Cortical Thickness and Density Changes Over the Proximal Femur Resulting From Switching To or Combining With Teriparatide After Prior Treatment With Raloxifene or Alendronate
Category: Osteoporosis - Treatment (Clinical)
Plenary Sessions, Presentation Number: FR0374
Session: Welcome Reception & Plenary Poster Session
Friday, October 4, 2013 5:45 PM - 7:00 PM, Baltimore Convention Center, Discovery Hall-Hall C
Poster Sessions, Presentation Number: SA0374
Session: Poster Session I & Poster Tours
Saturday, October 5, 2013 12:00 PM - 2:00 PM, Baltimore Convention Center, Discovery Hall-Hall C
* , UNITED KINGDOM, , UNITED KINGDOM, Andrew Gee, University of Cambridge, , UNITED KINGDOM
For osteoporotic women undergoing treatment with an antiresorptive drug, such as Raloxifene (RLX) or Alendronate (ALN), a following treatment of Teriparatide (TPT) is sometimes recommended. In this case, a decision has to be made to either switch to or add TPT to the current treatment. The effects of adding versus switching to TPT have been previously studied by examining aBMD changes from DXA (Cosman, J Clin Endocrinol Metab 2009) and vBMD changes from QCT (Cosman, JBMR 2012.). These indicated a significant increase in density for all treatment groups, which was of greater magnitude when adding than when switching in that trial. However, previous studies have not separated cortical mass and thickness effects, nor assessed the distribution and extent of more localised changes.
In previous work, a method was presented to map the cortical thickness and mass from clinical CT over the surface of the proximal femur, accurate down to a thickness of 0.3mm (Treece, Med Image Anal 2010, 2012). We use this technique to analyse changes in cortical mass and thickness from QCT scans acquired 18 months after switching to TPT after 12 months prior treatment with RLX (25 women aged 69±9 years) or ALN (40 women aged 69±8 years) and 18 months after combining a previous treatment of RLX (28 women aged 67±8 years) and ALN (41 women aged 67±10 years) with TPT. Fig. 1 shows the mean thickness and mass changes compared to baseline, and the significance of such changes, for each of the four treatment groups.
Averaging these results over the entire proximal femur reveals global mass increases for the add group (2.8% RLX, 1.6% ALN) which are significantly (p<0.001) greater than for the switch group (0.7% RLX, -0.8% ALN). For cortical thickness, the increases for the add group (3.7% RLX, 1.9% ALN) are not significantly different from the switch group (1.7% RLX, 3.0% ALN).
These results are broadly in agreement with previously published work, though we here reveal significant mass increases for the add compared to the switch groups, which are primarily located at the posterior side of the trochanter. Hence this study provides new insights into the effects of switching versus adding Teriparatide on the cortical thickness and mass changes.
A. Gee, Eli Lilly: Research Grants. A. Gee, Amgen: Research Grants. K. Poole, Amgen: Research Grants. K. Poole, Eli Lilly: Research Grants. K. Poole, Amgen: Non-remunerative positions of influence such as officer, board member, trustee, or public spokesperson. G. Treece, Amgen: Research Grants. G. Treece, Eli Lilly: Research Grants.
* Presenting Authors(s):
, UNITED KINGDOM