P 5 0.013) and more likely to have a family history of osteoporosis (non-re-sponders 50%, responders 38.4%, P 5 0.002). Non-responders had numericallyhigher baseline BMD at all sites and numerically lower baseline levels of allbone turnover markers examined (NTX, CTX, BSAP, and P1NP). Non-respondersand responders did not differ in baseline fracture history or baseline use of to-bacco, alcohol, or caffeine. In conclusion, more patients receiving OW RIS thanOW ALN for 24 months were apparent BMD non-responders to therapy. Althoughsmall differences were seen in baseline characteristics between non-respondersand responders, identifying non-responders prior to initiation of bisphosphonatetherapy is likely to be difficult in the clinic.

Poster Number 213 Treatment

PATIENTS PREFERENCE FOR OSTEOPOROSISMEDICATIONS: PREFER-INTERNATIONAL

Jesus A Walliser, MD, Medical Director of the Clinical de MetabolismoMexico City Mexico

Susan C Bolge, Senior Research Director, Consumer Health Sciences, Princeton,NJ; Shuvayu s Sen, Director, Outcomes Research, Merck & Co., Inc., WhitehouseStation

Objective: To evaluate patients preferences for two different osteoporosis medica-tion profiles and the reasons for their preferences.

Methods: Physicians were randomly selected in France, Germany, Mexico,Spain and UK, and asked to consecutively refer 4 osteoporotic women aged 50years or older seen in their practices. These patients were asked over telephoneor face-to-face (Mexico) to indicate their preference between two hypothetical os-teoporosis medication profiles, A and B, for treatment of osteoporosis which differin efficacy (proven to reduce risk of spine and hip fracture vs. proven to reduceonly spine fracture), time on market (10 year vs. recently introduced), dosing fre-quency (weekly vs. monthly) and dosing procedure (30 vs. 60 minute wait).Patients were also asked to rate and rank the importance of each of these 4 attri-butes as reason for their preferences.

Results: A total of 3000 patients were interviewed of whom 1500 were on pre-scription treatment for osteoporosis while rest were not. A majority of thesepatients (78%) preferred drug A over drug B. Effectiveness in reducing risk offracture was most frequently (72%) ranked as the most important reason for theirpreference followed by time on market (13%), dosing frequency (9%) and dosingprocedure (6%).

Conclusion: The drug profile A with proven hip fracture reduction was chosenby majority of the patients over drug B. Effectiveness in reducing risk of fracturewas the most important reason for selection of a drug profile.

Poster Number 214 Treatment

MODELLING OF SERUM CTX LEVELS WITH DAILYAND MONTHLY ORAL IBANDRONATE

SL Silverman, MD, Medical Director, Osteoporosis Medical Center, BeverlyHills, CA USA

RJ Derman, Schutte Chair in Women s Health, School of Medicine, Universityof Missouri-Kansas City, Kansas City, MO; R Civitelli M Sydney and H Stella,Schoenberg Professor of Medicine, Washington University School of Medicine,St Louis, MO; MP Ettinger, Medical Director Emeritus, Radiant Research andRegional Osteoporosis Center of South Florida, Stuart, FL; R Gieschke, PharmaDevelopment, F Hoffmann-La Roche, Basel, Switzerland; KE Friend, SeniorMedical Director, Roche Laboratories Inc., Nutley, NJ; S Epstein, Professorof Medicine and Ge

In the MOBILE study, we graphed serum C-telopeptide crosslinks of type I colla-gen (sCTX) concentrations obtained prior to dosing at 3, 6, 12, and 24 months forthe two approved ibandronate doses, 2.5 mg daily and 150 mg monthly.[1] Thesevalues represent pre-dosing residual turnover inhibition. We utilized a model de-rived from data from 720 patients [2,3] to elucidate the between-dose sCTXprofile.

Excellent correlation was found between modeled values and empirical dataavailable from the MOBILE study. In the modeled sCTX profiles, both the dailyand monthly regimens deliver rapid CTX reduction. The monthly dose consis-tently reduces sCTX more than the daily dose. Both regimens continuously main-tain a level of reduction known to provide fracture protection, with sCTXconcentrations within the premenopausal normal range.

