Effects of age and sex on bone density in the rhesus monkey.

Normative data for bone density of cortical and trabecular bone in the rhesus monkeys is described in the present study. Changes of bone density (g/cm2) for the humerus, the third lumbar vertebra, and the eighth caudal vertebra of the rhesus monkey show differences due to age and sex of the subjects (males n = 57; females n = 49). In general, bone density increased with age and then reached a plateau at approximately 3 to 4 years in all bones measured. In the humerus, older females (greater than 30 years) had a significantly lower bone density than females of 4 to 24 years, while bone density in older males did not decrease. In the vertebrae, some evidence of advanced age-related decreases in bone density was found in both sexes. These results indicate that the rhesus monkey shows a natural pattern of change in bone mineralization which parallels that seen in humans. The physiological similarity between the rhesus monkey and human further suggests a potential role for this species in the future investigation of osteoporosis.