Racial differences in pre- and postmenopausal bone homeostasis: association with bone density.

Area of Science:

• Endocrinology
• Bone Biology
• Racial Health Disparities

Background:

• Significant disparities exist in fracture incidence and bone mass between women of European (white) and African (black) ancestry.
• The underlying causes for these racial differences in bone health remain largely unknown.

Purpose of the Study:

• To investigate whether racial variations in bone mass are linked to differences in bone turnover mechanisms.
• To compare bone mineral loss rates and bone density between white and black women across different menopausal stages.

Main Methods:

• Measured serum osteocalcin, serum alkaline phosphatase, urinary calcium, hydroxyproline, and sodium excretion in 263 healthy women.
• Assessed dietary calcium and vitamin D intake.
• Cross-sectionally measured radial and spinal bone density.

Main Results:

• Lower bone resorption markers (urinary calcium and hydroxyproline) observed in black women compared to white women.
• Bone formation markers (alkaline phosphatase and osteocalcin) were similar in premenopausal women, but osteocalcin was lower in peri- and postmenopausal black women.
• Radial bone density increased with age in premenopausal black women but not white women; postmenopausal radial bone loss was slower in black women.

Conclusions:

• Racial differences in bone turnover mechanisms may contribute to disparities in bone mass and loss.
• Black women demonstrate a slower rate of radial bone loss after menopause compared to white women.
• Further research is needed to elucidate the specific mechanisms driving these observed racial differences in bone health.