Association of muscle strength and bone mineral density in adult survivors of childhood acute lymphoblastic leukemia

Bone mineral density in childhood cancer survivors during and after oncological treatment: A systematic review and meta-analysis

Osteoporosis poses a significant concern for childhood cancer survivors (CCS). While recommendations for surveillance and management of bone mineral density (BMD) exist, no systematic review and meta-analysis has been undertaken to quantify BMD Z-scores in childhood cancer patients undergoing cancer treatment and survivors who have completed treatments. Accordingly, we conducted a systematic review with a 3-level mixed-effects meta-analysis to examine the course of BMD Z-scores in childhood cancer patients and survivors and identified possible moderators using meta-regression models. A systematic search was conducted in CINAHL, Embase, PubMed, SPORTDiscus, and Web of Science databases from inception to November 2023. We included studies that involved children and adolescents diagnosed with cancer before the age of 18 who were undergoing cancer treatment or had completed treatments and reported lumbar spine, hip/femoral neck, or total body BMD Z-scores derived from dual-energy x-ray absorptiometry. Forty-nine studies (4547 participants) were included in the meta-analysis. BMD Z-scores across different sites decreased with respect to baseline in children undergoing cancer treatment (mean difference: - 0.36, 95% CI - 0.62 to - 0.11; p = .01) and remained low following treatment in child and adolescent CCS (lumbar spine: - 0.85 SD, 95% CI - 1.17 to - 0.54; p < .001; hip/femoral neck: - 1.03 SD, 95% CI - 1.38 to - 0.68; p < .001), and adult CCS (lumbar spine: - 0.46 SD, 95% CI - 0.67 to - 0.26; p < .001; hip/femoral neck: - 0.36 SD, 95% CI - 0.57 to - 0.16; p < .001). Hip/femoral neck BMD Z-scores were moderated by age at assessment (p = .006), time from diagnosis (p = .004), sex (p = .037), and height (p = .026). Lumbar spine BMD Z-scores were moderated by age at assessment (p = .018), and sex (p = .015). In conclusion, childhood cancer patients and survivors experience reductions in BMD. Future research should evaluate the implications of regular physical activity, targeted exercise medicine, and nutrition therapy as first-line countermeasures to mitigate the declines in bone health.

Bone mineral status at diagnosis οf children with hematologic malignancy

Reduced bone mineral density (BMD) has been reported during and after treatment of children with hematologic malignancies. However, little is known about the skeletal status of these patients at diagnosis. The aim of this study was to evaluate the skeletal profile of newly diagnosed pediatric patients with Acute lymphoblastic leukemia (ALL), Hodgkin Lymphoma (HL), and Non-Hodgkin Lymphoma (NHL). A case-control study included 50 children with ALL, 11 with HL, and 10 with NHL and compared them to 108 sex- and age-matched controls. Patients underwent bone metabolism evaluation and dual-energy X-ray absorptiometry (DXA) scan at the time of diagnosis. Seventy-one children were evaluated (43 boys) with a median age of 8.25 years (2.16-17.33 years). Twenty-one with ALL had bone pain (16 with a limp pain) at diagnosis. More than half (59.1%) of the patients were vitamin D sufficient (25-ΟΗ-D > 20 ng/ml). Patients had lower values of serum procollagen type I C-terminal propeptide (PICP), osteocalcin (OC), and tartrate-resistant acid phosphatase (bTRAP5b) (p < 0.001) than controls. A DXA scan was performed in 45 patients. Patients with ALL and Lymphoma had lower values of Lumbar Spine (L1-L4, LS) BMD Z-score (p < 0.001, p < 0.01, respectively) while those with ALL had lower values of Total Body Less Head (ΤBLH) BMD Z-score (p = 0.003) than controls. Skeletal health is adversely affected in pediatric patients with ALL and Lymphoma at diagnosis. These observations support bone health surveillance in cancer patients and timely intervention starting at the time of diagnosis.

Co-morbid sarcopenia and low bone mineral density in young paediatric cancer survivors

BACKGROUND

Sarcopenia and low areal bone mineral density (aBMD) are prevalent musculoskeletal complications after paediatric cancer treatment. However, their relationship has not been examined in young paediatric cancers survivors. This study aimed to evaluate aBMD differences according to sarcopenia status and the risk of low aBMD Z-score in young paediatric cancer survivors with sarcopenia confirmed/probable.

