Factors Related to Osteosarcopenia in Kidney Transplant Recipients

Prevalence of Musculoskeletal and Metabolic Disorders in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis

Introduction

Musculoskeletal disorders could be associated with metabolic disorders that are common after kidney transplantation, which could reduce the quality of life of patients. The aim of this study was to assess the prevalence of both musculoskeletal and metabolic disorders in kidney transplant patients.

Methods

MEDLINE, CINAHL, Cochrane Library, EMBASE and Web of Science were searched from their inception up to June 2023. DerSimonian and Laird random-effects method was used to calculate pooled prevalence estimates and their 95% confidence intervals (CIs).

Results

21,879 kidney transplant recipients from 38 studies were analysed. The overall proportion of kidney transplant patients with musculoskeletal disorders was 27.2% (95% CI: 18.4-36.0), with low muscle strength (64.5%; 95% CI: 43.1-81.3) being the most common disorder. Otherwise, the overall proportion of kidney transplant patients with metabolic disorders was 37.6% (95% CI: 21.9-53.2), with hypovitaminosis D (81.8%; 95% CI: 67.2-90.8) being the most prevalent disorder.

Conclusion

The most common musculoskeletal disorders were low muscle strength, femoral osteopenia, and low muscle mass. Hypovitaminosis D, hyperparathyroidism, and hyperuricemia were also the most common metabolic disorders. These disorders could be associated with poorer quality of life in kidney transplant recipients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier [CRD42023449171].

Sarcopenia and osteosarcopenia among patients undergoing hemodialysis

Background

Sarcopenia and osteoporosis are closely interconnected and associated with adverse health outcomes. Osteosarcopenia is the concurrent presence of the two conditions and has rarely been reported in hemodialysis patients. Whether hemodialysis patients with osteosarcopenia are at greater risk of mortality than those with either condition alone remains unknown. The aim of this study was to explore the prevalence of sarcopenia and its association with osteoporosis and to determine its impact on survival risk in hemodialysis patients.

Methods

A total of 209 adults undergoing hemodialysis were enrolled from the dialysis center in the West China Hospital of Sichuan University, and our study was registered at the Chinese Clinical Trial Register (number: ChiCTR2100043932). Muscle mass, handgrip strength, bone mineral density (BMD), and biochemical parameters were assessed. All deaths were recorded during a follow-up of 35.15 ± 15.37 months.

Results

Seventy-eight patients were diagnosed with sarcopenia, with a prevalence of 37.3%. After adjustment for potential confounders, age (OR=1.094, P <0.001), female sex (OR= 3.44, P =0.005), diabetes (OR=3.756, P =0.008), CRP (OR=1.09, P =0.015), serum magnesium (OR=0.755, p=0.042) and BMI (OR=0.701, P <0.001) were independently associated with sarcopenia. Among the 209 patients, 103 patients completed the BMD assessment. The prevalence of osteosarcopenia was 22.3%, while 20.4% of participants had sarcopenia alone and 12.6% had osteoporosis alone. The proportions of patients who died were 13.0% for nonsarcopenia&nonosteoporosis, 15.4% for osteoporosis alone, 47.6% for sarcopenia alone, and 52.2% for osteosarcopenia. Cox regression analysis showed that osteosarcopenia was independently associated with all-cause mortality (HR=3.74, 95% CI: 1.172-11.938), while osteoporosis alone and sarcopenia alone were not.

Conclusion

Patients undergoing hemodialysis had a high incidence of sarcopenia and osteosarcopenia, muscle mass and strength showed a significant association with BMD, and osteosarcopenia might have a powerful impact on mortality in those patients.

Clinical trial registration

http://www.chictr.org.cn/, identifier ChiCTR2100043932.

Treatment with fibroblast growth factor 19 increases skeletal muscle fiber size, ameliorates metabolic perturbations and hepatic inflammation in 5/6 nephrectomized mice

Chronic kidney disease (CKD) is associated with osteosarcopenia, and because a physical decline in patients correlates with an increased risk of morbidity, an improvement of the musculoskeletal system is expected to improve morbi-mortality. We recently uncovered that the intestinal hormone Fibroblast Growth Factor 19 (FGF19) is able to promote skeletal muscle mass and strength in rodent models, in addition to its capacity to improve glucose homeostasis. Here, we tested the effects of a treatment with recombinant human FGF19 in a CKD mouse model, which associates sarcopenia and metabolic disorders. In 5/6 nephrectomized (5/6Nx) mice, subcutaneous FGF19 injection (0.1 mg/kg) during 18 days increased skeletal muscle fiber size independently of food intake and weight gain, associated with decreased gene expression of myostatin. Furthermore, FGF19 treatment attenuated glucose intolerance and reduced hepatic expression of gluconeogenic genes in uremic mice. Importantly, the treatment also decreased gene expression of liver inflammatory markers in CKD mice. Therefore, our results suggest that FGF19 may represent a novel interesting therapeutic strategy for a global improvement of sarcopenia and metabolic complications in CKD.

