Young paediatric cancer survivors have compromised psychological health and tend to be more sedentary than their healthy peers. The main objective of this study is to examine the associations of 24-h movement behaviours (moderate-to-vigorous physical activity [MVPA], light physical activity [LPA], sedentary behaviour [SB] and sleep) with psychological well-being (happiness, optimism, positive affect, and self-esteem) and distress indicators (depression, anxiety and negative affect) in young paediatric cancer survivors by somatic maturity. This cross-sectional multicentre study included 116 participants (12.1 +/- 3.3 years old; 42% female) from the iBoneFIT framework. Psychological well-being and distress indicators were assessed by questionnaires and time spent in movement behaviours by accelerometer. Participants were classified according to their somatic maturity (pre or peri/post-pubertal depending on the estimated years from peak height velocity). The adjusted models' coefficients were used to predict the effect of reallocating time proportionally across behaviours on the outcomes. Concerning well-being, our results indicate that reallocating time to LPA from the remaining movement behaviours (MVPA, SB, and sleep time) was positively associated with happiness (B = 1.545, p = 0.022) in the prepubertal group. Additionally, reallocating time to SB was positively associated with positive affect (B = 2.860, p = 0.006), whereas reallocating time to sleep time was negatively associated (B =-4.090, p = 0.005). In the peri/post-pubertal group, reallocating time to MVPA was positively associated with happiness and optimism (B = 0.778, p = 0.032 and B = 0.920, p = 0.008, respectively). Concerning psychological distress, reallocating time to LPA or SB was negatively associated with depression (B =-1.786, p = 0.032 and B =-2.294, p = 0.029, respectively), whilst reallocating time to sleep was positively associated with depression (B = 4.707, p = 0.002) in the pre-pubertal group. In the peri/post-pubertal group, reallocating time to MVPA was negatively associated with depression and anxiety (B =-0.779, p = 0.026 and B =-0.749, p = 0.014, respectively). These results underline the importance of promoting LPA and MVPA in prepubertal cancer survivors as well as MVPA in peri/post-pubertal cancer survivors to improve their psychological health.

Adolescence is associated with declining physical activity (PA) levels, and potential prevailing changes into young adulthood are indicated, but less explored. This study investigates longitudinal changes in PA from adolescence to young adulthood among males and females in a North Norwegian cohort. In the population-based Fit Futures Study, PA was assessed with both questionnaires (Saltin-Grimby Physical Activity Level Scale) and accelerometers (ActiGraph) at ages 16 (nself−report=936; naccelerometer=674), 18 (nself−report=808; naccelerometer=507), and 27 (nself−report=648; naccelerometer=466). We used mixed effects models to analyze longitudinal changes in accelerometer-measured PA and sedentary time, alongside mixed effects multinomial logistic regression for changes in self-reported leisure time PA. We observed a significant non-linear U-shaped trend in accelerometer-measured moderate-to-vigorous PA (MVPA) over time (p < 0.001), with an initial decline in minutes per day from age 16 (mean ± SD: 70.7 ± 25.2) to age 18 (62.3 ± 23.8), followed by an increase to age 27 (67.5 ± 30.4). At age 16, males exhibited higher MVPA than females. By age 18 and 27, MVPA levels were similar between sexes. Accelerometer-measured sedentary time decreased linearly across all three surveys (p = 0.002). We observed distributional shifts in self-reported leisure time PA over time: vigorously- and highly active proportions declined, while the moderately active proportion increased, and the proportion of sedentary participants remained stable ( 20