METHODS

This cross-sectional study included 116 paediatric cancer survivors (12.1 ± 3.3 years old; 42.2% female). Handgrip strength was used to assessed muscle strength. Dual-energy X-ray absorptiometry estimated aBMD (g/cm2) and appendicular lean mass index (ALMI, kg/m2). 'No sarcopenia' was defined when muscle strength was >decile 2. 'Sarcopenia probable' was defined when muscle strength was ≤ decile 2 and ALMI Z-score was > -1.5 standard deviation (SD). 'Sarcopenia confirmed' was defined when muscle strength was ≤ decile 2 and ALMI Z-score ≤ -1.5 SD. Analysis of covariance and logistic regression, adjusted for time from treatment completion, radiotherapy exposure, calcium intake, and physical activity, was used to evaluate aBMD and estimate the odds ratios (ORs) of low aBMD (aBMD Z-score < -1.0).

RESULTS

Survivors with sarcopenia confirmed had significantly lower aBMD than those without sarcopenia at total body (-1.2 [95% CI: -1.5 to -0.8] vs. 0.2 [-0.2 to 0.6], P < 0.001), lumbar spine (-0.7 [-1.1 to -0.3] vs. 0.4 [0.0 to 0.8], P < 0.001), total hip (-0.5 [-0.9 to -0.2] vs. 0.4 [0.1 to 0.8], P < 0.001), and femoral neck (-1.0 [-1.4 to -0.6] vs. 0.1 [-0.3 to 0.4], P = 0.001). Compared with survivors with sarcopenia probable, survivors with sarcopenia confirmed had significantly lower aBMD Z-score at total body (-1.2 [-1.5 to -0.8] vs. -0.2 [-0.7 to 0.4], P = 0.009), total hip (-0.5 [-0.9 to -0.2] vs. 0.5 [-0.1 to 1.0], P = 0.010), and femoral neck (-1.0 [-1.4 to -0.6] vs. 0.1 [-0.5 to 0.7], P = 0.014). Survivors with sarcopenia confirmed were at higher risk of low aBMD Z-score at the total body (OR: 6.91, 95% CI: 2.31-24.15), total hip (OR: 2.98, 1.02-9.54), and femoral neck (OR: 4.72, 1.72-14.19), than those without sarcopenia. Survivors with sarcopenia probable were at higher risk of low aBMD Z-score at the total body (OR: 4.13, 1.04-17.60) than those without sarcopenia.

CONCLUSIONS

Young paediatric cancer survivors with sarcopenia present higher risk of low aBMD. Resistance training-based interventions designed to mitigate osteosarcopenia in this population should be implemented at early stages.

Predictors of low and very low bone mineral density in long-term childhood acute lymphoblastic leukemia survivors: Toward personalized risk prediction

BACKGROUND

Cohorts of childhood acute lymphoblastic leukemia (cALL) survivors reaching adulthood are increasing. Approximately 30% of survivors meet criteria for low bone mineral density (BMD) 10 years after diagnosis. We investigated risk factors for low BMD in long-term cALL survivors.

METHODS

We recruited 245 cALL survivors from the PETALE (Prévenir les effets tardifs des traitements de la leucémie aiguë lymphoblastique chez l'enfant) cohort, who were treated with the Dana Farber Cancer Institute protocols, did not experience disease relapse or hematopoietic stem cell transplants, and presented with more than 5 years of event-free survival. Median time since diagnosis was 15.1 years.

RESULTS

Prevalence of low DXA-derived BMD (Z-score ≤-1) ranged between 21.9% and 25.3%, depending on site (lumbar spine (LS-BMD), femoral neck (FN-BMD), and total body (TB-BMD), and between 3.7% and 5.8% for very low BMD (Z-score ≤-2). Males had a higher prevalence of low BMD than females for all three outcomes (26%-32% vs. 18%-21%), and male sex acted as a significant risk factor for low BMD in all models. Treatment-related factors such as cumulative glucocorticoid (GC) doses and cranial radiation therapy (CRT) were associated with lower BMDs in the full cohort and in females at the FN-BMD site.

CONCLUSION

Low and very low BMD is more prevalent in male cALL survivors. Male sex, high cumulative GC doses, CRT, risk group, and low body mass index (BMI) were identified as risk factors for low BMD. A longer follow-up of BMD through time in these survivors is needed to establish if low BMD will translate into a higher risk for fragility fractures through adulthood.

Muscle strength deficits are associated with low bone mineral density in young pediatric cancer survivors: The iBoneFIT project

BACKGROUND

Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density (aBMD). However, the prevalence of muscle strength deficits is not well documented, and the associations of muscle strength with aBMD are unknown in this population. Therefore, this study aimed to investigate the prevalence of upper- and lower-body muscle strength deficits and to examine the associations of upper- and lower-body muscle strength with age-, sex, and race-specific aBMD Z-scores at the total body, total hip, femoral neck, and lumbar spine.

