Patients with inflammatory bowel disease (IBD) have an increased risk of compromised bone mineral density (BMD) and body composition. There are limited data on the physical exercise (PE) habits of patients with childhood-onset IBD and on the associations between PE and BMD and body composition.
In total, 72 young adults with childhood-onset IBD and 1341 normative young adult controls answered questionnaires regarding PE [hours/week (h/w)] in the last 12 months. BMD and body composition were measured with dual x-ray absorptiometry (DXA) and presented as age- and gender-adjusted Z-scores for BMD, skeletal muscle index (SMI, the weight of lean mass in arms and legs/m), and percentage body fat (Fat %).
A total of 41 (57%) patients with IBD engaged in PE during the previous 12 months, as compared to 913 (68%) of the controls ( = .053). Sedentary patients had significantly lower median BMD, SMI, and Fat % Z-scores than the controls with corresponding PE habits (all  4 h/week) patients had total body BMD, SMI, and Fat % in the same range as the controls with corresponding PE levels ( = .151,  = .992, and  = .189, respectively), albeit with lower BMDs in the spine ( = .007) and femoral neck ( = .015). Using multiple regression analyses, a diagnosis of childhood-onset IBD was independently associated with inferior BMD and body composition, regardless of the amount of PE.
Physical exercise is associated with beneficial bone mineral density and body composition in patients with IBD despite the negative effects of the disease.