Body composition and bone density reference data for Korean children, adolescents, and young adults according to age and sex: results of the 2009-2010 Korean National Health and Nutrition Examination Survey (KNHANES)

Waist-height ratio and body mass index as indicators of obesity and cardiometabolic risk in Korean children and adolescents

PURPOSE

We assessed the clinical relevance of waist-height ratio (WHtR) as an indicator of cardiometabolic risk and body fat mass measured by dual-energy x-ray absorptiometry (DXA) among Korean children and adolescents.

METHODS

Data from 1,661 children and adolescents aged 10-18 years who participated in the Korea National Health and Nutrition Examination Survey were analyzed. Unadjusted Pearson correlation, age- and sex-adjusted Pearson correlation, and multiple linear regression analyses were performed to investigate the relationships between WHtR standard deviation score (SDS) and cardiometabolic risk factors, as well as DXA-assessed parameters.

RESULTS

WHtR SDS was correlated with cardiometabolic risk factors, including systolic blood pressure, glucose, total cholesterol, high-density lipoprotein cholesterol, triglyceride, and low-density lipoprotein cholesterol, as well as DXA-assessed parameters such as lean mass SDS, fat mass SDS, and fat mass percentage SDS in both whole body and trunk using an adjusted Pearson correlation analyses among all participants (p<0.001). WHtR SDS was strongly correlated with whole-body fat mass and trunk fat mass (r=0.792, p<0.001 and r=0.801, p<0.001, respectively) whereas WHtR SDS had a low correlation coefficient with whole-body lean mass and trunk lean mass SDS (r=0.512, p<0.001 and r=0.487, p<0.001, respectively). In multiple linear regression analyses, WHtR SDS was significantly associated with whole-body and trunk fat mass after adjustment for confounders.

CONCLUSION

Cardiometabolic risk factors and body fat mass assessed by DXA in Korean children and adolescents were highly correlated with WHtR. Additionally, WHtR has an advantage in distinguishing fat-free mass. WHtR can be a useful and convenient clinical indicator of cardiometabolic risk factors.

Causality between Sex Hormones and Bone Mineral Density in Childhood: Age- and Tanner-Stage-Matched Sex Hormone Level May Be an Early Indicator of Pediatric Bone Fragility

This study aimed to investigate the impact of hypogonadism on bone mineral density (BMD) in children and adolescents with chronic diseases to determine the relationship between sex hormones and BMD. This retrospective study included 672 children and adolescents with chronic diseases such as hemato-oncologic, rheumatoid, gastrointestinal, and endocrinologic diseases. The relationship between the sex- and Tanner-stage-matched Z-scores for sex hormones and the sex- and age-matched lumbar spine BMD (LSBMD) Z-scores was evaluated. Adjustments were made for confounders such as underlying diseases, age at diagnosis, and age- and sex-matched body mass index Z-scores. Patients had a mean LSBMD Z-score of -0.55 ± 1.31. In the multivariate regression analysis, male testosterone showed a positive association with the LSBMD Z-score (p < 0.001), whereas female estradiol, luteinizing hormone, and follicular-stimulating hormone showed no significant association with the LSBMD Z-scores. In the male group, the testosterone level was associated with LSBMD Z-scores > -1.0 (p < 0.001), > -2.0 (p < 0.001), and > -3.0 (p = 0.002), while the estradiol level was associated with LSBMD Z-scores > -2.0 (p = 0.001) and > -3.0 (p = 0.002) in the female group. In conclusion, sex hormones are associated with BMD in children and adolescents with chronic diseases. Therefore, various measures may be necessary to predict future skeletal problems and improve bone health in these patients.

Long-term endocrine sequelae after hematopoietic stem cell transplantation in children and adolescents

PURPOSE

As the survival rate from pediatric cancers has increased significantly with advances in treatment modalities, long-term endocrine complications have also risen. This study investigated the frequencies and risks of endocrine sequelae in childhood cancer survivors who received hematopoietic stem cell transplantation (HSCT).

METHODS

This study included 200 pediatric patients who underwent HSCT. Clinical and endocrinological findings were collected retrospectively. The median follow-up duration after HSCT was 14 years.

RESULTS

Endocrine complications occurred in 135 patients (67.5%). Children who underwent HSCT at pubertal age (n=100) were at higher risk of endocrine complications than those who received it at prepubertal age (79% vs. 56%, P=0.001). The most common complication was hypogonadism (40%), followed by dyslipidemia (22%). Short stature and diabetes mellitus were more prevalent in the prepubertal group, whereas hypogonadism and osteoporosis were more common in the pubertal group. Being female, pubertal age at HSCT, and glucocorticoid use were predictors of an increased risk for any complication. Radiation exposure increased the risk of short stature and hypothyroidism. Hypogonadism was significantly associated with being female, pubertal age at HSCT, and high-dose radiation. Pubertal age at HSCT also increased the risks of osteoporosis and dyslipidemia.