METHODS

This cross-sectional study included 116 pediatric cancer survivors (12.1 ± 3.3 years old, mean ± SD; 42.2% female). Upper- and lower-body muscle strength were assessed by handgrip and standing long jump test, respectively. Dual‑energy X‑ray absorptiometry was used to measure aBMD (g/cm2). Associations between muscle strength and aBMD were evaluated in multivariable linear regression models. Logistic regression was used to evaluate the contribution of muscle strength (1-decile lower) to the odds of having low aBMD (Z-score ≤ 1.0). All analyses were adjusted for time from treatment completion, radiotherapy exposure, and body mass index.

RESULTS

More than one-half of survivors were within the 2 lowest deciles for upper- (56.9%) and lower- body muscle strength (60.0%) in comparison to age- and sex-specific reference values. Muscle strength deficits were associated with lower aBMD Z-scores at all sites (B = 0.133-0.258, p = 0.001-0.032). Each 1-decile lower in upper-body muscle strength was associated with 30%-95% higher odds of having low aBMD Z-scores at all sites. Each 1-decile lower in lower-body muscle strength was associated with 35%-70% higher odds of having low aBMD Z-scores at total body, total hip, and femoral neck.

CONCLUSION

Muscle strength deficits are prevalent in young pediatric cancer survivors, and such deficits are associated with lower aBMD Z-scores at all sites. These results suggest that interventions designed to improve muscle strength in this vulnerable population may have the added benefit of improving aBMD.

Clinical applicability of short form of Bruininks-Oseretsky Test of Motor Proficiency Second Edition in patients after treatment of acute lymphoblastic leukemia

Introduction

Acute lymphoblastic leukaemia (ALL) ranks among paediatrics' most common oncological malignancies. Monitoring motor performance levels associated with self-sufficiency in the everyday activities of ALL patients is extremely important during treatment. The motor development of children and adolescents with ALL is most often assessed using the Bruininks-Oseretsky Test of Motor Proficiency Second Edition (BOT-2) complete form (CF) with 53 items or the short form (SF) with 14 items. However, there is no evidence in research that BOT-2 CF and SF give comparable results in the population of patients with ALL.

Objective

This study aimed to determine the compatibility of motor proficiency levels achieved from BOT-2 SF and BOT-2 CF in ALL survivors.

Materials and Method

The research sample consists of n = 37 participants (18 girls, 19 boys) aged 4-21 years (10.26, ± SD 3.9) after treatment for ALL. All participants passed BOT-2 CF and were at least 6 months and a maximum of 6 years from the last dose of vincristine (VCR). We used ANOVA with repeated measures, considering the sex, intra-class correlation (ICC) for uniformity between BOT-2 SF and BOT-2 CF scores and Receiving Operating Characteristic.

Results

BOT-2 SF and BOT-2 CF assess the same underlying construct, and BOT-2 SF and CF standard scores have good uniformity: ICC = 0.78 for boys and ICC = 0.76 for girls. However, results from ANOVA showed that the participants achieved a significantly lower standard score in SF (45.1 ± 7.9) compared to CF (49.1 ± 9.4) (p < 0.001; Hays ω ² = 0.41). ALL patients performed the worst in Strength and Agility. According to the ROC analysis, BOT-2 SF obtains acceptable sensitivity (72.3%) and high specificity (91.9%) with high accuracy of 86.1%, and the fair value of the Area Under the Curve (AUC) = 0.734 CI95% (0.47-0.88) in comparison to BOT-2 CF.

Conclusions

To reduce the burden on ALL patients and their families, we recommend using BOT-2 SF instead of BOT-2 CF as a useful screening tool. BOT-SF can replicate motor proficiency with as high probability as BOT-2 CF but systematically underestimates motor proficiency.

Physical and functional performance assessment in pediatric oncology: a systematic review

BACKGROUND

Research indicates reduced physical performance from diagnosis into survivorship of pediatric cancer patients. However, there is no systematic information or guideline available on the methods to assess physical performance and function in this population. The purpose was to systematically compile and describe assessments of physical performance and function in patients and survivors of pediatric cancer, including cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait and motor performance test batteries.

METHODS

We searched the databases PubMed, SPORTDiscus, and Cochrane Database and performed abstract and full-text selection of 2619 articles according to the Cochrane Handbook of Systematic Reviews. Information on patients characteristics, assessments, information on validity and reliability, and relevant references was extracted.

