Bone Mass In Adolescents Research Articles

Total Flavonoids Isolated from the Leaves of Eucommia ulmoides Augment Peak Bone Mass in Female Rats and Show no Side Effects in Other Organs.

Eucommia ulmoides is a unique monophyletic and tertiary relict in China and is listed as a national second-class precious protected tree species. Eucommia ulmoides, recognized as a traditional Chinese medicine, can tonify the liver and kidneys and strengthen bones and muscles. Modern pharmacological research has proved that Eucommia ulmoides has multiple osteoprotective effects, including prohibiting the occurrence of osteoporosis and arthritis and enhancing the healing of bone fractures and bone defects. To check its osteotropic effects, which may provide ideas for its potential use for the development of novel drugs to treat osteoporosis, this study evaluated the effect of total flavonoids from Eucommia ulmoides leaves (TFEL) on the acquisition of Peak Bone Mass (PBM) in young female rats. TFEL was isolated, and its purity was confirmed by using a UV spectrophotometer. TFEL with a purity of 85.09% was administered to 6-week-old female rats by oral gavage at a low (50), mid (100), or high (200 mg/kg/d) dose, and the control group was administrated only with the same volume of water. After 13 weeks of treatment, the rats were sacrificed, and serum, different organs, and limb bones (femurs and tibias) were harvested, and the bone turnover markers, organ index, Bone Mineral Density (BMD), biomechanical property, and microstructure parameters were assayed. Furthermore, molecular targets were screened, and network pharmacology analyses were conducted to reveal the potential mechanisms of action of TFEL. Oral administration of TFEL for 13 weeks decreased the serum level of bone resorption marker TRACP-5b. As revealed by micro-computer tomography analysis, it elevated BMD even at a low dose (50 mg/kg/d) and improved the microstructural parameters, which were also confirmed by H&E histological staining. However, TFEL showed no effects on body weights, organ index, and micromorphology in the uterus. In our network pharmacology study, an intersection analysis screened out 64 shared targets, with quercetin, kaempferol, naringenin, and apigenin regulating the greatest number of targets associated with osteoporosis. Flavonoids in Eucommia ulmoides inhibited the occurrence of osteoporosis potentially through targeting signaling pathways for calcium, VEGF, IL-17, and NF-κB. Furthermore, AKT1, EGFR, PTGS2, VEGFA, and CALM were found to be potentially important target genes for the osteoprotective effects of flavonoids in Eucommia ulmoides. The above results suggested that TFEL can be used to elevate the peak bone mass in adolescence in female individuals, which may prevent the occurrence of postmenopausal osteoporosis, and the good safety of TFEL also suggests that it can be used as a food additive for daily life to improve the bone health.

Bone impact after two years of low-dose oral contraceptive use during adolescence.

Data regarding the use and effect of hormonal contraceptives on bone mass acquisition during adolescence are contradictory. The present study was designed to evaluate bone metabolism in two groups of healthy adolescents using combined oral contraceptives (COC). A total of 168 adolescents were recruited from 2014 to 2020 in a non-randomized clinical trial and divided into three groups. The COC1 group used 20 μg Ethinylestradiol (EE)/150 μg Desogestrel and the COC2 group used 30 μg EE/3 mg Drospirenone over a period of two years. These groups were compared to a control group of adolescent non-COC users. The adolescents were submitted to bone densitometry by dual-energy X-ray absorptiometry and measurement of bone biomarkers, bone alkaline phosphatase (BAP), and osteocalcin (OC) at baseline and 24 months after inclusion in the study. The three groups studied were compared at the different time points by ANOVA, followed by Bonferroni's multiple comparison test. Incorporation of bone mass was greater in non-users at all sites analyzed (4.85 g in lumbar Bone mineral content (BMC)) when compared to adolescents of the COC1 and COC2 groups, with a respective increase of 2.15 g and loss of 0.43g in lumbar BMC (P = 0.001). When comparing subtotal BMC, the control increased 100.83 g, COC 1 increased 21.46 g, and COC 2 presented a reduction of 1.47 g (P = 0.005). The values of bone markers after 24 months are similar for BAP, being 30.51 U/L (± 11.6) for the control group, 34.95 U/L (± 10.8) for COC1, and 30.29 U/L for COC 2 (± 11.5) (P = 0.377). However, when we analyzed OC, we observed for control, COC 1, and COC 2 groups, respectively, 13.59 ng/mL (± 7.3), 6.44 ng/mL (± 4.6), and 9.48 ng/mL (± 5.9), with P = 0.003. Despite loss to follow-up occurring in the three groups, there were no significant differences between the variables in adolescents at baseline who remained in the study during the 24-month follow-up and those who were excluded or lost to follow-up. Bone mass acquisition was compromised in healthy adolescents using combined hormonal contraceptives when compared to controls. This negative impact seems to be more pronounced in the group that used contraceptives containing 30 μg EE. http://www.ensaiosclinicos.gov.br, RBR-5h9b3c. "Low-dose combined oral contraceptive use is associated with lower bone mass in adolescents".