CONCLUSION

This study demonstrates that long-term endocrine complications are common after HSCT in children and adolescents. Age at HSCT is a critical factor for endocrine complications after HSCT. These findings suggest that surveillance strategies for endocrine complications in childhood cancer survivors should be specified according to age at HSCT.

Comparison of anthropometric, metabolic, and body compositional abnormalities in Korean children and adolescents born small, appropriate, and large for gestational age: a population-based study from KNHANES V (2010-2011)

PURPOSE

The impacts of growth restriction and programming in the fetal stage on metabolic and bone health in children and adolescents are poorly understood. Moreover, there is insufficient evidence for the relationship between current growth status and metabolic components. Herein, we compared the growth status, metabolic and body compositions, and bone mineral density in Korean children and adolescents based on birth weight at gestational age.

METHODS

We studied 1,748 subjects (272 small for gestational age [SGA], 1,286 appropriate for gestational age [AGA], and 190 large for gestational age [LGA]; 931 men and 817 women) aged 10-18 years from the Korean National Health and Nutrition Examination Survey (KNHANES) V (2010-2011). Anthropometric measurements, fasting blood biochemistry, and body composition data were analyzed according to birth weight and gestational age.

RESULTS

The prevalence of low birth weight (14.7% vs. 1.2% in AGA and 3.2% in LGA, p<0.001) and current short stature (2.237 [1.296-3.861] compared to AGA, p=0.004) in SGA subjects was greater than that in other groups; however, the prevalence of overweight and obesity risks, metabolic syndrome (MetS), and MetS component abnormalities was not. Moreover, no significant differences were found in age- and sex-adjusted lean mass ratio, fat mass ratio, truncal fat ratio, bone mineral content, or bone density among the SGA, AGA, and LGA groups in Korean children and adolescents.

CONCLUSION

Our data demonstrate that birth weight alone may not be a determining factor for body composition and bone mass in Korean children and adolescents. Further prospective and longitudinal studies in adults are necessary to confirm the impact of SGA on metabolic components and bone health.

Establishing reference values for percentage of appendicular skeletal muscle mass and their association with metabolic syndrome in Korean adolescents

PURPOSE

The association between appendicular skeletal muscle mass (ASM) and cardiometabolic risk has been emphasized. We estimated reference values of the percentage of ASM (PASM) and investigated their association with metabolic syndrome (MS) in Korean adolescents.

METHODS

Data from the Korea National Health and Nutrition Examination Survey performed between 2009 and 2011 were used. Tables and graphs of reference PASM were generated using 1,522 subjects, 807 of whom were boys aged 10 to 18. The relationship between PASM and each component of MS in adolescents was further analyzed in 1,174 subjects, 613 of whom were boys. Moreover, the pediatric simple MS score (PsiMS), the homeostasis model assessment of insulin resistance (HOMA-IR), and the triglyceride-glucose (TyG) index were analyzed. Multivariate linear and logistic regressions adjusting for age, sex, household income, and daily energy intake were performed.

RESULTS

In boys, PASM increased with age; the trend was different in girls, in whom PASM declined with age. PsiMS, HOMA-IR, and TyG index showed inverse associations with PASM (PsiMS, β=-0.105, P<0.001; HOMA-IR, β=-0.104, P<0.001; and TyG index, β=-0.013, P<0.001). PASM z-score was negatively associated with obesity (adjusted odds ratio [aOR], 0.22; 95% CI, 0.17-0.30), abdominal obesity (aOR, 0.27; 95% CI, 0.20-0.36), hypertension (aOR, 0.65; 95% CI, 0.52-0.80), and elevated triglycerides (aOR, 0.67; 95% CI, 0.56-0.79).

CONCLUSION

The probability of acquiring MS and insulin resistance decreased as PASM values increased. The reference range may offer clinicians information to aid in the effective management of patients. We urge clinicians to monitor body composition using standard reference databases.

