Racial difference in the correlates of bone mineral content/density and age at peak among reproductive-aged women

Racial/ethnic differences were observed in age at peak bone density and their correlates, with whites peaking at least 5 years earlier at the femoral neck than black and Hispanic women. Race-specific standards generated in this study could be useful when interpreting bone densitometry data in young women. Introduction: The influence of race/ethnicity on bone measurements has not been widely examined. This study identifies age and amount of bone accumulated at peak density and their correlates by race/ethnicity. Methods: Bone mineral content (BMC) and bone mineral density (BMD) of the spine and femoral neck were measured by dual X-ray absorptiometry in 708 white, black, and Hispanic reproductive-aged women. Race-specific nonlinear models were used to describe the relationship between age and bone measurements, after adjusting for body weight and height. Log-transformed bone measurements were used to determine predictors based on multiple linear regression. Results: Predictors, which were race and site specific, included age, age at menarche, body weight, height, months of depot medroxyprogesterone acetate use, weight-bearing exercise, and alcohol use. Women of all races gained BMC and BMD at the spine up to 30-33 years of age. BMC and BMD of the femoral neck peaked among white women earlier (≤16 years) than among blacks (BMC 22 years; BMD 21 years) and Hispanics (BMC 29 years; BMD 20 years). Conclusion: Age at peak bone mass and its correlates differ by race/ethnicity. Race-specific standards generated in this study could be useful when interpreting bone densitometry data in young women.