Meta-analysis of the association between IL-6 −174G/C polymorphism and BMD stratified according to menopausal status (CC+CG vs. GG): (A) distal radius, (B) Ward's triangle, (C) trochanter, (D) femoral neck, (E) total hip, (F) lumbar spine. For each study, the estimate of mean BMD difference and its 95% CI is plotted with a diamond (♦) and a horizontal line. The size of a box (■) is proportional to the weight that the study has in calculating the summary effect estimate (⋄). The center of the diamond indicates the WMD and the ends of the diamond correspond to the 95% CI.