Reduced Peak Bone Mass in Young Adults With Low Motor Competence

Although suboptimal bone health has been reported in children and adolescents with low motor competence (LMC), it is not known whether such deficits are present at the time of peak bone mass. We examined the impact of LMC on bone mineral density (BMD) in 1043 participants (484 females) from the Raine Cohort Study. Participants had motor competence assessed using the McCarron Assessment of Neuromuscular Development at 10, 14, and 17 years, and a whole-body dual-energy X-ray absorptiometry (DXA) scan at 20 years. Bone loading from physical activity was estimated from the International Physical Activity Questionnaire at the age of 17 years. The association between LMC and BMD was determined using general linear models that controlled for sex, age, body mass index, vitamin D status, and prior bone loading. Results indicated LMC status (present in 29.6% males and 21.9% females) was associated with a 1.8% to 2.6% decrease in BMD at all load-bearing bone sites. Assessment by sex showed that the association was mainly in males. Osteogenic potential of physical activity was associated with increased BMD dependent on sex and LMC status, with males with LMC showing a reduced effect from increasing bone loading. As such, although engagement in osteogenic physical activity is associated with BMD, other factors involved in physical activity, eg, diversity, movement quality, may also contribute to BMD differences based upon LMC status. The finding of lower peak bone mass for individuals with LMC may reflect a higher risk of osteoporosis, especially for males; however, further research is required. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Sex-Specific Changes in Physical Risk Factors for Anterior Cruciate Ligament Injury by Chronological Age and Stages of Growth and Maturation From 8 to 18 Years of Age

OBJECTIVE

To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage.

DATA SOURCES

PubMed, CINAHL, Scopus, and SPORTDiscus databases were searched through December 2021.

STUDY SELECTION

Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on ≥1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included.

DATA EXTRACTION

Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated.

DATA SYNTHESIS

The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies.

CONCLUSIONS

Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.

Three pediatric patients with primary hyperparathyroidism caused by parathyroid adenoma

Primary hyperparathyroidism (PHPT) is a hypercalcemia disorder with inappropriately normal or increased serum parathyroid hormone (PTH) levels resulting from excessive secretion of PTH from one or more of the parathyroid glands. PHPT is uncommon in infants and children, with an estimated incidence of 2-5 cases per 100,000 persons. Patients with PHPT usually present with bone pain, urolithiasis, or nephrolithiasis, as well as nonspecific symptoms such as fatigue and weakness. Asymptomatic hypercalcemia may also be detected incidentally. Only a few cases of pediatric PHPT have been reported in Korea. We present three patients (a 9-year-old girl, a 14-year-old boy, and a 14-year-old girl) with PHPT who manifested variable clinical features of hypercalcemia. The first and second patients each had a parathyroid adenoma and presented with abdominal pain caused by pancreatitis and a ureter stone, respectively. The third patient had an ectopic mediastinal parathyroid adenoma and presented with gait disturbance and weakness of the lower extremities. All of the patients underwent surgical resection of parathyroid adenoma, and their serum calcium levels subsequently normalized without medication.

Metabolic Impacts of Discontinuation and Resumption of Recombinant Human Growth Hormone Treatment during the Transition Period in Patients with Childhood-Onset Growth Hormone Deficiency

BACKGROUND

Discontinuing growth hormone (GH) treatment during the transition to adulthood has been associated with adverse health outcomes in patients with childhood-onset growth hormone deficiency (CO-GHD). This study investigated the metabolic changes associated with interrupting GH treatment in adolescents with CO-GHD during the transition period.

METHODS

This study included 187 patients with CO-GHD who were confirmed to have adult GHD and were treated at six academic centers in Korea. Data on clinical parameters, including anthropometric measurements, metabolic profiles, and bone mineral density (BMD) at the end of childhood GH treatment, were collected at the time of re-evaluation for GHD and 1 year after treatment resumption.

RESULTS

Most patients (n=182, 97.3%) had organic GHD. The median age at treatment discontinuation and re-evaluation was 15.6 and 18.7 years, respectively. The median duration of treatment interruption was 2.8 years. During treatment discontinuation, body mass index Z-scores and total cholesterol, low-density lipoprotein, and non-high-density lipoprotein (HDL) cholesterol levels increased, whereas fasting glucose levels decreased. One year after GH treatment resumption, fasting glucose levels, HDL cholesterol levels, and femoral neck BMD increased significantly. Longer GH interruption (>2 years, 60.4%) resulted in worse lipid profiles at re-evaluation. The duration of interruption was positively correlated with fasting glucose and non-HDL cholesterol levels after adjusting for covariates.

CONCLUSION

GH treatment interruption during the transition period resulted in worse metabolic parameters, and a longer interruption period was correlated with poorer outcomes. GH treatment should be resumed early in patients with CO-GHD during the transition period.

