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Featured researches published by Marc-Antoine Krieg.


Journal of Bone and Mineral Research | 2011

Bone microarchitecture assessed by TBS predicts osteoporotic fractures independent of bone density: The manitoba study

Didier Hans; Andrew L. Goertzen; Marc-Antoine Krieg; William D. Leslie

The measurement of BMD by dual‐energy X‐ray absorptiometry (DXA) is the “gold standard” for diagnosing osteoporosis but does not directly reflect deterioration in bone microarchitecture. The trabecular bone score (TBS), a novel gray‐level texture measurement that can be extracted from DXA images, correlates with 3D parameters of bone microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow‐up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women.


Journal of Clinical Densitometry | 2008

Quantitative Ultrasound in the Management of Osteoporosis: The 2007 ISCD Official Positions

Marc-Antoine Krieg; Reinhart Barkmann; Stefano Gonnelli; Alison Stewart; Douglas C. Bauer; Luis Del Rio Barquero; Jonathan J. Kaufman; Roman Lorenc; Paul D. Miller; Wojciech P. Olszynski; Catalina Poiana; Anne-Marie Schott; E. Michael Lewiecki; Didier Hans

Dual-energy X-ray absorptiometry (DXA) is commonly used in the care of patients for diagnostic classification of osteoporosis, low bone mass (osteopenia), or normal bone density; assessment of fracture risk; and monitoring changes in bone density over time. The development of other technologies for the evaluation of skeletal health has been associated with uncertainties regarding their applications in clinical practice. Quantitative ultrasound (QUS), a technology for measuring properties of bone at peripheral skeletal sites, is more portable and less expensive than DXA, without the use of ionizing radiation. The proliferation of QUS devices that are technologically diverse, measuring and reporting variable bone parameters in different ways, examining different skeletal sites, and having differing levels of validating data for association with DXA-measured bone density and fracture risk, has created many challenges in applying QUS for use in clinical practice. The International Society for Clinical Densitometry (ISCD) 2007 Position Development Conference (PDC) addressed clinical applications of QUS for fracture risk assessment, diagnosis of osteoporosis, treatment initiation, monitoring of treatment, and quality assurance/quality control. The ISCD Official Positions on QUS resulting from this PDC, the rationale for their establishment, and recommendations for further study are presented here.


Journal of Clinical Densitometry | 2011

Correlations Between Trabecular Bone Score, Measured Using Anteroposterior Dual-Energy X-Ray Absorptiometry Acquisition, and 3-Dimensional Parameters of Bone Microarchitecture: An Experimental Study on Human Cadaver Vertebrae

Didier Hans; Nicole Barthe; Stephanie Boutroy; Laurent Pothuaud; Renaud Winzenrieth; Marc-Antoine Krieg

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to dual-energy X-ray absorptiometry (DXA) images. Significant correlations between TBS and standard 3-dimensional (3D) parameters of bone microarchitecture have been obtained using a numerical simulation approach. The main objective of this study was to empirically evaluate such correlations in anteroposterior spine DXA images. Thirty dried human cadaver vertebrae were evaluated. Micro-computed tomography acquisitions of the bone pieces were obtained at an isotropic resolution of 93μm. Standard parameters of bone microarchitecture were evaluated in a defined region within the vertebral body, excluding cortical bone. The bone pieces were measured on a Prodigy DXA system (GE Medical-Lunar, Madison, WI), using a custom-made positioning device and experimental setup. Significant correlations were detected between TBS and 3D parameters of bone microarchitecture, mostly independent of any correlation between TBS and bone mineral density (BMD). The greatest correlation was between TBS and connectivity density, with TBS explaining roughly 67.2% of the variance. Based on multivariate linear regression modeling, we have established a model to allow for the interpretation of the relationship between TBS and 3D bone microarchitecture parameters. This model indicates that TBS adds greater value and power of differentiation between samples with similar BMDs but different bone microarchitectures. It has been shown that it is possible to estimate bone microarchitecture status derived from DXA imaging using TBS.


Journal of Clinical Densitometry | 2009

Evaluation of the Potential Use of Trabecular Bone Score to Complement Bone Mineral Density in the Diagnosis of Osteoporosis: A Preliminary Spine BMD–Matched, Case-Control Study

Laurent Pothuaud; Nicole Barthe; Marc-Antoine Krieg; Nadia Mehsen; Pascal Carceller; Didier Hans

The trabecular bone score (TBS) is a new parameter that is determined from gray-level analysis of dual-energy X-ray absorptiometry (DXA) images. It relies on the mean thickness and volume fraction of trabecular bone microarchitecture. This was a preliminary case-control study to evaluate the potential diagnostic value of TBS as a complement to bone mineral density (BMD), by comparing postmenopausal women with and without fractures. The sample consisted of 45 women with osteoporotic fractures (5 hip fractures, 20 vertebral fractures, and 20 other types of fracture) and 155 women without a fracture. Stratification was performed, taking into account each type of fracture (except hip), and women with and without fractures were matched for age and spine BMD. BMD and TBS were measured at the total spine. TBS measured at the total spine revealed a significant difference between the fracture and age- and spine BMD-matched nonfracture group, when considering all types of fractures and vertebral fractures. In these cases, the diagnostic value of the combination of BMD and TBS likely will be higher compared with that of BMD alone. TBS, as evaluated from standard DXA scans directly, potentially complements BMD in the detection of osteoporotic fractures. Prospective studies are necessary to fully evaluate the potential role of TBS as a complementary risk factor for fracture.


