Acute appendicitis among adolescents has protective effect against ulcerative colitis

Swedish researchers have found in a sibling comparison study that acute appendicitis had a protective effect against ulcerative colitis. The study has been published in BMJ Open Gastroenterology.  

Past literature has shown an inverse relationship between appendicitis and ulcerative colitis (UC). But recent research has suggested that this relationship is influenced by genetic or environmental factors. Hence researchers from Sweden conducted a cohort study to assess the inverse relationship between acute appendicitis and ulcerative colitis (UC) using a sibling comparison design to adjust for unmeasured familial genetic and environmental factors between 1984 and 2018.  

Using several Swedish national registers nearly 3.1 million Sweden residents were involved in the study. Fitting Cox hazards models, the risk for developing UC in individuals with and without acute appendicitis was calculated by the age of 20 years, adjusting for several potential confounding factors. Further, sibling-stratified analyses were performed to adjust for shared unmeasured familial confounding factors.