M Gregorini1, G Sileno2, E F Pattonieri3, V Corradetti4, M Abelli5, E Ticozzelli5, L Scudeller6, M A Grignano2, P Esposito2, L Bogliolo7, A Giacomoni8, T Rampino2. 1. Unit of Nephrology, Dialysis and Transplantation, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy. 2. Unit of Nephrology, Dialysis and Transplantation, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 3. Unit of Nephrology, Dialysis and Transplantation, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Clinic and Surgical Science, University of Pavia, Pavia, Italy. Electronic address: ef.pattonieri@gmail.com. 4. Unit of Nephrology, Dialysis and Transplantation, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Clinic and Surgical Science, University of Pavia, Pavia, Italy. 5. Unit of General Surgery 2, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. 6. Clinical Epidemiology Unit, Fondazione IRCCS Policlinico San Matteo of Pavia, Pavia, Italy. 7. Unit of Reumatology, Fondazione IRCCS Policlinico San Matteo of Pavia, Pavia, Italy. 8. Department of Surgery, Niguarda Transplant Center, Grande Ospedale Metropolitano Niguarda, Milano, Italy.
Abstract
BACKGROUND: Kidney transplantation (KT) immunosuppression may induce bone tissue damage with bone mineral density (BMD) loss increasing bone fractures risk. Steroid therapy is considered the major player, but others factors are still under review. PATIENTS AND METHODS: We designed an observational retrospective cohort study to evaluate bone damage after KT. The prevalence of osteopenia, osteoporosis, bone fractures, and the associated risk factors were investigated. The following parameters were recorded before transplantation and at the last follow-up: demographic indexes, cumulative steroid dose (CSD), dialytic and transplantologic age, previous nephropathy, femoral and lumbar BMD, fractures, immunosuppressors, calcemia, phosphoremia, rejection episodes, estimated glomerular filtration rate, and parathyroid hormone and vitamin D levels. Stata software (Stata Corporation, College Station, Texas, United States) was used for the statistical analysis, to perform the Fisher's exact test, Kruskal-Wallis test, Student t test, as well as univariate and multivariate analyses. RESULTS: The analyzed cohort was composed of 297 patients (65.3% males and 34.7% females). Sixty percent of KT patients had normal BMD, 24% had osteopenia, and 15% had osteoporosis. Twelve percent were victims of bone fractures (8.4% minor, 2% femoral, and 1.7% vertebral). A significant correlation (P <.05) was observed for both osteopenia and osteoporosis with menopause, transplantologic age, CSD, previous glomerulonephritis, and mammalian target of rapamycin (mTOR) inhibitors treatment (imTOR). CONCLUSION: This study confirms the correlation between CSD (both before and after transplantation) and post-transplantation bone damage. It also shows that a large fraction of these patients had normal BMD related with a low steroid dose in our protocols. This correlation between imTOR assumption and osteoporosis deserves attention and warrants further in vitro analyses to be performed.
BACKGROUND: Kidney transplantation (KT) immunosuppression may induce bone tissue damage with bone mineral density (BMD) loss increasing bone fractures risk. Steroid therapy is considered the major player, but others factors are still under review. PATIENTS AND METHODS: We designed an observational retrospective cohort study to evaluate bone damage after KT. The prevalence of osteopenia, osteoporosis, bone fractures, and the associated risk factors were investigated. The following parameters were recorded before transplantation and at the last follow-up: demographic indexes, cumulative steroid dose (CSD), dialytic and transplantologic age, previous nephropathy, femoral and lumbar BMD, fractures, immunosuppressors, calcemia, phosphoremia, rejection episodes, estimated glomerular filtration rate, and parathyroid hormone and vitamin D levels. Stata software (Stata Corporation, College Station, Texas, United States) was used for the statistical analysis, to perform the Fisher's exact test, Kruskal-Wallis test, Student t test, as well as univariate and multivariate analyses. RESULTS: The analyzed cohort was composed of 297 patients (65.3% males and 34.7% females). Sixty percent of KT patients had normal BMD, 24% had osteopenia, and 15% had osteoporosis. Twelve percent were victims of bone fractures (8.4% minor, 2% femoral, and 1.7% vertebral). A significant correlation (P <.05) was observed for both osteopenia and osteoporosis with menopause, transplantologic age, CSD, previous glomerulonephritis, and mammalian target of rapamycin (mTOR) inhibitors treatment (imTOR). CONCLUSION: This study confirms the correlation between CSD (both before and after transplantation) and post-transplantation bone damage. It also shows that a large fraction of these patients had normal BMD related with a low steroid dose in our protocols. This correlation between imTOR assumption and osteoporosis deserves attention and warrants further in vitro analyses to be performed.