Osteoporosis International | 2012

Quantitative ultrasound of the heel and fracture risk assessment: an updated meta-analysis

Alireza Moayyeri; Judith E. Adams; Robert A. Adler; Marc-Antoine Krieg; Didier Hans; Juliet Compston; Em Lewiecki

SummaryMeta-analysis of prospective studies shows that quantitative ultrasound of the heel using validated devices predicts risk of different types of fracture with similar performance across different devices and in elderly men and women. These predictions are independent of the risk estimates from hip DXA measures.IntroductionClinical utilisation of heel quantitative ultrasound (QUS) depends on its power to predict clinical fractures. This is particularly important in settings that have no access to DXA-derived bone density measurements. We aimed to assess the predictive power of heel QUS for fractures using a meta-analysis approach.MethodsWe conducted an inverse variance random effects meta-analysis of prospective studies with heel QUS measures at baseline and fracture outcomes in their follow-up. Relative risks (RR) per standard deviation (SD) of different QUS parameters (broadband ultrasound attenuation [BUA], speed of sound [SOS], stiffness index [SI], and quantitative ultrasound index [QUI]) for various fracture outcomes (hip, vertebral, any clinical, any osteoporotic and major osteoporotic fractures) were reported based on study questions.ResultsTwenty-one studies including 55,164 women and 13,742 men were included in the meta-analysis with a total follow-up of 279,124 person-years. All four QUS parameters were associated with risk of different fracture. For instance, RR of hip fracture for 1 SD decrease of BUA was 1.69 (95% CI 1.43–2.00), SOS was 1.96 (95% CI 1.64–2.34), SI was 2.26 (95%CI 1.71–2.99) and QUI was 1.99 (95% CI 1.49–2.67). There was marked heterogeneity among studies on hip and any clinical fractures but no evidence of publication bias amongst them. Validated devices from different manufacturers predicted fracture risks with similar performance (meta-regression p values > 0.05 for difference of devices). QUS measures predicted fracture with a similar performance in men and women. Meta-analysis of studies with QUS measures adjusted for hip BMD showed a significant and independent association with fracture risk (RR/SD for BUA = 1.34 [95%CI 1.22–1.49]).ConclusionsThis study confirms that heel QUS, using validated devices, predicts risk of different fracture outcomes in elderly men and women. Further research is needed for more widespread utilisation of the heel QUS in clinical settings across the world.


Journal of Bone and Mineral Research | 2006

Prediction of Hip Fracture Risk by Quantitative Ultrasound in More Than 7000 Swiss Women ≥70 Years of Age: Comparison of Three Technologically Different Bone Ultrasound Devices in the SEMOF Study†‡

Marc-Antoine Krieg; Jacques Cornuz; Christiane Ruffieux; Guy van Melle; Daniel Büche; Maximilian A. Dambacher; Didier Hans; Florian Hartl; Hansjörg Häuselmann; Marius E. Kraenzlin; Kurt Lippuner; Maurus Neff; Pierro Pancaldi; René Rizzoli; Franco Tanzi; Robert Theiler; Alan Tyndall; Claus Wimpfheimer; Peter Burckhardt

To compare the prediction of hip fracture risk of several bone ultrasounds (QUS), 7062 Swiss women ≥70 years of age were measured with three QUSs (two of the heel, one of the phalanges). Heel QUSs were both predictive of hip fracture risk, whereas the phalanges QUS was not.


Journal of Clinical Densitometry | 2008

Peripheral dual-energy X-ray absorptiometry in the management of osteoporosis: the 2007 ISCD Official Positions

Didier Hans; John A. Shepherd; Elliott N. Schwartz; David M. Reid; Glen Blake; John N. Fordham; Thomas Fuerst; Peyman Hadji; Akira Itabashi; Marc-Antoine Krieg; E. Michael Lewiecki

Peripheral assessment of bone density using photon absorptiometry techniques has been available for over 40 yr. The initial use of radio-isotopes as the photon source has been replaced by the use of X-ray technology. A wide variety of models of single- or dual-energy X-ray measurement tools have been made available for purchase, although not all are still commercially available. The Official Positions of the International Society for Clinical Densitometry (ISCD) have been developed following a systematic review of the literature by an ISCD task force and a subsequent Position Development Conference. These cover the technological diversity among peripheral dual-energy X-ray absorptiometry (pDXA) devices; define whether pDXA can be used for fracture risk assessment and/or to diagnose osteoporosis; examine whether pDXA can be used to initiate treatment and/or monitor treatment; provide recommendations for pDXA reporting; and review quality assurance and quality control necessary for effective use of pDXA.


