Inflammatory Bowel Disease in Kazakhstan: Phenotypes, Disease Activity, and Treatment Patterns from a National Registry

Abstract

Background/Objectives: Inflammatory bowel diseases (IBDs) are an increasingly important global health problem, yet Central Asia remains underrepresented in international IBD data. To evaluate the clinical and demographic characteristics of patients included in the national multicenter clinical IBD registry of the Republic of Kazakhstan (IBD Registry) according to disease activity at registry enrollment visit and to identify factors associated with active IBD at that time. Methods: We conducted a cross-sectional analysis of the registry enrollment visit data from the national multicenter clinical IBD registry of the Republic of Kazakhstan. The study included patients with ulcerative colitis (UC) and Crohn’s disease (CD) registered between 2021 and 2024. Disease activity at the registry enrollment visit was assessed using the full Mayo score for UC and the Harvey–Bradshaw index for CD. Univariable and multivariable logistic regression analyses were performed to identify factors associated with active disease. Results: The analysis included 1521 patients with IBD, 68.4% with ulcerative colitis and 31.6% with Crohn’s disease. At the registry enrollment visit, 77.5% of patients had clinically active disease. In UC, active disease was independently associated with rural residence (aOR 2.11; 95% CI 1.25–3.56), ≥2 exacerbations per year (aOR 3.47; 95% CI 2.18–5.51), current corticosteroid therapy (aOR 5.96; 95% CI 3.04–11.69), and immunosuppressive therapy (aOR 2.71; 95% CI 1.15–6.38), whereas rare exacerbations were associated with lower odds of activity (aOR 0.41; 95% CI 0.23–0.73). In CD, active disease was independently associated with ≥2 exacerbations per year (aOR 2.41; 95% CI 1.47–3.95), colonic (L2) location (aOR 2.32; 95% CI 1.25–4.30), ileocolonic (L3) location (aOR 2.24; 95% CI 1.25–4.04), extraintestinal manifestations (aOR 2.88; 95% CI 1.68–4.93), and current corticosteroid therapy (aOR 1.77; 95% CI 1.03–3.05), whereas immunosuppressive therapy was associated with lower odds of active disease (aOR 0.46; 95% CI 0.24–0.89). Biologic therapy was not independently associated with disease activity in either UC or CD. Conclusions: A high proportion of patients treated at participating secondary and tertiary centers had clinically active IBD at registry enrollment. The profiles of factors associated with activity differed between UC and CD, while frequent exacerbations were consistently associated with active disease in both conditions. These findings should be interpreted as cross-sectional associations rather than causal or prognostic relationships, particularly for treatment-related factors.