Management of osteoporosis in patients with chronic kidney disease

Patients with CKD have a 4-fivefold higher rate of fractures. The incidence of fractures increases with deterioration of kidney function. The process of skeletal changes in CKD patients is characterized by compromised bone strength because of deterioration of bone quantity and/or quality. The fractures lead to a deleterious effect on the quality of life and higher mortality in patients with CKD. The pathogenesis of bone loss and fracture is complex and multi-factorial. Renal osteodystrophy, uremic milieu, drugs, and systemic diseases that lead to renal failure all contribute to bone damage in CKD patients. There is no consensus on the optimal diagnostic method of compromised bone assessment in patients with CKD. Bone quantity and mass can be assessed by dual-energy x-ray absorptiometry (DXA) or quantitative computed tomography (QCT). Bone quality on the other side can be assessed by non-invasive methods such as trabecular bone score (TBS), high-resolution bone imaging methods, and invasive bone biopsy. Bone turnover markers can reflect bone remodeling, but some of them are retained by kidneys. Understanding the mechanism of bone loss is pivotal in preventing fracture in patients with CKD. Several non-pharmacological and therapeutic interventions have been reported to improve bone health. Controlling laboratory abnormalities of CKD-MBD is crucial. Anti-resorptive therapies are effective in improving BMD and reducing fracture risk, but there are uncertainties about safety and efficacy especially in advanced CKD patients. Accepting the prevalent of low bone turnover in patients with advanced CKD, the osteo-anabolics are possibly promising. Parathyroidectomy should be considered a last resort for intractable cases of renal hyperparathyroidism. There is a wide unacceptable gap in osteoporosis management in patients with CKD. This article is focusing on the updated management of CKD-MBD and osteoporosis in CKD patients. Chronic kidney disease deteriorates bone quality and quantity. The mechanism of bone loss mainly determines pharmacological treatment. DXA and QCT provide information about bone quantity, but assessing bone quality, by TBS, high-resolution bone imaging, invasive bone biopsy, and bone turnover markers, can guide us about the mechanism of bone loss.

Obesity and Lifestyle Habits among Kidney Transplant Recipients

Background: Obesity may negatively impact clinical outcomes in kidney transplant (KT) recipients. Limited information is available on the prevalence of obesity in this population, and on the lifestyle habits associated with obesity. Methods: we conducted an online, anonymous survey to assess of the proportion of KT recipients with obesity, adherence to the Mediterranean diet (i.e., a dietary regimen with proven renal and cardiovascular outcomes) using the MEDI-Lite questionnaire, and level of physical activity using the International Physical Activity Questionnaire (IPAQ) short form among KT recipients. Results: 255 KT recipients participated. Median (25th−75th quartile) age was 56.0 (48.0; 62.0) years, 43.9% female, median BMI 23.9 (21.6; 26.5) kg/m2. The proportion of KT recipients with obesity was 9.8% (95% confidence interval, 6.4 to 14.1%). Adequate adherence to the Mediterranean diet (Medi-Lite score >9) was overall low (44.7%; 40.0 vs. 45.2% in those with or without obesity, respectively; p = 0.618). In participants with obesity the Medi-Lite score inversely correlated with BMI (R = −0.45; p < 0.025). Overall, 30.6% of participants had a low level of physical activity (44.0 vs. 29.1% of those with or without obesity, respectively; p = 0.125). The amount of energy expended walking was significantly lower among participants with obesity (462 (0.0; 1436) vs. 1056 (433; 2005) METs/week, p = 0.017). Conclusions: the burden of obesity among KT recipients is similar to that of the general population. Adherence to the Mediterranean diet was generally low, and nearly one-third of participants had a low level of physical activity. Building specialized multidisciplinary teams to manage obesity in KT recipients is urgently needed.

Neutrophil-lymphocyte Ratio and C-Reactive Protein Levels are not Associated with Strength, Muscle Mass, and Functional Capacity in Kidney Transplant Patients