Decreased bone mass in adolescents with bone fragility fracture but not in young children: a case-control study.

The incidence of distal forearm fracture due to minimal/moderate trauma shows a bimodal distribution for age at event, with one peak occurring during early adolescence, in both boys and girls and the other one in postmenopausal females. The aim of this study was, therefore, to document whether the relationship between bone mineral density and fracture is different in young children compared with adolescents. A matched-pair, case-control study has been conducted to evaluate bone mineral density in 469 young children and 387 adolescents of both sexes, with/without fracture due to minimal/moderate trauma with assurance that the compared groups were equally susceptible to the outcome event. All fractures were radiographically confirmed. The study utilized bone mineral areal density of the total body, spine, hips, and forearm; volumetric bone mineral density of the forearm; and metacarpal radiogrammetry measurements. The study controlled for skeletal development, bone geometry, body composition, hand grip strength, calcium intake, and vitamin D status. Adolescents with distal forearm fracture have reduced bone mineral density at multiple skeletal regions of interest. This was documented by the bone mineral areal density measurements at multiple skeletal sites (p < 0.001), volumetric bone mineral density measurements of the forearm (p < 0.0001), and metacarpal radiogrammetry (p < 0.001). Adolescent females with fracture had reduced cross-sectional areas of the radius and metacarpals. The bone status of young female and male children with fracture was no different to its controls. Increased body fatness was more prevalent among fracture cases than in controls. Around 72% of young female and male children with fracture had serum 25-hydroxyvitamin D levels below the threshold of 31 ng/ml, compared with only 42% of female controls and to 51% of male controls. Adolescents with bone fragility fracture had reduced bone mineral density at multiple skeletal regions of interest, whereas this was not the case with younger children. The results of the study may have implications for the prevention of bone fragility in this segment of the pediatric population.

Linear growth and relative weight gain in childhood and bone mass in adolescence: findings from the Pelotas (Brazil) 2004 birth cohort.

To investigate independent relationships of linear growth and relative weight gain during defined periods of infancy, childhood, and early adolescence with areal bone mineral density (aBMD) of three sites at 11years. Data on weight and length/height were obtained at birth, 3, 12, and 24months, and the ages of 4, 6, and 11. The outcome was whole body, femoral neck, and lumbar spine aBMD (g/cm2) measured at 11years using dual-energy X-ray absorptiometry. The effects of weight gain and linear growth were analyzed using conditional relative weight and conditional length/height. Associations between conditional growth and outcomes were analyzed using linear regression, adjusted for multiple confounders. Individuals with data available for exposures and bone outcomes were 2875 and comprised the sample. For boys, the greatest magnitude of increase for whole body and height gain was at 48months (β 0.014, 95% CI 0.010; 0.018). For girls, higher aBMD was observed for those with greater height gain at 11years, representing for lumbar spine an increase of 0.056g/cm2 (95% CI 0.050; 0.062). For body weight, among boys, the greatest magnitude in the whole body was also associated with weight gain at 48months (β 0.014, 95% CI 0.010; 0.018). For girls, the highest coefficient was at 24months, representing for lumbar spine an increase of 0.028g/cm2, (95% CI 0.021; 0.035). Positive associations were demonstrated between length/height and weight gain and aBMD in both sexes, with emphasis on girls' aBMD in response to the linear growth achieved mainly at 11years.

