[Biochemical markers of bone in steroid (glucocorticoid)-induced osteoporosis (GIOP)]

The pathogenesis of steroid (glucocorticoid)-induced bone loss is still unclear. But, bone formation is known to be quickly decreased in early stage of steroid administration, followed by reduction of bone resorption. The reductions of bone resorption markers are small if low dose of steroid is administered, and the changes are accelerated dose dependently, probably due to secondary hyperparathyroidism. The short term intravenous administration of steroid induces transient suppression of bone turnover even in high dose administration. Therefore, it seems that the degree of changes in bone turnover markers induced by steroid is affected not only by the dosage but also by the period of steroid administration. The reduction of osteocalcin is more sensitive than bone alkaline phosphatase for the detection of the suppression of bone formation, although metabolism of osteocalcin induced by steroid may influence the change.