Adolescents: at increased risk for osteoporosis?

Breakfast Consumption and Diet Quality of Teens in Southwestern Ontario

Background

Breakfast skipping has previously been associated with worse diet quality among adolescents; the latter increases the risk of chronic disease. However, many studies do not consider diet quality as a function of calories, which is problematic as skippers tend to consume less energy than consumers. Additionally, due to the lack of one accepted definition of both breakfast skipping and diet quality, it is unclear how differences found may change when using varying definitions.

Objectives

We aimed to compare the Healthy Eating Index-2015 (HEI-2015) scores and nutrient intakes of teen breakfast skippers and consumers in Southwestern Ontario, Canada.

Methods

Cross-sectional, baseline data were used from SmartAPPetite, an ongoing nutrition intervention study. Singular 24-h dietary recalls and sociodemographic data from 512 adolescents aged 13-19 y were used to compare HEI-2015 scores and nutrient intakes via multivariable linear regression.

Results

Previous day breakfast skippers had significantly lower HEI-2015 scores (-4.4; 95% CI: -8.4, -0.4) and significantly lower intakes of calories, saturated fat, and vitamin C, as well as significantly higher intake of sodium and total fat.

Conclusions

Previous day breakfast consumers had significantly higher diet quality scores and better nutrient intakes than breakfast skippers, although, on average, both had poor diet quality. Consequently, it is unlikely that simply advising teens to consume breakfast will result in meaningful change in diet quality, and more effort should be placed on promoting nutritious breakfasts.

Risk factors associated with low bone mineral density in children with idiopathic scoliosis: a scoping review

BACKGROUND

Children with idiopathic scoliosis (IS) have a high risk of osteoporosis and IS with low bone mineral density (BMD) are susceptible to curve progression. This review aims to explore the risk factors of low BMD in children with IS.

METHODS

Studies were retrieved from 5 databases that were published up to January 2022. Search terms are keywords in titles or abstracts, including subject headings related to "Scoliosis", "Bone Mineral Density", and "Risk Factors". Observational studies on risk factors of low BMD in children with IS were enrolled in this review. The number of studies, sample size, outcome measures, research type, endocrine, and lifestyle-related factors, gene/signal pathway, and other contents were extracted for qualitative analysis.

RESULTS

A total of 56 studies were included in this scoping review. Thirty studies involved genetic factors that may affect BMD, including the Vitamin-D receptor gene, RANK/RANKL signal pathway, the function of mesenchymal stem cells, Runx2, Interleukin-6 (IL-6), and miR-145/β-catenin pathway. Eight studies mentioned the influence of endocrine factors on BMD, and the results showed that serum levels of IL-6, leptin and its metabolites, and ghrelin in children with IS were different from the age-matched controls. In addition, there were 18 articles on lifestyle-related factors related to low BMD in children with IS, consisting of physical activity, calcium intake, Vitamin D level, and body composition.

CONCLUSIONS

Genetic, endocrine, and lifestyle-related factors might relate to low BMD and even osteoporosis in IS. To prevent osteoporosis, the effectiveness of regular screening for low BMD risk factors in children with IS needs to be investigated. Additionally, clear risk factors suggest strategies for bone intervention. Future studies should consider the effectiveness of calcium and vitamin D supplements and physical activity in BMD improvement.

Bone mineral density comparison of adolescents with constitutional thinness and anorexia nervosa

BACKGROUND

The negative impact of anorexia nervosa (AN) on bone health is well defined. However, there are very few studies evaluating the effect of constitutional thinness on bone health, especially in the adolescent period and in the male gender. The aim of this study is to compare the bone mineral density (BMD) measurements of adolescents with AN and with constitutional thinness.

METHODS

Between April 2013 and March 2014, 40 adolescents with AN and 36 adolescents with constitutional thinness participated in the study. The femoral neck and lumbar spine BMD were measured by dual energy X-ray absorptiometry (DXA).

RESULTS

Mean lumbar z and BMD scores of adolescents with constitutional thinness were significantly lower than in adolescents with AN, whereas the mean femoral z and BMD scores were not significantly different. When males were compared separately, lumbar z and BMD values of the constitutionally thin group were found to be significantly lower than in the AN group. This difference was not significant for females.

CONCLUSIONS

The difference between the male and female results of our study suggested two hypotheses. The significantly lower BMD values in constitutionally thin boys are attributed to their longer duration of low body mass index (BMI). Although the duration of low BMI is also longer for constitutionally thin girls, similar BMD values of AN and constitutionally thin female groups are attributed to the additional negative impact of estrogen deficiency on the bone health of girls with AN.

Effects of Short-Term Calcium Supplementation in Children and Adolescents with Phenylketonuria

Reduction of bone mineral density and the risk of osteopenia have been reported to occur in phenylketonuria (PKU) patients. This study aimed to evaluate the short-term effects of calcium supplementation in phenylketonuric children and adolescents. The study included 18 patients with PKU aged 5-18 yr (61% male) under clinical and nutritional treatment. Evaluation of food intake, anthropometry, and biochemical and phalangeal quantitative ultrasound were performed before (phase 1) and after (phase 2) calcium supplementation (1000 mg/d) for 34 d. Statistical analysis was performed using t test for paired samples, Wilcoxon's test, and McNemar's test (p <0.05). There was an inadequate intake of phosphorus and vitamin D, the same occurring with serum concentrations of these nutrients. About 50% of the patients had an accumulation of adipose tissue measures, with a negative correlation between Z-score, body mass index, and phalangeal quantitative ultrasound (amplitude-dependent speed of sound [AD-SoS]). There was a significant difference in urinary phosphorus excretion with higher values before supplementation. Comparison of the two phases revealed significantly higher AD-SoS values after the supplementation (p = 0.017). The reduction in phosphorus excretion associated with increased AD-SoS between the two phases suggested increased bone formation, and showed no negative effects in relation to short-term calcium supplementation in children and in adolescents with PKU.

