Decreased trabecular bone mineral density in patients with phenylketonuria measured by peripheral quantitative computed tomography.

The bone mineral density (BMD) of 14 children, adolescents, and adults with phenylketonuria (PKU) on dietary treatment (age 5-28 y; 6F, 8M) was investigated using peripheral quantitative computed tomography (pQCT) of the distal radius. BMD of total (TBMD) and spongy bone (SBMD) were compared to those of healthy gender-, age-, weight- and height-matched controls. We found a significant decrease of SBMD in patients with PKU while TBMD was only slightly decreased, reaching no statistical significance. These results indicate minor changes of BMD in patients with PKU under treatment, which are more accentuated in the trabecular bone compartment. One additional patient who was untreated until the pQCT investigation at the age of 10 y also showed markedly decreased SBMD and TBMD.