Osteoporosis in patients referred for lung transplantation

High risk of osteoporosis and fracture following solid organ transplantation: a population-based study

Background

Osteoporosis and fractures increase morbidity and mortality rates after solid organ transplantation (SOT), but few studies have analyzed the risk of osteoporosis and related fractures after SOT. In this retrospective cohort study, we investigated the risk of osteoporosis and fractures in different SOT recipients.

Methods

This study was a retrospective cohort study using a nationally representative database in Taiwan. We collected the data of SOT recipients and used the propensity score matching method to obtain a comparison cohort. To reduce bias, we excluded patients who had been diagnosed with osteoporosis or fracture before inclusion. All participants were followed up until the date of diagnosis as having a pathological fracture, death, or the end of 2018, whichever occurred first. The Cox proportional hazards model was used to investigate the risk of osteoporosis and pathological fracture in SOT recipients.

Results

After adjustment for the aforementioned variables, SOT recipients were observed to have a higher risk of osteoporosis (hazard ratio (HR) = 1.46, 95% confidence interval (CI): 1.29-1.65) and fracture (HR: 1.19, 95% CI: 1.01-1.39) than the general individuals. Among the different SOT recipients, the highest risk of fractures was noted in heart or lung transplant recipients, with a HR of 4.62 (95% CI: 2.05-10.44). Among the age groups, patients aged >61 years had the highest HRs for osteoporosis (HR: 11.51; 95% CI, 9.10-14.56) and fracture (HR: 11.75, 95% CI: 8.97-15.40).

Conclusion

SOT recipients had a higher risk of osteoporosis and related fractures than the general population, with the highest risks observed in patients receiving heart or lung transplants, older patients, and patients with CCI scores of >3.

Bone Disease in Long-Term Lung Transplant Survivors

Background: During the first two years after lung transplantation (LTx), the incidence of fragility fractures (FX) is estimated to be 15–50% and it is lower in patients with cystic fibrosis (CF) as compared with other end-stage lung diseases (nCF). The aim of our study is to compare the skeletal outcomes, after the first 2 years post-LTx, in long-term survivors with CF and nCF. Materials and Methods: We evaluated the FX rate, the changes in bone mineral density (BMD) and trabecular bone score (TBS) in 68 patients (38 CF and 30 nCF) who underwent LTx in our center and with a follow-up after LTx longer than 5 years (7.3 ± 2.0 years). Results: After the second year post-LTx: (i) the FX rate was lower than during the first two years post-LTx (4.4 vs. 20.6%, p = 0.004), with no difference between CF and nCF patients (5.3 vs. 3.3%, p = 0.589); (ii) BMD at lumbar spine, femoral neck and total hip remained stable (−1.6 ± 1.0 vs. −1.4 ± 1.1, p = 0.431, −1.8 ± 0.9 vs. −1.9 ± 0.9, p = 0.683, −1.5 ± 0.9 vs. −1.4 ± 0.9, p = 0.678, respectively) as well as TBS (1.200 ± 0.124 vs. 1.199 ± 0.205, p = 0.166). Conclusions: After the second year post-LTx, the skeletal complications become less frequent and have similar incidence in patients with CF and nCF.

The Utility of Prophylactic Zoledronic Acid in Patients Undergoing Lung Transplantation