Risk factors and surveillance for reduced bone mineral density in pediatric cancer survivors

BACKGROUND

Pediatric cancer survivors are at increased risk of developing low bone mineral density (BMD) due to cancer treatment. This study assessed the yield of screening for low BMD in pediatric-aged cancer survivors as per the Children's Oncology Group Long-Term Follow-Up (COG-LTFU) Guidelines, which recommend screening survivors who received steroids, methotrexate, or hematopoietic cell transplant (HCT).

METHODS

This is a retrospective cohort study of 475 pediatric blood cancer and noncentral nervous system solid tumor survivors screened for low BMD with dual-energy X-ray absorptiometry (DXA) as per the COG-LTFU Guidelines from 2003 to 2010. Risk factors for low BMD (DXA Z-score ≤-2) were evaluated by univariate and multivariate analysis.

RESULTS

The mean DXA Z-score was -0.1 for both whole body and lumbar spine measurements. Among at-risk survivors, 8.2% (39/475) had low BMD. Multivariate analysis of survivors with low BMD showed significant association with male gender (odds ratio [OR] 3.4, 95% confidence interval [CI], 1.3-9.0), exposure to total body irradiation (TBI), cranial, or craniospinal radiation (OR 5.2, 95% CI, 1.8-14.9), and gonadal dysfunction (OR 4.3, 95% CI, 1.4-13.0). Methotrexate exposure was not significantly associated with low BMD. Survivors receiving HCT had a reduced risk of low BMD (OR 0.2, 95% CI, 0.1-0.9).

CONCLUSION

The highest risk factors for low BMD were male gender, exposure to TBI, cranial, or craniospinal radiation, and gonadal dysfunction. Survivors receiving methotrexate or HCT therapy have the lowest risk for low BMD among those screened. Future studies should investigate risk of low BMD for survivors receiving HCT without radiation exposure.

The Impact of Fat and Obesity on Bone Microarchitecture and Strength in Children

A complex interplay of genetic, environmental, hormonal, and behavioral factors affect skeletal development, several of which are associated with childhood fractures. Given the rise in obesity worldwide, it is of particular concern that excess fat accumulation during childhood appears to be a risk factor for fractures. Plausible explanations for this higher fracture risk include a greater propensity for falls, greater force generation upon fall impact, unhealthy lifestyle habits, and excessive adipose tissue that may have direct or indirect detrimental effects on skeletal development. To date, there remains little resolution or agreement about the impact of obesity and adiposity on skeletal development as well as the mechanisms underpinning these changes. Limitations of imaging modalities, short duration of follow-up in longitudinal studies, and differences among cohorts examined may all contribute to conflicting results. Nonetheless, a linear relationship between increasing adiposity and skeletal development seems unlikely. Fat mass may confer advantages to the developing cortical and trabecular bone compartments, provided that gains in fat mass are not excessive. However, when fat mass accumulation reaches excessive levels, unfavorable metabolic changes may impede skeletal development. Mechanisms underpinning these changes may relate to changes in the hormonal milieu, with adipokines potentially playing a central role, but again findings have been confounding. Changes in the relationship between fat and bone also appear to be age and sex dependent. Clearly, more work is needed to better understand the controversial impact of fat and obesity on skeletal development and fracture risk during childhood.

Youth receiving orthodontic care are not immune to poor diet and overweight: a call for dental providers to participate in prevention efforts

OBJECTIVES

While obesity is common in the US, disparities exist. Orthodontic samples are assumed to be more affluent than the general population and not in need of assistance in developing or maintaining healthy lifestyles. This paper evaluates the need of the orthodontic population for intervention by examining diet and weight status of an orthodontic patient sample and describes a role for dental clinicians in obesity prevention efforts.

METHODS

552 patients age 8-14 years, 54% female, 51% non-Hispanic white, 26% Hispanic were recruited from orthodontic practices in Southern California to participate in a randomized controlled trial of clinician-delivered health promotion. Height, weight, demographics, and diet were recorded. Chi-Square analyses were used to test for differences at baseline by gender, age, ethnicity, and income.

RESULTS

13% of the sample was overweight and 9% was obese. Males had a higher rate of obesity than females. Lower income youth had a higher rate than higher income youth. Hispanic youth had a higher rate than non-Hispanic white youth. Failure to meet national dietary guidelines was common, differing significantly by demographic group.

CONCLUSIONS

Within a sample not typically thought of as needing assistance, nearly 25% were overweight or obese and the majority failed to meet dietary recommendations. While most patients could benefit from intervention, male, Hispanic, and lower income groups were in greatest need of assistance. Dental providers, who see youth frequently and already discuss nutrition in the context of oral health, have the opportunity to contribute to obesity prevention.

Poor bone health at the end of puberty in childhood cancer survivors

BACKGROUND

Although the survival rate following childhood cancer is >80%, late effects are a major concern. We aimed to determine the clinical factors affecting bone health after puberty in childhood cancer survivors at risk for low bone mineral density (BMD).

PROCEDURES

We performed dual-energy X-ray absorptiometry at the lumbar spine, femoral neck, and total hip regions for survivors with the following bone densitometry indications (BDIXs): brain or nasopharyngeal cancer, head or neck area radiotherapy, or corticosteroid treatment (N = 92). Additionally, we evaluated 16 survivors without these BDIXs but with other clinical factors that could affect bone health. We assessed the effects of these factors on BMD using univariate and logistic regression analyses. Moderate BMD deficit was defined as a Z-score of <-1.0 and ≥-2.0, and severe BMD deficit was defined as <-2.0.

RESULTS

Severe BMD deficits were found in 18 survivors (16.7%) and moderate BMD deficits were in 39 (36.1%) in at least one bone region. BMD deficits tended to increase as the number of BDIXs increased (P < 0.010). There were no severe BMD deficits in survivors without BDIXs. The duration since cancer treatment completion was correlated with higher BMD (P < 0.05). Endocrine dysfunction was a significant risk factor for decreased BMD in univariate and multivariate analyses (P < 0.05 for both).