RESULTS

In summary, 63 different assessments were found in 149 studies including 11639 participants. Most studies evaluated cardiorespiratory fitness and muscle strength with the majority conducted off treatment. Some outcomes (e.g. speed) and diagnoses (e.g. neuroblastoma) were severely underrepresented. With the exception of gait, leukemia patients represented the largest group of individuals tested.

CONCLUSIONS

Insufficient data and patient heterogeneity complicate uniform recommendations for assessments. Our results support researchers and practitioners in selecting appropriate assessment to meet their specific research questions or individual daily practice needs.

IMPACT

This systematic review includes 149 studies and provides a comprehensive summary of 63 assessments to evaluate cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait or motor performance test batteries in patients and survivors of pediatric cancer. We present the most studied fields within the pediatric cancer population, which are cardiorespiratory fitness and muscle strength, off treatment phase, and leukemia patients. We propose research priorities by identification of subgroups in terms of cancer type, phase of treatment, and outcome of interest that are underrepresented in studies currently available.

Bone mineral density surveillance for childhood, adolescent, and young adult cancer survivors: evidence-based recommendations from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Childhood, adolescent, and young adult cancer survivors are at increased risk of reduced bone mineral density. Clinical practice surveillance guidelines are important for timely diagnosis and treatment of these survivors, which could improve bone mineral density parameters and prevent fragility fractures. Discordances across current late effects guidelines necessitated international harmonisation of recommendations for bone mineral density surveillance. The International Late Effects of Childhood Cancer Guideline Harmonization Group therefore established a panel of 36 experts from ten countries, representing a range of relevant medical specialties. The evidence of risk factors for very low and low bone mineral density and fractures, surveillance modality, timing of bone mineral density surveillance, and treatment of very low and low bone mineral density were evaluated and critically appraised, and harmonised recommendations for childhood, adolescent, and young adult cancer survivors were formulated. We graded the recommendations based on the quality of evidence and balance between potential benefits and harms. Bone mineral density surveillance is recommended for survivors treated with cranial or craniospinal radiotherapy and is reasonable for survivors treated with total body irradiation. Due to insufficient evidence, no recommendation can be formulated for or against bone mineral density surveillance for survivors treated with corticosteroids. This surveillance decision should be made by the survivor and health-care provider together, after careful consideration of the potential harms and benefits and additional risk factors. We recommend to carry out bone mineral density surveillance using dual-energy x-ray absorptiometry at entry into long-term follow-up, and if normal (Z-score > -1), repeat when the survivor is aged 25 years. Between these measurements and thereafter, surveillance should be done as clinically indicated. These recommendations facilitate evidence-based care for childhood, adolescent, and young adult cancer survivors internationally.

Relationships of Bone Mineral Density to Whole Body Mass, Fat Mass and Fat-free Mass in Long-term Survivors of Acute Lymphoblastic Leukemia in Childhood

Body size influences bone mineral density (BMD) in health. Relationships of BMD with body mass index, fat mass (FM), fat-free mass, and appendicular lean mass were explored in acute lymphoblastic leukemia (ALL) survivors (n=75; 41 males; 45 standard risk ALL) >10 years from diagnosis. Dual energy radiograph absorptiometry performed body composition analysis. Relationships were assessed by regression analyses and Pearson correlation coefficients (r). Twenty subjects (26.3%) were osteopenic; lumbar spine (LS) BMD Z score <-1.00. Age at diagnosis, sex, ALL risk-category, type of post-induction steroid or cranial radiation did not correlate with LS or whole body (WB) BMD. Body mass index correlated significantly with LS BMD (r=0.333, P=0.004) and WB BMD (r=0.271, P=0.033). FM index (FM/height²) Z score showed no significant correlation with LS or WB BMD. Fat-free mass index Z score correlated strongly with LS BMD (r=0.386, P=0.013) and WB BMD (r=0.605, P<0.001) in males but not in females. The appendicular lean mass index, a surrogate for skeletal muscle mass, correlated significantly with LS BMD (r=0.367, P=0.018) and WB BMD (r=0.604, P<0.001) in males but not in females. Future studies to evaluate interventions to enhance BMD focused on improving body composition particularly skeletal muscle mass are warranted.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Prevention of Long-term Adverse Health Outcomes With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Most childhood acute lymphoblastic leukemia (ALL) survivors develop chronic treatment-related adverse effects several years after the end of therapy. A regular practice of physical activity and a good cardiorespiratory fitness have the potential to reduce the risk of chronic disease and improve quality of life. The aim of this study was to evaluate in a cohort of ALL survivors, the association between a good cardiorespiratory fitness or the respect of physical activity guidelines and major long-term health outcomes.

