Bone mineral and osteoporosis in aging rhesus monkeys.

55 femora of free ranging rhesus monkeys from the Caribbean Primate Research Center ranging in age from 2-25 years were analyzed using histology, density fractionation and chemical analysis and correlated with morphometric data. The vertebral density was determined by photon absorptiometry. 119 caudal vertebrae from the skeletal collection were analyzed chemically. Cortical mineral density and porosity increased with age, and vertebral density and cortical area increased with weight. There was significant sexual dimorphism in many histological variables reflecting size differences and cortical porosity was greater in males. The chemical analysis showed no influence of the diet on bone mineral but that Ca increase with age in females but not in males. Finally a subgroup of aged, animals had hypermineralized, and more porous bone. This subpopulation may prove to be a valuable model for senile osteoporosis.