Background and aim: Low bone mineral density (BMD) has recently been recognized as a potential health problem in children with inflammatory bowel disease (IBD). Our aim was to investigate the familial resemblance of BMD in pediatric patients with IBD.
Patients and methods: In this population-based study from western Sweden, we assessed 144 children with IBD, 83 with ulcerative colitis, 45 with Crohn disease, 16 with indeterminate colitis, and their parents (136 mothers and 130 fathers) with dual-energy X-ray absorptiometry (DEXA). After adjustment for sex, age, weight, height, and parental IBD, we correlated the BMD of the patients to the BMD of their mothers, fathers, and the midparent value ([mother's BMD + father's BMD]/2) at different skeletal sites and calculated the Pearson correlation coefficient (r) to evaluate the extent of familial resemblance.
Results: The BMD of the children with IBD was clearly related to the BMD of their parents. The strongest correlation was found in the femoral neck with r = 0.55 (P < 0.001, 95% CI 0.41-0.66) between BMD of the children and the midparent value. The group of children with IBD had an odds ratio of 5.96 for decreased BMD (lumbar spine z score < -1 standard deviation) given that decreased BMD was diagnosed in both parents.
Conclusions: We conclude that BMD in children and adolescents with IBD is significantly related to that of their parents. In a clinical setting, it may be helpful to assess the parents of children with IBD with DEXA to interpret the children's DEXA measurements.