Journal of Bone and Mineral Research | 2008

Assessment of the 10-Year Probability of Osteoporotic Hip Fracture Combining Clinical Risk Factors and Heel Bone Ultrasound: The EPISEM Prospective Cohort of 12,958 Elderly Women†‡

Didier Hans; Claire Durosier; John A. Kanis; Helena Johansson; Anne-Marie Schott-Pethelaz; Marc-Antoine Krieg

This study aimed to develop a hip screening tool that combines relevant clinical risk factors (CRFs) and quantitative ultrasound (QUS) at the heel to determine the 10‐yr probability of hip fractures in elderly women. The EPISEM database, comprised of ∼13,000 women ≥70 yr of age, was derived from two population‐based white European cohorts in France and Switzerland. All women had baseline data on CRFs and a baseline measurement of the stiffness index (SI) derived from QUS at the heel. Women were followed prospectively to identify incident fractures. Multivariate analysis was performed to determine the CRFs that contributed significantly to hip fracture risk, and these were used to generate a CRF score. Gradients of risk (GR; RR/SD change) and areas under receiver operating characteristic curves (AUC) were calculated for the CRF score, SI, and a score combining both. The 10‐yr probability of hip fracture was computed for the combined model. Three hundred seven hip fractures were observed over a mean follow‐up of 3.2 yr. In addition to SI, significant CRFs for hip fracture were body mass index (BMI), history of fracture, an impaired chair test, history of a recent fall, current cigarette smoking, and diabetes mellitus. The average GR for hip fracture was 2.10 per SD with the combined SI + CRF score compared with a GR of 1.77 with SI alone and of 1.52 with the CRF score alone. Thus, the use of CRFs enhanced the predictive value of SI alone. For example, in a woman 80 yr of age, the presence of two to four CRFs increased the probability of hip fracture from 16.9% to 26.6% and from 52.6% to 70.5% for SI Z‐scores of +2 and −3, respectively. The combined use of CRFs and QUS SI is a promising tool to assess hip fracture probability in elderly women, especially when access to DXA is limited.


IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control | 2008

The clinical use of quantitative ultrasound (QUS) in the detection and management of osteoporosis

Didier Hans; Marc-Antoine Krieg

For the detection and management of osteoporosis and osteoporosis-related fractures, quantitative ultrasound (QUS) is emerging as a relatively low-cost and readily accessible alternative to dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) in certain circumstances. The following is a brief, but thorough review of the existing literature with respect to the use of QUS in 6 settings: 1) assessing fragility fracture risk; 2) diagnosing osteoporosis; 3) initiating osteoporosis treatment; 4) monitoring osteoporosis treatment; 5) osteoporosis case finding; and 6) quality assurance and control. Many QUS devices exist that are quite different with respect to the parameters they measure and the strength of empirical evidence supporting their use. In general, heel QUS appears to be most tested and most effective. Overall, some, but not all, heel QUS devices are effective assessing fracture risk in some, but not all, populations, the evidence being strongest for Caucasian females over 55 years old. Otherwise, the evidence is fair with respect to certain devices allowing for the accurate diagnosis of likelihood of osteoporosis, and generally fair to poor in terms of QUS use when initiating or monitoring osteoporosis treatment. A reasonable protocol is proposed herein for case-finding purposes, which relies on a combined assessment of clinical risk factors (CR.F) and heel QUS. Finally, several recommendations are made for quality assurance and control.


Bone | 2009

Alkaline mineral water lowers bone resorption even in calcium sufficiency: alkaline mineral water and bone metabolism.

Emma Wynn; Marc-Antoine Krieg; Jean-Marc Aeschlimann; Peter Burckhardt

BACKGROUND Dietary acid charge enhances bone loss. Bicarbonate or alkali diet decreases bone resorption in humans. We compared the effect of an alkaline mineral water, rich in bicarbonate, with that of an acid one, rich in calcium only, on bone markers, in young women with a normal calcium intake. METHODS This study compared water A (per litre: 520 mg Ca, 291 mg HCO(3)(-), 1160 mg SO(4)(-), Potential Renal Acid load (PRAL) +9.2 mEq) with water B (per litre: 547 mg Ca, 2172 mg HCO(3)(-), 9 mg SO(4)(-), PRAL -11.2 mEq). 30 female dieticians aged 26.3 yrs (SD 7.3) were randomized into two groups, followed an identical weighed, balanced diet (965 mg Ca) and drank 1.5 l/d of the assigned water. Changes in blood and urine electrolytes, C-telopeptides (CTX), urinary pH and bicarbonate, and serum PTH were measured after 2 and 4 weeks. RESULTS The two groups were not different at baseline, and showed a similar increase in urinary calcium excretion. Urinary pH and bicarbonate excretion increased with water B, but not with water A. PTH (p=0.022) and S-CTX (p=0.023) decreased with water B but not with water A. CONCLUSION In calcium sufficiency, the acid calcium-rich water had no effect on bone resorption, while the alkaline water rich in bicarbonate led to a significant decrease of PTH and of S-CTX.

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Didier Hans

University of California

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Didier Hans

University of California

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