Screen Time and Bone Status in Children and Adolescents: A Systematic Review

Introduction: Technological advances over the last 2 decades have led to an increase in the time spent by children and youth engaged in screen-based activities, and growing recognition of deleterious effects on health. In this systematic review of cohort and cross-sectional studies, we assess current data on the relationship between screen time and bone status in children and teenagers.Methods: We searched PUBMED and SCOPUS databases for studies of children and adolescents that assessed screen time and bone status, determined by measuring bone mineral content or density, bone stiffness index, bone speed of sound, bone broadband ultrasound attenuation, or frame index. Searches were limited to studies published between 1900 and 2020, and performed in accordance with Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The studies included were evaluated using the Newcastle-Ottawa quality assessment scale.Results: Ten cohort and cross-sectional studies including pediatric population were selected. The combined study population was 20,420 children/adolescents, of whom 18,444 participated in cross-sectional studies. Four studies assessed the effects of total screen time, seven the consequences of TV viewing time, and six the effects of recreational computer use on bone health. Our findings indicate an inverse association between total and weekly screen time and bone health in children and adolescents. In 57% of the studies included also a negative correlation between television viewing time and bone status was observed, while recreational computer time did not have a significant impact on bone health. According to the only four studies that included dietetic factors, no relevant differences were found between calcium intake and screen time or bone broadband ultrasound attenuation and bone speed of sound.Conclusions: Review of the literature of the past three decades provides strong support for comprehensive education of screen time on bone status. The findings of this systematic review support a negative association between screen time and bone status in children and adolescents, with a different impact when considering the different technological devices. As peak bone mass in adolescents is the strongest predictor of osteoporosis risk, strategies aimed at improving bone health should incorporate conscious use of digital technology.

Associations of vascular and bone status in arthritis patients

Cardiovascular (CV) disease and osteoporosis (OP) have been associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Bone and vascular biomarkers and parameters along with the effect of 1-year anti-TNF therapy on these markers were assessed in order to determine correlations between vascular pathophysiology and bone metabolism in RA and AS. Thirty-six patients treated with etanercept or certolizumab pegol and 17 AS patients treated with ETN were included in a 12-month follow-up study. Bone and vascular markers were previously assessed by ELISA. Bone density was measured by DXA and quantitative CT (QCT). Flow-mediated vasodilation (FMD), common carotid intima-media thickness (IMT) and pulse-wave velocity (PWV) were assessed by ultrasound. Multiple correlation analyses indicated associations between bone and vascular markers. Osteoprotegerin, sclerostin and cathepsin K were significantly associated with FMD, IMT and PWV, respectively (p < 0.05). Moreover, total and trabecular BMD determined by QCT inversely correlated with IMT (p < 0.05). On the other hand, among vascular parameters, platelet-derived growth factor BB and IMT correlated with DXA femoral and QCT total BMD, respectively (p < 0.05). In the RM-ANOVA analysis, anti-TNF treatment together with baseline osteocalcin, procollagen 1 N-terminal propeptide (P1NP) or vitamin D3 levels determined one-year changes in IMT (p < 0.05). In the MANOVA analysis, baseline disease activity indices (DAS28, BASDAI), the one-year changes in these indices, as well as CRP exerted effects on multiple correlations between bone and vascular markers (p < 0.05). As the pattern of interactions between bone and vascular biomarkers differed between baseline and after 12 months, anti-TNF therapy influenced these associations. We found a great number of correlations in our RA and AS patients undergoing anti-TNF therapy. Some of the bone markers have been associated with vascular pathophysiology, while some vascular markers correlated with bone status. In arthritis, systemic inflammation and disease activity may drive both vascular and bone disease.