Evaluating and optimizing bone health in children with chronic health conditions.

Paediatric health care providers (HCPs) play an important role in optimizing bone health. Early intervention is essential to maximize the accrual of peak bone mass in adolescence and young adulthood and to reduce osteoporosis and fracture risk later in life. Children and adolescents with chronic health conditions may have several risk factors for poor bone health, including underlying inflammatory conditions, reduced weight-bearing activity, delayed puberty, and inadequate intake of calcium and vitamin D. Some medications-particularly glucocorticoids-can compromise bone mass and place a child at risk for fragility fractures. This practice point describes a targeted approach to identifying bone health risk factors in children and youth with chronic health conditions, highlights office initiatives aimed at optimizing bone mass accrual, and links HCPs to useful web-based tools and medical references. Indications for referral to a bone health specialist and bone-specific pharmacotherapeutic interventions are also reviewed.

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.

The Relationship Between Prediabetes and Bone Mass in Adolescents: Analysis of the National Health and Nutrition Examination Survey From 2005 to 2010.

ObjectiveThe purpose of this study was to observe the relationship between impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and bone mineral density (BMD) in different sites in adolescents.MethodsA retrospective study was conducted on adolescents age 12–19 years of the United States. Data were extracted from the National Health and Nutrition Examination Survey (NHANES) 2005–2006, 2007–2008, and 2009–2010 cycles. IFG was defined as fasting plasma glucose (FPG) levels that were ≥5.6 and <7.0 mmol/L. IGT was defined as 2-h plasma glucose levels that were ≥7.8 and <11.1 mmol/L after the oral glucose tolerance test (OGTT).ResultsAfter controlling for age, gender, race, and body mass index (BMI) Z-score, adolescents in different categories of IGT had significantly different levels of areal BMD (aBMD) and bone mineral apparent density (BMAD) (IGT main effect: P < 0.05 for all, two-way ANOVA). There was no main effect between different categories of IFG with regard to aBMD and BMAD (P > 0.05). There was no interaction between IFG and IGT with regard to aBMD and BMAD (P > 0.05). In multiple regression analysis, the 2-h plasma glucose maintained an independent association with femoral neck aBMD (β = −0.011, 95% CI: −0.017~−0.006, P < 0.001, R 2 = 0.012), total femur aBMD (β = −0.015, 95% CI: −0.021~−0.009, P < 0.001, R 2 = 0.018), total spine aBMD (β = −0.015, 95% CI: −0.020~−0.010, P < 0.001, R 2 = 0.018), and total spine BMAD (β = −0.002, 95% CI: −0.003~0.000, P = 0.006, R 2 = 0.003).ConclusionThe present study demonstrates that BMD was decreased in adolescents with IGT. Two-hour plasma glucose, not FPG, negatively correlated with BMD. The effect of 2-h plasma glucose was consistent across the sites of bone.

Evaluation of eating habits and unhealthy eating patterns in high-school girls from Varna, Bulgaria