BACKGROUND:Due to the lack of available knowledge in the current literature, this systematic review and meta-analysis was aimed to assess the effectiveness of exercise-based lifestyle interventions, including healthy diet and/or psychological well-being on mental, physical and global health-related quality of life (HRQoL) in adults after cancer treatment. METHODS:MEDLINE (via PubMed) and Web of Science databases were searched for randomised controlled trials (RCTs) published until August 2024 evaluating exercise-based lifestyle interventions, including healthy diet and/or psychological well-being, which assessed mental, physical and global HRQoL. RESULTS:Of 6193 screened studies, 32 RCTs met the criteria. The total sample comprised 5528 participants (3003 intervention and 2525 control). There was a small effect size in a pooled analysis that found exercise-based lifestyle interventions improve mental HRQoL (d 0.11, 95 % CI 0.05 to 0.18). These effects were greater in those studies that combined exercise with psychological well-being (d = 0.19, P = 0.004), and with moderate-to-high intensity aerobic exercise (moderate intensity; d = 0.11, P = 0.02, high intensity; d = 0.16, P = 0.02, aerobic exercise; d = 0.16, P = 0.26). CONCLUSIONS:Exercise-based lifestyle interventions do not enhance physical nor global HRQoL, yet those combined with psychological well-being seem to improve mental HRQoL in individuals after cancer treatment. PROSPERO REGISTRATION NUMBER:CRD42022369169.

Background/Objectives: This study aims to evaluate the health-related quality of life (HRQoL) of children and adolescent cancer survivors in relation to previously published normative values for typically developing children and adolescents, as well as to analyze the differences in HRQoL based on their levels of physical activity and fitness. Methods: Cross-sectional study with 116 cancer survivors (12.1 ± 3.3 years, 57.8% boys) from two pediatric oncology units in Andalusia (Spain). HRQoL was assessed using PedsQL 4.0 Generic Core Scales. Physical activity was measured with accelerometers, and fitness was evaluated using self-reported and objective tests for muscular fitness. Independent samples t-tests to compare HRQoL between our sample and the normative values published for typically developing children and adolescents of the same age and analysis of covariance (ANCOVA) were conducted to assess differences in HRQoL according to physical activity and fitness categories in our sample. Results: Children and adolescent cancer survivors had lower HRQoL scores compared to typically developing children's and adolescents' normative values, except for social functioning. Higher levels of moderate-to-vigorous physical activity were associated with better total, physical, and psychosocial HRQoL scores. Children and adolescent cancer survivors with better levels of cardiorespiratory fitness, motor fitness, and flexibility reported better HRQoL scores in total and psychosocial domains. However, muscular fitness (self-reported and objectively measured) did not show a significant difference in HRQoL. Conclusions: Children and adolescent cancer survivors experience lower HRQoL than their typically developing counterparts. Engaging in at least 30 min of moderate-to-vigorous physical activity per day is associated with fewer HRQoL impairments. Improved fitness, particularly cardiorespiratory fitness, motor fitness, and flexibility, are associated with better HRQoL outcomes. These findings highlight the association between physical activity, fitness levels, and HRQoL in children and adolescent cancer survivors, suggesting the potential benefits of promoting physical activity and enhancing fitness levels.

We aimed to analyze the intra-set reliability of 5 sit-to-stand (5-STS) exercises with a functional electromechanical dynamometer (FEMD) and to determine and compare the load-velocity (L-V) profile in the STS exercise in adult pediatric cancer survivors by sex, age, body mass index, and type and treatment of cancer. A total of 47 participants performed the 5-STS test with 5

CONTEXT:Type 1 diabetes in youth increases the risk of compromised bone health due to glycemic dysregulation. Muscular fitness may play a role in improving bone health during growth. OBJECTIVE:This study aimed to investigate the association between muscular fitness and bone health in youth with type 1 diabetes. METHODS:A total of 83 young individuals with type 1 diabetes (aged 6-18 years; 44.6% girls) from the Diactive-1 cohort study were followed for 2 years. Dual-energy x-ray absorptiometry whole-body scans were used to assess bone mineral content (BMC) and areal bone mineral density (aBMD) of the total body less head (TBLH), arms, legs, pelvis, and spine. Muscular fitness (handgrip strength, 1 repetition maximum, and muscle power) was assessed with a dynamometer and eGYM devices. Handgrip strength and TBLH bone parameters were age- and sex-standardized using the FitBack Project and BMD Childhood Study, respectively. RESULTS:Linear mixed models showed longitudinal associations of handgrip strength with TBLH-BMC (unstandardized beta coefficient [B] = 17.18, 95% confidence interval [CI] 12.47-21.90) and TBLH-aBMD (B = 0.004, 95% CI 0.002-0.006); RM with TBLH-BMC (B = 20.09, 95% CI 10.88-29.31) and TBLH-aBMD (B = 0.007, 95% CI 0.004-0.011); and power with TBLH-BMC (B = 26.80, 95% CI: 17.31-36.28) and TBLH-aBMD (B = 0.009, 95% CI 0.005-0.012). Comparable results were observed across the other regions (P < .05). Additionally, analyses with standardized data confirmed the relationships of handgrip z-scores with TBLH-BMC z-scores (B = 0.19, 95% CI 0.08-0.30) and TBLH-aBMD z-scores (B = 0.350, 95% CI: 0.210-0.490). CONCLUSION:In pediatric patients with type 1 diabetes, higher muscular fitness could serve as a complementary therapeutic strategy to preserve or enhance bone health.