Genotype-phenotype correlations and long-term efficacy of pamidronate therapy in patients with osteogenesis imperfecta

PURPOSE

Osteogenesis imperfecta (OI) is a rare bone fragility disorder caused by defects in type 1 collagen biosynthesis. This study investigated the genotype-phenotype correlations and the efficacy of pamidronate therapy in patients with OI in a single academic center.

METHODS

This study included 24 patients with OI. A clinical scoring system was used to evaluate disorder severity. COL1A1 and COL1A2 genes were analyzed in 13 patients using Sanger sequencing. Genotype-phenotype correlations and the efficacy of pamidronate therapy were analyzed through a retrospective medical chart review.

RESULTS

Of the 24 patients, 18 (75%) were classified as type I (12 with type Ia and 6 with type Ib), 2 as type III (8.4%), and 4 as type IV (16.7%). Type Ia patients showed relatively higher lumbar bone mineral density (BMD) standard deviation scores (SDS) and lower clinical scores than those with other types. Seven patients with qualitative mutations had lower lumbar BMD-SDS (P=0.015) and higher clinical scores (P=0.008) than 6 patients with quantitative mutations. The annual fracture frequency and lumbar BMD-SDS improved in patients with qualitative mutations after pamidronate treatment.

CONCLUSION

This study demonstrated that OI patients with qualitative mutations in COL1A1/2 had a more severe phenotype than those with quantitative mutations. Patients with qualitative mutations showed a significant reduction in fracture frequency and an increase in lumbar BMD-SDS after pamidronate treatment. Clinical score and genotype might be helpful for predicting phenotype and response to pamidronate therapy in OI patients.

Relationship Between Bone Mineral Density and Body Composition According to Obesity Status in Children

OBJECTIVE

To analyze the relationship between body composition, metabolic parameters, and bone mineral density (BMD) according to sex and the degree of obesity in children and adolescents.

METHODS

A total of 236 subjects with obesity, aged 10 to 15 years (36.9% girls), were enrolled. Obesity was classified into simple (SmOb) and extreme (ExOb) forms. The BMD of the total body, less head, was measured by dual energy x-ray absorptiometry, and the BMD z-score was used to evaluate the relationship of body composition with metabolic parameters.

RESULTS

BMD z-scores were higher in subjects with ExOb than in those with SmOb. Lean mass index (LMI), body mass index z-score, and vitamin D intake showed positive relationships, whereas percentage of body fat and serum leptin level showed negative relationships with BMD z-scores in boys. In girls, LMI and body mass index z-score showed positive relationships with BMD z-scores. In multivariable linear regressions, serum leptin level showed negative relationships with BMD z-score, only in boys. In addition, positive relationships of LMI and negative relationships of percentage of body fat with BMD z-scores were observed in subjects with SmOb. However, positive relationships of LMI with BMD z-scores were attenuated in subjects with ExOb.

CONCLUSION

High BMD appears to be positively associated with lean mass in children and adolescents with obesity, which might be a natural protective mechanism to withstand the excess weight. However, excessive body fat appears to be negatively associated with BMD, which might attenuate the positive relationship between lean mass and BMD in subjects with ExOb.

Overview of pediatric obesity: diagnosis, epidemiology, and significance

Background: The prevalence of pediatric obesity has increased over the past several decades worldwide and in Korea. Childhood obesity has become a serious social problem.Current Concepts: Diagnosis of obesity is based on body mass index (BMI) in children and adolescents aged ≥2 years. Overweight and obese are defined as BMI ≥85th percentile to <95th percentile and BMI ≥95th percentile, respectively, corresponding to sex and age. Obesity is further classified as Class I (BMI ≥95th percentile to <120% of 95th percentile), Class II (BMI ≥120% of 95th percentile to <140% of 95th percentile), and Class III (BMI ≥140% of 95th percentile). Waist circumference and waist-height ratio are used to evaluate abdominal obesity. Pediatric obesity can cause childhood comorbidities, including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and hypertension. Adult obesity, cardiovascular diseases, and other adult comorbidities, together with increased medical costs are additional consequences of pediatric obesity.Discussion and Conclusion: Prevention, diagnosis, and proper management of pediatric obesity are important.

Efficacy and safety of intravenous pamidronate infusion for treating osteoporosis in children and adolescents

PURPOSE

Osteoporosis is a skeletal disorder characterized by reduced bone mass that results in increased risk of fractures. Pediatric osteoporosis can be caused by monogenic diseases, chronic diseases, and/or their treatment. This study was performed to investigate the effect of pamidronate infusion on osteoporosis in children and adolescents.