Abstract Background Eating habits in children and adolescents are fundamental for their optimal physical and mental health and development. In adolescent girls, adequate nutritional status is paramount for the reproductive system function and reaching peak bone mass. Epidemiological studies have found an increased incidence of unhealthy eating patterns that pose a risk of nutritional deficiencies in adolescents from different European countries. More data is needed on the prevalence of the problem among Bulgarian adolescents, and especially school-aged girls, who are a specific risk group. Methods The study included 226 adolescent girls aged 17-19 from Varna, Bulgaria. Data was collected after receiving informed consent. The methods used include: Anthropometric measurements, including height and weight; Bioelectric impedance analysis using calibrated Tanita BC-420MA (ISSO 9001) and following ESPEN guidelines; Food frequency questionnaire (FFQ). Results 10% of girls were underweight, 78.5% had normal BMI (18.7-25kg/m2) and 11.5% were overweight/obese. Underweight girls had an average BF%=13.78±4.28, with the lowest BF%=3. Underweight girls had significantly lower consumption of vegetables, whole grains, and dairy products. More than half of the underweight group didn't consume vegetables daily (54.5%). 27.7% of the underweight participants consumed whole grain foods every day compared to 42.9% overweight/obese group. 27,2% of underweight girls met the recommendations for consuming daily dairy consumption, compared to 58.1% in the normal BMI and 65.4% in the overweight/obese group. Fish consumption was low in all groups - 13.6% of underweight girls, 17.7% of the participants with normal BMI, and 3.8% in the overweight/obese group consume fish at least twice per week or more. Conclusions Underweight teenage girls have inadequate intake of vegetables, whole grains, and dairy products. The majority of adolescent females do not meet the minimum requirement for fish consumption. Key messages The combination of low body weight and inadequate intake of foods rich in bioavailable calcium are risk factors for not achieving peak bone mass in adolescence. Underweight teenage girls are at an increased risk of vitamin and mineral deficiencies due to inadequate intake of vegetables, whole grains, fish, and dairy products.

Association between sedentary behavior and bone mass in adolescents.

To analyze the relationship between sedentary behaviors and bone mass in adolescents. One hundred four adolescent boys and girls, aged 10 to 14years, were divided into normal weight and overweight according to weight status. Specific sedentary behaviors (time spent on the Internet for school and non-school purposes, using the computer, watching television, and playing videogames) were assessed by questionnaire, and the total sedentary behavior time by accelerometry. Bone parameters were collected using X-ray absorptiometry, using total and lumbar bone mineral density (BMD) and total and lumbar bone mineral content (BMC) values. In both groups, the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMD. Also, while in the overweight group, the time spent using the computer was negatively correlated to lumbar BMD, and the time spent on the Internet for non-school purposes was positively correlated to the total and lumbar BMC, and in the normal weight group, the time spent on the Internet for non-school purposes was positively correlated to lumbar BMC. Adolescents who spend more time in sedentary behavior, especially using the Internet for non-school purposes, have higher BMD and BMC, while normal weight adolescents who spend more time on the computer have lower BMD.

Position Statement: Exercise Guidelines to Increase Peak Bone Mass in Adolescents

PURPOSE: An increase in bone mineral density during adolescence increases resistance to fractures in older age. The Korean Society for Bone and Mineral Research and the Korean Society of Exercise Physiology developed exercise guidelines to increase the peak bone mass (PBM) in adolescents based on evidence through a systematic review of previous research.METHODS: Articles were selected using the systematic method, and the exercise guidelines were established by selecting key questions (KQs) and defining the effects of exercises based on evidence through a literature review for selecting the final exercise method. There were 9 KQs. An online search was conducted on articles published since 2000, and 93 articles were identified.RESULTS: An increase in PBM in adolescence was effective for preventing osteoporosis and fractures in older age. Exercise programs as part of vigorous physical activity (VPA) including resistance and impact exercise at least 5 to 6 months were effective for improving PBM in adolescents. It is recommended that resistance exercise is performed 10 to 12 rep·set&lt;sup&gt;-1&lt;/sup&gt; 1-2 set·region&lt;sup&gt;-1&lt;/sup&gt; and 3 days·week&lt;sup&gt;-1&lt;/sup&gt; using the large muscles. For impact exercises such as jumping, it is recommended that the exercise is performed at least 50 jumps·min&lt;sup&gt;-1&lt;/sup&gt;, 10 min·day&lt;sup&gt;-1&lt;/sup&gt;, and 2 days·week&lt;sup&gt;-1&lt;/sup&gt;.CONCLUSIONS: Exercise guidelines were successfully developed, and they recommend at least 5 to 6 months of VPA, which includes both resistance and impact exercises. With the development of exercise guidelines, the incidence of osteoporosis and fractures in the aging society can be reduced in the future, thus contributing to improved public health.

