A nonhuman primate model of age-related bone loss: A longitudinal study inmale and premenopausal female rhesus monkeys

Aging is associated with gradual bone loss in men and premenopausal women, with an accelerated rate of loss after menopause in women. Although many st udies have investigated bone loss due to surgically induced estrogen deplet ion, little is known regarding normal age-related changes in bone mass in a nimal models, We used dual-energy X-ray absorptiometry (DXA) to measure bon e mineral density (BMD), bone mineral content (BMC), and projected area (PA ) at four skeletal sites over 4 years in 20 premenopausal female (8-23 year s) and 29 male (8-27 years) rhesus monkeys (Macaca mulatta). Forearm BMD de clined with age in both male and female monkeys, Lean mass was positively a ssociated with BMD at all sites in males acid with the distal radius in fem ales, Serum osteocalcin declined and urinary cross-links increased with age in males but not females. Serum 25-hydroxyvitamin D concentrations decreas ed with ape in females, and a similar trend was observed in males. In concl usion, an age-related decline in forearm BMD was observed in male and femal e rhesus monkeys, Total body BMC declined over time in older females, with a similar trend in males. Changes in markers of bone turnover with age were also observed in male monkeys. The results of this longitudinal study sugg est that the rhesus monkey is a potential model for age-related changes in the human skeleton. (Bone 28:395-302; 2001) (C) 2001 by Elsevier Science In c. All rights reserved.