Is there a positive association between mammographic density and bone mineral density?
We read with interest the issues raised by Dite and coworkers [1] in their response to our recent research article [2], and we are pleased to address them. In their letter, Dite and colleagues present previously unpublished results that reveal no association between bone mineral density and mammographic density in female twins. Relevant information about the characteristics of the study participants, the methods of measuring mammographic density, and the timing of the mammograms in relation to the bone density assessment are not supplied. Differences in study samples, methods, and sample size could account for the difference between their results and ours. Dite and coworkers [1] posit several explanations for the apparent discrepancy between their study and ours. First, they suggest that our results were an artefact of our performance of multiple analyses. In fact, we performed only three regression analyses, and these analyses were based on clearly stipulated a priori hypotheses. We b