OBJECTIVE:To examine the effects of 24-week moderate (MOD-EX) and vigorous-intensity concurrent training (VIG-EX) on bone parameters and plasma levels of osteoglycin and sclerostin and their interplay with body composition and cardiometabolic risk factors in young, sedentary men and women. DESIGN:Secondary study from the ACTIBATE randomized controlled trial (ClinicalTrials.gov ID: NCT02365129). METHODS:This study was performed at the Sport and Health University Research Institute and the Virgen de las Nieves University Hospital of the University of Granada. Bone parameters were measured by dual-energy X-ray absorptiometry, and osteoglycin and sclerostin levels, by enzyme-linked immunosorbent assay. RESULTS:145 young sedentary adults were assigned to a control (CON, n = 54), a MOD-EX (n = 48), or a VIG-EX (n = 43). 106 participants were included in the per-protocol analyses (CON, n = 42; MOD-EX, n = 33; and VIG-EX, n = 31). After 24 weeks of concurrent training, we observed no differences in changes in bone parameters (all P time × group ≥ .300), osteoglycin (P time × group = .250), and sclerostin levels (P time × group = .489). Moreover, we found no correlations between osteoglycin and sclerostin levels with body composition (all P ≥ .639) and cardiometabolic risk factors (all P ≥ .119). CONCLUSION:24 weeks of concurrent training did not alter bone parameters, and plasma levels of osteoglycin and sclerostin in young, sedentary adults. Moreover, osteoglycin and sclerostin are not related with bone parameters and cardiometabolic risk factors in this population. These findings suggest that longer concurrent training interventions may be needed to enhance bone parameters in young, sedentary adults.

ABSTRACT Purpose We aimed to examine the associations of 24-h movement behaviors (moderate to vigorous physical activity [MVPA], light physical activity [LPA], sedentary behavior [SB], and sleep) with age-, sex-, and race-specific areal bone mineral density (aBMD) z -score parameters at clinical sites in young pediatric cancer survivors. Methods This cross-sectional multicenter study was carried out within the iBoneFIT framework in which 116 young pediatric cancer survivors (12.1 ± 3.3 yr old; 42% female) were recruited. We obtained anthropometric and body composition data (i.e., body mass, stature, body mass index, and region-specific lean mass), time spent in movement behaviors over at least seven consecutive 24-h periods (wGT3x-BT accelerometer, ActiGraph), and aBMD z -score parameters (age-, sex-, and race-specific total at the body, total hip, femoral neck and lumbar spine). Survivors were classified according to somatic maturity (pre or peri/postpubertal depending on the estimated years from peak height velocity). The adjusted models’ coefficients were used to predict the effect of reallocating time proportionally across behaviors on the outcomes. Results In prepubertal young pediatric cancer survivors, reallocating time to MVPA from LPA, SB, and sleep was significantly associated with higher aBMD at total body ( B = 1.765, P = 0.005), total hip ( B = 1.709, P = 0.003), and lumbar spine ( B = 2.093, P = 0.001). In peri/postpubertal survivors, reallocating time to LPA from MVPA, SB, and sleep was significantly associated with higher aBMD at all sites ( B = 2.090 to 2.609, P = 0.003 to 0.038). Reallocating time to SB from MVPA or LPA was significantly associated with lower aBMD at most sites in prepubertal and peri/postpubertal survivors, respectively. Finally, reallocating time to sleep from MVPA, LPA, and SB was significantly associated with lower aBMD at total body ( B = −2.572, P = 0.036) and total hip ( B = −3.371, P = 0.015). Conclusions These findings suggest that every move counts and underline the benefits of increasing MVPA or LPA, when low MVPA levels are present, for bone regeneration after pediatric cancer treatment completion.