Metabolic Profile and Bone Status in Post-Menopausal Women with Rheumatoid Arthritis: A Monocentric Retrospective Survey

Background: Rheumatoid arthritis (RA) and metabolic syndrome (MetS) are chronic conditions that share common inflammatory mechanisms. Both diseases can lead to an impairment of the bone microarchitecture. The aims of our study were to evaluate clinical, metabolic, and bone parameters in RA patients with or without MetS (MetS+, MetS−) and potential correlations between the glico-lipidic profile, RA disease activity, and bone status. Methods: A total of thirty-nine RA female post-menopausal patients were recruited (median age 66.6 ± 10.4, disease duration 3 ± 2.7). Anthropometric data, medical history, and current treatment were recorded along with basal blood tests, bone, and lipid metabolism biomarkers. RA disease activity and insulin resistance were evaluated through standard scores. Quantitative assessment of the bone (bone mineral density—BMD) was performed by dual-energy-X ray absorption (DXA), whereas bone quality was quantified with the trabecular bone score (TBS). Results: No statistically significant differences concerning both BMD and TBS were detected between the MetS+ and MetS− RA patients. However, the MetS+ RA patients exhibited significantly higher disease activity and lower serum 25-hydroxyvitamin D [25(OH)D] concentrations (respectively, p = 0.04 and p = 0.01). In all RA patients, a significant negative correlation emerged between the BMD of the femoral trochanter with plasmatic triglycerides (TG) concentrations (r = −0.38, p = 0.01), whereas the lumbar BMD was positively correlated with the abdominal waist (AW) and fasting glucose (FG) concentrations. On the other hand, the TBS was negatively correlated with insulin concentrations, FG, and RA disease activity (respectively, r = −0.45, p = 0.01, r = −0.40, p = 0.03, r = −0.37, p = 0.04), the last one was further negatively correlated with 25-OHD serum concentrations (r = −0.6, p = 0.0006) and insulin-resistance (r = 0.3, p = 0.04). Conclusions: Bone quantity (BMD) and quality (TBS) do not seem significantly changed among MetS+ and MetS− RA patients; however, among MetS+ patients, both significantly higher disease activity and lower vitamin D serum concentrations were observed. In addition, the significant negative correlations between the alterations of metabolic parameters limited to the TBS in all RA patients might suggest that qualitative bone microarchitecture impairments (TBS) might manifest despite unchanged BMD values.

Bone Status in a Mouse Model of Experimental Autoimmune-Orchitis

Investigations in male patients with fertility disorders revealed a greater risk of osteoporosis. The rodent model of experimental autoimmune-orchitis (EAO) was established to analyze the underlying mechanisms of male infertility and causes of reduced testosterone concentration. Hence, we investigated the impact of testicular dysfunction in EAO on bone status. Male mice were immunized with testicular homogenate in adjuvant to induce EAO (n = 5). Age-matched mice were treated with adjuvant alone (adjuvant, n = 6) or remained untreated (control, n = 7). Fifty days after the first immunization specimens were harvested. Real-time reverse transcription-PCR indicated decreased bone metabolism by alkaline phosphatase and Cathepsin K as well as remodeling of cell-contacts by Connexin-43. Micro computed tomography demonstrated a loss of bone mass and mineralization. These findings were supported by histomorphometric results. Additionally, biomechanical properties of femora in a three-point bending test were significantly altered. In summary, the present study illustrates the induction of osteoporosis in the investigated mouse model. However, results suggest that the major effects on bone status were mainly caused by the complete Freund’s adjuvant rather than the autoimmune-orchitis itself. Therefore, the benefit of the EAO model to transfer laboratory findings regarding bone metabolism in context with orchitis into a clinical application is limited.