Targeting 1,25(OH)2D-mediated calcium absorption machinery in proximal colon with calcitriol glycosides and glucuronides

High intestinal calcium (Ca) absorption efficiency is associated with high peak bone mass in adolescents and reduced bone loss in adulthood. Transepithelial intestinal Ca absorption is mediated by 1,25-dihydroxyvitamin D (1,25(OH)2D, calcitriol) through the vitamin D receptor (VDR). Most research on Ca absorption focuses on the proximal small intestine but evidence shows that large intestine plays a crucial role in whole body Ca homeostasis. We directly assessed and compared Ca absorption capacity at the proximal colon and duodenum using in situ ligated loops (2 mM Ca, 10 min). In C57BL/6 J mice, the proximal colon (26.2 ± 3.7 %) had comparable ability to absorb Ca as the duodenum (30.0 ± 6.7 %). In VDR knockout (KO) mice, Ca absorption efficiency was reduced by 67 % in duodenum and 48 % in proximal colon. These data suggest that large intestine could be targeted to improve Ca absorption and protect bone in at risk-groups (e.g. bariatric patients). Glycoside forms of calcitriol found in Solanum Glaucophyllum (Sg) leaf are biologically inert but can be activated in the colon upon bacterial cleavage of the glycosides. We conducted a study to test whether Sg leaf, as well as a novel, synthetic 1,3-diglucuronide form of calcitriol (1,3-diG) could target the proximal colon and upregulate genes involved in Ca absorption (i.e. Trpv6, S100g). 13-week-old female C57BL6/J mice were fed AIN93 G diet containing increasing levels of one of the two compounds for 2 weeks (delivering 0, 0.25, 0.5, 1, or 2 ng calcitriol equivalent per day). Both compounds induced a dose-dependent upregulation of Cyp24a1 and Trpv6 gene expression in the proximal colon. 1,3-diG also induced S100g gene expression in the proximal colon. Duodenal expression of Trpv6 was upregulated at higher doses of 1,3-diG but not Sg leaf. These data suggest that both glycosylated and glucuronidated calcitriol could be used to target the proximal colon but that dosing must be optimized to limit systemic effects that could cause hypercalcemia. Future studies will test the translational potential of these compounds to determine if they can increase Ca absorption at proximal colon and whether this can help protect bone.

Does height catch‐up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort

ObjectiveTo analyze the effect of height catch‐up at school age on the bone mass of adolescents of a Brazilian birth cohort. MethodsA cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts‐RPS study. Height catch‐up was defined based on the difference between the schoolchild's z‐score and birth z‐score. The adolescents’ bone mineral mass was analyzed using the z‐score index for the lumbar spine measured by dual emission X‐ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest‐neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. ResultsOf the 297 studied children, 24.5% achieved height catch‐up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z‐score was −0.34 (±1.01). After the adjustment, no effect was observed between height catch‐up at school age and bone mass in adolescents (Coeff=0.598; 95% CI −0.117 to 1.313; p=0.101). ConclusionEven using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch‐up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

Is vigorous-intensity physical activity required for improving bone mass in adolescence? Findings from a Brazilian birth cohort

SummaryThe association between moderate and vigorous physical activity throughout adolescence and areal bone density (aBMD) at 18 years of age was evaluated. Vigorous-intensity physical activity at 11, 15, and 18 years was associated with aBMD in early adulthood, especially in boys. Cross-sectional analyses showed a positive association between moderate physical activity and aBMD.IntroductionTo evaluate independent associations of moderate and vigorous physical activity (MPA, VPA) across adolescence with areal bone mineral density (aBMD).MethodsPhysical activity (PA) was assessed at 11, 15, and 18 years of age by self-report and at 18 years by accelerometry in the 1993 Pelotas Birth Cohort Study. Time spent in MPA and VPA was determined using metabolic equivalents and specific cutoffs based on raw acceleration. Lumbar spine and femoral neck aBMD were measured by DXA at 18 years. Statistical analyses evaluated the association of MPA and VPA with aBMD, after adjusting for skin color, asset index, current height and age at menarche, and peak strain score (based on ground reaction forces of PA).ResultsLumbar spine and femoral neck aBMD were available for 3947 (49.9% of boys) and 3960 (49.6% of boys) individuals, respectively. Time spent in MPA at 11 and 15 years was not associated with aBMD. VPA at all time points was positively related to both lumbar spine and femoral neck aBMD in boys. Results were consistent for objectively measured VPA. Girls who achieved 75+ minutes/week of VPA in at least two follow-ups showed higher aBMD at 18 years of age. Boys who reached 75+ minutes/week of VPA at all follow-ups had on average 0.117 g/cm2 (95% CI: 0.090; 0.144) higher femoral neck aBMD than those who never achieved this threshold.ConclusionsSelf-reported VPA but not MPA throughout adolescence was associated with aBMD. Recommendation for PA in young people should consider the importance of VPA.

