Body Mass and Composition Affect Bone Density in Recently Diagnosed Inflammatory Bowel Disease: The Manitoba IBD Cohort Study

Background: This prospective study was undertaken to clarify the role of body mass and composition as a determinant of bone mineral density (BMD) in recently diagnosed inflammatory bowel disease (IBD) Methods: A nested subgroup of 101 adult subjects of the population-based Manitoba IBD Cohort Study were enrolled. Baseline BMD and body composition were measured and repeated 2.3 +/- 0.3 years later. Results: Greater weight, height. and body mass measurements were positively correlated with bone density at all sites (P < 0.01). Although both fat tissue and lean tissue showed positive relationships with BMD, lean tissue showed a much stronger correlation than fat tissue, especially for the total hip (r = 0.66, P < 0.001 versus r = 0.23, P < 0.05) and total body measurements (r = 0.59, P < 0.001 versus r = 0.04, P NS). Increase (or decrease) in hip bone density was strongly associated with an increase (or decrease) in all body mass variables (r = 0.49-0.54, P < 0.001). Conclusions: Measures of body mass are important determinants of baseline BMD in recently diagnosed IBD patients. Furthermore, change in body mass is correlated with change in BMD, especially at the total hip. Early optimization and maintenance of nutrition and body weight, particularly toward lean tissue mass, may play an important role in preventing IBD-related bone disease.