Changes in diaphyseal cross-sectional properties with age in macaques

Area of Science:

• Primatology
• Osteology
• Skeletal Biology

Background:

• Bone remodeling and structural changes are key aspects of skeletal aging.
• Understanding primate skeletal aging provides insights into human bone health.

Purpose of the Study:

• To quantify age-related changes in long bone cross-sectional properties in rhesus macaques.
• To compare macaque skeletal aging patterns with those of other primates, including humans.

Main Methods:

• Peripheral quantitative computed tomography (pQCT) analyzed midshaft bone sections from 115 macaques (7-31 years).
• Linear regressions assessed age-related changes in bone properties.
• Analysis of covariance compared age-related changes between sexes.

Main Results:

• Medullary area increased, while cortical area decreased with age in both sexes.
• Torsional and bending strength showed age-related decline primarily in female macaque hindlimb bones.
• Volumetric bone mineral density (vBMD) decreased with age, but the overall change was modest (<10% material strength loss).
• No significant sex-based differences were found in the rate of skeletal property changes with age.

Conclusions:

• Macaque skeletal aging shares similarities with other primates but differs in sex-specific bone loss patterns compared to humans.
• The extended post-reproductive period in human females contributes to greater bone loss than observed in macaques.