Bone mineral density according to age, bone age, and pubertal stages in korean children and adolescents

The association of serum irisin with anthropometric, metabolic, and bone parameters in obese children and adolescents

Background

Irisin is an adipomyokine secreted by muscle and adipose cells, and it plays a role in glucose, fat, and bone metabolism. This study aimed to determine the correlation of serum irisin levels with anthropometric, metabolic, and bone parameters in obese children and adolescents.

Methods

This single-center study included 103 Korean children and adolescents: 54 (52.4%) obese participants with a body mass index (BMI) ≥95th percentile and 49 (47.6%) healthy controls with BMI within the 15th to 85th percentile. Various parameters were measured, including fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride and glucose (TyG) index, lipid profile, alkaline phosphatase (ALP), osteocalcin, and 25(OH)-Vitamin D levels. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DEXA) in 33 healthy subjects.

Results

Serum irisin was significantly higher in the obese group than in the control group (mean 18.1 ± 3.5 vs. 16.2 ± 2.0 ng/mL; p = 0.001). Serum irisin level was positively correlated with chronological age (r = 0.28; p = 0.004), height SDS (r = 0.24; p = 0.02), BMI SDS (r = 0.37; p < 0. 001), fasting glucose (r = 0.27; p = 0.007), fasting insulin (r = 0.23; p = 0.03), HOMA-IR (r = 0.21; p = 0.04), osteocalcin (r = 0.27; p = 0.006) and negatively correlated with HDL cholesterol (r = -0.29; p = 0.005). All these correlations were evident in obese subjects but not in healthy subjects. ALP and 25(OH)-Vitamin D were unrelated to irisin levels. Among 33 healthy subjects, total body-less head (TBLH) BMD Z-score was positively correlated with serum irisin (r = 0.39; p = 0.03), osteocalcin (r = 0.40; p = 0.02), fasting insulin (r = 0.39; p = 0.04), and HOMA-IR (r = 0.38; p = 0.047).

Conclusion

This study demonstrated an association between irisin levels and glucose, lipid, and bone parameters in children and adolescents. Our findings suggest that irisin has a potential role in metabolic disorders and bone health in obese children and adolescents.

Elevated bone turnover markers predict bone mineral density accrual in adolescents with 21-hydroxylase deficiency

CONTEXT

Prognostic biomarkers for monitoring bone health in adolescents with 21-hydroxylase deficiency (21OHD) are needed.

OBJECTIVES

To assess associations between concentrations of baseline bone turnover markers (BTMs) including osteocalcin (OC) and type-I collagen C-terminal telopeptide (CTX) and changes in lumbar spine bone mineral density (LSBMD) in adolescents with classic 21OHD.

DESIGNS AND PATIENTS

A retrospective-prospective study of 33 adolescents with classic 21OHD who had baseline data for LSBMD, bone age (BA), and BTM concentrations.

METHODS

BTM concentrations were converted into z-scores according to BA. We measured LSBMD at the follow-up study visit and calculated the annual percentage change in LSBMD (%∆LSBMD).

RESULTS

At baseline, participants (55% female, 79% Tanner 5) had mean (±SD) age of 14.6 ± 3.6 years, BA 16.7 ± 2.9 years, and average glucocorticoid (GC) dose 17.3 ± 5.6 mg/m2 /day of hydrocortisone equivalent. The mean follow-up duration was 14.4 ± 5.6 months. Median (Q1-Q3) %∆LSBMD was 3.6% (0-8.5)/year. %∆LSBMD was similar among genders or 21OHD subtypes. Prednisolone versus hydrocortisone replacement resulted in lower %∆LSBMD (p = .004). %∆LSBMD was increased across tertiles of CTX z-score (p = .014). %∆LSBMD correlated negatively with GC dose (p = .01) and positively with CTX and OC z-scores (p < .01). In regression analyses, only CTX z-score positively associated with %∆LSBMD (p = .003), adjusting for sex, BA, body mass index, testosterone, 25-hydroxyvitamin D, and GC type and dose.

CONCLUSIONS

Higher GC dose and the use of prednisolone were associated with decreased LSBMD accrual in adolescents with 21OHD. CTX z-score independently associated with LSBMD accrual, suggesting its potential for prognostic bone biomarker.