PurposeTo compare the strength of associations between different indices of cardiorespiratory fitness (CRF) and brain health outcomes in children with overweight/obesity.MethodsParticipants were 100 children aged 8-11 years. CRF was assessed using treadmill exercise test (peak oxygen uptake [VO2peak], treadmill time, and VO2 at ventilatory threshold) and 20-metre shuttle run test (20mSRT, laps, running speed, estimated VO2peak using the equations by Leger et al., Mahar et al., and Matsuzaka et al.). Intelligence, executive functions, and academic performance were assessed using validated methods. Total gray matter and hippocampal volumes were assessed using structural MRI.ResultsVO2peak/body mass (beta = 0.18, 95% CI = 0.01-0.35) and treadmill time (beta = 0.18-0.21, 95% CI = 0.01-0.39) were positively associated with gray matter volume. 20mSRT laps were positively associated with executive functions (beta = 0.255, 95% CI = 0.089-0.421) and academic performance (beta = 0.199-0.255, 95% CI = 0.006-0.421), and the running speed was positively associated with executive functions (beta = 0.203, 95% CI = 0.039-0.367). Estimated VO2peak/Leger et al. was positively associated with intelligence, executive functions, academic performance, and gray matter volume (beta = 0.205-0.282, 95% CI = 0.013-0.500). Estimated VO2peak/Mahar et al. and VO2peak/Matsuzaka et al. (speed) were positively associated with executive functions (beta = 0.204-0.256, 95% CI = 0.031-0.436).ConclusionAlthough VO2peak is considered the gold standard indicator of CRF in children, peak performance (laps or running speed) and estimated VO2peak/Leger et al. derived from 20mSRT had stronger and more consistent associations with brain health outcomes than other indices of CRF in children with overweight/obesity.

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/cm(2)). 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.

Abstract 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.

SummaryBackgroundWe assessed the effects of a 20‐week combined (aerobic and resistance) exercise training programme on the inflammatory profile of prepubertal children with overweight or obesity.MethodsTotally 109 participants (10.1 ± 1.1 years, 41% girls) were randomly allocated to an exercise or control group. Adiponectin, C‐reactive protein, epidermal growth factor, insulin‐like growth factor‐1, interleukin (IL)‐1β, IL‐6, leptin, tumour necrosis factor‐α and vascular endothelial growth factor A (VEGFA) were analysed in plasma. Total white blood cell (WBC) count and immune subpopulations (eosinophils, basophils, neutrophils, lymphocytes and monocytes) were also determined.ResultsNo intervention effect was found for any of the analysed biomarkers (all p ≥ 0.05). We observed a significant sex by intervention interaction for IL‐1β (p = 0.03). When stratifying the sample by sex, the exercise programme induced a significant effect on IL‐1β levels (mean Z‐score difference, 0.66 [95% confidence interval 0.32–1.01]) in girls, but not in boys. A lower number of girls in the exercise group showed a meaningful reduction in IL‐1β (i.e., ≥0.2 standard deviations) than in the control group (15% vs. 85%, p = 0.01).ConclusionsThis exercise programme failed to improve the inflammatory profile in prepubertal children with overweight/obesity. Future studies should explore the effect of longer exercise interventions and in combination with diet.