Chronic inflammation has been associated with components of sarcopenia; however, these associations are unknown in kidney transplant patients (KTPs). The aim of this study was to associate neutrophil-lymphocyte ratio (NLR) and C-reactive protein (CRP) with strength, muscle mass, and functional capacity in KTPs. A cross-sectional study evaluating 108 KTPs was performed. Strength was evaluated by handgrip strength and five-times-sit-to-stand test (5STS), and appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. The ASM index (ASMI) was calculated using the ASM (kg)/height (m²). Functional capacity was assessed by the 4-m gait speed test and short physical performance battery (SPPB). The electrochemiluminescence method was used for analyzing CRP levels, and the cytometric method XN-3000 Sysmex was used for obtaining leukogram values to calculate the NLR. Linear regression analysis was used to assess the association between systemic inflammation and sarcopenia components, adjusting for confounders. NLR and CRP levels were not associated with handgrip strength (β =  - 0.231, p = 0.389; β =  - 0.291, p = 0.577), 5STS (β =  - 0.114, p = 0.288; β =  - 0.202, p = 0.334), ASM (β =  - 0.027, p = 0.813; β = 0.062, p = 0.788), ASMI (β =  - 0.036, p = 0.242; β = 0.040, p = 0.505), 4-m gait speed (β = 0.013, p = 0.082; β = 0.004, p = 0.769), and SPPB (β = 0.076, p = 0.170; β = 0.152, p = 0.157), respectively. In conclusion, NLR and CRP levels were not associated with muscle mass, strength, and functional capacity in KTPs.

The renal patient seen by non-renal physicians: the kidney embedded in the 'milieu intérieur'

Chronic kidney disease is defined as a decrease in renal function or evidence of kidney injury for >3 months. This represents an oversimplification that may confuse physicians. Thus kidney function is equated to glomerular filtration rate, which represents one of multiple kidney functions. Some potentially more important renal functions are lost earlier, such as the production for the anti-ageing factor Klotho. Overall, these changes modify the emergent properties of the body, altering the relationships between different organs and systems, in a manner that is difficult to predict the response to interventions based on normal physiology concepts, as there is a novel steady state of interorgan relations. In this regard we now discuss the impact of CKD on heart failure; osteomuscular and joint pain and bone fragility and fractures; and osteosarcopaenia as seen by a cardiologist, a rheumatologist and a geriatrician.

Body composition, adipokines, FGF23-Klotho and bone in kidney transplantation: Is there a link?

BACKGROUND

Kidney transplantation-associated mineral and bone disorder (KT-MBD) still represents a black box on the long-term due to scarce available data. We aimed to investigate the impact of non-classical bone regulating factors (body composition, adipokines, inflammatory markers, fibroblast growth factor 23-FGF23 and α-Klotho) in long-standing kidney transplant (KT) recipients compared to the general population.

METHODS

Our cross-sectional study, enrolling 59 KT patients and age, sex and body mass index-matched healthy general population volunteers, assessed the predictive role of the body composition, serum adipokines (leptin, adiponectin, resistin), inflammatory markers (erythrocyte sedimentation rate, C-reactive protein) and parathyroid hormone (PTH)-FGF23/α-Klotho axis upon bone mineral density (BMD) and osteocalcin, using correlation and linear multiple regression.

RESULTS

The 59 KT recipients (mean transplantation span of 57.7 ± 7.2 months) had similar body composition but significantly lower BMD (p < 0.01) compared to the general population group. Total lean mass was independently associated with BMD in both groups. In KT patients, age, time spent on dialysis and PTH were the main negative independent predictors of BMD, after adjusting for possible confounders. Resistin and α-Klotho also negatively predicted lumbar bone density (p < 0.001), while adiponectin and α-Klotho positively predicted osteocalcin levels (p < 0.001) in KT recipients, independently of inflammatory markers. No significant associations were found between FGF23 and bone parameters in any of the groups.

CONCLUSIONS

Age, PTH, time on dialysis and lean mass are among the main bone density predictors in long-standing KT patients. The bone impact of adipokine dysregulation and of α-Klotho merits further investigations in KT-MBD. Preserving lean mass for improved bone outcomes should be part of KT-MBD management on the long-term.

Physical activity and renal function in the Italian kidney transplant population

Background

The well-documented benefits of physical activity (PA) are still poorly characterized in long-term kidney transplant outcome. This study analyzed the impact over a 10-year follow-up of PA on graft function in Italian kidney transplant recipients (KTRs).

Methods

Since 2002, the Italian Transplant-Information-System collected donor and recipient baseline and transplant-related parameters in KTRs. In 2015, ‘penchant for PA’ (PA ≥ 30-min, 5 times/week) was added. Stable patients aged ≥18 years at the time of first-transplantation were eligible. KTRs with at least 10-year follow-up were also analyzed. Mixed-effect regression models were used to compare eGFR changes over time in active versus non-active patients.

Results

PA information was available for 6,055 KTRs (active 51.6%, non-active 48.4%). Lower penchant for PA was found in overweight and obese patients (OR = 0.84; OR = 0.48, respectively), in those with longer dialysis vintage (OR = 0.98 every year of dialysis), and older age at transplant. Male subjects showed greater penchant for PA (OR = 1.25). A slower decline of eGFR over time was observed in active KTRs compared to non-active, and this finding was confirmed in the subgroup with at least 10-year follow-up (n = 2,060). After applying the propensity score matching to reduce confounding factors, mixed-effect regression models corroborated such better long-term trend of graft function preservation in active KTRs.