Position Statement: Exercise Guidelines to Increase Peak Bone Mass in Adolescents

BackgroundAn increase in bone mineral density during adolescence increases resistance to fractures in older age. The Korean Society for Bone and Mineral Research and the Korean Society of Exercise Physiology developed exercise guidelines to increase the peak bone mass (PBM) in adolescents based on evidence through a systematic review of previous research.MethodsArticles were selected using the systematic method, and the exercise guidelines were established by selecting key questions (KQs) and defining the effects of exercises based on evidence through a literature review for selecting the final exercise method. There were 9 KQs. An online search was conducted on articles published since 2000, and 93 articles were identified.ResultsAn increase in PBM in adolescence was effective for preventing osteoporosis and fractures in older age. Exercise programs as part of vigorous physical activity (VPA) including resistance and impact exercise at least 5 to 6 months were effective for improving PBM in adolescents. It is recommended that resistance exercise is performed 10 to 12 rep·set−1 1-2 set·region−1 and 3 days·week−1 using the large muscles. For impact exercises such as jumping, it is recommended that the exercise is performed at least 50 jumps·min−1, 10 min·day−1 and 2 days·week−1.ConclusionsExercise guidelines were successfully developed, and they recommend at least 5 to 6 months of VPA, which includes both resistance and impact exercises. With the development of exercise guidelines, the incidence of osteoporosis and fractures in the aging society can be reduced in the future, thus contributing to improved public health.

Does height catch-up in schoolchildren have an effect on bone mass in adolescents? Analysis in a Brazilian birth cohort

ObjectiveTo analyze the effect of height catch-up at school age on the bone mass of adolescents of a Brazilian birth cohort. MethodsA cohort study using data obtained from the three moments (birth, 7/9 years and 18/19 years of age) of the Cohorts-RPS study. Height catch-up was defined based on the difference between the schoolchild's z-score and birth z-score. The adolescents’ bone mineral mass was analyzed using the z-score index for the lumbar spine measured by dual emission X-ray absorptiometry. A theoretical model was developed for the proposed analysis using directed acyclic graphs paired through the nearest-neighbor matching propensity score using the STATA software, version 14.0. The level of significance was set at 5%. ResultsOf the 297 studied children, 24.5% achieved height catch-up. The bone mass below the expected for age was observed in 5.39% of the subjects. The mean lumbar spine z-score was −0.34 (±1.01). After the adjustment, no effect was observed between height catch-up at school age and bone mass in adolescents (Coeff=0.598; 95% CI −0.117 to 1.313; p=0.101). ConclusionEven using the directed acyclic graphs and the causal inference method by adjusting the propensity score, the height catch-up did not seem to affect bone mass in adolescents, a result perhaps related to the sample size.

How Is Adolescent Bone Mass and Density Influenced by Early Life Body Size and Growth? The Tromsø Study: Fit Futures-A Longitudinal Cohort Study From Norway.