METHODS

This study included 13 unrelated pediatric patients (10 males and 3 females) whose bone mineral density (BMD) z-score was &lt;-2.0. Pamidronate was administered intravenously at a dosage of 1 mg/kg for 3 consecutive days every 4 months. Clinical and biochemical findings were reviewed retrospectively. The BMD values of the lumbar spine and femoral neck were assessed by dual energy x-ray absorptiometry at baseline and annually.

RESULTS

The underlying diseases were immobilization (62%), inflammatory bowel disease (23%), protein-losing enteropathy (8%), and idiopathic juvenile osteoporosis (8%). The mean age at the start of treatment was 12.7±4.3 years. Duration of treatment ranged from 12-50 months. The baseline height-standard deviation score (SDS) and weight-SDS were -2.01±2.08 and -2.60±1.62, respectively. The lumbar spine BMD z-scores improved significantly after 1 year of pamidronate treatment, but the femoral neck BMD z-scores did not. However, both z-scores had significantly increased by the end of treatment.

CONCLUSION

This study demonstrated that pamidronate treatment increased BMD in pediatric patients with osteoporosis with no significant adverse events. Further studies are required to better define the long-term efficacy and safety of pamidronate therapy in a large number of pediatric patients.

Growth, puberty, and bone health in children and adolescents with inflammatory bowel disease

BACKGROUND

Endocrine complications such as impaired growth, delayed puberty, and low bone mineral density (BMD) can be associated with inflammatory bowel disease (IBD) in children and adolescents. This study was performed to investigate the frequency, characteristics, and outcomes of endocrine complications of IBD in children and adolescents.

METHODS

This study included 127 patients with IBD diagnosed before 18 years of age [117 with Crohn disease (CD) and 10 with ulcerative colitis (UC)]. Growth profiles, pubertal status, 25-hydroxyvitamin D₃ [25(OH)D₃] levels, and BMD were reviewed retrospectively.

RESULTS

Short stature was observed in 14 of 127 (11.0 %) with a mean height-SDS of -2.31 ± 0.72. During a 2-year follow-up period, height-SDS did not significantly improve, while weight-SDS significantly improved. Among 109 patients who were older than 13 (girls) or 14 (boys) years of age during the study period, 11 patients (10.1 %) showed delayed puberty, which was associated with low weight-SDS. Vitamin D deficiency was documented in 81.7 % (94/115) with the average 25(OH)D₃ level of 14.5 ± 7.0 ng/mL. Lumbar BMD Z-score was below - 2 SDS in 25 of 119 patients (21.0 %). Height-SDS, weight-SDS, and body mass index (BMI)-SDS were lower in patients with osteoporosis than those without osteoporosis. When pediatric CD activity index scores were high (≥ 30), weight-SDS, BMI-SDS, insulin-like growth factor 1 (IGF-1)-SDS, and testosterone levels were significantly decreased.

CONCLUSIONS

Vitamin D deficiency and osteoporosis are common in pediatric IBD patients. As disease severity deteriorates, weight-SDS, IGF-1-SDS, and testosterone levels were decreased. Optimal pubertal development is necessary for bone health.

Endocrine Complications in Children and Adolescents With Non-Central Nervous System Solid Tumors

BACKGROUND

Due to remarkable progress in cancer treatment, endocrine complications are now the major medical issues facing childhood cancer survivors. Although non-central nervous system solid tumors (NCSTs) account for approximately 40% of all pediatric cancers, there have been few studies on endocrine complications associated with NCSTs. This study investigated endocrinopathies following the treatment of pediatric NCSTs.

DESIGN AND SETTING

Retrospective study in a single academic center.

METHODS

This study analyzed 253 survivors of childhood NCSTs who were diagnosed between January of 2000 and December of 2018. The medical charts were reviewed regarding the frequency of endocrinopathies and treatment modalities. The hazard ratios were assessed by multivariable Cox regression analysis. The final height-SDS were analyzed by multivariable linear regression analysis.

RESULTS

There were 76 patients (30%) that developed at least one endocrine complication. Forty-four patients (17.4%) experienced endocrine complications within five years of their cancer diagnosis. The most common endocrine complication was growth failure (n = 35), followed by obesity (n = 18), and primary gonadal failure (n = 16). High cumulative doses of alkylating agents increased the risk of developing at least one endocrine complication. Hematopoietic stem cell transplantation was an important risk factor for primary gonadal failure.

CONCLUSIONS

This study described the comprehensive endocrine outcomes, including growth failure, obesity, primary gonadal failure, primary hypothyroidism, dyslipidemia, and osteoporosis, following the treatment of childhood NCSTs. As endocrinopathies occurred within five years of primary tumor diagnosis, surveillance for endocrine dysfunction is required for early intervention and management.

