Trabecular bone score in kidney transplant recipients
It is uncertain whether bone mineral density (BMD) can accurately predict fracture in kidney transplant recipients. Trabecular bone score (TBS) provides information independent of BMD. Kidney transplant recipients had abnormal bone texture as measured by lumbar spine TBS, and a lower TBS was associated with incident fractures in recipients.
Trabecular bone score (TBS) is a texture measure derived from dual energy X-ray absorptiometry (DXA) lumbar spine images, providing information independent of bone mineral density. We assessed characteristics associated with TBS and fracture outcomes in kidney transplant recipients.
We included 327 kidney transplant recipients from Manitoba, Canada, who received a post-transplant DXA (median 106 days post-transplant). We matched each kidney transplant recipient (mean age 45 years, 39 % men) to three controls from the general population (matched on age, sex, and DXA date). Lumbar spine (L1-L4) DXA images were used to derive TBS. Non-traumatic incident fracture (excluding hand, foot, and craniofacial) (n = 31) was assessed during a mean follow-up of 6.6 years. We used multivariable linear regression models to test predictors of TBS, and multivariable Cox proportional hazard regression was used to estimate hazard ratios (HRs) per standard deviation decrease in TBS to express the gradient of risk.
Compared to the general population, kidney transplant recipients had a significantly lower lumbar spine TBS (1.365 ± 0.129 versus 1.406 ± 0.125, P < 0.001). Multivariable linear regression revealed that receipt of a kidney transplant was associated with a significantly lower mean TBS compared to controls (−0.0369, 95 % confidence interval [95 % CI] −0.0537 to −0.0202). TBS was associated with fractures independent of the Fracture Risk Assessment score including BMD (adjusted HR per standard deviation decrease in TBS 1.64, 95 % CI 1.15–2.36).
Kidney transplant recipients had abnormal bone texture as assessed by TBS and a lower lumbar spine TBS was associated with fractures in recipients.
KeywordsBone mineral density Fracture Kidney transplant recipient Trabecular bone score
Dr. Naylor is supported by the Canadian Institutes of Health Research Fellowship and the Canadian National Transplant Research Program Astellas Training Award. The authors are indebted to Manitoba Health for the provision of data (HIPC File No. 2011/2012–31). The results and conclusions are those of the authors, and no official endorsement by Manitoba Health is intended or should be inferred. This article has been reviewed and approved by the members of the Manitoba Bone Density Program Committee.
Compliance with ethical standards
Conflicts of interest
Didier Hans: Co-ownership in the TBS patent. Stock options or royalties: Med-Imaps. William Leslie: Speaker bureau (paid to facility): Amgen, Eli Lily, Novartis. Research grants (paid to facility): Amgen, Genzyme. Amit Garg: Investigator-initiated grant from Astellas and Roche for a Canadian Institutes of Health Research study in living kidney donors and his institution received unrestricted research funding from Pfizer. David Rush: Advisory board member, Astellas; Grant investigator, Astellas; Speaker: Astellas, STA Communications, Pfizer. Kyla Naylor, Lisa M Lix, and Anthony B. Hodsman declare that they have no conflict of interest.
- 3.Kalker AJ, Pirsch JD, Heisey D, Sollinger HW, Beizer FO, Knechtle SJ, D'Alessandro AM (1996) Foot problems in the diabetic transplant recipient. Clin Transpl 10:503–510Google Scholar
- 8.Rizzari MD, Suszynski TM, Gillingham KJ, Dunn TB, Ibrahim HN, Payne WD, Chinnakotla S, Finger EB, Sutherland DE, Kandaswamy R, Najarian JS, Pruett TL, Kukla A, Spong R, Matas AJ (2012) Ten-year outcome after rapid discontinuation of prednisone in adult primary kidney transplantation. Clin J Am Soc Nephrol 7:494–503CrossRefPubMedPubMedCentralGoogle Scholar
- 10.Kidney Disease Imrpoving Global Outcomes (KDIGO) Work Group (2009) KDIGO clinical practice guidelines for the prevention, diagnosis, evaluation, and treatment of chronic kidney disease-mineral and bone disorder (CKD-MBD). Kidney Int Suppl 113:S1–130Google Scholar
- 19.Pothuaud L, Barthe N, Krieg MA, Mehsen N, Carceller P, Hans D (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. J Clin Densitom 12:170–176CrossRefPubMedGoogle Scholar
- 20.Hans D, Barthe N, Boutroy S, Pothuaud L, Winzenrieth R, Krieg MA (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. J Clin Densitom 14:302–312CrossRefPubMedGoogle Scholar
- 22.Rabier B, Heraud A, Grand-Lenoir C, Winzenrieth R, Hans D (2010) A multicentre, retrospective case-control study assessing the role of trabecular bone score (TBS) in menopausal Caucasian women with low areal bone mineral density (BMDa): analysing the odds of vertebral fracture. Bone 46:176–181CrossRefPubMedGoogle Scholar
- 24.Popp AW, Meer S, Krieg MA, Perrelet R, Hans D, Lippuner K (2015) Bone mineral density (BMD) and vertebral trabecular bone score (TBS) for the identification of elderly women at high risk for fracture: the SEMOF cohort study. Eur Spine J. Epub 2015 May 27.Google Scholar
- 29.Manitoba Health (2012) Part Two Manitoba Health Population Report. http://www.gov.mb.ca/health/population/parttwo.pdf. Accessed 27 June 2015.
- 34.World Health Organization (2011) FRAX World Health Organization Fracture Risk Assessment Tool. http:// www.shef.ac.uk/FRAX/index.aspx. Accessed 29 June 2015.