ABSTRACTThe effect of birth weight and childhood body mass index (BMI) on adolescents’ bone parameters is not established. The aim of this longitudinal, population‐based study was to investigate the association of birth weight, childhood BMI, and growth, with adolescent bone mass and bone density in a sample of 633 adolescents (48% girls) from The Tromsø Study: Fit Futures. This population‐based cohort study was conducted in 2010–2011 and 2012–2013 in Tromsø, Norway. Bone mineral content (BMC) and areal BMD (aBMD) were measured at total hip (TH) and total body (TB) by dual‐energy X‐ray absorptiometry (DXA) and converted to internal Z‐scores. Birth weight and childhood anthropometric measurements were retrospectively obtained from the Medical Birth Registry of Norway and childhood health records. Associations between birth weight, BMI, and growth were evaluated by fitting linear mixed models with repeated measures of BMC and aBMD at ages 15 to 17 and 18 to 20 years as the outcome. In crude analysis, a significant positive association (p < 0.05) with TB BMC was observed per 1 SD score increase in birth weight, observed in both sexes. Higher rate of length growth, conditioned on earlier size, from birth to age 2.5 years, and higher rate of weight gain from ages 6.0 to 16.5 years, conditioned on earlier size and concurrent height growth, revealed stronger associations with bone accrual at ages 15 to 20 years compared with other ages. Compared with being normal weight, overweight/obesity at age 16.5 years was associated with higher aBMD Z‐scores: β coefficient (95% confidence interval [CI]) of 0.78 (0.53, 1.03) and 1.08 (0.85, 1.31) in girls, 0.63 (0.42, 0.85) and 0.74 (0.54, 0.95) in boys at TH and TB, respectively. Similar associations were found for BMC. Being underweight was consistently negatively associated with bone parameters in adolescence. In conclusion, birth weight influences adolescent bone mass but less than later growth and BMI in childhood and adolescence. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research

Total flavonoid extract of Epimedium herb increases the peak bone mass of young rats involving enhanced activation of the AC10/cAMP/PKA/CREB pathway

Ethnopharmacological relevanceEpimedium sagittatum brevicornum Maxim. is an important traditional Chinese herb that has long been used to promote bone fracture healing and treat osteoporosis. Aim of the studyAchieving peak bone mass by adolescence has now been accepted to be fundamental for preventing osteoporosis in adulthood life. This study investigated the possibility of increasing peak bone mass in young rats using the total flavonoid extract of Epimedium herb (TFE). Materials and methodsTFE was intragastrically administered to one-month-old Wistar rats at a low (100 mg/kg), middle (200 mg/kg) or high dose (400 mg/kg). Whole body bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry every two weeks. When BMD of any one of TFE groups was found to be significantly higher than that of the control, all rats were sacrificed, serum samples were collected for bone turnover biochemical assays, and femurs, tibiae and vertebrae were isolated and used in BMD, mechanical, micro-structural, histomorphometric and mechanistic studies. ResultsAdministration of TFE at middle and high doses for two months significantly increased the whole body, femoral and vertebral BMDs, and improved the bone mechanical and micro-architectural properties. The serum turnover biochemical results and the enhanced expression levels of bone-formation regulatory genes (Runx-2, OSX, and BMP-2) demonstrated that TFE administration increased bone formation but had no effect on bone resorption. The increased phosphorylation levels in femurs of PKA and CREB and expression of AC10 (the only soluble form of adenylyl cyclase) and the increased serum cAMP level after 4 h of TFE administration indicated that TFE promoted bone formation by activating the AC10/cAMP/PKA/CREB pathway in vivo. ConclusionsOral administration of TFE at 200 mg/kg for two months can increase the peak bone mass of growing rats, suggesting the possibility of using total flavonoid extract of Epimedium herb to increase the peak bone mass in adolescence which is important for preventing osteoporosis in adult life.

Calcium: Nutrient in Adolescent Girls

Bone health is important to health and quality of life. It is important to optimize bone health throughout life cycle. Adolescence is a transitional journey from childhood to adult life along with physical development. This may be considered as physical, psychological and emotional rebirth. Nutrition in adolescence has preventive role related to diet causing chronic diseases like cardiovascular disease, cancer and osteoporosis. Diet and physical factors play a major role in promoting bone health, which begins in childhood and continues into old age. Calcium and protein in the diet with sunlight exposure and weight bearing exercises are important for building the peak bone mass in adolescents. Calcium as nutrient in adolescence is critical for prevention of osteoporosis and improving quality of life.