Associations between cola consumption and bone mineral density in Korean adolescents and young adults: a cross-sectional study using data from the Korea National Health and Nutrition Examination Survey, 2008-2011

The present study aimed to elucidate the relationship between cola consumption and bone mineral density (BMD) in Korean adolescents and young adults. We used data from the Korea National Health and Nutrition Examination Survey 2008–2011. A total of 2499 adolescents and young adults aged 12–25 years were included. The study participants were classified as cola drinkers and non-cola drinkers according to 24-h dietary recall data. BMD was measured using dual X-ray absorptiometry. In the male population, whole body, whole femur and femoral neck BMD in cola drinkers were lower than that of non-cola drinkers by 4% (95% CI −0⋅071, −0⋅007), 5% (−0⋅092, −0⋅012) and 5% (−0⋅090, −0⋅001), respectively. In both sex groups, cola drinkers had less frequent milk consumption than non-cola drinkers. However, there were no significant differences in cola consumption according to calcium intake in both sexes. In conclusion, cola intake and BMD were inversely associated with Korean male adolescents and young adults. Considering the importance of peak bone mass attainment at adolescents and the increasing trend in carbonated beverage consumption in South Korea, further studies are needed to elucidate the causality between cola intake and lower BMD.

Changes in Body Composition and Its Relationship to Performance in Elite Female Track and Field Athletes Transitioning to the Senior Division

Many elite female athletes struggle to maintain performance while transitioning from high school to university-level (senior) sports. This study explores factors of body composition that influenced performance in elite junior female track and field athletes transitioning to the senior division. Forty-two elite female track and field athletes, ranked among the top 100 in Japan, were enrolled in this study. Whole-body mode dual-energy X-ray absorptiometry scans were performed during the post-season of 2016 and 2017. Athletes’ performances were assessed using the International Association of Athletics Federation scoring system. Relationships between changes in performance and those in body composition were investigated. There were significant negative correlations between changes in performance and fat mass (FM), and percentage FM (FM%). This was seen in total body and lower extremities, and not in the trunk and upper extremities. In addition, there was a positive correlation between changes in performance and percentage lean mass (LM%). However, there were no correlations between changes in performance and LM and total mass. Elite female track and field athletes transitioning to senior division should decrease their FM and FM% and increase LM%, to sustain or improve performance. It is also more important to monitor changes in body composition than body mass.

Maturity Related Differences in Body Composition Assessed by Classic and Specific Bioimpedance Vector Analysis among Male Elite Youth Soccer Players

The aim of this study was to analyze the efficiency of classic and specific bioelectrical impedance vector analysis (BIVA) in the assessment of maturity related differences in body composition among male elite youth soccer players, and to provide bioelectrical impedance reference data for this category. A group of 178 players (aged 12.1 ± 1.6 years) were registered in a professional Italian soccer team participating in the first division (Serie A). They were divided into three groups according to their maturity status while bioelectrical resistance and reactance were obtained. The classic and specific BIVA procedures were applied, which correct bioelectrical values for body height and body geometry, respectively. Percentage of fat mass (FM%) and total body water (TBW (L)) were estimated from bioelectrical values. Age-specific z-scores of the predicted age at peak height velocity identified 29 players as earlier-, 126 as on time-, and 23 as later-maturing. TBW was higher (p < 0.01) in adolescents classified as “early” maturity status compared to the other two groups and classic BIVA confirmed these results. Conversely, no differences in FM% were found among the groups. Specific vector length showed a higher correlation (r = 0.748) with FM% compared with the classic approach (r = 0.493). Classic vector length showed a stronger association (r = −0.955) with TBW compared with specific (r = −0.263). Specific BIVA turns out to be accurate for the analysis of FM% in athletes, while classic BIVA shows to be a valid approach to evaluate TBW. An original data set of bioelectric impedance reference values of male elite youth soccer players was provided.

The Role of Somatic Maturation on Bioimpedance Patterns and Body Composition in Male Elite Youth Soccer Players

The purpose of this study was to examine the influence of chronological age (CA) and somatic maturation on body composition (BC) and bioimpedance parameters in male elite soccer players. BC and bioimpedance variables were measured in a sample of 249 players aged 9-18 years of age and registered in two professional Italian soccer teams. Results from segmental analysis showed transition time points where the influence of CA and somatic maturation on bioimpedance patterns and BC characteristics increased or subsided. The accelerated phases were assessed for fat free mass, total body water, and upper muscle area, with a starting time point at approximately -2.00 years from peak at velocity (YPHV), and for body cell mass, whose developmental tempo sped up around -1.00 YPHV. An increase in the rate of development was also observed close to -2.00 YPHV for phase angle (PA), although without accelerated phases. From a CA point of view, significant slope changes were found for all BC and bioimpendance variables, except for the calf muscle area. Although the starting points and the span of the accelerated phases were different, they subsided or disappeared at ~ 15 years, except for PA, whose growth waned at ~ 17 years.