Mineral bone disorder in children with chronic kidney disease: Data from the KNOW-Ped CKD (Korean cohort study for outcome in patients with pediatric chronic kidney disease) study

BACKGROUND

Children with chronic kidney disease (CKD) are at high risk of mineral bone disorder (MBD), which leads to fractures, growth retardation, and cardiovascular disease. We aimed to comprehensively understand the relationship between renal function and factors related to MBD and evaluate the prevalence and distribution characteristics of MBD, specifically among Korean patients from the KNOW-PedCKD cohort.

METHODS

From the baseline data of the KNOW-PedCKD cohort, we examined the prevalence and distribution of MBD in 431 Korean pediatric CKD patients, including the level of corrected total calcium, serum phosphate, serum alkaline phosphatase, serum intact parathyroid hormone (iPTH), fibroblast growth factor 23 (FGF-23), serum vitamin D, fractional excretion of phosphate (FEP), and bone densitometry Z-scores.

RESULTS

The median serum calcium level remained relatively normal regardless of the CKD stage. The levels of 1,25-dihydroxy vitamin D, urine calcium-to-creatinine ratio, and bone densitometry Z-score significantly decreased with advancing CKD stage, while those of serum phosphate, FGF-23, and FEP significantly increased with CKD stage. The prevalence of hyperphosphatemia (17.4%, 23.7%, and 41.2% from CKD stages 3b, 4, and 5, respectively) and hyperparathyroidism (37.3%, 57.4%, 55.3%, and 52.9% from CKD stages 3a, 3b, 4, and 5, respectively) significantly increased with the CKD stage. Prescriptions of medications, such as calcium supplements (39.1%, 42.1%, 82.4%), phosphate binders (39.1%, 43.4%, 82.4%), and active vitamin D (21.7%, 44.7%, and 64.7%) significantly increased with CKD stage 3b, 4, and 5, respectively.

CONCLUSIONS

The results demonstrated the prevalence and relationship of abnormal mineral metabolism and bone growth according to CKD stage in Korean pediatric CKD patients for the first time.

Bone Age Reading by DXA Images should not Replace Bone Age Reading by X-ray Images

X-ray image of the hand is the most used technique to estimate bone age in children. For the analysis of bone mineral density using DXA in children, bone age may help to adjust such measurement in some cases. During image acquisition in DXA, an anteroposterior image of the hand may be acquired and used to evaluate bone age but few studies have evaluated the agreement between conventional X-ray and DXA images. The aim of the study was to determine bone age estimation agreement between conventional X-ray images and DXA in children and adolescents aged 5 to 16 years of age. We performed an analytical cross-sectional study of 711 healthy subjects. Subject´s bone age, both in conventional X-ray, and DXA images were read independently by two expert evaluators blinded for chronological age. Intraobserver and inter-observer reproducibility were evaluated using Intraclass Correlation Coefficient (ICC), and the agreement between bone age estimations made by both evaluators was analyzed using ICC and Bland-Altman analysis. General agreement between techniques measured through ICC was 0.99 with a mean difference of 6 months between techniques being older the ages obtained by DXA. The agreement limits were around ±2 years, which means that 95% of all differences between techniques were covered within this range. We found a high level of ICC agreement in bone age readings from X-ray and DXA images although we observed overestimation of bone age measurements in DXA. Differences between techniques were greater in women than in men, especially at the ages corresponding to puberty. Bone age measurement in DXA images appears not to be reliable; hence it should be suggested to perform conventional radiography of the hand to assess bone age taking into account that X-ray images have better resolution.

Endocrine and Metabolic Illnesses in Young Adults with Prader-Willi Syndrome

Prader−Willi syndrome (PWS) is a rare genetic disorder characterized by an insatiable appetite that leads to morbid obesity. Previous studies reported health problems in adults with PWS. However, studies on younger adults are lacking, and there are no specific studies of endocrine and metabolic illness in this age group. We performed a retrospective cohort study of 68 individuals with PWS aged 19 to 34 years at Samsung Medical Center. The prevalence of endocrine and metabolic illnesses were compared with those in an age-, sex-, and BMI-matched healthy control group. Young adults with PWS had a higher prevalence of metabolic syndrome (35.3% vs. 4.4%), type 2 diabetes mellitus (50.0% vs. 5.4%), hypertension (30.8% vs. 16.1%), dyslipidemia (38.2% vs. 14.7%), decreased bone density (26.4% vs. 0.9%), and sleep apnea (32.3% vs. 4.4%) than controls (all p < 0.05). The PWS group that maintained recombinant human growth (rhGH) treatment in adulthood had a lower probability of having a BMI ≥ 30 at the last follow-up (odds ratio = 0.106 (0.012−0.948), p = 0.045). Endocrine and metabolic illnesses in individuals with PWS may have already started in the early teens; therefore, appropriate screening and early intervention are important. Better understanding of the natural history of PWS and age-related complications will lead to better-quality medical care for individuals with PWS.

