A Population-based Study of Incidence, Risk Factors, Clinical Spectrum, and Outcomes of Ischemic Colitis

Abstract

Background & Aims Little is known about progression of ischemic colitis (IC) among unselected patients. We aimed to estimate the incidence, risk factors, and natural history of IC in a population-based cohort in Olmsted County, Minnesota. Methods We performed a retrospective population-based cohort and nested case–control study of IC. Each IC case was matched to 2 controls from the same population based on sex, age, and closest registration number. Conditional logistic regression, the Kaplan-Meier method, and proportional hazards regression were used to assess comorbidities, estimate survival, and identify characteristics associated with survival, respectively. Results Four hundred forty-five county residents (median age, 71.6 years; 67% female) were diagnosed with IC from 1976 through 2009 and were matched with 890 controls. The age- and sex-adjusted incidence rates of IC nearly quadrupled, from 6.1 cases/100,000 person-years in 1976–1980 to 22.9/100,000 in 2005–2009. The odds for IC were significantly higher among subjects with atherosclerotic diseases; odds ratios ranged from 2.6 for individuals with coronary disease to 7.9 for individuals with peripheral vascular disease. Of IC cases, 59% survived for 5 years (95% CI, 54%–64%), compared to 90% of controls (95% CI, 88%–92%). Age >40 years, male sex, right-sided colon involvement, concomitant small bowel involvement, and chronic obstructive pulmonary disease were all independently associated with mortality (P<.05). Conclusions The incidence of IC increased over the past 3 decades in a population-based cohort in Minnesota. IC typically presents in older patients with multiple co-morbidities and is associated with high in-hospital mortality (11.5%) and rates of surgery (17%).

Antihypertensive Drugs, Hypotension, and Ischemic Colitis

“…It is also a diagnosis of exclusion with no identified cause [10,11]. The age-and sex-adjusted incidence rate was estimated to be 22.9 per 100,000 patient-years (PYs) (95 % confidence interval [CI] 18.6-27.3) for the period 2006-2009 among unselected subjects in a US county [12]. The incidence was twice as frequent for women and increased strongly with age, from 1.1 per 100,000 PYs before the age of 40 years to 107 per 100,000 PYs for subjects aged 80 years or older [10].…”

“…In this study, the main risk factor was a hypotensive episode in the previous month (odds ratio [OR] 33.0, 95 % CI 13.3-80.9) [11]. Other independent risk factors identified were collagen vascular disease (OR 8.0, 95 % CI 2.2-28.3), peripheral vascular disease (OR 7.9, 95 % CI 4.7-13.2), congestive heart failure (OR 4.1, 95 % CI 2.6-6.3), psychotropic medications used in the past 30 days (OR 3.7, 95 % CI 1.3-11.0), digoxin used in the past 30 days (OR 3.6, 95 % CI 2.1-6.2), cerebrovascular disease (OR 3.2, 95 % CI 2.3-4.6), chronic obstructive pulmonary disease (COPD) (OR 3.1, 95 % CI 1.8-5.2), coronary artery disease (OR 2.6, 95 % CI 2.0-3.5), aortic aneurysm or coronary bypass surgery (OR 2.5, 95 % CI 1.5-4.2), hypertension (OR 2.1, 95 % CI 1.6-2.7), diabetes mellitus (OR 2.0, 95 % CI 1.4-2.8), history of thromboembolism (OR 1.9, 95 % CI 1.2-3.3), current smoking (OR 1.9, 95 % CI 1.3-2.7), and diuretic used in the past 30 days (OR 1.6, 95 % CI 1.2-2.1) [12].…”

“…The lack of adjustment or standardization makes comparisons or even overall medical appreciation between groups complex. Indeed, any lower or greater incidence rate could be due to a small unbalanced distribution of gender, age, or other risk factors [12]. For example, the incidence rate was 34 % higher in the prevalent medication group than in the incident medication group.…”

“…Although the paper by Hines et al [1] brings important information on the general risk of ischemic colitis in treated hypertensive patients, further research is needed to differentiate the attributable risk of hypertension from that of its treatment, which of the available antihypertensive drugs, drug classes, and combinations have a higher risk of ischemic colitis, and whether the higher risk is constant during exposure or mainly at the beginning of exposure (initiation or switch). One of the best designs to address these questions is that used by Yadav et al [12], applied to a hypertensive population with a cohort to estimate the overall age-and sex-adjusted incidence rate of ischemic colitis in this population, and a nested case-control analysis, or self controlled design [13], to estimate crude and adjusted ORs for risk factors, antihypertensive drugs, classes, and combinations commonly used in medical practice.…”

Olanzapine-induced ischemic colitis

“…Incidence rates vary with age, and oscillate from 1.1 per 100,000 inhabitant-years among patients younger than 40 years to 107 per 100,000 inhabitant-years among those at or above 80 years of age. It typically involves elderly patients with multiple comorbidities, and is associated with high in-hospital mortality (11.5%) and surgery (17%) rates (3). In clinical practice many cases are overlooked because of mild or transient presentations with no clear trigger.…”