METHODS

In total, 247 ALL survivors underwent a cardiopulmonary exercise test, completed a physical activity questionnaire and a battery of clinical examinations. We calculated the odds ratio to obtain the preventive fraction (PF) to evaluate the effects of the cardiorespiratory fitness and physical activity levels on health outcomes (ie, obesity, metabolic health, cardiac health, cognitive health and mood, bone health).

RESULTS

Despite their young age, 88% of the participants presented at least one adverse health outcome, and 46% presented ≥3. Their cardiorespiratory fitness was also lower than expected with a median VO2 peak reaching 84% of the predicted value. In the analyses using cardiorespiratory fitness, statistically significant PFs were observed for obesity (0.30), low-high-density lipoprotein-cholesterol (0.21) and depression (0.26). In the physical activity level analyses, statistically significant PFs were observed for obesity, depression, and low bone mineral density, with a PF of 0.55, 0.81, and 0.60, respectively.

CONCLUSIONS

Our results indicate that a good cardiorespiratory fitness and physical activity level induced a preventive action for most health outcomes studied and was associated with a lower late adverse effects prevalence in ALL survivors.

Severity of reduced bone mineral density and risk of fractures in long-term survivors of childhood leukemia and lymphoma undergoing guideline-recommended surveillance for bone health

BACKGROUND

Survivors of childhood leukemia/lymphoma are at increased risk for reduced bone mineral density (BMD). The authors sought to determine the frequency of reduced BMD detected by off-therapy surveillance, factors associated with reduced BMD, and the association of reduced BMD with fractures.

METHODS

This cross-sectional study included childhood leukemia/lymphoma survivors attending 2 survivorship clinics who received guideline-recommended BMD surveillance ≥2 years post-therapy with dual-energy x-ray absorptiometry (from January 1, 2004 to August 31, 2016). Lumbar spine BMD z-scores were height-for-age-adjusted. Low and very low BMD were >1 SD and >2 SDs below norms, respectively. Treatment, chronic conditions, and fractures were abstracted from medical records. Logistic regression was used to examine the association of low BMD with patient/treatment factors and fractures.

RESULTS

In total, 542 patients (51.5% female) with a mean age of 15.5 years (range, 4.4-52.2 years) who were 6 years post-therapy (range, 2.0-35.1 years) were evaluated, including 116 who reported post-therapy fractures. Lumbar spine low BMD was identified in 17.2% of survivors, and very low BMD was identified in 3.5% of survivors, but frequencies varied considerably between subgroups; 10.8% of survivors aged 15 to 19 years at diagnosis had very low BMD. In multivariable analyses, older age at diagnosis, white race, and being underweight were significantly associated with low BMD. Survivors with low BMD had greater odds of nondigit fractures (odds ratio, 2.2; 95% CI, 1.3-3.7) and specifically long-bone fractures (odds ratio, 2.7; 95% CI, 1.5-4.7).

CONCLUSIONS

In this study of childhood leukemia/lymphoma survivors undergoing guideline-recommended dual-energy x-ray absorptiometry surveillance, patients who were older at diagnosis, white, and underweight were at the highest risk for lumbar spine low BMD. Low BMD was associated with a greater risk of fractures, emphasizing the clinical importance of surveillance.

Prediction of Low and Very Low Bone Mineral Density Among Adult Survivors of Childhood Cancer

PURPOSE

To develop and validate prediction models for low and very low bone mineral density (BMD) on the basis of clinical and treatment characteristics that identify adult survivors of childhood cancer who require screening by dual-energy x-ray absorptiometry.

PATIENTS AND METHODS

White survivors of childhood cancer (n = 2,032; median attained age, 29.3 years [range, 18.1 to 40.9 years]) enrolled in the St Jude Lifetime Cohort (SJLIFE; development) and survivors treated at the Erasmus Medical Center (validation) in the Netherlands (n = 403; median age, 24.2 years [range, 18.0 to 40.9 years]) were evaluated with dual-energy x-ray absorptiometry to determine lumbar spine BMD and total-body BMD. Low and very low BMD were defined as lumbar spine BMD and/or total-body BMD z scores of -1 or lower or -2 or lower, respectively. Multivariable logistic regression was used to build prediction models; performance was assessed using receiver operating characteristic curves. Diagnostic values were calculated at different probabilities.

