Colonic diverticulosis was not associated with mucosal inflammation or gastrointestinal symptoms in a single-center, prospective study of adults undergoing their first screening colonoscopy.
After adjustment for age, sex, and body mass index, there were no significant links between diverticulosis and tumor necrosis factor, CD4+ cells, CD8+ cells, CD57+ cells, irritable bowel syndrome, or chronic abdominal pain, reported Anne F. Peery, MD, with her associates at the University of North Carolina at Chapel Hill. “Our findings strongly question the rationale for treating symptomatic uncomplicated diverticular disease with mesalamine,” they wrote in the June issue of Clinical Gastroenterology and Hepatology ().
Colonic diverticula affect more than half of individuals in the United States over the age of 60 years, according to the results of past studies. “Although colonic diverticulosis can be complicated by the overt inflammation of acute diverticulitis, there is some thought that colonic diverticulosis is associated with low-grade mucosal inflammation,” the researchers said. “Moreover, this low-grade diverticular inflammation is believed to contribute to chronic gastrointestinal symptoms.” However, no rigorous prospective study had tested these assertions.
Accordingly, the researchers evaluated prospective data from 619 outpatients aged 30 years and older who underwent screening colonoscopies for the first time during 2013-2015. These patients had consented to participate in a study of risk factors for colonic diverticulosis. Most were white (76%) or black (21%), and most were aged 50-59 years.
A total of 255 individuals had diverticula while 364 controls did not. Patients with diverticula tended to be older and were more often male (47% vs. 41% of controls) and overweight or obese (72% vs. 62%). After adjustment for age, sex, and body mass index, there was no evidence linking diverticulosis with tumor necrosis factor alpha expression (odds ratio, 0.9; 95% confidence interval, 0.6-1.2), CD4+ cells (OR, 1.2; 95% CI, 0.9-1.6), CD8+ cells (OR, 1.0; 95% CI, 0.7-1.3), or CD57+ cells (OR, 0.8; 95% CI, 0.6-1.1).
Among 42 patients who met Rome III criteria for irritable bowel syndrome, 11 had diverticulosis. Diverticulosis in IBS was not associated with changes in expression of the mucosal inflammatory markers interleukin-6, interleukin-10, tumor necrosis factor, CD4, CD8, or mast cell tryptase, said the researchers. A total of 63 patients had chronic abdominal pain, of whom 22 also had diverticulosis. There were no significant differences in mucosal inflammatory markers between symptomatic patients with diverticula and those without. Adjusted analysis found no association between number of diverticula and chronic abdominal pain (OR, 0.7; 95% CI, 0.4-1.2) or IBS (OR, 0.5; 95% CI, 0.3-1.1).
The number of patients with IBS in this study was small, and the researchers did not ascertain IBS symptom severity, they noted. “Although we studied several immune markers and cytokines, there are other potential markers that may be associated with chronic inflammation,” they added. “Multianalyte profiling could be used to assess an array of cytokines, and markers for macrophages (CD68), global T cells (CD3), and B cells (CD19). Whether there is utility in further studies given our negative results is debatable.”
The National Institutes of Health provided funding. The investigators reported having no conflicts of interest.
SOURCE: Peery AF et al. Clin Gastroenterol Hepatol. 2017 Jun 8. .