The aim of the study was to evaluate the influence of
prednisone therapy on selected parameters of bone metabolism [carboxyterminal propeptide of
type I procollagen (
PICP), carboxyterminal
pyridinoline crosslinked telopeptide of
type I collagen (ICTP),
alkaline phosphatase (AP),
parathormone (PTH), and calciuria (Cau) in children with
nephrotic syndrome. Twenty patients (aged 4-15 years, mean: 9.2 years) were treated with
prednisone. Blood and urine samples were taken: T0--before
prednisone treatment; T1--after two weeks of treatment with
prednisone 1-2 mg/kg/24 h; T2--after two weeks of treatment with
prednisone 1-2 mg/kg/48 h; T3--after 3 months of treatment with
prednisone; T6--in 6th month of treatment with
prednisone, at dose 0.2-0.4 mg/kg/48 h. Mean values of
PICP, ICTP, AP concentration, and
PICP/ICTP ratio found in the T1 period were significantly lower, and mean Cau value was higher in comparison to means of these parameters observed before
steroid treatment. After two weeks of
prednisone administered every 48 hours mean values of
PICP, ICTP concentrations and
PICP/ICTP ratio were significantly higher than in the T1 period of treatment. There were no significant differences in mean concentrations of PTH before and during everyday doses of
prednisone therapy. Mean value of PTH concentration decreased significantly during T2 in comparison with T1 period of
prednisone treatment. Our data demonstrate that short-term treatment with high daily doses of
prednisone in children with
nephrotic syndrome is associated with increase of calciuria and suppression of
serum markers of
type I collagen's turnover. Changes of
PICP, ICTP, and
PICP/ICTP ratio depend on a method of
steroid administration. Decreased
PICP/ICTP ratio during daily
steroid treatment may indicate stronger inhibition of bone formation than
bone resorption, but significance of
PICP/ICTP ratio in later phases of treatment needs further studies. Present study suggests that
prednisone influences bone metabolism directly rather than by stimulating the parathyroids.