RESULTS

Low BMD was present in 51% and 45% of SJLIFE and Dutch participants, respectively, and very low BMD was present in 20% and 10%, respectively. The model for low BMD included male sex (odds ratio [OR], 3.07), height (OR, 0.95), weight (OR, 0.98), attained age (OR, 0.97), current smoking status (OR, 1.48), and cranial irradiation (OR, 2.11). Areas under the curve were 0.72 (95% CI, 0.70 to 0.75) in the SJLIFE cohort and 0.69 (95% CI, 0.64 to 0.75) in the Dutch cohort. The sum of the sensitivity (69.0%) and specificity (64.0%) was maximal at the predicted probability of 50%. The model for very low BMD included male sex (OR, 3.28), height (OR, 0.95), weight (OR, 0.97), attained age (OR, 0.98), cranial irradiation (OR, 2.07), and abdominal irradiation (OR, 1.61), yielding areas under the curve of 0.76 (95% CI, 0.73 to 0.78; SJLIFE cohort) and 0.75 (95% CI, 0.67 to 0.83; Dutch cohort).

CONCLUSION

Validated prediction models for low and very low BMD, using easily measured patient and treatment characteristics, correctly identified BMD status in most white adult survivors through age 40 years.

Combating osteoporosis and obesity with exercise: leveraging cell mechanosensitivity

Osteoporosis, a condition of skeletal decline that undermines quality of life, is treated with pharmacological interventions that are associated with poor adherence and adverse effects. Complicating efforts to improve clinical outcomes, the incidence of obesity is increasing, predisposing the population to a range of musculoskeletal complications and metabolic disorders. Pharmacological management of obesity has yet to deliver notable reductions in weight and debilitating complications are rarely avoided. By contrast, exercise shows promise as a non-invasive and non-pharmacological method of regulating both osteoporosis and obesity. The principal components of exercise - mechanical signals - promote bone and muscle anabolism while limiting formation and expansion of fat mass. Mechanical regulation of bone and marrow fat might be achieved by regulating functions of differentiated cells in the skeletal tissue while biasing lineage selection of their common progenitors - mesenchymal stem cells. An inverse relationship between adipocyte versus osteoblast fate selection from stem cells is implicated in clinical conditions such as childhood obesity and increased marrow adiposity in type 2 diabetes mellitus, as well as contributing to skeletal frailty. Understanding how exercise-induced mechanical signals can be used to improve bone quality while decreasing fat mass and metabolic dysfunction should lead to new strategies to treat chronic diseases such as osteoporosis and obesity.

Modifying bone mineral density, physical function, and quality of life in children with acute lymphoblastic leukemia

BACKGROUND

The early effects of childhood acute lymphoblastic leukemia (ALL) include decreased physical function, bone mineral density (BMD/g/cm2 ), and health-related quality of life (HRQL). We assessed the capacity of a physical therapy and motivation-based intervention, beginning after diagnosis and continuing through the end of treatment, to positively modify these factors.

PROCEDURE

A 2.5-year randomized controlled trial of 73 patients aged 4-18.99 years within 10 days of ALL diagnosis assessed BMD at baseline (T0 ) and end of therapy (T3 ), strength, range of motion, endurance, motor skills, and HRQL at baseline (T0 ), 8 (T1 ), 15 (T2 ), and 135 (T3 ) weeks.

RESULTS

There were no significant changes between groups (intervention, n = 33; usual care, n = 40) in BMD (P = 0.059) at T3 or physical function and HRQL at T0 -T3 . While BMD declined in both the intervention (T0  = -0.21, T3  = -0.55) and usual care (T0  = -0.62, T3  = -0.78) groups, rates of decline did not differ between groups (P = 0.56). Univariate analysis (n = 73) showed associations of higher T3 bone density with body mass index T1 (P = 0.01), T2 (P = <0.0001), T3 (P = 0.01), T3 ankle flexibility/strength (P = 0.001), and T2 parent (P = 0.02)/T0 child (P = 0.03) perceptions of less bodily pain.

CONCLUSIONS

The intervention delivered during treatment was not successful in modifying BMD, physical function, or HRQL. Physical activity, at the level and intensity required to modify these factors, may not be feasible during early treatment owing to the child's responses to the disease and treatment. Future studies will consider intervention implementation during late maintenance therapy, extending into survivorship.

