Collagen metabolites in plasma and urine in osteogenesis imperfecta

Collagen metabolism was studied in 16 patients with osteogenesis imperfecta by measuring hyproprotein in plasma as well as free and peptide-bound hydroxyproline in plasma and urine. Results were compared to those for normal individuals as a function of age. All of the above parameters, with the exception of hyproprotein, were found to be age dependent. The hyproprotein level and amount of total urinary hydroxyproline were significantly higher in osteogenesis imperfecta patients. Values for these two measures of collagen metabolism appeared to be correlated. The results are discussed in relation to known peculiarities of collagen metabolism and structure in osteogenesis imperfecta.