Effect of whole-body vibration training on bone mass in adolescents with and without Down syndrome: a randomized controlled trial.

Whole-body vibration training (WBV) attracts great interest as osteoporosis prevention strategy. Twenty-six adolescents with and without Down syndrome (DS) (13 DS; 12-18 years) performed 20 weeks of WBV. The results indicate that WBV seems to provoke a lesser response in adolescents with DS than in those without DS. This study aims to observe the differences between adolescents with and without DS in the effects of 20 weeks of WBV training, on bone mineral content (BMC) and density (BMD). Twenty-six adolescents (13 DS; 12-18 years) were measured with dual-energy X-ray absorptiometry before and after the intervention (3/week, 10 repetitions (30-60 s) and 1-min rest, frequency 25-30 Hz and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)). Both, an intention-to-treat (ITT) analysis designed to assess the effects on bone mass and a per-protocol analysis, designed to compare poor and high compliers, were performed. The ITT analysis revealed significant increases in all BMC and BMD parameters (dz = 0.66 to 1.64; all p < 0.05) in the non-DS group, whilst DS group improved whole-body, subtotal (whole-body less head), upper limbs (ULIMBS), pelvis, lower limbs (LLIMBS) and spine BMC (dz = 0.75 to 1.76; all p < 0.05) and subtotal, pelvis, LLIMBS and spine BMD (dz = 0.73 to 1.28; all p < 0.05). Significantly greater increases were evident in the absolute and percent changes of the non-DS group over DS group (d = 0.88 to 3.85; all p < 0.05). ULIMBS BMD showed a tendency towards an interaction (f = 0.41 and p = 0.086) with higher increase for non-DS group. When a per-protocol analysis was considered, high-complier adolescents had 8.1 versus 5.3 % of gains in the spine BMC over poor-complier adolescents (d = 0.93; p < 0.05). Twenty weeks of WBV training may improve BMC and BMD in clinically relevant skeletal sites in both groups. Nevertheless, this type of training seems to provoke a lesser response in adolescents with DS than in those without DS.

Strong relationship between vitamin D status and bone mineral density in anorexia nervosa

BackgroundAnorexia nervosa (AN) is associated with impaired bone health and low bone mineral density (BMD) as a consequence of an inadequate peak bone mass in adolescence and bone loss in young adulthood. The vitamin D status with its implications for bone health in patients affected by AN has only been examined previously in small studies. ObjectiveTo evaluate the prevalence of vitamin D deficiency and test the hypothesis that patients with AN and vitamin D deficiency might have worse bone metabolism and lower bone density as compared with AN with adequate vitamin D repletion. DesignWe analysed the vitamin D status and bone metabolism in a large cohort (n=89) of untreated patients affected by AN, with amenorrhoea. ResultsVitamin D deficiency is widespread in untreated patients with AN: 16.9% had 25OH vitamin D levels below 12ng/ml, 36% below 20ng/ml and 58.4% below 30ng/ml. PTH values were higher and BMD at both femoral sites were lower in patients with vitamin D<20ng/ml. Progressively higher values of BMD were observed by 4 ranks of 25 OH vitamin D values (severe deficiency: <12ng/ml, deficiency: ≥12ng/ml and <20ng/ml, insufficiency: ≥20 and <30ng/ml and normal: ≥30ng/ml). In patients with severe vitamin D deficiency BMD at the hip were significantly lower than that measured in groups with values over 20ng/ml (p<0.001 for trend). The level of significance did not change for values adjusted for BMI or body weight. ConclusionWe found a strong relationship between vitamin D status and hip BMD values with additional benefits for those with 25OHD levels above 20ng/ml. Our results support the design of a randomized placebo-controlled clinical trial on the effect of vitamin D on BMD in patients with AN. The second point, whether 25OHD should be above 20 or 30ng/ml remains a discussion point.