Impairments of Lower Extremity Muscle Strength and Balance in Childhood Cancer Patients and Survivors: A Systematic Review

This review aims to summarize the evidence for impairments of muscle strength and balance during and after treatment for childhood cancer. Thirty-two articles, identified in scientific databases by means of a structured search for investigations of muscle strength and balance in pediatric cancer patients and survivors, are evaluated. A summary of results is given with respect to matching reporting items to provide a qualitative analysis of the evidence. The majority of the studies reached a level 3 rating according to Oxford Centre for Evidence-Based Medicine (OCEBM) 2011 levels of evidence. Muscle strength and balance seem to be impaired in varying degrees depending on the diagnosis, treatment received, and time elapsed between treatment and evaluation. Drawing specific conclusions from the identified studies is difficult because of heterogeneous study samples and methods of research. Individual targeted exercise therapy programs during treatment and follow-up of childhood cancer could help to prevent and further diminish impairments of muscle strength and balance function among childhood cancer patients and survivors.

Dietary Protein Intake and Lean Muscle Mass in Survivors of Childhood Acute Lymphoblastic Leukemia: Report From the St. Jude Lifetime Cohort Study

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for low lean muscle mass and muscle weakness, which may contribute to inactivity and early development of chronic diseases typically seen in older adults. Although increasing protein intake, in combination with resistance training, improves lean muscle mass in other populations, it is not known whether muscular tissue among survivors of ALL, whose impairments are treatment-related, will respond similarly.

OBJECTIVE

The aim of this study was to evaluate associations among dietary protein intake, resistance training, and lean muscle mass in survivors of ALL and age-, sex-, and race-matched controls.

DESIGN

This was a cross-sectional study.

METHODS

Lean muscle mass was determined with dual-energy x-ray absorptiometry, dietary information with 24-hour recalls, and participation in resistance training with a questionnaire. Participants were 365 survivors of ALL (52% male; 87% white; median age=28.5 years, range=23.6-31.7) and 365 controls with no previous cancer.

RESULTS

Compared with controls, survivors of ALL had lower lean muscle mass (55.0 versus 57.2 kg, respectively) and lower percentage of lean muscle mass (68.6% versus 71.4%, respectively) than controls. Similar proportions of survivors (71.1%) and controls (69.7%) met recommended dietary protein intake (0.8 g/kg/d). Survivors (45.4%) were less likely to report resistance training than controls (53.8%). In adjusted models, 1-g higher protein intake per kilogram of body mass per day was associated with a 7.9% increase and resistance training ≥1×wk, with a 2.8% increase in lean muscle mass.

LIMITATIONS

The cross-sectional study design limits temporal evaluation of the association between protein intake and lean muscle mass.

CONCLUSIONS

The findings suggest that survivors of childhood ALL with low lean muscle mass may benefit from optimizing dietary protein intake in combination with resistance training. Research is needed to determine whether resistance training with protein supplementation improves lean muscle mass in survivors of childhood ALL.

Bone mineral density after childhood cancer in 346 long-term adult survivors of childhood cancer

SUMMARY

More than 45 % of long-term childhood cancer survivors (CCS) were diagnosed with osteopenia. Our data suggest that greater awareness for osteopenia is warranted in long-term CCS, especially in survivors who are older than 30 years, male, and underweight and were treated with cranial-spinal radiotherapy and/or steroids.

INTRODUCTION

Osteopenia is a potential complication of childhood cancer treatment, but the magnitude of this problem in survivors is unknown. We examined (determinants of) bone mineral density (BMD) status in long-term survivors of adult childhood cancer.

METHODS

This retrospective single-centre cohort study included 346 subjects with the most common types of childhood cancer. Subjects had a median age at diagnosis of 7.0 years (range 0.1-16.8 years), a median age at follow-up of 24.5 years (range 18.0-47.6 years) and a median follow-up time of 16.7 years (range 5.6-39.9 years). Total body BMD (BMDTB) and BMD of the lumbar spine (BMDLS) were measured by dual X-ray absorptiometry. Osteopenia was defined as BMD standardized deviation score (SDS) below -1.

RESULTS

Survivors had a lower BMDTB and BMDLS (mean SDS -0.55; p<0.001 and -0.30; p<0.001, respectively) as compared to healthy peers. Osteopenia (BMDTB and/or BMDLS) was present in 45% of the survivors. Multivariate logistic regression analyses identified age at diagnosis<12 years, age>30 years at follow-up, male gender, underweight at follow-up and treatment with cranial-spinal radiotherapy or prednisone as independent prognostic factors for osteopenia.

CONCLUSIONS

This large cohort of childhood cancer survivors identified osteopenia in 45% of CCS. This indicates that greater awareness is warranted, especially in survivors who are older than 30 years, male, have underweight and were treated with cranial-spinal radiotherapy and/or steroids.

