Impairment of bone mass development in children with chronic cholestatic liver disease

To analyse aspects of mineral metabolism, bone mineral density (BMD), bone remodelling activity and serum IGF-1 levels in children with chronic cholestatic disease (CCLD).

A total of 13 children with chronic cholestatic liver disease (CCLD; mean age 7.2 +/- 4.8 years) and 22 control subjects (mean age 7.6 +/- 4.5 years) were studied. Serum osteocalcin, bone alkaline phosphatase (BAP), 25-hydroxyvitamin D, PTH and IGF-1 levels and urinary deoxypyridinoline were determined. BMD was measured by dual-energy X-ray absorptiometry in the lumbar spine, total hip and whole body. Lumbar spine areal BMD was converted mathematically to apparent volumetric BMD (aBMD) and corrected for the bone age of the patient.

Z-score of lumbar spine BMD was lower in CCLD patients than in controls and the difference was maintained when BMD was expressed as aBMD (control = 0.107 +/- 0.02 vs. CCLD = 0.092 +/- 0.02 g/cm(3), P < 0.05) and after conversion for bone age. All participants showed normal 25-hydroxyvitamin D levels, with no significant differences in serum levels of 25-hydroxyvitamin D and PTH between groups. IGF-1 levels were significantly lower in the CCLD group (control = 19.6 +/- 16.8 vs. CCLD = 6.4 +/- 7.6 nmol/l, P < 0.05) and a positive correlation was observed between whole body BMD and IGF-1 in this group.

These results indicate that CCLD limits bone mass gain in children. A reduction in hepatic IGF-1 production might be responsible, at least in part, for the low bone mass of these patients.