To investigate the effect of physical activity (PA) (both general and its type) on self-esteem during and after cancer treatment. A systematic search was conducted across PubMed, Web of Science, Scopus, SPORTDiscuss, and PsycINFO from their inception to February 2024. The systematic review included 32 studies, with 15 studies (13 RCT and 2 quasi-experimental) and 3604 participants (66.7% female) included in the meta-analysis involving controlled trials using a control group and at least one PA intervention group. The study was registered in PROSPERO (CRD42022309771). Risk of bias for RCTs was assessed using the Cochrane Collaboration's tool for assessing risk of bias (RoB2), and quasi-experimental studies with the Joanna Briggs Institute critical appraisal tool. PA significantly improved self-esteem during and after cancer treatment (pooled SMD = 0.32, p < 0.01). Specifically, aerobic PA (pooled SMD = 0.33, p = 0.04) and mind-body exercise (pooled SMD = 0.70, p = 0.03) had positive effects on self-esteem. Overall, PA interventions improved self-esteem during cancer treatment (pooled SMD = 0.50, p = 0.01) and in PA interventions lasting more than 12 weeks (pooled SMD = 0.44, p = 0.02). In conclusion, PA (specifically, aerobic and mind-body exercises) may have a positive effect on self-esteem during and after cancer treatment, with cancer status and the duration of the intervention being key factors.

10070 Background: Required treatments to cure pediatric cancer at such a young age increase the risk of later health-related complications. Early exposure to DNA damaging agents, during a vital period of active skeletal growth, interferes with accrual of bone mass. Treatments not only impair bone health, but also affect skeletal muscle function and mass. Long-term pediatric cancer survivors present these limitations due to myofibrillary atrophy caused by degradation of myosin heavy chain and decrease in myosin synthesis death. Muscle weakness (both muscle strength deficits and low lean mass hereafter referred to as sarcopenia) and low areal bone mineral density (aBMD) have been observed to coexist in adult survivors of paediatric cancer. However, in young pediatric cancers survivors, associations between sarcopenia and low aBMD are not well described. Therefore, this study aimed to examine the risk of low aBMD in young pediatric cancer survivors with sarcopenia confirmed/probable, compared to not having sarcopenia. Methods: This cross-sectional study included 116 pediatric cancer survivors (12.1±3.3 years old; 42% female) enrolled on a randomized controlled trial designed to improve bone health (iBoneFIT project). Handgrip strength was used to assessed muscle strength. Dual-energy X-ray absorptiometry estimated aBMD (g/cm2) at the total body (less head), lumbar spine, total hip and femoral neck, and appendicular lean mass index (ALMI, kg/m2). Sarcopenia status was determined using age and sex specific international reference data from a healthy population. “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. Logistic regression, adjusted for time from treatment completion and radiation exposure, was used to evaluate the risk of low aBMD (age-, sex- and race-specific aBMD Z-score < -1.0) by sarcopenia status. Results: More than one-third of survivors met criteria for sarcopenia confirmed (37.9%); 19.0% met criteria for sarcopenia probable. Survivors with sarcopenia confirmed had higher risk of low aBMD at the total body (odd ratio [OR]: 6.91, 95% confidence interval [CI]: 2.31-24.15), total hip (OR: 2.98, 95% CI: 1.02-9.54) and femoral neck (OR: 4.72, 95% CI: 1.72-14.19) than those without sarcopenia. Survivors with sarcopenia probable had higher risk of having low aBMD only at the total body (OR: 4.13, 95% CI: 1.04-17.60) than those without sarcopenia. Conclusions: Over one-third of young paediatric cancer survivors presented sarcopenia confirmed with higher risk of low aBMD. These findings suggest that interventions to mitigate osteosarcopenia in this population should be implemented at early stages after treatment completion.

Background/Objectives: This study aims to investigate the association of movement behaviors with irisin, sclerostin, and bone turnover markers in young pediatric cancer survivors. Methods: A total of 116 young pediatric cancer survivors (12.1 ± 3.3 years; 42% female) were recruited. Time spent in movement behaviors over at least seven consecutive 24 h periods was measured by accelerometers (wGT3x-BT accelerometer, ActiGraph). Blood samples were collected at rest and serum was analyzed for irisin, sclerostin, cross-linked telopeptide of type I collagen (CTX), procollagen type I amino-terminal propeptide (P1NP), total osteocalcin (OC), alkaline phosphatase (ALP), 25-hydroxyvitamin D, parathyroid hormone (PTH), calcium, phosphorous, and magnesium. Results: Irisin and sclerostin were not significantly correlated with bone turnover markers. Sedentary time was negatively correlated with the P1NP (r = −0.411, p = 0.027) and total OC (r = −0.479, p = 0.015) Z-scores, whereas moderate-to-vigorous physical activity was positively correlated with the P1NP (r = 0.418, p = 0.024) and total OC (r = 0.478, p = 0.016) Z-scores. Moreover, total physical activity was positively correlated with the total OC Z-score (r = 0.448, p = 0.025). Finally, the uncoupling index [CTX/P1NP] was positively correlated with sedentary time (r = 0.424, p = 0.012) and negatively correlated with light physical activity (r = −0.352, 0.041). Conclusions: Reducing sedentary time and increasing physical activity may favor bone formation over resorption in young pediatric cancer survivors.