CONCLUSIONS

Decreased BMD was prevalent in our study cohort. Endocrine dysfunction was found to be a significant risk factor, and it should be managed in survivors to ensure future bone health.

Longitudinal bone mineral content and density in Rett syndrome and their contributing factors

Bone mass and density are low in females with Rett syndrome. This study used Dual energy x-ray absorptiometry to measure annual changes in z-scores for areal bone mineral density (aBMD) and bone mineral content (BMC) in the lumbar spine and total body in an Australian Rett syndrome cohort at baseline and then after three to four years. Bone mineral apparent density (BMAD) was calculated in the lumbar spine. Annual changes in lean tissue mass (LTM) and bone area (BA) were also assessed. The effects of age, genotype, mobility, menstrual status and epilepsy diagnosis on these parameters were also investigated. The baseline sample included 97 individuals who were representative of the total live Australian Rett syndrome population under 30years in 2005 (n=274). Of these 74 had a follow-up scan. Less than a quarter of females were able to walk on their own at follow-up. Bone area and LTM z-scores declined over the time between the baseline and follow-up scans. Mean height-standardised z-scores for the bone outcomes were obtained from multiple regression models. The lumbar spine showed a positive mean annual BMAD z-score change (0.08) and a marginal decrease in aBMD (-0.04). The mean z-score change per annum for those 'who could walk unaided' was more positive for LS BMAD (p=0.040). Total body BMD mean annual z-score change from baseline to follow-up was negative (-0.03). However this change was positive in those who had achieved menses prior to the study (0.03, p=0,040). Total body BMC showed the most negative change (-0.60), representing a decrease in bone mineral content over time. This normalised to a z-score change of 0.21 once adjusted for the reduced lean tissue mass mean z-score change (-0.21) and bone area mean z-score change (-0.14). Overall, the bone mineral content, bone mineral density, bone area and lean tissue mass z-scores for all outcome measures declined, with the TB BMC showing significant decreases. Weight, height and muscle mass appear to have impacts on bone formation and we recommend that nutritional intake should be closely monitored and a physical activity plan developed to optimise bone health. Pubertal progression should also be assessed in conjunction with serial densitometry assessments to track bone mass and density changes over time.

Bone health in children with long-term idiopathic subclinical hypothyroidism

Background

Subclinical hypothyroidism (SH) is a relatively common condition characterized by a mild persistent thyroid failure. The management of children with SH is still a controversial issue and the decision to treat with L-thyroxine represents a clinical dilemma. Thyroid hormone and TSH play an important role in skeletal growth and bone mineral homeostasis.

Aim

To evaluate whether untreated idiopathic SH may affect bone health in childhood and to compare two different diagnostic tools such as dual-energy X-ray densitometry (DXA) and quantitative ultrasound (QUS).

Patients and Methods

Twenty-five children and adolescents (11 males) aged 9.8 ± 3.5 years (range 4.2-18.7) with untreated idiopathic SH were enrolled in the study. SH was diagnosed on the basis of normal FT4 levels with TSH concentrations between 4.2 and 10 mU/l. Children have been followed for 3.3 ± 0.3 years from the time of SH diagnosis. Twenty-five healthy children, age- and sex-matched, were enrolled as controls. Patients and controls underwent DXA to evaluate lumbar spine bone mineral density (BMD) and QUS at proximal phalanges of the non-dominant hand to assess bone quality, measured as amplitude-dependent speed of sound (Ad-SoS) and bone transmission time (BTT).

Results

Mean BMD Z-score was −0.4 ± 1.36 in patients and −0.2 ± 1.2 in controls. Mean Ad-SoS Z-score was 0.01 ± 1.0 in patients and 0.1 ± 1.2 in controls and mean BTT Z-score was −0.03 ± 0.8 and 0.04 ± 1.1 respectively. All values were within the normal range, both in patients and in controls. There were no statistically significant differences between the two groups.

Conclusion

Bone health, evaluated by lumbar spine DXA and phalangeal QUS, is not impaired in our children, despite long-term duration of idiopathic SH. Data about bone status provided by QUS are comparable to those provided by DXA. Therefore, QUS may represent a good, cheaper and safe screening test for bone evaluation in children with SH.

MRI-measured pelvic bone marrow adipose tissue is inversely related to DXA-measured bone mineral in younger and older adults

BACKGROUND/OBJECTIVES

Recent research has shown an inverse relationship between bone marrow adipose tissue (BMAT) and bone mineral density (BMD). There is a lack of evidence at the macro-imaging level to establish whether increased BMAT is a cause or effect of bone loss. This cross-sectional study compared the BMAT and BMD relationship between a younger adult group at or approaching peak bone mass (PBM; age 18.0-39.9 years) and an older group with potential bone loss (PoBL; age 40.0-88.0 years).

SUBJECTS/METHODS

Pelvic BMAT was evaluated in 560 healthy men and women with T1-weighted whole-body magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry.

RESULTS

An inverse correlation was observed between pelvic BMAT and pelvic, total and spine BMD in the younger PBM group (r=-0.419 to -0.461, P<0.001) and in the older PoBL group (r=-0.405 to -0.500, P<0.001). After adjusting for age, sex, ethnicity, menopausal status, total body fat, skeletal muscle, subcutaneous and visceral adipose tissue, neither subject group (younger PBM vs older PoBL) nor its interaction with pelvic BMAT significantly contributed to the regression models with BMD as dependent variable and pelvic BMAT as independent variable (P=0.434-0.928).

CONCLUSIONS

Our findings indicate that an inverse relationship between pelvic BMAT and BMD is present both in younger subjects who have not yet experienced bone loss and also in older subjects. These results provide support at the macro-imaging level for the hypothesis that low BMD may be a result of preferential differentiation of mesenchymal stem cells from osteoblasts to adipocytes.

