Metabolic bone disease in pediatric intestinal failure patients: prevalence and risk factors

Patients with intestinal failure (IF) are known to have impaired absorption of nutrients required for maintenance of skeletal mass. Rates and risk factors of low bone mineral density (BMD) are unknown in pediatric IF patients.

Following IRB approval, patients with IF having undergone DXA scans were identified and laboratory, clinical, and nutritional intake variables were recorded. Low BMD was defined by a z-score of less than or equal to -2.0. Univariate followed by multivariable regression analysis was performed.

Sixty-five patients underwent a total of 99 routine DXA scans. Twenty-seven (41%) had vitamin D deficiency, 22 (34%) had low BMD, and nineteen (29%) had a history of fractures. Variables noted to be associated with low BMD (p<0.1) on univariate analysis were considered for multivariable regression. Multivariable regression identified WAZ and serum calcium levels (p<0.05) as independent predictors of low BMD z-score. None of the other evaluated factors were associated with the risk of low BMD. Low BMD was not associated with risk of fractures.

There is a significant incidence of low BMD in children with IF. WAZ and lower serum calcium levels are associated with risk of low BMD. Additional long term prospective studies are needed to further characterize the risk factors associated with low BMD.