Osteoporosis is prevalent among lung transplant candidates and is exacerbated post-transplant by immunosuppressive therapy. Low bone mineral density (BMD) is a well-recognized surrogate for fragility fracture risk, which is associated with significant morbidity and mortality. Intravenous zoledronic acid (ZA) effectively reduces BMD loss and prevents fractures in postmenopausal osteoporosis. Many groups, ours included, prophylactically treat lung transplant recipients (LTR) with bisphosphonates, but no documented consensus currently exists. Our protocol comprises ZA every 6-months from transplant wait-listing, with interval reassessment to guide ongoing treatment. We evaluate the impact of a dose of ZA within 6 months of transplantation on BMD and fracture occurrence. A retrospective analysis was performed on all adult LTR from April 2012 to October 2014, of which 60 met our inclusion criteria. LTR who received ZA within 6 months of transplantation (n = 37) were compared to those who did not (n = 23), and followed up for a minimum of three years. Outcome measures were BMD change at the lumbar spine and femur (primary), and fracture occurrence (secondary). LTR treated with ZA within 6 months of transplantation experienced a median BMD change of +8.11% at the lumbar spine and +1.39% at the femur, compared to -1.20% and -3.92%, respectively, in LTR who did not receive a ZA dose within 6 months of transplantation (p = 0.002 & p = 0.008 respectively). Our findings indicate that prophylactic ZA within 6 months of transplantation prevents BMD loss in LTR.

Impact of bone-active drugs and underlying disease on bone health after lung transplantation: A longitudinal study

INTRODUCTION

the effect of bone-active drugs on the risk of fragility fractures (Fx), bone mineral density (BMD) and trabecular bone score (TBS) changes in patients receiving lung transplantation (LTx) is largely unknown. This study assessed the bone-active drugs effect in patients undergoing LTx both with (CF) and without (nCF) cystic-fibrosis.

METHODS

We evaluated incident Fx, both clinical and morphometric vertebral Fx by spinal X-ray, BMD and trabecular bone score (TBS) in 117 patients (CF=50, nCF n = 67) before and 24-months after LTx. A bone-active therapy was proposed to all LTx candidates.

RESULTS

83.8% of patients started a bone-active drug. Lumbar-spine (LS) T-score improved significantly only in treated patients (-1.4 ± 1.0 vs -2.0±1.0, p = 0.0001), whereas femur BMD and TBS remained stable in treated and not treated subjects. The rate of incident Fx was 15.3%, with no difference between treated and not treated patients. After LTx, LS T-score improved significantly only in nCF group (-1.3 ± 1.0 vs -1.8 ± 1.1, p = 0.0001), while femur remained stable in both nCF and CF groups. Patients with CF showed a significant Z-TBS increase (-3.6 ± 1.7 vs -3.0 ± 1.7, p = 0.019) and a lower Fx incidence as compared with nCF patients (4.1% vs 24.2%, p  =0.003). Incident Fx were associated with nCF diagnosis (OR 7.300, CI95% 1.385-38.461, p = 0.019) regardless of prevalent Fx, previous glucocorticoid therapy and bone-active therapy introduced at least 6 months before LTx.

CONCLUSIONS

A prompt medical intervention helps in preventing BMD loss after LTx. As compared with nCF patients, CF patients show a TBS increase and a lower Fx risk after LTx.

Exercise training for adult lung transplant recipients

BACKGROUND

Pulmonary transplantation is the final treatment option for people with end-stage respiratory diseases. Evidence suggests that exercise training may contribute to speeding up physical recovery in adults undergoing lung transplantation, helping to minimize or resolve impairments due to physical inactivity in both the pre- and post-transplant stages. However, there is a lack of detailed guidelines on how exercise training should be carried out in this specific sub-population.