Predictors of bony morbidity in children with acute lymphoblastic leukemia

BACKGROUND

To evaluate the relationship between lumbar spine (LS) bone mineral density (BMD) and patient-, disease-, and therapy-related variables, and to define the risk-factors for fractures in children receiving therapy on Dana-Farber Cancer Institute acute lymphoblastic leukemia (ALL) protocols.

METHODS

Children (≤18 years) diagnosed with ALL during the period 1995-2006, who are in first clinical remission, were included (n = 124). Dual-energy X-ray absorptiometry provided LS-BMD at diagnosis (n = 46) and during continuation therapy. LS-BMD was expressed as Z scores based on local population norms. Regression analyses evaluated the risk of osteopenia (Z-score -1.01 to -1.99, osteoporosis (Z-score -2.00 or less) and fractures.

RESULTS

At diagnosis, 14 0f 46 (30%) patients had osteopenia and 5 (11%) had osteoporosis; whereas, during continuation therapy, 47 of 124 (39.5%) patients had osteopenia, and 10 (8%) had osteoporosis. LS-BMD at diagnosis had a positive linear relationship with LS-BMD during continuation therapy (Pearson correlation coefficient 0.619, P < 0.0001). Multivariable analyses identified age ≥10 years and LS-BMD at diagnosis as independent predictors of LS-BMD during continuation therapy. Twenty-three (18.5%) patients developed fractures. Dexamethasone therapy (OR 3.4, 95% CI 1.31, 7.52, P = 0.01) and lower LS-BMD during the continuation therapy (OR 1.8, 95% CI 1.2, 2.8, P = 0.01) were independent predictors of fracture.

CONCLUSIONS

Older age and lower LS-BMD at diagnosis are predictors of lower LS-BMD during continuation therapy. Dexamethasone and lower LS-BMD during continuation therapy are associated with fractures. Using these variables it is feasible to develop a predictor model to define the risk of bony morbidity in children receiving ALL therapy.

[Preliminary comparison between phalangeal quantitative ultrassonography and bone densitometry for bone mass evaluation in adolescents]

OBJECTIVE

To evaluate the association between quantitative ultrasonography at hand phalanges (QUS) and dual energy X-ray absorptiometry (DXA), and between these methods with food intake and history of bone fractures.

SUBJECTS AND METHODS

After two years of follow up of 270 schoolchildren, 10 of them, who showed bone mass below - 2 SD in QUS, were included in the present study. Laboratory results and DXA data were analyzed.

RESULTS

Bone mass evaluated by DXA at L1-L4 ranged from -2.8 to -1.1 SDS, and whole body bone mass, from -2.9 to -1.2 SDS. Three children had history of non-pathological bone fractures. Dietary assessment showed low intake of calcium in 10 cases, of phosphorus in 6, and of vitamin D in 8 cases. There were no differences among the cases of bone mass below-2 SD in any of the three used methods. There was no association between history of bone fractures and food intake, and between these evaluations and bone mass.

CONCLUSION

In this small group of schoolchildren there was an association between the methods QUS and DXA. However, there was no association between bone mass and the history of bone fractures, or calcium, phosphorus and vitamin D intake.

Efficacy of the Survivor Health and Resilience Education (SHARE) program to improve bone health behaviors among adolescent survivors of childhood cancer

PURPOSE

The purpose of this study is to test the efficacy of the Survivor Health and Resilience Education Program intervention--a manualized, behavioral intervention focusing on bone health behaviors among adolescent survivors of childhood cancer.

METHODS

Participants were 75 teens aged 11-21 years, one or more years post-treatment, and currently cancer-free. Teens were randomized to a group-based intervention focusing on bone health or a wait-list control. Bone health behaviors were assessed at baseline and 1-month post-intervention.

RESULTS

Controlling for baseline outcome measures and theoretical predictors, milk consumption frequency (p=0.03), past month calcium supplementation (p<0.001), days in the past month with calcium supplementation (p<0.001), and dietary calcium intake (p=0.04) were significantly greater at 1-month follow-up among intervention participants compared with control participants.

CONCLUSIONS

The intervention had a significant short-term impact on self-reported bone health behaviors among adolescent survivors of childhood cancer. Research examining long-term intervention effectiveness is warranted.

Updated recommendations for the diagnosis and management of osteoporosis: a local perspective

Postmenopausal osteoporosis and osteoporosis in elderly men are major health problems, with a significant medical and economic burden. Although osteopenia and osteoporosis are more common locally than in the West, fracture rates are generally less than in Western countries. Vitamin D deficiency is common in the region and contributes adversely to bone health. Vitamin D deficiency should be suspected and treated in all subjects with ostopenia or osteoporosis. The use of risk factors to determine fracture risk has been adopted by the World Health Organization and many international societies. Absolute fracture risk methodology improves the use of resources by targeting subjects at higher risk of fractures for screening and management. The King Faisal Specialist Hospital Osteoporosis Working Group recommends screening for women 65 years and older and for men 70 years and older. Younger subjects with clinical risk factors and persons with clinical evidence of osteoporosis or diseases leading to osteoporosis should also be screened. These guidelines provide recommendations for treatment for postmenopausal women and men older than 50 years presenting with osteoporotic fractures for persons having osteoporosis-after excluding secondary causes-or for persons having low bone mass and a high risk for fracture. The Working Group has suggested an algorithm to use at King Faisal Specialist Hospital that is based on the availability, cost, and level of evidence of various therapeutic modalities. Adequate calcium and vitamin D supplement are recommended for all. Weekly alendronate (in the absence of contraindications) is recommended as first-line therapy. Alternatives to alendronate are raloxifene or strontium ranelate. Second-line therapies are zoledronic acid intravenously once yearly, when oral therapy is not feasible or complicated by side effects, or teriparatide in established osteoporosis with fractures.

