Bone mineral density in patients with classic galactosaemia.

BACKGROUND

Diminished bone mineral density (BMD) is a well known complication in women with classic galactosaemia caused by premature ovarian failure. Diminished BMD in prepubertal patients of either sex has, however, only been reported once.

OBJECTIVE

To assess BMD in children with classic galactosaemia.

METHODS

Eleven treated patients (five males, six females, aged 2-18 years) had BMD determined by dual energy x ray absorptiometry. Two measurements were performed, an areal measurement of the total body and a volumetric measurement of the femoral neck. Results were expressed as Z scores. Dietary calcium intake, blood calcium, phosphate, vitamin D, parathormone, and markers of bone formation (bone alkaline phosphatase, osteocalcin) and bone resorption (NTX) were determined.

RESULTS

All patients had a significantly diminished BMD. Mean Z score of the volumetric BMD was -1.76 (range -0.7 to -3.3), and of the areal BMD -0.99 (range -0.5 to -1.4). Dietary calcium intake and calcium, phosphate, parathormone, bone alkaline phosphatase, vitamin D metabolites, and osteocalcin (free and carboxylated) were normal in all patients. NTX levels in blood were significantly lower (p < 0.001) than in control subjects.

CONCLUSIONS

BMD in this group of children of both sexes with classic galactosaemia under dietary treatment was decreased. Lower NTX levels in galactosaemics point to an apparent decreased bone resorption.