Bone mineral metabolism and its relationship to leptin levels in survivors of childhood leukemia and lymphoma

Leptin Levels and Bone Mineral Density: A Friend or a Foe for Bone Loss? A Systematic Review of the Association Between Leptin Levels and Low Bone Mineral Density

The introduction of CFTR modulators in the clinics has improved body mass index in cystic fibrosis (CF) individuals. Leptin is a major regulator of appetite and energy expenditure but is also involved in bone metabolism. Whether circulating leptin levels are associated with low bone mineral density (BMD) and fracture risk in CF remains unknown. Therefore, the present study aims to analyze and integrate the current evidence linking leptin and bone loss in CF. As no scientific evidence was found, we focused on secondary dysregulations of bone loss in CF that may be linked to pathologies that are similar to the various dysregulations and multisystemic manifestations in CF. Studies published from 2001 to 2022 were identified through the PubMed, Scopus, and Web of Science databases, and screening was performed following the PRISMA guidelines. The included studies were assessed using a quality checklist. From the 774 records identified, 28 studies met the inclusion criteria. Although no evidence has been found directly related to bone loss in CF individuals, some studies revealed a positive association between leptin levels and BMD, while others found an inverse association. Current evidence suggests that for circulating leptin levels to be a predictive biomarker of bone health, further research will be needed to reveal the direct and indirect mechanisms behind leptin and bone loss and to understand whether changes in leptin levels correlate with changes in BMD. Of note, studies with CF people would be of high importance to understand the role of leptin in CF-related bone disease.

Bone Mineral Density in Survivors of Childhood Cancer: A Meta-Analysis

CONTEXT

There is an increasing population of childhood cancer survivors (CCS) at risk for treatment-related toxicities, including skeletal morbidities. Bone mineral density (BMD) is a proxy for bone health and reductions are associated with osteoporosis and fractures.

OBJECTIVE

To investigate bone health in CCS by conducting a systematic review and meta-analysis of BMD after completed treatments.

DATA SOURCES

We searched Medline, Embase, Cochrane, and Web of Science in May 2019 and updated in May 2023.

STUDY SELECTION

Studies reporting BMD Z-scores measured with dual-energy x-ray absorptiometry in CCS after treatment completion.

DATA EXTRACTION

We performed a pooled analysis of studies reporting BMD Z-scores and thereafter we analyzed studies comparing BMD in survivors and healthy controls. All analyses were performed based on the site of BMD measurement.

RESULTS

Of 4243 studies, 84 were included (N = 8106). The mean time off-treatment across the studies ranged from 2 months to 24 years. The overall pooled mean Z-score was -0.57 (95% confidence interval [CI] -0.59 to -0.55) in the whole-body, -0.84 (95% CI -0.86 to -0.83) in the lumbar spine, -0.79 (95% CI -0.81 to -0.77) in the femoral neck and -0.14 (95% CI -0.18 to -0.11) in the total hip. When comparing survivors with controls, BMD was significantly lower in survivors at all sites.

LIMITATIONS

English publications, study-level meta-analysis.

CONCLUSIONS

We showed a significant reduction of BMD Z-scores in CCS. Given the increased fracture risk already within -1 SD, these results emphasize the need for BMD surveillance and secondary prevention in CCS.

Obesity and Risk for Lymphoma: Possible Role of Leptin

Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses.

SEARCH METHODS

On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017.

SELECTION CRITERIA

Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies.

AUTHORS' CONCLUSIONS

The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

The role of adiponectin, LEPTIN, and ghrelin in the progress and prognosis of childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Dysregulation of adipokine pathways is implicated in the carcinogenesis and ALL. The aim of this study is to present the most recent data available regarding the role of leptin, adiponectin and ghrelin in the pathogenesis and prognosis of ALL. The PubMed database was searched using 'Leptin', 'Adiponectin', 'Ghrelin', 'Cancer', 'Children' and 'Acute Lymphoblastic Leukemia' as keywords. The majority of the studies indicated that leptin levels are increased and adiponectin levels are decreased in ALL children at diagnosis, as well as in ALL survivors. Ghrelin levels were found to be lower at diagnosis and progressively increased during treatment. Further research is warranted, as the heterogeneity of the current studies, various treatment protocols and differences in sample sizes make it difficult to deduce solid conclusions regarding the role of adipokines in ALL.