[Association among weight loss, bone mass, body composition and dietary intake of post-pubertal obese adolescents]

OBJECTIVE

To verify the effects of weight loss on bone mass of obese adolescents submitted to a nutritional intervention based on a hypocaloric diet and nutritional advice over a nine-month-period.

METHODS

Anthropometry, body composition, BMD and dietary intake were evaluated.

RESULTS

Fifty-five adolescents, 78.2% females, within an average age of 16.6 (1.4) years old participated in the study. Sixteen participants who completed the study did not lose weight. The group that adhered to the nutritional intervention had a mean weight loss of 6.2 (4.6)% baseline. There was a significant increase in total BMD and bone mineral content (BMC) in those adolescents who did not lose weight, while increased BMC and bone area were verified in participants who lost weight, mainly when associated with body composition alterations while changing weight.

CONCLUSION

The increment in bone mineral density, even throughout weight loss, has showed no negative effect on bone mass and has also emphasized the importance of nutritional improvement in total bone mass during adolescence.

Metabolismo do cálcio na fenilcetonúria

A Fenilcetonúria é um erro inato do metabolismo do aminoácido fenilalanina. O tratamento é essencialmente dietético e envolve uma restrição severa no consumo de alimentos contendo aminoácido fenilalanina. Embora a alimentação seja complementada com fórmulas a fim de suprir as necessidades de vitaminas, minerais e aminoácidos essenciais, carências nutricionais ainda ocorrem. Isto se deve, principalmente, à restrição de fontes protéicas, que acarreta deficiência na ingestão de diversos nutrientes, dentre eles o cálcio. O cálcio possui importante relação com a formação mineral óssea. Estudos recentes demonstram que portadores de fenilcetonúria apresentam freqüentemente osteopenia e fraturas, sendo a maior incidência em crianças acima de 8 anos de idade. O rápido aumento da estatura, a dieta deficiente em cálcio e níveis de aminoácido fenilalanina elevados têm sido descritos como os principais fatores para a aquisição de massa óssea inadequada. A suplementação de cálcio em crianças saudáveis mostrou um efeito positivo sobre a aquisição de massa óssea na fase da pré-puberdade. Assim, torna-se relevante compreender a necessidade da suplementação de cálcio em pacientes fenilcetonúria, a fim de favorecer o desenvolvimento ósseo esperado.

Bone mineral density deficits in survivors of childhood cancer: long-term follow-up guidelines and review of the literature

The development of curative therapy for most pediatric malignancies has produced a growing population of childhood cancer survivors who are at increased risk for a variety of health problems resulting from their cancer or its treatment. Because of the fact that many treatment-related sequelae may not become clinically apparent until the survivor attains maturity or begins to age, the ability of primary care providers to anticipate late effects of treatment is essential for providing timely interventions that prevent or correct these sequelae and their adverse effects on quality of life. Altered bone metabolism during treatment for childhood cancer may interfere with attainment of peak bone mass, potentially predisposing to premature onset of and more severe complications related to osteopenia and osteoporosis. Bone mineral deficits have been reported after treatment for a variety of pediatric malignancies and represent morbidity that can be reduced or prevented through lifestyle changes and attention to other common cancer-related sequelae such as hypogonadism. The Children's Oncology Group long-term follow-up guidelines for survivors of childhood, adolescent, and young adult cancers provide risk-based surveillance recommendations that are based on expert opinion and review of the scientific literature for potential late effects of pediatric cancer therapy including osteopenia. This review summarizes the existing literature that has defined characteristics of cancer survivors at risk for bone mineral deficits and contributed to the surveillance and counseling recommendations outlined in the Children's Oncology group long-term follow-up guidelines.

Bone health knowledge, self-efficacy, and behaviors in adolescent females

PURPOSE

To determine whether an educational program about osteoporosis will improve knowledge and confidence about osteoporosis prevention, self-efficacy, and self-reported bone-health lifestyle behaviors in adolescent girls.

METHODS

Tests of knowledge, self-efficacy, calcium intake, and physical activity were compared before and after an osteoporosis educational in-service program. The differential effects of intervention, an osteoporosis in-service program versus no intervention, were determined using 2 x 2 analyses of variance.

RESULTS

The intervention group showed a significant increase in knowledge (p < 0.01) as well as self-efficacy (p < 0.03) whereas the control group results did not (p > 0.05). Results for calcium intake and exercise were also statistically significant; however, unusual performance trends raise questions related to clinical interpretation of the lifestyle behavior variables.

CONCLUSION

An osteoporosis educational in-service can significantly improve knowledge, self-efficacy, and reported calcium consumption in adolescent girls; however, it may not be an adequate intervention to change lifestyle behaviors.

Children's dairy intake in the United States: too little, too fat?

OBJECTIVE

To compare reported dairy/calcium intake with intake recommendations and examination of food sources and fat levels of dairy intake in the National Health and Nutrition Examination Survey 1999-2002.

STUDY DESIGN

Dietary, anthropometric, and sociodemographic data for 2- to 18-year-olds (n = 7716) were evaluated to compare intakes of dairy (MyPyramid) and calcium (Adequate Intake [AI]) recommendations. US Department of Agriculture food codes were used to identify mutually exclusive food groups of dairy-contributing foods, which were ranked in descending order proportional to total intake. Complex sample survey Student t tests were used to determine statistical significance among intakes in 4 age groups and between reported and recommended intakes.

RESULTS

Dairy consumption was not significantly different among age groups, but only 2- to 3-year-olds met the MyPyramid recommendation. Calcium intake was significantly different among age groups, and 2- to 8-year-olds met the AI. Intake of flavored milk ranged from 9% to 18%. More than half of the milk consumed by 2- to 3-year-olds was whole milk, and, with the exception of yogurt consumption in 2- to 3-year-olds, children choose to consume more of the highest-fat varieties of cheese, yogurt, ice cream, and dairy-based toppings.