OBJECTIVES

To determine the benefits and safety of exercise training in adult patients who have undergone lung transplantation, measuring the maximal and functional exercise capacity; health-related quality of life; adverse events; patient readmission; pulmonary function; muscular strength; pathological bone fractures; return to normal activities and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 6 October 2020 using relevant search terms for this review. Studies in the CKTR are identified through CENTRAL, MEDLINE, and EMBASE searches, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were included comparing exercise training with usual care or no exercise training, or with another exercise training program in terms of dosage, modality, program length, or use of supporting exercise devices. The study population comprised of participants older than 18 years who underwent lung transplantation independent of their underlying respiratory pathology.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed all records identified by the search strategy and selected studies that met the eligibility criteria for inclusion in this review. In the first instance, the disagreements were resolved by consensus, and if this was not possible the decision was taken by a third reviewer. The same reviewers independently extracted outcome data from included studies and assessed risk of bias. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Eight RCTs (438 participants) were included in this review. The median sample size was 60 participants with a range from 16 to 83 participants. The mean age of participants was 54.9 years and 51.9% of the participants were male. The median duration of the exercise training programs for the groups undergoing the intervention was 13 weeks, and the median duration of training in the active control groups was four weeks. Overall the risk of bias was considered to be high, mainly due to the inability to blind the study participants and the selective reporting of the results. Due to small number of studies included in this review, and the heterogeneity of the intervention and outcomes, we did not obtain a summary estimate of the results. Two studies comparing resistance exercise training with no exercise reported increases in muscle strength and bone mineral density (surrogate outcomes for pathological bone fractures) with exercise training (P > 0.05), but no differences in adverse events. Exercise capacity, health-related quality of life (HRQoL), pulmonary function, and death (any cause) were not reported. Three studies compared two different resistant training programs. Two studies comparing squats using a vibration platform (WBVT) compared to squats on the floor reported an improvement in 6-minute walk test (6MWT) (28.4 metres, 95% CI 3 to 53.7; P = 0.029; and 28.3 metres, 95% CI 10.0 to 46.6; P < 0.05) with the WBVT. Supervised upper limb exercise (SULP) program improved 6MWT at 6 months compared to no supervised upper limb exercise (NULP) (SULP group: 561.2 ± 83.6 metres; NULP group: 503.5 ± 115.2 metres; P = 0.01). There were no differences in HRQoL, adverse events, muscular strength, or death (any cause). Pulmonary function and pathological bone fractures were not reported. Two studies comparing multimodal exercise training with no exercise reported improvement in 6MWT at 3 months (P = 0.008) and at 12-months post-transplant (P = 0.002) and muscular strength (quadriceps force (P = 0.001); maximum leg press (P = 0.047)) with multimodal exercise, but no improvement in HRQoL, adverse events, pulmonary function, pathological bone fractures (lumbar T-score), or death (any cause). One study comparing the same multimodal exercise programs given over 7 and 14 weeks reported no differences in 6MWT, HRQoL, adverse events, pulmonary function, muscle strength, or death (any cause). Pathological bone fractures were not reported. According to GRADE criteria, we rated the certainty of the evidence as very low, mainly due to the high risk of bias and serious imprecision.

AUTHORS' CONCLUSIONS

In adults undergoing lung transplantation the evidence about the effects of exercise training is very uncertain in terms of maximal and functional exercise capacity, HRQoL and safety, due to very imprecise estimates of effects and high risk of bias.

[Osteoporosis in pneumological diseases : Joint guideline of the Austrian Society for Bone and Mineral Research (ÖGKM) and the Austrian Society for Pneumology (ÖGP)]

Chronic inflammation induces proinflammatory cytokine cascades. In addition to systemic inflammation, hypoxemia, hypercapnia, a catabolic metabolism, gonadal or thyroid dysfunction, musculoskeletal dysfunction and inactivity as well as vitamin D deficiency contribute to an increased risk of fragility fractures. Iatrogenic causes of osteoporosis are long-term use of inhaled or systemic glucocorticoids (GC). Inhalative GC application in asthma is often indicated in childhood and adolescence, but interstitial lung diseases such as chronic organizing pneumonia, COPD, sarcoid or rheumatic diseases with lung involvement are also treated with inhalative or oral GC. In patients with cystic fibrosis, malabsorption in the context of pancreatic insufficiency, hypogonadism and chronic inflammation with increased bone resorption lead to a decrease in bone structure. After lung transplantation, immunosuppression with GC is a risk factor.The underlying pneumological diseases lead to a change in the trabecular and cortical bone microarchitecture and to a reduction in osteological formation and resorption markers. Hypercapnia, acidosis and vitamin D deficiency can accelerate this process and thus increase the individual risk of osteoporotic fragility fractures.A bone mineral density measurement with a T‑Score < -2.5 is a threshold value for the diagnosis of osteoporosis; in contrast the vast majority of all osteoporotic fractures occur with a T‑Score > -2.5. A history of low-trauma fracture indicates osteological therapy.All antiresorptive or anabolic drugs approved in Austria for the treatment of osteoporosis are also indicated for pneumological patients with an increased fragility fracture risk of bone fractures in accordance with the national reimbursement criteria.

