Objective: In acromegaly, overproduction of GH and IGF-I causes abnormal extracellular matrix regulation. We hypothesized that this may predispose to the development of colonic diverticula. Because the relation between acromegaly and colonic diverticula is unknown, the study aim was to assess the prevalence of colonic diverticula in patients with cured acromegaly.
Design: This was a case-control study.
Methods: We screened reports of colonoscopies performed for the purpose of screening for polyps in 107 patients with cured or biochemically controlled acromegaly and in 214 age- and sex-matched controls for the presence of diverticula, dolichocolon, and polyps. In patients, the findings were related to GH/IGF-I concentrations at the time of diagnosis of acromegaly and to the duration of GH/IGF-I excess.
Results: In acromegaly, colonic diverticula were present in 37% of patients, dolichocolon in 34%, and adenomatous polyps in 34%, which was increased compared with controls (odds ratio 3.6, 95% confidence interval 1.4, 5.7; 12.4, 95% confidence interval 6.8, 18.0; 4.1, 95% confidence interval 1.9, 6.4, respectively). The presence of colonic diverticula was associated with both GH and IGF-I concentrations at the time of diagnosis of acromegaly, when adjusted for the duration of active disease. The presence of dolichocolon and adenomatous polyps was associated with higher IGF-I concentrations at diagnosis.
Conclusions: Acromegaly is associated with an increased prevalence of colonic diverticula. In addition to the known irreversible effect of GH excess on collagen of joints and cardiac valves, this observation indicates an irreversible effect of GH and/or IGF-I on the collagen in the colon.