CONCLUSIONS

Dairy and calcium intakes are inadequate in 4- to 18-year-olds. Most children consume the high-fat varieties of milk and dairy products. Focusing nutrition guidance efforts on increasing the intake of the low-fat dairy products, with special emphasis on increasing calcium intake in school-age children and adolescents through flavored low-fat milk products, may be beneficial.

Physical activity, calcium intake and bone health in children and adolescents

Osteoporosis is a serious and potentially debilitating disease, which can lead to a variety of health complications and a diminished quality of life. Consequently, the development of bone mineral density (BMD) and content (BMC) during childhood and adolescence is of great importance, as it may attenuate the effects and incidence of osteoporosis later in life. Identifying the mechanisms by which bones are strengthened early in life is crucial. This review highlights research examining factors that influence BMD and BMC in children and adolescents. While a sizeable amount of variation in BMD and BMC in children and adolescents can be attributed to genetic factors and body size, studies have also shown the positive influence of physical activity and calcium intake on bone development. Research supporting the role of these modifiable factors varies according to age, sex and the bone site studied. During the pubertal years, large gains in BMD and BMC are evident. However, physical activity and calcium intake are also important to the development of BMD and BMC during the prepubertal years. Thus, actions taken throughout childhood may exert a great impact on BMD and BMC, and overall bone health as an adult.

Influence of sports participation and menarche on bone mineral density of female high school athletes

Weight-bearing exercise during adolescence may enhance peak bone mineral density (BMD) and reduce osteoporosis risk. The association of sports participation before and after menarche with areal BMD (by central DXA) was investigated in 99 female high school athletes (age 15.5+/-1.3 year). The frequency and duration of structured sports (school-based or other organized team) were assessed using an interviewer-assisted questionnaire. Overall, the average number of years of weight-bearing sport participation was 7.4+/-3.4 years; 72% of the athletes began sport participation before menarche. Training patterns and BMD were examined by tertiles of yearly weight-bearing sport participation (hours/year) before (WBpre), after (WBpost) menarche, and in total (WBtotal). After adjusting for chronological age, gynecological age, and BMI, compared to athletes in the WBtotal low tertile, athletes in the WBtotal high tertile had significantly greater BMD at the spine (p=0.009), total hip (p=0.03), trochanter (p=0.03), and total body (p=0.009). Similar patterns were found by WBpre or WBpost status, separately, with the exception of spine BMD which was significantly different across tertiles in WBpost only (p<0.01). While the number of years of participation was similar across tertiles of WBtotal, the number of months/year was significantly greater among athletes in the high tertile than athletes in the low tertile (9.2+/-3.4 month/year versus 5.0+/-2.9 month/year, respectively (p<0.001)). These results indicate that near year-round participation in structured weight-bearing sports during early adolescence may help young girls optimize bone mineral accrual during these critical years, and may decrease their risk of osteoporosis with advancing age.

Vitamin D status and its relationship with parathyroid hormone and bone mineral status in older adolescents

Osteoporosis is an important contributor to the global burden of disease, and in the UK alone results in one in three women and one in twelve men aged >50 years experiencing a fragility fracture. Optimising peak bone mass in early adulthood is thought to reduce osteoporosis risk by offsetting bone losses in later life. Ensuring sufficient vitamin D status (measured as 25-hydroxyvitamin D (25OHD) in plasma), among other factors, is believed to facilitate the achievement of optimum peak bone mass. Lower 25OHD is associated with a higher plasma concentration of parathyroid hormone (PTH). As PTH is associated with increased bone turnover and bone loss, maintenance of sufficient 25OHD is thought to have a protective effect on bone health. However, there is a lack of consensus internationally on what constitutes an optimum 25OHD concentration, and values between 30 and 80 nmol/l have been suggested. These values have been based on findings from various studies in adults in which PTH has been observed to plateau at a 25OHD concentration of >30 nmol/l; however, not all studies have found such a plateau. Although studies in younger adolescents (14–16 years) have shown an inverse relationship between PTH and 25OHD, the concentration of 25OHD required for achievement of optimum peak bone mass is unknown. The present review examines the evidence defining vitamin D insufficiency thresholds, and the relevance of such thresholds to adolescent bone health.

Bone mineral content and bone mineral density at lumbar spine and forearm in Chinese girls aged 6-18 years

We investigated the age-related bone mineral content (BMC), bone mineral density (BMD) and the tempo of growth in BMC and BMD at lumbar spine and forearm in 455 Chinese girls aged 6-18 yr. BMC and BMD at the anteroposterior lumbar spine (LS), the left forearm (radius+ulna ultradistal, R+UUD) and one-third region (R+U1/3) were measured using a dual-energy X-ray bone densitometer (DXA). BMC and BMD exhibited different change patterns with the age changes. There were significant correlations between age, height, weight and BMC and BMD at LS, R+UUD and R+U1/3 sites. BMC and BMD increased significantly with increments in pubertal stages at LS, R+UUD and R+U1/3 sites. In conclusion, our study showed that Tanner stage had a significant positive association with BMC and BMD of the lumbar spine and forearm. The differences were found in the growth tempo of BMC and BMD within a region and between the spine and forearm. Both BMD and BMC were recommended to evaluate the bone health in children and adolescents.

Evaluation of an osteoporosis prevention education programme for young adults

AIM

This paper reports a study exploring the effectiveness of an osteoporosis prevention education programme for young adults.

METHODS

A quasi-experimental study was carried out with two groups, using pre-, post- and follow-up measures and was conducted in one integrated services centre during the period July 2005 to November 2005.

RESULTS

The results showed statistically significant increases in the reported follow-up for each outcome: osteoporosis knowledge test scores, osteoporosis health brief scores, and osteoporosis self-efficacy scores, for those in the intervention group compared with those in the control group. On the satisfaction score, most participants in the intervention group rated the nurse's performance in the educational programme positively.

