Background: Ischemic colitis (IC) incidence rates (IRs) among treated hypertensive patients are poorly understood, and existing literature on the subject is sparse. Antihypertensive drugs may raise the risk of developing IC. Novel antihypertensive agents—such as the direct renin inhibitor aliskiren—have not been assessed for IC risk.
Objectives: The aims of this study were to evaluate (1) the IRs of probable IC (pIC) in treated hypertensive adults, with a focus on aliskiren-treated patients; (2) the antihypertensive therapies used; and (3) the IRs of pIC in non-hypertensive adults.
Methods: This study selected hypertensive and non-hypertensive patients (N = 2,356,226 each) from a US health plan claims database. pIC was defined as diagnosis of IC within 3 months after colonoscopy, recto-sigmoidoscopy, or colectomy. IRs were calculated per 100,000 person-years (PYs) with 95% confidence intervals (CIs) and stratified by antihypertensive regimen.
Results: IRs of pIC in hypertensive and non-hypertensive subjects were 18.6 (95% CI 17.6-19.8) and 4.0 (95% CI 3.4-4.7), respectively. The non-hypertensive cohort consisted of younger patients who may have been less prone to developing IC. The overall (i.e., all antihypertensive regimens combined) monotherapy IR per 100,000 PYs was 17.5 (95% CI 16.2-18.8), the overall dual-combination regimen IR per 100,000 PYs was 19.5 (95% CI 17.37-21.83), and the overall triple-plus combination regimen IR per 100,000 PYs was 27.7 (95% CI 22.72-33.38).
Conclusion: Study results indicate that the treated hypertensive patients may have a higher risk of pIC compared with non-hypertensive populations. The quantity of antihypertensive agents prescribed may contribute to IC more than treatment duration.