Bone disease following solid organ transplantation: A narrative review and recommendations for management from The European Calcified Tissue Society

INTRODUCTION

Solid organ transplantation is an established therapy for end-stage organ failure. Both pre-transplantation bone disease and immunosuppressive regimens result in rapid bone loss and increased fracture rates.

METHODS

The European Calcified Tissue Society (ECTS) formed a working group to perform a systematic review of existing literature on the consequences of end-stage kidney, liver, heart, and lung disease on bone health. Moreover, we assessed the characteristics of post-transplant bone disease and the skeletal effects of immunosuppressive agents and aimed to provide recommendations for the prevention and treatment of transplantation-related osteoporosis.

RESULTS

Characteristics of bone disease may differ depending on the organ that fails, but patients awaiting solid organ transplantation frequently depict a wide spectrum of bone and mineral abnormalities. Common features are a decreased bone mass and impaired bone strength with consequent high fracture risk, all of which are aggravated in the early post-transplantation period.

CONCLUSION

Both the underlying disease leading to end-stage organ failure and the immunosuppression regimens implemented after successful organ transplantation have detrimental effects on bone mass, quality and strength. Given existing ample data confirming the high frequency of bone disease in patients awaiting solid organ transplantation, we recommend that all transplant candidates should be assessed for osteoporosis and fracture risk and, if indicated, treated before and after transplantation. Since bone loss in the early post-transplantation period occurs in virtually all solid organ recipients and is associated with glucocorticoid administration, the goal should be to use the lowest possible dose and to taper and withdraw glucocorticoids as early as possible.

Bone involvement in young adults with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure

Patients with cystic fibrosis awaiting lung transplantation for end-stage respiratory failure have high prevalence of reduced bone mineral density and fragility fracture. Suboptimal 25-hydroxyvitamin D levels could significantly contribute to the development of cystic fibrosis-related bone disease.

INTRODUCTION

The assessment of the prevalence of cystic fibrosis-related bone disease (CFBD) and its associated risk factors in young adults with cystic fibrosis (CF) awaiting lung transplantation for end-stage respiratory failure.

METHODS

Clinical characteristics, bone mineral density (BMD), the parameters of calcium metabolism, including vitamin D (25OHVitD) levels, and the presence of fragility fractures were evaluated in 42 CF patients (24 females, age 34.0 ± 8.4 years) consecutively referred as lung transplant candidates.

RESULTS

Mean 25OHVitD levels (54.9 ± 26.2 nmol/L) were below the reference range and hypovitaminosis D (25OHVitD < 75 nmol/L) was found in 34 patients (81%) and daily calcium intakes (median 550 mg/day) were lower than recommended. A BMD below the expected range for age (Z-score of - 2.0 or lower) and at least one prevalent fragility fracture were found in 22 patients (52.4%) and 18 patients (45.2%), respectively. The coexistence of low BMD and the presence of fracture was observed in 13 patients (31.0%). In these patients, the prevalence of nephrolithiasis was higher than in the remaining ones (p = 0.046). The presence of kidney stones was associated with a worse bone status and with severe vitamin D deficiency. In the whole sample, femoral BMD Z-scores were directly correlated with albumin-adjusted calcium (p < 0.05) and 25OHVitD levels (p < 0.01).

CONCLUSIONS

Despite the improvement of CF care, CFBD is still highly prevalent in young adults awaiting lung transplantation for end-stage CF. Suboptimal 25OHVitD levels could significantly contribute to the development of CFBD. The presence of nephrolithiasis could be an additional warning about the need for a careful evaluation of bone health in CF patients.