CONCLUSION

Strategies used in this programme may provide guidance for the design of future programmes.

Optimizing bone health and calcium intakes of infants, children, and adolescents

Most older children and adolescents in the United States currently do not achieve the recommended intake of calcium. Maintaining adequate calcium intake during childhood and adolescence is necessary for the development of peak bone mass, which may be important in reducing the risk of fractures and osteoporosis later in life. Optimal calcium intake is especially relevant during adolescence, when most bone mineral accretion occurs. Because of the influence of the family's diet on the diet of children and adolescents, adequate calcium intake by all members of the family is important. Assessment of calcium intake can be performed in the physician's office. A well-rounded diet including low-fat dairy products, fruits, and vegetables and appropriate physical activity are important for achieving good bone health. Establishing these practices in childhood is important so that they will be followed throughout the life span.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

Osteoporosis due to Glucocorticoid Use in Children with Chronic Illness

Osteoporosis is increasingly recognized as a complication of chronic childhood illnesses, particularly when glucocorticoids (GCs) are necessary for treatment. Elucidation of the mechanisms leading to bone fragility in these settings requires disentanglement of the relative contributions of myriad risk factors, including disease activity, muscle weakness, immobilization, delayed growth and puberty, compromised nutrition, and osteotoxic medications. Over the years, bone mass and density evaluations by dual energy X-ray absorptiometry (DXA) have become popular for assessing bone health in children; however, such measurements are difficult to interpret because of the confounding effect of bone size and the lack of DXA-based densitometric criteria for defining osteoporosis in childhood. Recently, a new diagnostic approach for evaluation of densitometric data in children has been suggested, driven by Frost's mechanostat theory. A diagnostic algorithm based on the mechanostat theory of bone-muscle development is proposed for the characterization of bone disease in children with chronic illness. In addition to DXA-based assessments, techniques such as peripheral quantitative computerized tomography and ilial histomorphometry, for which there are pediatric reference data, are gaining ground in the characterization of skeletal changes due to chronic illness. Although these diagnostic techniques expand our understanding of osteoporosis in children, they do not replace clinical assessment. Concrete clinical evidence for GC-induced bone fragility can be seen in spinal changes due to vertebral compression, with spinal morphometry emerging as an essential, but frequently overlooked, tool in the evaluation of children's bone health. Presently, osteoporosis treatment in the chronic illness setting remains experimental and should be restricted to clinical studies. Following an understanding of the natural history of GC-induced osteoporosis in children, randomized, placebo-controlled prevention and intervention trials will be the next step toward the development of clinical practice guidelines.

Calcium, dairy products, and bone health in children and young adults: a reevaluation of the evidence

OBJECTIVE

Numerous nutrition policy statements recommend the consumption of 800 to 1500 mg of calcium largely from dairy products for osteoporosis prevention; however, the findings of epidemiologic and prospective studies have raised questions about the efficacy of the use of dairy products for the promotion of bone health. The objective of this study was to review existing literature on the effects of dairy products and total dietary calcium on bone integrity in children and young adults to assess whether evidence supports (1) current recommended calcium intake levels and (2) the suggestion that dairy products are better for promoting bone integrity than other calcium-containing food sources or supplements.

METHODS

A Medline (National Library of Medicine, Bethesda, MD) search was conducted for studies published on the relationship between milk, dairy products, or calcium intake and bone mineralization or fracture risk in children and young adults (1-25 years). This search yielded 58 studies: 22 cross-sectional studies; 13 retrospective studies; 10 longitudinal prospective studies; and 13 randomized, controlled trials.

RESULTS

Eleven of the studies did not control for weight, pubertal status, and exercise and were excluded. Ten studies were randomized, controlled trials of supplemental calcium, 9 of which showed modest positive benefits on bone mineralization in children and adolescents. Of the remaining 37 studies of dairy or unsupplemented dietary calcium intake, 27 studies found no relationship between dairy or dietary calcium intake and measures of bone health. In the remaining 9 reports, the effects on bone health are small and 3 were confounded by vitamin D intake from milk fortified with vitamin D. Therefore, in clinical, longitudinal, retrospective, and cross-sectional studies, neither increased consumption of dairy products, specifically, nor total dietary calcium consumption has shown even a modestly consistent benefit for child or young adult bone health.

CONCLUSION

Scant evidence supports nutrition guidelines focused specifically on increasing milk or other dairy product intake for promoting child and adolescent bone mineralization.

Impacto da ingestão de cálcio sobre a mineralização óssea em adolescentes

A puberdade destaca-se como período fundamental para a aquisição de massa óssea. Durante essa fase da vida, a mineralização encontra-se aumentada com taxas de formação óssea superior às de reabsorção. Nesse sentido, o objetivo desta revisão foi investigar a inter-relação da ingestão dietética de cálcio com a mineralização óssea, durante a puberdade. Entre os fatores influenciadores nutricionais, merecem destaque o fosfato e o magnésio, que, juntamente com o cálcio, mantêm a integridade estrutural do esqueleto. A revisão de literatura indicou que os excessos de proteína e de refrigerantes, na alimentação dos jovens, acarretam comprometimento na mineralização óssea, embora os dados sejam ainda contraditórios. Conclui-se que, durante o período da puberdade, é indicado manter o aporte de cálcio em níveis adequados, na perspectiva de maximizar o pico da massa óssea.

Bone mineral density in adolescent females using depot medroxyprogesterone acetate

STUDY OBJECTIVE

To examine bone mineral density (BMD) on a semi-annual basis among control subjects and adolescent females receiving depot medroxyprogesterone acetate (DMPA) injection or oral contraceptives.

DESIGN

Non-randomized prospective study.

SETTING

Teenage pregnancy prevention intervention clinic.