Skeletal, neuromuscular and fitness impairments among children with newly diagnosed acute lymphoblastic leukemia

This study describes skeletal, neuromuscular and fitness impairments among 109 children (median age 10 [range 4-18] years, 65.1% male, 63.3% white) with acute lymphoblastic leukemia (ALL). Outcomes were measured 7-10 days after diagnosis and compared to age- and sex-specific expected values. Associations between function and health-related quality of life (HRQL) were evaluated with logistic regression. Children with ALL had sub-optimal bone mineral density (BMD) Z-score/height (mean ± standard error: - 0.53 ± 0.16 vs. 0.00 ± 0.14, p < 0.01), body mass index percentile (57.6 ± 3.15 vs. 50.0 ± 3.27%, p = 0.02), quadriceps strength (201.9 ± 8.3 vs. 236.1 ± 5.4 N, p < 0.01), 6 min walk distance (385.0 ± 13.1 vs. 628.2 ± 7.1 m, p < 0.001) and Bruininks-Oseretsky Test of Motor Proficiency scores (23 ± 2.5 vs. 50 ± 3.4%, p < 0.01). Quadriceps weakness was associated with a 20.9-fold (95% confidence interval 2.5-173.3) increase in poor physical HRQL. Children with newly diagnosed ALL have weakness and poor endurance and may benefit from early rehabilitation that includes strengthening and aerobic conditioning.

Musculoskeletal disorders in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by airway obstruction and inflammation but also accompanied by several extrapulmonary consequences, such as skeletal muscle weakness and osteoporosis. Skeletal muscle weakness is of major concern, since it leads to poor functional capacity, impaired health status, increased healthcare utilization, and even mortality, independently of lung function. Osteoporosis leads to fractures and is associated with increased mortality, functional decline, loss of quality of life, and need for institutionalization. Therefore, the presence of the combination of these comorbidities will have a negative impact on daily life in patients with COPD. In this review, we will focus on these two comorbidities, their prevalence in COPD, combined risk factors, and pathogenesis. We will try to prove the clustering of these comorbidities and discuss possible preventive or therapeutic strategies.

Bone mineral density deficits and fractures in survivors of childhood cancer

Although substantial increases in survival rates among children diagnosed with cancer have been observed in recent decades, survivors are at risk of developing therapy-related chronic health conditions. Among children and adolescents treated for cancer, acquisition of peak bone mass may be compromised by cancer therapies, nutritional deficiencies, and reduced physical activity. Accordingly, failure to accrue optimal bone mass during childhood may place survivors at increased risk for deficits in bone density and fracture in later life. Current recommendations for the treatment of bone density decrements among cancer survivors include dietary counseling and supplementation to ensure adequate calcium and vitamin D intake. Few strategies exist to prevent or treat bone loss. Moving forward, studies characterizing the trajectory of changes in bone density over time will facilitate the development of interventions and novel therapies aimed at minimizing bone loss among survivors of childhood cancer.

Do childhood cancer survivors with physical performance limitations reach healthy activity levels?

BACKGROUND

The extent to which physical performance limitations affect the ability of childhood cancer survivors to reach healthy activity levels is unknown. Therefore this study aims to describe the effect of different types of limitations on activity levels in survivors.

PROCEDURE

Within the Swiss Childhood Cancer Survivor Study we sent a questionnaire to all survivors (≥16 years) registered in the Swiss Childhood Cancer Registry, who survived >5 years and were diagnosed 1976-2005 aged <16 years. We measured healthy activity levels using international guidelines and assessed different kinds of performance limitations (visual impairment, weight and endurance problems, cardiorespiratory, musculoskeletal, and neurological problems, pain and fatigue syndromes).

RESULTS

The sample included 1,560 survivors (75% response rate), of whom 209 (13.5%) reported they have performance limitations. Forty-two percent of survivors with limitations reached healthy activity levels, compared to 57% of survivors without limitations. Least active were survivors with vision impairments (25% active), weight and endurance problems (27.3%), cardiorespiratory problems (36.4%), and musculoskeletal problems (43.1%). After adjusting for socio-demographic variables and type of cancer, we found that survivors with limitations were 1.4 (95%CI 1.0-2.0; P = 0.047) times more likely to be inactive.

CONCLUSIONS

Although many survivors with physical performance limitations maintain healthy activity levels, there is room for improvement. Adapted and targeted physical activity counseling for survivors with performance limitations might help them to raise level of activity and pursue a healthy lifestyle.