Visfatin is a positive predictor of bone mineral density in young survivors of acute lymphocytic leukemia

Bone mass acquisition may be compromised in survivors of childhood acute lymphocytic leukemia due to various factors, including adiposity. Fat accumulation can affect bone through the direct effect of adipokines or indirectly through the state of chronic inflammation. The aim of this study was to evaluate the effect of body composition and adipokines on bone mass in survivors of acute lymphocytic leukemia. This was a cross-sectional study of 56 survivors aged between 15 and 24 years, 44.6 % of whom received cranial radiotherapy (18-24 Gy), assessed according to body fat, lean mass, and bone mineral density (dual energy X-ray absorptiometry), computed tomography scan-derived abdominal adipose tissue, and adipokines by a multiple regression analysis. Both lumbar spine L₁-L₄ (trabecular bone) and total body (cortical bone) bone mineral density were positively correlated with visfatin (p < 0.050). Lean mass index was positively correlated, while waist-to-height ratio was negatively correlated with cortical bone (p < 0.010). Low bone mineral density for chronological age was detected in 5.4 % of patients in total body, and 8.9 % at the lumbar spine. In survivors of acute lymphocytic leukemia, visfatin may play an important role in the complex relationship between body composition and bone. At present, visfatin may represent a model for further study of bone metabolism, and could possibly explain the unknown mechanisms linking bone metabolism and cancer.

Body composition parameters and adipokines levels in relation to bone mineral density in patients with malignant bone tumors after treatment

BACKGROUND

Recent data support the concept that adipokines, which are secreted by fat cells, are important modulators of bone metabolism. The aim of this study was to assess the relationships between body composition parameters, adipokines (leptin, adiponectin) and bone mineral density (BMD) in patients with malignant bone tumors after anticancer therapy.

PROCEDURE

The study included 35 patients (median age 14.8 years) with diagnosed malignant bone tumors treated according to obligatory protocols. Total fat mass, lean mass, bone mineral content (BMC) and BMD measurements were performed after treatment completion by dual energy-ray absorptiometry (DXA). Serum concentrations of leptin, leptin receptor and adiponectin were determined using immunoenzymatic assays. The control group consisted of 28 healthy children (median age 14.3 years).

RESULTS

Patients with bone tumor after chemotherapy had significantly higher fat mass (P < 0.01), increased ratio of fat mass/lean mass (P < 0.001), and a decrease (P < 0.001) in total body and lumbar spine BMD compared with controls. We observed higher serum leptin concentration (P < 0.01) and lower soluble leptin receptor (P < 0.001) and adiponectin (P = 0.01) in patients than in controls. The ratios of leptin/leptin receptor and leptin/adiponectin were about three-fold higher in patients compared with the control group (P = 0.001). We found a significant positive correlation between BMD and body composition and a negative correlation between BMD and adiponectin in the patients group.

CONCLUSIONS

Changes in body composition parameters coexisting with disturbed adipokine levels, especially higher levels of leptin and lower levels of adiponectin, might be associated with bone status in patients treated for malignant bone tumors.

Early and late renal adverse effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Great improvements in diagnostics and treatment for malignant disease in childhood have led to a major increase in survival. However, childhood cancer survivors (CCS) are at great risk for developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is one of these known (acute) side effects of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate impairment, proteinuria, tubulopathy and hypertension. However, evidence about the long-term effects of these treatments on renal function remains inconclusive. To reduce the number of (long-term) nephrotoxic events in CCS, it is important to know the risk of, and risk factors for, early and late renal adverse effects, so that ultimately treatment and screening protocols can be adjusted.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of and associated risk factors for renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with healthy controls or CCS treated without potentially nephrotoxic treatment.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2011), MEDLINE/PubMed (from 1945 to December 2011) and EMBASE/Ovid (from 1980 to December 2011).