PARTICIPANTS

Adolescent females who were new users of DMPA injection (N=58, age 12-21) or the oral contraceptive pill (N=71, age 11-19) and normal menstruating girls (N=19, age 15-18).

INTERVENTIONS

Baseline and 6-monthly measures of lumbar vertebral BMD using dual-energy X-ray absorptiometry over a 2-year period.

MAIN OUTCOME MEASURES

comparison of percent change on BMD over time between DMPA users, pill users, and normal menstruating girls.

RESULTS

There was no difference on group characteristics at baseline except for the ethnicity between the controls and the DMPA group. There was a statistically significant decrease in BMD between DMPA users and controls at 6 months (-3.02% change, P=0.014) 12 months (-3.38% change, P=0.001) 18 months (-4.81% change, P<0.001) and 24 months (-6.81% change, P=0.010). There was no statistical difference between pill users and controls.

CONCLUSION

There is a relationship between DMPA use and a decrease in BMD compared to normal menstruating controls that seems to persist up to 24 months.

Effects of ethnicity, family income, and education on dietary intake among adolescents

BACKGROUND

The aim of the study is to describe the overall diet and potential effects of gender, ethnicity, family income, and parents' education on dietary patterns in adolescents aged 11 to 20 years who participated in a cohort study in 12 Southern California communities.

METHODS

A validated 131-item youth/adolescent food frequency questionnaire was administrated among 3,201 participants in the Children's Health Study at follow-up visits between 1998 and 2000. Sociodemographic characteristics included ethnicity, family income, and parents' education. Stratified analysis and analysis of covariance were used to describe the intakes of selected nutrients and food groups.

RESULTS

Mean intakes for all nutrients except calcium met 100% of the Recommended Dietary Allowances. Average daily food intakes were below the minimum recommended number of servings for all major food groups. The majority of subjects had an excessive intake of added sugar. A gender difference was found in intakes of energy, total fat (TF), saturated fat (SF), monounsaturated fat (MUSF), and calcium (P < 0.05). Non-Hispanic Whites had the lowest intakes of fruits while Blacks and Asians had significantly higher intakes of vegetables (P < 0.05). Subjects from higher income families had significantly higher intakes of polyunsaturated fat, protein, calcium, and folate and more frequently consumed dairy products. Intakes of TF, SF, MUSF, and cholesterol decreased as parents' education levels increased. Subjects from families with parents who had higher educational attainment were more likely to meet the recommendations of dairy products, fruits, and vegetables.

CONCLUSION

Overall, subjects in our study did not have healthy eating habits. Dietary patterns varied by sex, ethnicity, income, and education.

Puberty and bone development

Puberty has a key role for bone development. Skeletal mass approximately doubles at the end of adolescence. The main determinants of pubertal gain of bone mass are the sex steroids, growth hormone and insulin-like growth factors (by their effects on bone and muscle mass), 1,25-dihydroxyvitamin D (by stimulating calcium absorption and retention) and muscle mass (by regulating modelling/remodelling thresholds). Calcium intake is an additional factor influencing bone formation. The interactions among these factors are undefined. The accrual of bone mass during puberty is a major determinant of peak bone mass and, thereby, of the risk of osteoporotic fractures during advanced age.

Osteoporosis in children and adolescents: diagnosis, risk factors, and prevention

Bone mass acquired during childhood and adolescence is a key determinant of adult bone health. Peak bone mass, which is achieved in late adolescence, is a main determinant of osteoporosis in adulthood. Therefore, any factor adversely impacting on bone acquisition during childhood or adolescence can potentially have long-standing detrimental effects on bone health predisposing to osteoporosis and fracture risk. Thus, osteoporosis can well have its origin in childhood and adolescence. Pediatricians should be playing an active role in osteoporosis diagnosis and prevention. It is increasingly recognized that osteoporosis may occur in some disorders of children and adolescents. In this paper we review the diagnostic criteria of osteopenia/osteoporosis by densitometric assessment of bone mineral density, the contributing factors, and the mechanisms whereby several disorders may affect the acquisition of bone mass in children and adolescents. Finally, some recommendations to optimize peak bone mass in order to prevent osteopenia/osteoporosis are suggested.

Calcium intake and bone mass development among Israeli adolescent girls

OBJECTIVE

To determine the possible relationship between food and life style habits and bone health in adolescent Israeli females.

METHODS

2,000 adolescent Israeli Jewish and Arab high-school girls (mean age 14.5) completed a semi-quantitative food frequency questionnaire and a personal history questionnaire. 27 food components were calculated for each subject. Bone mineral content and density were determined for 112 subjects with calcium intake below 800 mg/day.

RESULTS

Average calcium intake was found to be 1,260 mg/day, but 20% of all girls had a calcium intake below 800 mg/day. All low-energy diets were very low in calcium, as mean calcium intake per 1,000 calories was 411 128 grams. A large percentage of diets with less than 800 mg calcium were also deficient in phosphorus (95.2%), magnesium (84.8%). iron (90.5%) and zinc (100%). Due to differences in food sources. Jewish girls had more phosphorus in their diet, but less magnesium and iron compared to Arab girls. Calcium and zinc deficiencies in Jewish and Arab diets were similar. A negative correlation was found between body mass index (BMI) and age at menarche for all girls in the study. Bone mineral density (BMD) measured for girls with calcium intake below 800 mg/day distributed normally around the average when compared to age matched controls despite their low calcium intake. There was a strong positive correlation between BMD and bone mineral content (BMC) at all sites and body weights.

CONCLUSIONS

Low calcium intake, other nutritional deficiencies and delayed menarche due to low-energy diet in the growing period and in adolescence may prevent the formation of healthy bones. There is no evidence of lower bone mass among the low calcium intake group in the study population at this stage. It remains to be documented if the window of opportunity for optimal bone accretion for this group will be missed in the future. possibly leading to increased risk of osteoporosis.