OBJECTIVE:To investigate the associations of television (TV) watching time with bone parameters and to examine whether high lean mass attenuates the negative impact of watching TV more than one hour per day on bone parameters. METHODS:This cross-sectional study comprised 116 young paediatric cancer survivors. Dual-energy X-ray Absorptiometry was used to obtain total body and regional areal bone mineral density (g/cm2), and lean mass (kg) outcomes. Hip Structural Analysis was performed at the narrowest point of the femoral neck. Trabecular Bone Score was obtained in the lumbar spine. TV watching time was obtained using the "Youth Activity Profile" questionnaire. RESULTS:Multiple linear regression models showed negative associations of watching TV more than one hour with bone parameters in peri/post pubertal survivors (β = -0.359 to -0.614, P < 0.001 to 0.047). Those survivors watching TV more than one hour per day and with high lean mass presented higher bone parameter Z-score than those with low lean mass. CONCLUSION:These findings underline the necessity of identifying strategies that promote musculoskeletal development while reducing TV watching time in young paediatric cancer survivors to maximise bone regeneration. IMPACT:The results indicate that watching television (TV) more than one hour (compared to not watching TV) is negatively associated with bone parameters in peri/post pubertal survivors. Survivors with high lean mass counteract these negative associations of watching TV with bone parameters. It is important to promote musculoskeletal development in this vulnerable population to maximise bone regeneration.

Aim Patients with type 2 diabetes (T2DM) have more risk of bone fractures. However, areal bone mineral density (aBMD) by conventional dual-energy x-ray absorptiometry (DXA) is not useful for identifying this risk. This study aims to evaluate 3D-DXA parameters determining the cortical and trabecular compartments in patients with T2DM compared to non-diabetic subjects and to identify their determinants. Materials and methods Case-control study in 111 T2DM patients (65.4 ± 7.6 years old) and 134 non-diabetic controls (64.7 ± 8.6-year-old). DXA, 3D-DXA modelling via 3D-Shaper software and trabecular bone score (TBS) were used to obtain aBMD, cortical and trabecular parameters, and lumbar spine microarchitecture, respectively. In addition, biochemical markers as 25-hydroxyvitamin d, type I procollagen N-terminal propeptide (P1NP), C-terminal telopeptide of type I collagen (CTX), and glycated haemoglobin (HbA1c) were analysed. Results Mean-adjusted values showed higher aBMD (5.4%-7.7%, ES: 0.33-0.53) and 3D-DXA parameters (4.1%-10.3%, ES: 0.42-0.68) in the T2DM group compared with the control group. However, TBS was lower in the T2DM group compared to the control group (-14.7%, ES: 1.18). In addition, sex (β = 0.272 to 0.316) and body mass index (BMI) (β = 0.236 to 0.455) were the most consistent and positive predictors of aBMD (p ≤ 0.01). BMI and P1NP were negative predictors of TBS (β = -0.530 and -0.254, respectively, p ≤ 0.01), while CTX was a positive one (β = 0.226, p=0.02). Finally, BMI was consistently the strongest positive predictor of 3D-DXA parameters (β = 0.240 to 0.442, p<0.05). Conclusion Patients with T2DM present higher bone mass measured both by conventional DXA and 3D-DXA, suggesting that 3D-DXA technology is not capable of identifying alterations in bone structure in this population. Moreover, BMI was the most consistent determinant in all bone outcomes.