Bone mineral status in children with phenylketonuria under treatment.

Bone mineral status was assessed in 48 children with phenylketonuria (PKU) (20M, 28 F, aged 2.5-17 y). Bone density was measured in the distal third of the right forearm using single photon absorptiometry and was expressed as +/-SD with respect to age- and gender-matched controls. Serum calcium (Ca), magnesium (Mg), phosphorus (P), alkaline phosphatase (ALP), parathyroid hormone and 25-hydroxyvitamin D were measured in morning samples. The ratios of urinary Ca/creatinine (UCa/UCr), UP/UCr, UMg/UCr and hydroxyproline (OH-Pr)/UCr were calculated in urine samples collected over a period of 3 h. Patients' data were compared with those of 50 controls (22 M, 28 F, aged 3-15 y). The data showed severe osteopenia (below -2SD) in 22/48 patients. Bone loss was more prominent in patients over 8 y old. Bone density correlated significantly with age (r=-0.56,p < 0.001) and with Phe (r=-0.49, p < 0.007) but did not correlate with the other biochemical indices studied. Comparing PKU children with controls, significantly higher serum calcium and magnesium (p=0.04, p < 0.001, respectively), lower ALP (p=0.01), higher UCa/UCr ratio (p < 0.001), lower UP/UCr (p < 0.001) and lower UOH-Pr/UCr (p < 0.001) were found. Dietary compliance was poor in patients over the age of 8y, as only 3/22 of < or = 8y had mean serum phenylalanine >10mgdl(-1), in contrast to 21/26 in the older group. It is clear from the data that osteopenia is commonly found in PKU patients from early life. The biochemical data indicate a metabolic state of low bone turnover in PKU patients. In conclusion, a better, more restricted diet may correct osteopenia.

Treatment of osteopenia in children with insulin-dependent diabetes mellitus: the effect of 1 alpha-hydroxyvitamin D3.

UNLABELLED: Twelve children (8 boys and 4 girls) with insulin-dependent diabetes mellitus (IDDM), aged 9-15 years, received 1 alpha-hydroxyvitamin D3 (1 alpha-OHD3) in a dose of 0.05 microgram/kg per day for 1 year. Duration of disease varied between 2.8 and 9 years. Bone density was determined in the distal third of forearm using single photon absorptiometry, and was expressed as standard scores (+/- SD) with respect to sex- and age-matched controls. Bone density measurements and ultrasound studies of the kidneys were performed at 0, 6 and 12 months. Serum calcium, ionized calcium, phosphorus, magnesium, creatinine, alkaline phosphatase, glycosylated haemoglobin in morning blood samples and urinary Ca, P, Mg, and hydroxyproline were regularly determined. One patient was excluded from the study because of hypercalciuria and one because of lack of compliance. Bone density increased significantly after 6 and 12 months of 1 alpha-OHD3 administration (P = 0.015, P < 0.001 respectively). None of the biochemical parameters changed significantly. CONCLUSION: Osteopenia is not uncommon in children and adolescents with IDDM. In 10 children with IDDM and osteopenia the administration of 1 alpha-OHD3 for 1 year corrected bone loss.

Inhibitors of stone formation in hypercalciuric children with and without stone disease.

The extretion of two inhibitors of urinary stone formation (citrate, magnesium) was evaluated in 71 hypercalciuric children and 50 controls. Patients were classified into two groups: 42 nonstone former (NSF), 22 boys and 20 girls, 3-14 years old, and 29 stone formers (SF), 18 boys and 11 girls, 2.5-18 years old. Our study was unable to show significant differences in magnesium and citrate urinary outputs between controls and patient groups. The Mg/Ca ratio was found significantly lower in hypercalcuric children than in controls (p less than 0.001), but not between NSF and SF patients. Our data demonstrated that both NSF and SF groups had a significantly lower citrate/Ca ratio than controls (p less than 0.001), also it was lower in SF than in NSF (p less than 0.05). We found no significant difference in citrate excretion between boys and girls neither in patients nor in controls.

Electrophysiological study (EEG, VEPs, BAEPs) in patients with Charcot Marie Tooth (type HMSN I) disease.

A laboratory investigation consisting of EEG recordings, BAEPs and VEPs evaluation as well as estimation of the facial nerve distal latency was performed in 9 patients who had Charcot Marie Tooth (type HMSN I) disease. 3 patients showed VEP's abnormalities (2 of them had prolonged P100 latency and one had an abnormal interocular latency difference). Another patient showed an upper normal limit value in the interocular latency difference. Abnormal BAEPs were found in 8 patients (one had I-III/IPLD prolonged, 2 of them had the latency of wave I prolonged and the remaining 6 had no readable or repeatable responses unilaterely or bilaterally). 7 out of 9 patients had the facial nerve distal latency prolonged, without any evident clinical facial weakness. Abnormal EEG recordings were found in 2 of all tested patients. Our results provide some evidence that in Charcot Marie Tooth disease the involvement of the II, VII and VIII nerves is more frequent than clinically expected and is probably related to a demyelinated process.