Nutritional factors associated with femoral neck bone mineral density in children and adolescents

Background

Nutritional factors including vitamin D, magnesium, and fat are known to affect bone mineral accrual. This study aimed to evaluate associations between dietary nutrient intakes (both macronutrients and micronutrients) and bone mineral density (BMD) in children and adolescents.

Methods

Data for this cross-sectional, population-based study were derived from the National Health and Nutrition Examination Survey (NHANES). Participants aged from 8 to 19 years were included. The primary outcome was femoral neck BMD.

Results

Multivariate analyses revealed that for participants aged 8 to 11, daily sodium intake was significantly and positively associated with femoral neck BMD (B = 0.9 ×  10^− 5, p = 0.031); in particular, subgroup analyses by sex found that in male participants aged 8–11, daily total cholesterol intake (B = 5.3 × 10^− 5, p = 0.030) and calcium intake (B = − 2.0 × 10^− 5, p < 0.05) were significantly associated with femoral neck BMD in a positive and negative manner, respectively, but neither were observed in female participants of this age group. In contrast, daily intakes of vitamin D and magnesium were significantly and positively associated with femoral neck BMD in female participants aged 8–11 (B = 246.8 × 10^− 5 and 16.3 × 10^− 5, p = 0.017 and 0.033, respectively). For participants aged 16 to 19, daily total fat intake was significantly and negatively associated with femoral neck BMD (B = − 58 × 10^− 5, p = 0.048); further stratification by sex found that magnesium and sodium intakes were significantly and positively associated with femoral neck BMD only in females of this age group (B = 26.9 × 10^− 5 and 2.1 × 10^− 5, respectively; both p < 0.05). However, no significant associations between daily nutrient intakes and femoral neck BMD were identified in participants aged 12–15 before or after subgroup stratification.

Conclusion

The study found that associations of specific nutrition-related variables with BMD of the femoral neck is dependent upon age and gender.

The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position

Dual-energy X-ray absorptiometry (DXA) is widely used in the evaluation of bone fragility in children. Previous recommendations emphasized total body less head and lumbar spine DXA scans for clinical bone health assessment. However, these scan sites may not be possible or optimal for all groups of children with conditions that threaten bone health. The utility of DXA scans of the proximal femur, forearm, and radius were evaluated for adequacy of reference data, precision, ability of predict fracture, and applicability to all, or select groups of children. In addition, the strengths and limitations of vertebral fracture assessment by DXA were evaluated. The new Pediatric Positions provide guidelines on the use of these additional measures in the assessment of skeletal health in children.

The Efficacy of Long-Term Estrogen Replacement Therapy in Turner Syndrome Women with Premature Ovarian Insufficiency

STUDY OBJECTIVE

To evaluate the efficacy of long-term estrogen replacement therapy (ERT) in uterine development and bone mineral density (BMD) of Turner syndrome (TS) women with premature ovarian insufficiency (POI).

DESIGN AND SETTING

Retrospective study.

PARTICIPANTS AND INTERVENTIONS

Thirty-seven TS women grouped according to ovarian function status: TS women with POI (n = 32), aged 11-26 years, and those with intact ovarian function (IOF; n = 5), aged 13-17 years. TS women with POI underwent ERT.

MAIN OUTCOME MEASURES

Changes in uterine length, anterior-posterior (AP) fundal diameter of the uterus, and BMD were assessed. Statistical methods included Mann-Whitney U test and paired t test.

RESULTS

In TS women with POI, uterine length, AP fundal diameter, and BMD significantly increased after ERT (P < .001). TS women with POI were subdivided into classic (n = 11) and variant (n = 21) types, and there were no significant differences in uterine development and BMD according to types of chromosome. After receiving ERT, AP fundal diameter was significantly longer in classic TS women (P = .034) compared with those with variant type.

CONCLUSION

Long-term ERT increased uterine length (before: 4.4 cm; after: 7.2 cm) and AP fundal diameter (before: 0.9 cm; after: 2.4 cm), and improved BMD in TS women with POI. After ERT, in TS women with POI, uterine length, BMD at lumbar 2-4 and femoral neck were similar to those of TS women with IOF. Therefore, TS women with POI can catch up to those with IOF by receiving ERT.