SELECTION CRITERIA

With the exception of case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment) in children and adults who were treated for a paediatric malignancy (aged 18 years or younger at diagnosis) with cisplatin, carboplatin, ifosfamide, radiation including the kidney region and/or a nephrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction using standardised data collection forms. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

The search strategy identified 5504 studies, of which 5138 were excluded on the basis of title and/or abstract. The full-text screening of the remaining 366 articles resulted in the inclusion of 57 studies investigating the prevalence of and sometimes also risk factors for early and late renal adverse effects of treatment for childhood cancer. The 57 studies included at least 13,338 participants of interest for this study, of whom at least 6516 underwent renal function testing. The prevalence of renal adverse effects ranged from 0% to 84%. This variation may be due to diversity in included malignancies, prescribed treatments, reported outcome measurements and the methodological quality of available evidence.Chronic kidney disease/renal insufficiency (as defined by the authors of the original studies) was reported in 10 of 57 studies. The prevalence of chronic kidney disease ranged between 0.5% and 70.4% in the 10 studies and between 0.5% and 18.8% in the six studies that specifically investigated Wilms' tumour survivors treated with a unilateral nephrectomy.A decreased (estimated) glomerular filtration rate was present in 0% to 50% of all assessed survivors (32/57 studies). Total body irradiation; concomitant treatment with aminoglycosides, vancomycin, amphotericin B or cyclosporin A; older age at treatment and longer interval from therapy to follow-up were significant risk factors reported in multivariate analyses. Proteinuria was present in 0% to 84% of all survivors (17/57 studies). No study performed multivariate analysis to assess risk factors for proteinuria.Hypophosphataemia was assessed in seven studies. Reported prevalences ranged between 0% and 47.6%, but four of seven studies found a prevalence of 0%. No studies assessed risk factors for hypophosphataemia using multivariate analysis. The prevalence of impairment of tubular phosphate reabsorption was mostly higher (range 0% to 62.5%; 11/57 studies). Higher cumulative ifosfamide dose, concomitant cisplatin treatment, nephrectomy and longer follow-up duration were significant risk factors for impaired tubular phosphate reabsorption in multivariate analyses.Treatment with cisplatin and carboplatin was associated with a significantly lower serum magnesium level in multivariate analysis, and the prevalence of hypomagnesaemia ranged between 0% and 37.5% in the eight studies investigating serum magnesium.Hypertension was investigated in 24 of the 57 studies. Reported prevalences ranged from 0% to 18.2%. A higher body mass index was the only significant risk factor noted in more than one multivariate analysis. Other reported factors that significantly increased the risk of hypertension were use of total body irradiation, abdominal irradiation, acute kidney injury, unrelated or autologous stem cell donor type, growth hormone therapy and older age at screening. Previous infection with hepatitis C significantly decreased the risk of hypertension.Because of the profound heterogeneity of the studies, it was not possible to perform any meta-analysis.

AUTHORS' CONCLUSIONS

The prevalence of renal adverse events after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region and/or nephrectomy ranged from 0% to 84%. With currently available evidence, it was not possible to draw any conclusions with regard to prevalence of and risk factors for renal adverse effects. Future studies should focus on adequate study design and reporting and should deploy multivariate risk factor analysis to correct for possible confounding. Until more evidence becomes available, CCS should be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Vitamin D status and bone biomarkers in childhood cancer

Early detection of abnormalities in bone turnover may be facilitated by assessing biomarkers of bone metabolism including vitamin D status. In many children with cancer, biomarkers of bone formation (osteocalcin, bone specific alkaline phosphatase and carboxy-(or N terminal) propeptide of type 1 procollagen) were observed to be suppressed, while bone resorption was elevated as measured by serum cross-linked (or C-terminal) telopeptide of type 1 collagen. Insulin-like growth factor 1, which stimulates bone formation, may be suppressed indirectly indicating a growth hormone insufficiency. Leptin may also play a role in bone remodeling as hyperleptinemia has been observed in association with acute lymphoblastic leukemia. Evaluation of bone status using such biomarkers is complicated by the lack of universally accepted reference values and the variation by age, gender, or pubertal status. Etiologic factors contributing to the observed skeletal morbidities include disease process, chemotherapy (drugs such as glucocorticoids and methotrexate) and radiotherapy. Other factors common to children with cancer, such as chronic inflammation, dietary changes and physical inactivity, must also be taken into account. The current evidence for abnormalities in biomarkers of vitamin D status and bone turnover will be the focus of this review of published studies.