Low bone density and fractures before and after pediatric lung transplantation

INTRODUCTION

Children undergoing lung transplant are at risk for low bone mineral density (BMD) and fractures. The effect of lung transplantation on bone health in pediatric patients is unknown.

MATERIALS AND METHODS

We performed a retrospective chart review of all patients ages 2-21 years who underwent lung transplantation at our hospital from January 2000 to January 2015.

RESULTS

51 patients were studied. At the time of transplant evaluation, BMD Z-score was -2.2 ± 1.4, and 59% of patients had low BMD. BMD Z-score declined in the first year after treatment and returned to near-baseline by the third post-transplant year. Fractures occurred in 9 patients (18%) before and 15 patients (29%) after transplant. Bisphosphonate use was associated with improvement in BMD Z-score and lower mortality risk.

CONCLUSIONS

Pediatric patients had a high prevalence of low BMD at the time of lung transplant evaluation. BMD Z-scores declined in the year after transplant and returned to the pre-transplant level by the third post-transplant year while remaining below normal levels. Fractures were common at sites associated with significant morbidity. These findings support efforts to optimize bone health before and after pediatric lung transplantation, and future studies are needed to evaluate the role of bisphosphonates in these patients.

Correction of Spinal Deformity on a Lung Transplantation Recipient

BACKGROUND

The coexistence of lung disease and scoliosis entails a dramatic situation. There are no papers reporting scoliosis surgery in patients who suffered lung transplantation.

PURPOSE

To describe the case of a patient who underwent surgery to correct progressive spinal deformity after two consecutive lung transplants.

STUDY DESIGN

Case report, including review of patient records, imaging and pulmonary function tests, and literature review.

METHODS

A 9-year-old woman diagnosed of idiopathic pulmonary fibrosis and progressive scoliosis underwent lung transplant. Retransplantation of right lung was performed at the age of 14 due to chronic rejection. When she was 16, respiratory function was stable and spinal deformity severely impaired her quality of life. Patient and family demanded a surgical correction. At that moment, she had severe osteoporosis and immunosuppression as a result of anti-rejection therapy. The pattern was a severe double thoracic curve T1-T6 89° and T7-L1 139°. To correct it, a posterior instrumented spine fusion from T2 to L4 using a hybrid configuration was performed.

RESULTS

No significant complications occurred in perioperative, postoperative, and midterm follow-up periods. Solid fusion was achieved and patient was satisfied with surgery. Unfortunately, chronic lung graft rejection worsened her long-term general status.

CONCLUSIONS

Scoliosis surgery on lung transplant recipients is feasible, regardless of potential complications related to immunosuppression and osteoporosis. The goal is to improve quality of life.

The Role of Tumor Necrosis Factor Alpha and TNF Superfamily Members in Bone Damage in Patients with End-Stage Chronic Obstructive Lung Disease Prior to Lung Transplantation

A disequilibrium of tumor necrosis superfamily (TNF) members, including the serum osteoprotegerin, soluble receptor activator of nuclear factor-κB ligand, soluble TNF-related apoptosis-inducing ligand and TNF-α, was associated with the occurrence of a reduced skeletal mass and osteoporosis in male patients with end-stage chronic obstructive pulmonary disease (COPD). The purpose of this study was to explore the associations between serum biomarkers of tumor necrosis factor (TNF) superfamily and body and bone compositions in end-stage COPD males. Pulmonary function, T-score at the lumbar spine and femoral neck, lean mass, serum osteoprotegerin (OPG), soluble receptor activator of nuclear factor-κB ligand (sRANKL), TNF-α and its receptors (sTNFR-I, sTNFR-II) and soluble TNF-related apoptosis-inducing ligand (sTRAIL) levels were evaluated in 48 male patients with end-stage COPD and 36 healthy male volunteers. OPG was lower in male COPD patients than in control subjects, whereas sRANKL, TNF-α and its receptors were higher. The serum sTRAIL level showed a tendency to increase compared with that of healthy subjects (P = 0.062). Serum OPG showed a positive correlation with bone density. In contrast, serum TNF-α, sRANKL and sTRAIL were inversely associated with pretransplant bone density. We have noted the appearance of statistically significant inverse relationships between lean mass values and TNF-α, sTNFR-I and II and sRANKL levels in male COPD patients. Moreover, there was a negative correlation between sTRAIL levels with airway obstruction (P = 0.005) and hypercapnia (P = 0.042) in advanced COPD patients. Through a multiple linear regression analysis, our study revealed that a disequilibrium of TNF family members was strongly associated with the occurrence of a reduced skeletal mass and osteoporosis. These results provide further evidence that abnormal levels of TNF superfamily molecules may cause not only a decrease in BMD, but also lower muscle mass in end-stage COPD.

