An article published in the journal, Clinical Gastroenterology and Hepatology, sheds light on ulcerative colitis diagnosed in the later stages of adulthood.1
Ulcerative colitis (UC) is an inflammatory bowel disease consisting of fine ulcerations in the inner mucosal lining of the large intestine (colon). Its primary symptoms are rectal bleeding and diarrhea, but may also include anemia, constipation, fever, inflammation of the joints or eyes, ulcers of the mouth, or tender, inflamed nodules on the shins.
In a retrospective cohort study looking at the years 2001-2008, researchers sorted the records of 295 patients with UC into two groups, based on their age at diagnosis. Patients diagnosed between the ages of 18 and 30 were defined as early-onset, whereas those diagnosed at age 50 or older were defined as late-onset.
Although there were no significant differences between the groups in terms of disease extent or severity at time of diagnosis, at one year after diagnosis 64% of the late-onset group had achieved steroid-free clinical remission, whereas only 49% of the early-onset group reached this remission. In the group of people who received systemic steroid therapy, 50% of the late-onset patients achieved remission, whereas only 32% of the early-onset patients reached the same state.
The researchers are not certain why this occurs, but they did identify some interesting factors. They found that more than one in five early-onset UC patients had a family occurrence of inflammatory bowel disease, whereas most late-onset UC patients seemed to have developed the disease due to issues associated with the aging process and/or environmental contaminants (predominantly cigarette smoke). Nearly 52% in the late-onset group were former smokers, compared with only 13.5% of the early-onset group.
Also, ulcerative colitis is associated with an overactive immune system, which may be even more active in younger individuals because they naturally have stronger immune systems, making it more difficult for a younger person to enter remission. In the late-onset group, the findings may be a result of quicker diagnosis or better adherence to therapy. Further investigation into the environmental and genetic factors that differentiate late-onset versus early-onset ulcerative colitis may give insight into the observed differences between these two populations.
What is a Retrospective Cohort Study?
In a retrospective cohort study, all of the events have already taken place and researchers examine and compare the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic or behaviour. This is unlike a prospective cohort study, in which none of the events have taken place, and researchers examine and compare the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic or behaviour over time.