The incidence of ischemic colitis has increased in recent decades and is most common in older patients with multiple comorbidities, according to findings from a retrospective population-based cohort and nested case-control study.
“We wanted to do this study for a couple of reasons,” Edward V. Loftus, MD, FACG, AGAF, from Mayo Clinic in Rochester, Minnesota, told Healio Gastroenterology. “First of all, we wanted to get an estimate of the incidence of this condition, and the unique resources of the Rochester Epidemiology Project allowed us to do this. Secondly, most studies of ischemic colitis come from referral centers, and we wanted to see if the risk factors for and the clinical outcomes of ischemic colitis were similar to what had been previously established — we know from other conditions that the ‘natural history’ of a condition can look different depending upon the study setting. Thirdly, we wanted to see if there was a link between ischemic colitis and irritable bowel syndrome or the medications used to treat IBS.”
Edward V. Loftus
Loftus and colleagues identified 445 patients with ischemic colitis diagnosed from 1976 to 2009 in the same county in Minnesota. Their median age was 71.6 years (range, 21.6-96.9), 74% were older than 60 years at diagnosis, 67% were women, 17% underwent surgery and 11.5% had in-hospital mortality. These patients were matched to 890 controls from the same county based on age, sex and closest registration number.
Incidence rates adjusted for age and sex increased nearly fourfold, from 6.1 cases per 100,000 person-years (95% CI, 3.2-9.1) from 1976 to 1980 to 22.9 cases per 100,000 person-years (95% CI, 18.6-27.3) from 2006 to 2009. The age-adjusted rate increased 2.5-fold for men and more than fivefold for women.
Risk for ischemic colitis was higher in patients with atherosclerotic diseases; compared with those without atherosclerotic diseases, ORs ranged from 2.6 (95% CI, 2-3.5) for coronary artery disease to 7.9 (95% CI, 4.7-13.2) for peripheral vascular disease. Among patients with ischemic colitis, 59% (95% CI, 54-64) survived for 5 years after diagnosis compared with 90% (95% CI, 88-92) of controls. Independent risk factors for mortality included age older than 40 years, male sex, right-sided colonic involvement, concomitant small bowel involvement and chronic obstructive pulmonary disease (P < .05).
“We found that ischemic colitis is more common among the elderly and those with cardiovascular conditions and that its incidence is increasing over time,” Loftus said. “Risk factors and natural history are similar to what has been described, and we found no apparent link between ischemic colitis and IBS.” – by Adam Leitenberger
Disclosure: Loftus reports receiving research support form GlaxoSmithKline.