Idiopathic pulmonary fibrosis a rare disease with severe bone fragility

Idiopathic pulmonary fibrosis (IPF) is a rare form of chronic, progressive fibrosing interstitial pneumonia of unknown cause. The aim of this cross-sectional study was to assess the prevalence of osteoporosis and fragility fracture in a population of adults with IPF and to identify whether any possible clinical and pulmonary function parameters may be associated with increased bone fragility. In 58 IPF patients (mean age 65.1 ± 9.1 years), we measured bone mineral density (BMD) of the lumbar spine, the femoral neck, and the entire hip. Moreover, the presence of vertebral fractures on a lateral chest X-ray study was evaluated, and a vertebral fracture burden was quantified using the spinal deformity index (SDI). As expected, osteoporosis was significantly more frequent in females with respect to males (57.9 vs 20.5 %, respectively), whereas the fractures prevailed in males with respect to females (38.5 vs 26.3 %, respectively). There were positive correlations between BMD at all skeletal sites and respiratory parameters; in particular for FVC % and DLCO % with BMD at femoral sub-regions. Moreover, we compared the average of DLCO (%) measure by values of SDI score that was higher in those patients with lower values of DLCO (%). The study shows a high prevalence of fragility with vertebral fractures in IPF patients, especially in males. Moreover, the vertebral fracture burden is associated with a worsening of FVC (%) and DLCO (%). Therefore, an evaluation of bone status is recommended, especially in those patients who are candidates for lung transplantation.

Current Status of Research on Osteoporosis after Solid Organ Transplantation: Pathogenesis and Management

Improved survival following organ transplantation has brought to the forefront some long-term complications, among which osteoporosis and associated fractures are the major ones that adversely affect the quality of life in recipients. The pathogenesis of osteoporosis in transplant recipients is complex and multifactorial which may be related to increased bone resorption, decreased bone formation, or both. Studies have shown that the preexisting underlying metabolic bone disorders and the use of immunosuppressive agents are the major risk factors for osteoporosis and fractures after organ transplantation. And rapid bone loss usually occurs in the first 6–12 months with a significant increase in fracture risk. This paper will provide an updated review on the possible pathogenesis of posttransplant osteoporosis and fractures, the natural history, and the current prevention and treatment strategies concerning different types of organ transplantation.

Bone disease after transplantation: osteoporosis and fractures risk

Organ transplantation is the gold standard therapy for several end-stage diseases. Bone loss is a common complication that occurs in transplant recipients. Osteoporosis and fragility fractures are serious complication, mainly in the first year post transplantation. Many factors contribute to the pathogenesis of bone disease following organ transplantation. This review address the mechanisms of bone loss including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and management of bone loss in the transplant recipient should be included in their post transplant follow-up in order to prevent fractures.

Osteoporosis after transplantation

Transplantation is an established therapy for end-stage diseases of kidney, lung, liver, and heart among others. Osteoporosis and fragility fractures are serious complications of organ transplantation, particularly in the first post-transplant year. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. This review addresses the mechanisms of bone loss that occurs both in the early and late post-transplant periods, including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac, and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient are also discussed.