Indexes in Patients with Lactase Deficiency, Pandeficiency, Patients with Normal Activity Pain Cramping Constipation Belching Bloating Fullness Indigestion Nausea Diarrhea Vomiting Gas F-Value 0.591 1.227 0.024 0.936 0.805 1.530 0.011 0.175 2.278 0.828 0.516 P-Value 0.554 0.294 0.976 0.393 0.217 0.218 0.989 0.839 0.104 0.438 0.597