Taken together, our data strongly suggest that OI animals have alterations in whole body energy metabolism that are consistent with the action of undercarboxylated osteocalcin.
Compared to healthy controls, patients with OI had decreased levels of PINP (-22.7%, p<0.0001), increased osteocalcin (+73%, p<0.0001) and increased Col I helical peptide (+58%, p=0.0007).
We measured serum levels of total alkaline phosphatase activity, osteocalcin, carboxy-terminal propeptide of human type I procollagen (PICP), tartrate-resistant acid phosphatase activity (TRAP), and the fasting urinary hydroxyproline/creatinine ratio (OHPr/Cr) in seven affected members (four men, three women; age, 43.3 +/- 16.6 years [mean +/- SD]) of a family with clinically diagnosed type I-A osteogenesis imperfecta (OI) and in eight (five men, three women) normal age-matched (38.2 +/- 10.3) relatives.
Pilot studies of short-term growth hormone therapy in patients with achondroplasia and hypochondroplasia and nasal-osteocalcin therapy in osteogenesis imperfecta patients has been described, but the long-term effectiveness of these treatments remains to be determined.