Long-term use of steroids protects from the development of symptomatic diverticulitis requiring hospitalization in the Asian population.

Objective: The pathophysiology of diverticulitis is poorly understood. Factors such as physical inactivity, constipation, obesity, smoking, and the use of nonsteroidal antiinflammatory drugs (NSAIDs) have been associated with an increased risk of diverticular disease. To evaluate whether patients exhibiting long-term steroid use are at increased risk of colonic diverticulitis.

Method: We conducted a population-based, nested case-control study. Data were retrospectively collected from the National Health Insurance Research Database. The study cohort comprised patients diagnosed with diverticulitis, identified using inpatient discharge records using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes (562.11 and 562.13), and those who were administered one or more prescriptions for corticosteroids for systemic use. Control patients were matched to cases by age, sex, NSAID use, laxative drug use, and index date. We enrolled 690 patients with colonic diverticulitis and 2760 in the control group. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression.

Results: Compared with steroid nonusers, the adjusted ORs were 0.60 (95% CI = 0.35-1.06) and 0.80 (95% CI = 0.64-1.008) in current steroid users and previous steroid users, respectively. In addition, the adjusted ORs were 0.55 (95% CI = 0.31-0.98), 0.57 (95% CI = 0.31-0.98), and 0.44 (95% CI = 0.22-0.86) for steroid use duration more than half time by an exposure period of 90 days, 180 days, and 365 days before the claim date of colonic diverticulitis, respectively.

Conclusions: The results indicated that long-term steroid use within one year is associated with lower risk of colonic diverticulitis.