An observational study in Kidney Transplantation, Bone Loss and Osteoporosis, sponsored by Medical University Innsbruck. Recruiting at 1 site in Austria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-13.
Sponsored by Medical University Innsbruck · Observational
Help build ClinicalTrials.gg — short surveys, remote interviews or testing, in your language. Take part →
The goal of this observational study is to learn how bone health changes during the first year after kidney transplantation in adults receiving their first kidney transplant.
The main questions it aims to answer are:
Participants will:
The study does not change any treatment. All treatment decisions remain with the patients' physicians.
Bone mineral density declines rapidly during the first 6-12 months after kidney transplantation, driven by glucocorticoid exposure, persistent chronic kidney disease-mineral and bone disorder (CKD-MBD) and changes in bone turnover. This period coincides with the highest fracture risk. DXA-scans provide areal bone mineral density only and cannot distinguish cortical from trabecular bone or assess microarchitecture, so it may underestimate early cortical deterioration. HR-pQCT measures volumetric bone mineral density, cortical and trabecular microarchitecture and, by finite element analysis, estimated bone strength.
DXACT is an investigator-initiated, prospective, single-centre observational cohort study at the Medical University of Innsbruck. Baseline clinical and laboratory assessment is performed 7 +/- 2 days and imaging 10 +/- 7 days after transplantation; assessments are repeated at 12 months, with an optional 6-month visit for participants followed locally. HR-pQCT is performed at the distal radius and distal tibia of the dominant side (contralateral side if a vascular access or implant is present); DXA at the lumbar spine (L1-L4), hip and distal radius (33%).
Clinically relevant skeletal deterioration is defined as a change exceeding the least significant change (LSC = 2.77 x precision CV) of the respective modality and parameter. Laboratory assessments include parathyroid hormone, 25-hydroxy- and 1,25-dihydroxyvitamin D, calcium, phosphate, P1NP, bone-specific alkaline phosphatase, TRAP5b, CTX, osteocalcin and osteoprotegerin. EDTA plasma and urine are stored in a pseudonymised biobank at -80 °C.
Analyses are primarily descriptive and exploratory. Planned analyses include agreement and discordance between DXA- and HR-pQCT-based classification, associations of imaging changes with biochemical markers and clinical factors (age, sex, dialysis vintage, cumulative glucocorticoid dose, rejection, graft function), and comparison by graft function at 12 months. Incident fragility fractures beyond 12 months may be retrieved from routine clinical records without further participant contact.
662 studies on the registry are indexed under Bone Diseases, Metabolic; 94 are open to participants now.
This study's planned enrollment of 100 is above the median of 80 across 139 observational studies indexed under Bone Diseases, Metabolic.
Browse Bone Diseases, Metabolic studies →Medical University Innsbruck is the lead sponsor of 187 studies on the registry; 48 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adult recipients of a first kidney transplant (living or deceased donor) treated at the Medical University of Innsbruck, Austria, who are approached by the study team within 10 days after transplantation.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults (18 years or older) who received a first kidney transplant (living or deceased donor) at the Medical University of Innsbruck and are enrolled within 10 days after transplantation.
Diagnostic Test: DXA and HR-pQCT · Other: Blood and urine sampling
Dual-energy X-ray absorptiometry of the lumbar spine (L1-L4), hip and distal radius (33%) and high-resolution peripheral quantitative computed tomography of the distal radius and distal tibia, performed at baseline (10 +/- 7 days after kidney transplantation) and at 12 months, with an optional 6-month visit. Imaging is used for research only; no treatment is assigned.
Also known as: Dual-energy X-ray absorptiometry, High-resolution peripheral quantitative computed tomography
Blood and urine samples at each study visit, taken together with routine blood draws, for markers of bone and mineral metabolism and storage in a biobank.
Proportion of Participants With Clinically Relevant Skeletal Deterioration on HR-pQCT
Deterioration exceeding the least significant change (LSC = 2.77 x precision CV) in at least one of cortical thickness, cortical porosity or finite element-derived failure load at the distal radius or distal tibia.
Time frame: Baseline (10 +/- 7 days after transplantation) to 12 months
Proportion of Participants With Clinically Relevant Skeletal Deterioration on DXA
Decrease in areal bone mineral density exceeding the site-specific least significant change at the lumbar spine (L1-L4), hip or distal radius (33%).
Time frame: Baseline (10 +/- 7 days after transplantation) to 12 months
Change in Cortical Thickness
Absolute (mm) and relative (%) change in cortical thickness at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Cortical Porosity
Absolute (percentage points) and relative change in cortical porosity at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Total Volumetric BMD
Absolute (mg HA/cm³) and relative (%) change in total volumetric bone mineral density at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Cortical Volumetric BMD
Absolute (mg HA/cm³) and relative (%) change in cortical volumetric bone mineral density at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Trabecular Volumetric BMD
Absolute (mg HA/cm³) and relative (%) change in trabecular volumetric bone mineral density at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Trabecular Number
Absolute (1/mm) and relative (%) change in trabecular number at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Trabecular Thickness
Absolute (mm) and relative (%) change in trabecular thickness at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Trabecular Separation
Absolute (mm) and relative (%) change in trabecular separation at the distal radius and distal tibia measured by HR-pQCT.
Time frame: Baseline to 12 months
Change in Biochemical Markers of Bone and Mineral Metabolism
Change in parathyroid hormone, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, calcium, phosphate, P1NP, bone-specific alkaline phosphatase, TRAP5b, CTX, osteocalcin and osteoprotegerin
Time frame: Baseline to 12 months
Change in Estimated Bone Strength (Failure Load)
Absolute and relative change in finite element-derived failure load (N) at the distal radius and distal tibia.
Time frame: Baseline to 12 months
Change in Areal Bone Mineral Density
Absolute and relative change in areal BMD (g/cm2) at the lumbar spine (L1-L4), total hip, femoral neck and distal radius (33%) measured by DXA.
Time frame: Baseline to 12 months
Skeletal Changes by Graft Function
Comparison of HR-pQCT and DXA changes between participants with eGFR \>= 60 and \< 60 mL/min/1.73 m2 (CKD-EPI 2021) at 12 months.
Time frame: 12 months
Discordance Between DXA and HR-pQCT Classification
Proportion of participants classified differently by DXA and HR-pQCT, in particular stable DXA with deterioration on HR-pQCT.
Time frame: 12 months
Association of Dialysis Vintage With Skeletal Deterioration
Pre-transplant dialysis duration (continuous; pre-emptive, \< 12, \>= 12 months) as predictor of imaging-derived skeletal changes.
Time frame: Baseline to 12 months
Incident Fragility Fractures
Fragility fractures retrieved from routine clinical records without participant contact.
Time frame: Up to 5 years after transplantation
Plan to share: No — Individual participant data will not be shared publicly, as participant consent does not cover transfer to third parties. De-identified data may be made available by the study lead upon reasonable request, subject to approval by the ethics committee and data protection regulations.
Started Oct 2026 (actual). Primary completion is estimated for Dec 2029, 38 months after the start.
Of 52 non-industry observational studies under Bone Diseases, Metabolic, half reached primary completion within 60 months of starting (the median), counting those still running; a quarter within 19. This study's planned 38 months is below that.
Counting every sponsor, half of 53 studies reached it within 60 months; a quarter within 19.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Medical University Innsbruck →