Summary characteristics of the study populations.

Mean age, height, weight, and BMI are shown for each study with standard deviations (SD) in parenthesis. Mean of adjusted hip BMD and spine BMD is shown (SD) and the age-range of each study. Hong Kong-II: low BMD subjects are defined as an individual having BMD Z-score ≤−1.28 at either lumbar spine (LS) or femoral neck (FN), which is equivalent to the lowest 10% of the total population, while high BMD subjects are individuals with BMD Z-scores ≥ +1.0 at either of the two skeletal sites.