Bone ALP and OC reference standards in adult baboons (Papio hamadryas) by sex and age.

BACKGROUND: Serum bone-specific alkaline phosphatase (bone ALP) and intact osteocalcin (OC) are markers of bone formation of interest because of easy measurability and potential utility as identifiers of those at risk for fractures associated with bone metabolism disorders. The baboon (Papio hamadryas) exhibits extensive biological similarities to humans making it particularly well suited to studies of bone maintenance and turnover. METHODS: We measured serum bone ALP and OC in 591 baboons. RESULTS: We report significant sex and age effects and present reference ranges and percentile distributions for these markers. CONCLUSIONS: This study is the first to characterize normal variation in bone ALP and OC levels in baboons and to assess the age and sex effects on this variation. The results provide much-needed reference standards to allow researchers to evaluate the status of their animals in cross-sectional studies and assess the meaning of changes in bone ALP and OC levels in longitudinal studies.