Conclusions

Penchant for PA is more frequent among male and younger KTRs. Moreover, in our group of Italian KTRs, active patients revealed higher eGFR values and preserved kidney function over time, up to 10-years of follow-up.

Sarcopenia in chronic kidney disease: what have we learned so far?

The term sarcopenia was first introduced in 1988 by Irwin Rosenberg to define a condition of muscle loss that occurs in the elderly. Since then, a broader definition comprising not only loss of muscle mass, but also loss of muscle strength and low physical performance due to ageing or other conditions, was developed and published in consensus papers from geriatric societies. Sarcopenia was proposed to be diagnosed based on operational criteria using two components of muscle abnormalities, low muscle mass and low muscle function. This brought awareness of an important nutritional derangement with adverse outcomes for the overall health. In parallel, many studies in patients with chronic kidney disease (CKD) have shown that sarcopenia is a prevalent condition, mainly among patients with end stage kidney disease (ESKD) on hemodialysis (HD). In CKD, sarcopenia is not necessarily age-related as it occurs as a result of the accelerated protein catabolism from the disease and from the dialysis procedure per se combined with low energy and protein intakes. Observational studies showed that sarcopenia and especially low muscle strength is associated with worse clinical outcomes, including worse quality of life (QoL) and higher hospitalization and mortality rates. This review aims to discuss the differences in conceptual definition of sarcopenia in the elderly and in CKD, as well as to describe etiology of sarcopenia, prevalence, outcome, and interventions that attempted to reverse the loss of muscle mass, strength and mobility in CKD and ESKD patients.

Intake of polyunsaturated fatty acids and ω-3 are protective factors for sarcopenia in kidney transplant patients

OBJECTIVES

The aim of this study was to associate dietary intake with sarcopenia and its components in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 125 KTPs. Strength was evaluated by handgrip strength (HGS) and appendicular muscle mass was estimated by bioelectrical impedance. Functional capacity was assessed by 4-m walking test. Sarcopenia was diagnosed by revised European Consensus on Definition and Diagnosis (2019). Dietary assessment was carried out through two 24-h dietary recalls. It evaluated the consumption of energy (kcal), carbohydrates, protein (total and from animal and vegetable food sources), total fat, saturated fatty acids, monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and ω-3 (g) and ω-6 (g).

RESULTS

Intake of ω-3 was positively associated with appendicular skeletal muscle mass index (ASMI; kg/m²). The greater intake of PUFA (g and %) and ω-3 (g) was associated with lower chance to present low ASMI and sarcopenia. None of the other dietary components evaluated in the present study were associated with ASMI and sarcopenia. Walking speed and HGS were not associated with dietary variables.

CONCLUSIONS

Intake of ω-3 and PUFAs are protective factors for sarcopenia and low muscle mass, but not for strength and functional capacity, in KTPs.

Skeletal Muscle Mass Index Is Positively Associated With Bone Mineral Density in Hemodialysis Patients

Background: Patients with chronic kidney disease (CKD) are at risk for bone loss and sarcopenia because of associated mineral and bone disorders (MBD), malnutrition, and chronic inflammation. Both osteoporosis and sarcopenia are associated with a poor prognosis; however, few studies have evaluated the relationship between muscle mass and bone mineral density (BMD) in hemodialysis (HD) patients. The present study examined the association between skeletal muscle mass index (SMI) and BMD in the lumbar spine and femoral neck in HD patients. Methods: Fifty HD patients (mean age, 69 ± 10 years; mean HD duration, 9.0 ± 8.8 years) in Minami-Uonuma City Hospital were evaluated. BMD was measured by dual-energy X-ray absorptiometry, and SMI was measured by bioelectrical impedance analysis (InBody^TM) after HD. The factors affecting lumbar spine and femoral neck BMD were investigated, and multivariate analysis was performed. Results: In simple linear regression analysis, the factors that significantly affected the lumbar spine BMD were sex, presence of hypertension, presence of diabetes mellitus, body mass index, triglyceride level, grip strength, and SMI; the factors that significantly affected the femoral neck BMD were sex, HD duration, serum creatinine level, tartrate-resistant acid phosphatase 5b level, undercarboxylated osteocalcin (ucOC) level, N-terminal propeptide of type I procollagen level, grip strength, and SMI. In multivariate analysis, SMI (standardized coefficient: 0.578) was the only independent factor that affected the lumbar spine BMD; the independent factors that affected the femoral neck BMD were SMI (standardized coefficient: 0.468), ucOC (standardized coefficient: -0.366) and sex (standardized coefficient: 0.231). Conclusion: SMI was independently associated with the BMD in the lumbar spine and femoral neck in HD patients. The preservation of skeletal muscle mass could be important to prevent BMD decrease in HD patients, in addition to the management of CKD-MBD.

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.