At steady state, a minimal variation in sCTX peak-trough fluctuation is pre-dicted with the monthly dose. This pharmacokinetic profile is associated with sig-nificant increases in BMD of a magnitude superior to that produced by daily 2.5mg. Thus, the temporary recovery of sCTX between monthly doses does not neg-atively affect efficacy, but rather suggests that bone mass can be increased withoutirreversibly or excessively depressing bone remodelling. Interestingly, a cyclicalCTX variation has been described in normal, menstruating women.[4].

1. Miller PD, et al. J Bone Miner Res 2005;20, 1315–1322.2. Gieschke R, et al. Osteoporos Int 2002;13(Suppl. 3), Abstract P36.3. Pillai G, et al. Br J Clin Pharmacol 2004;58, 618–631.4. Gorai I., et al. J Clin Endocrinol. Metab. 1998;83, 326–332.

Poster Number 215 Ultrasonometry

OSTEOPOROSIS RISK IN RESIDENTS OF ASSISTEDLIVING

Anne M Kenny, MD, Associate Professor of Medicine, Universityof Connecticut, CT US

Jo-Anne Smith, University of Connecticut; Kristen Annis, Universityof Connecticut Center on Aging; Emre Noteroglu, University of ConnecticutCenter on Aging; Kleppinger A, Dauser D, Walsh

The extended life expectancy with its resultant increase in frailty and disability hasled to the demand for a variety of long term care services and the rapid growth inassisted living (AL) facilities. Little has been done to assess osteoporosis (OP) riskin AL. 47 individuals (30 community-dwelling controls [C], 17 AL) have providedinformation on fracture history, OP evaluation, qualitative heel ultrasound (QUS),25-hydroxyvitamin D (25OHD), intact parathyroid hormone (PTH) and physicalfunction measures including walking speed, 6 minute walk, balance measures,Get Up and Go, and strength. The mean age was 81 1 6 years. Seven (23%) ofC and 9 (53%) AL reported fracture (p 5 .04). 7 (23%) C and 4 (24%) AL hadbeen diagnosed with OP (p 5 1.00). Twenty-three (77%) C and 6 (35%) ALreported bone density assessment (p 5 .005). Twelve (40%) C and 3 (18%) ALreported taking medications for OP (p 5 .11). QUS stiffness index was 85.6 1

24.3 C and 64.5 1 21.0 AL (p 5 .004). 25OHD levels were 48.8 1 14.8 ng/mlC and 26.0 1 14.0 ng/ml AL (p ! .001) and PTH levels were 54 1 24pg/ml C and 65 1 35 pg/ml AL (p 5 .278). Physical performance wasmore impaired in AL (p ! .05), except for hand grip strength (p 5 .450).

Residents of AL are less likely to be diagnosed with or receive treatment for OPdespite higher fracture rates, lower QUS and 25OHD levels. AL residents are moreimpaired in physical performance. OP risk assessment needs to be improved in ALresidents.

Poster Number 216 Ultrasonometry

HAS LEAD EXPOSURE BEEN OVERLOOKED AS A RISKFACTOR FOR LOW BONE MINERAL DENSITY

Selected for a Young Investigator Award

CA Muzytchuk, Technologist University of Rochester NY USA

RN Rosier, Unversity of Rochester; JR Campbell, University of Rochester;JE Puzas, University of Rochester

Lead exposure continues to be a serious environmental issue. Virtually all of thelead in humans resides in the mineral compartment of the skeleton and thusbone cells are exposed to sustained high levels. Laboratory and animal studiesevaluating cell function and trabecular bone volume have clearly demonstratedthe adverse effects of this toxic heavy metal. However, the few reports evaluatingit on human BMD measurements indicate little or no effect.

We have generated data to demonstrate that the early generation DXA scannersdisplay an artifactual overestimate of bone density that is not observable in ultra-sound (US) bone densitometers. Using specimens of bovine bone we were able toshow that adding lead (from 4 to 40 micrograms/gram of bone) increased the ap-parent density when measured on a Lunar DPX-L scanner but had no effect whenmeasured on the Lunar Achilles ultrasound densitometer. Moreover, we were ableto show a statistically significant inverse relationship (r 5 0.58; p 5 0.013) be-tween areal DXA density and ultrasound stiffness in lead exposed human subjects.That is, the ratio of DXA BMD/US stiffness decreased as a function of increasingblood lead levels. The study was performed in 19 subjects with blood lead levelsranging from 1 to 45 micrograms/dl.

Abstracts 251

Journal of Clinical Densitometry Volume 9, 2006