AB0438 SERUM HOMOCYSTEINE AND BONE STATUS IN SYSTEMIC SCLEROSIS PATIENTS

Background:Systemic sclerosis (SSc) is a complex autoimmune connective tissue disease characterized by self-amplifying microvascular damage sustained by autoimmune response and progressive skin and visceral fibrosis. Besides, SSc patients show higher incidence of bone micro/macroarchitectural damages and bone fractures. Emerging data demonstrate that high serum levels of homocysteine (Hcy) could modulate osteoclastogenesis and are recognized as risk factors for osteoporosis (2). Furthermore, serum levels of Hcy were found to be higher in SSc patients than in healthy controls (3).Objectives:to evaluate the bone status according to HCy serum levels in a cohort of SSc patients.Methods:20 female patients fulfilling ACR 2013 criteria for SSc underwent a dual-energy X-ray absorptiometry scan (DXA) (Lunar Prodigy) to evaluate bone status. We analysed bone quantity and quality respectively by bone mineral density (BMD) and trabecular bone score (TBS). According to the WHO criteria, osteoporosis was defined as a bone density of 2.5 standard deviations below that of a young adult (T-Score). Fasting blood samples were obtained from all patients in order to test serum Hcy level and bone turnover markers after obtaining the informed consent. All subjects underwent morphometric spine X-Ray to evaluate vertebral fractures. Statistical analysis was performed using non-parametric tests.Results:The mean age of patients was 64.15 ± 10.8 years with a mean disease duration of 9.1 ± 2.3 years. The mean modified Rodnan Skin Score (mRSS) was 10.7 ± 8.5. All patients showed a “scleroderma pattern” at nailfold Videocapillaroscopy (NVC): in particular, 7 patients showed the “Late” pattern, 9 patients the “Active” pattern and 4 patients the “Early” NVC pattern. Hyperomocisteinemia (HHcy) was found in 25% of patients. Interestingly, SSc patients with the “Late” NVC pattern showed a significantly higher serum level of Hcy compared to the “Early/Active” group (11.15 ± 4.4 vs 17.17 ± 6.4, p=0.03). No significant differences were observed in relation to the autoantibody profiles. Of note, 60% of patients with HHcy were found osteoporotic and 40% had bone fractures.Considering the bone status, patients with Hcy showed a significantly lower TBS (p=0.03); the average values of BMD on the lumbar spine (p=0.79) and femoral neck (p=0.13) were found lower compared to, but without any statistical significance. Furthermore, no significant differences were observed in bone turnover markers according to Hcy levels.Conclusion:The study demonstrates a relationship between higher levels of Hcy and lower TBS values within SSc patients, particularly in those with most severe microvascular damage al NVC (“Late” SSc pattern). Therefore it is concluded that higher serum levels of Hcy associate to both bone microarchitectural and microvascular damage in SSc.References:[1]Cutolo M et al Expert Rev Clin Immunol 2019; 15: 753-64[2]Behera J et al. J Cell Physiol 2017;232(10):2704-2709[3]Yan-lie Zhang et al. Rheumatol 2018; 28(4):681-689Disclosure of Interests:None declared

Bone Mineral Density in Adolescent Boys: Cross-Sectional Observational Study

Physical inactivity of children can be a precursor of reduced bone mineral density, considered to be a typical problem only in old age. The aim of this study was to evaluate bone mineral density in 96 Polish boys aged 14–17 years with varied physical activity (swimmers, track and field athletes, non-athletes) and the effect of bone composition, birth weight and breastfeeding during infancy on bone parameters. Anthropometric and body composition measurements were performed according to the kinanthropometric standards. Bone parameters of the forearm were measured by means of dual-energy X-ray absorptiometry. Data on the infant’s birth weight and the length of breastfeeding were collected during direct interviews with mothers. The strongest links with bone parameters were found for the type of physical activity and birth weight. Regardless of birth weight, track and field athletes had the most advantageous bone parameters (mainly sT-score prox values). Swimmers with normal or low birth weight had less favourable sT-score prox values than non-athletes. The type of physical activity proved to be an important determinant of bone parameters. Childhood and adolescence are important periods of bone development and increasing the content of bone mineral components, and the bone status in later years of life depends to a large extent on this period. The perinatal period, especially the correct birth weight of the child, not only has a significant effect on general health, but also on bone status.