Low Muscle Mass and Depressed Mood in Korean Adolescents: a Cross-Sectional Analysis of the Fourth and Fifth Korea National Health and Nutrition Examination Surveys

BACKGROUND

Muscle mass and muscle function are related to depressed mood in studies of adults. Like adults, Korean students are highly likely to suffer from decreased muscle mass due to social conditions. In this study, we evaluated the muscle mass status of Korean adolescents and assess the effect of muscle on depressive mood.

METHODS

A total of 1,233 adolescent boys and girls participants from the Korea National Health and Nutrition Examination Survey were enrolled in our study. Participants underwent dual-energy X-ray absorptiometry for assessment of appendicular muscle mass and completed questionnaires regarding depressed mood, stress, suicidal ideations, and attempts.

RESULTS

There was no difference in depressive mood according to muscle mass among boys (P = 0.634); girls with decreased muscle mass had a greater tendency for depressed mood compared to girls with optimal muscle mass (P = 0.023). After adjusting for age, waist circumference-to-height ratio, smoking status, alcohol consumption, frequency of physical activity, self-reported obesity, weight-loss efforts, and monthly household income, girls with low muscle mass (LMM) were 2.60 times more at risk of developing depression than girls with normal muscle mass (95% confidence interval [CI], 1.05-6.49; P = 0.040). This trend was similar for girls with LMM with obesity (95% CI, 1.00-11.97; P = 0.049).

CONCLUSION

Adolescent girls who have insufficient muscle mass are more likely to report depressed mood than girls who have ideal muscle mass. Interventions for maintaining proper muscle mass are required.

Tracking of bone mass from childhood to puberty: a 7-year follow-up. The CHAMPS study DK

Bone mass in childhood is highly influenced by puberty. At the same age, bone mass was higher for pubertal than pre-pubertal children. A high level of tracking during 7 years from childhood through puberty was shown, indicating that early levels of bone mass may be important for later bone health.

INTRODUCTION

Bone mass development in childhood varies by sex and age, but also by pubertal stage. The objectives of this study were to (1) describe bone mass development in childhood as it relates to pubertal onset and to (2) determine the degree of tracking from childhood to adolescence.

METHODS

A longitudinal study with 7 years of follow-up was initiated in 2008 to include 831 children (407 boys) aged 8 to 17 years. Participants underwent whole body dual-energy X-ray absorptiometry (DXA) scanning, blood collection to quantify luteinizing hormone levels, and Tanner stage self-assessment three times during the 7-year follow-up. Total body less head bone mineral content, areal bone mineral density, and bone area were used to describe development in bone accrual and to examine tracking over 7 years.

RESULTS

Bone mass in pubertal children is higher than that of pre-pubertal children at the same age. Analysing tracking with quintiles of bone mass Z-scores in 2008 and 2015 showed that more than 80% of participants remained in the same or neighbouring quintile over the study period. Tracking was confirmed by correlation coefficients between Z-scores at baseline and 7-year follow-up (range, 0.80-0.84).

CONCLUSIONS

Bone mass is highly influenced by pubertal onset, and pubertal stage should be considered when examining children's bone health. Because bone mass indices track from childhood into puberty, children with low bone mass may be at risk of developing osteoporosis later in life.

The Role of Overweight and Obesity on Bone Health in Korean Adolescents with a Focus on Lean and Fat Mass

As the associations between pediatric overweight/obesity and bone health remain controversial, we investigated the effects of overweight/obesity as well as lean mass (LM) and fat mass (FM) on bone parameters in adolescents. Bone parameters were evaluated using dual-energy X-ray absorptiometry (DXA) data of 982 adolescents (aged 12-19 years) from the Korea National Health and Nutrition Examination Survey (2009-2010). Z-scores for LM, FM, bone mass, bone mineral density (BMD), and bone mineral apparent density (BMAD) using Korean pediatric reference values were used for analysis. Adolescents with overweight/obesity had significantly higher bone mass and density of the total-body-less-head (TBLH), lumbar spine, and femur neck than underweight or normal-weight adolescents (P < 0.001) after adjusting for vitamin D deficiency, calcium intake, and insulin resistance in both sexes. LM was positively associated with bone parameters at all skeletal sites in both sexes (P < 0.001). FM was negatively related to TBLH BMD in boys (P = 0.018) but was positively associated to BMD and BMAD of the lumbar spine and femur neck in girls. In conclusion, overweight/obesity and LM play a positive role in bone health in adolescents. The effect of FM on bone parameters is sex- and site-specific.