Demographics and Phenotypic Behavior of Inflammatory Bowel Disease in South Asians Living in the United States

Abstract

2807_A Figure 1. Characteristics of South Asian IBD patientsIntroduction: The incidence and prevalence rates of inflammatory bowel disease (IBD) has been rising in Southasian populations. Studies from United Kingdom and Canada have shown increased risk of developing IBD when immigration occurred at a younger age and incidence among second generation immigrants similar to non-immigrants suggesting the role of environment as a risk factor for developing IBD. Thus far no studies in the United States (US) population address this issue. Our aim was to determine the demographics, disease type, behavior and phenotypic variation of IBD in Southasians living in the US. Methods: Clinical and demographic data from adult Southasians with IBD were abstracted from review of medical records and telephone interview after institutional review board approval. Additional information regarding patients and parents' place of birth, time of immigration, family history of IBD, diet, smoking history, disease extent and behavior, as well as need for hospitalizations and surgical history was obtained. Results: Among 37 Southasians with IBD; 18 (49%) had ulcerative colitis (UC) and 19 (51%) had Crohn's disease (CD). Mean age at diagnosis was 27+/-11 years. 2 patients (11%) with UC and 2 patients (10%) with CD had a positive family history of IBD. Patient characteristics comparing UC versus CD is reported in Table 1. Additional data regarding immigration status and diet were obtained via telephone interview from 20 patients. Sixteen out of 20 were first generation immigrants [UC: 8(50%) and CD: 8(50%)]. Mean age at IBD diagnosis was significantly younger in second generation immigrants comparing to first generation immigrants (18+/-3 vs 32+/-14; p< 0.02). Prevalence of EIMs, hospitalizations and history of bowel surgeries were similar between first and second generation immigrants (Table 2). Although second generation had more of a westernized diet, this did not seem to influence the disease severity and/or behavior.2807_B Figure 2. Patient demographics and disease characteristics by generationConclusion: Disease extent and location in our Southasians was predominantly pancolitis in UC and ileocolonic in CD. Second generation patients were younger age at diagnosis of IBD and had more of a westernized diet, but no other differences were found in comparison to first generation patients. Information on racial variability in disease phenotypic expression may help identify both genetic and environmental factors associated with IBD.