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.

Clinical practice guidelines for optimizing bone health in Korean children and adolescents

The Committee on Pediatric Bone Health of the Korean Society of Pediatric Endocrinology has newly developed evidence-based clinical practice guidelines for optimizing bone health in Korean children and adolescents. These guidelines present recommendations based on the Grading of Recommendations, which includes the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. These guidelines include processes of bone acquisition, definition, and evaluation of low bone mineral density (BMD), causes of osteoporosis, methods for optimizing bone health, and pharmacological treatments for enhancing BMD in children and adolescents. While these guidelines provide current evidence-based recommendations, further research is required to strengthen these guidelines.

Total, bioavailable and free 25-hydroxyvitamin D levels as functional indicators for bone parameters in healthy children

Objectives

Vitamin D is essential for bone health. Not only total but also free 25-hydroxyvitamin D (25OHD) may contribute to bone mass. We sought to determine which vitamin D measure best reflected clinical and bone parameters in healthy children.

Methods

A cross-sectional study including 146 healthy children (71 boys, 9.5 ± 1.9 years) conducted at a tertiary medical center. We used a multiplex liquid chromatography-tandem mass spectrometry-based assay to simultaneously measure vitamin D metabolites. The bioavailable and free 25OHD (25OHD_BioA and 25OHD_Free) levels were calculated using the genotype-specific or genotype-constant affinity coefficients of vitamin D-binding proteins (yielding spe-25OHD_BioA, spe-25OHD_Free and con-25OHD_BioA, con-25OHD_Free respectively). The 25OHD_Free level was directly measured (m-25OHD_Free). Bone mineral content (BMC) and bone mineral density (BMD) were assessed via dual-energy X-ray absorptiometry.

Results

The total 25OHD (25OHD_Total), the two forms of 25OHD_BioA, the three forms of 25OHD_Free, and 24,25-dihydroxyvitamin D₃ levels correlated with parathyroid hormone level (all p < 0.01). Serum 25OHD_Total and m-25OHD_Free levels were influenced by age, pubertal status, season, body mass index (BMI), daylight hours, and vitamin D intake (all p < 0.05). The con-25OHD_BioA and con-25OHD_Free levels better reflected pubertal status and daylight hours than did the spe-25OHD_BioA and spe-25OHD_Free levels (both p < 0.01). The association between the 25OHD_Total level and bone parameters varied according to the BMI (interaction p < 0.05). In 109 normal-weight children, the con-25OHD_BioA and con-25OHD_Free levels correlated with total body BMC and BMD (both p < 0.05), whereas the 25OHD_Total and 24,25-dihydroxyvitamin D₃ levels were associated with total body BMC (both p < 0.05). No such association was found in overweight or obese children.

Conclusions

In healthy children, total, bioavailable, and free 25OHD levels comparably reflected lifestyle factors. In normal-weight children, the con-25OHD_BioA and con-25OHD_Free, but not m-25OHD_Free levels, reflected bone mass, as did the 25OHD_Total level.

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.

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.

Low Bone Mineral Density at Initial Diagnosis in Children and Adolescents with Graves' Disease

Previous studies have reported reduced bone mineral density (BMD) in patients with hyperthyroidism. We assessed the association of BMD in children and adolescents with Graves' disease (GD) after correcting for potential confounders affecting BMD such as age, sex, and pubertal status. Forty-four children and adolescents with GD and 172 age- and sex-matched healthy controls were enrolled in this study. We analyzed auxological features, BMD, and levels of thyroid hormone, thyroid-stimulating hormone, and thyroid autoantibodies. We measured BMD by dual-energy X-ray absorptiometry at the time of diagnosis in all patients. The mean age of all patients with GD (9 boys and 32 girls) was 12.1 ± 2.2 years (range, 7.0-16.0). Their initial mean free T4 and thyroid-stimulating hormone levels were 3.51 ± 1.56 ng/dL and 0.04 ± 0.03 IU/L, respectively. The mean BMD Z-scores of the lumbar spine (LS), femoral neck, and total body less head of patients with GD were significantly lower than those of control subjects. Eleven patients (26.8%) had low bone density (LS BMD Z-scores < -2.0). To identify correlations of patient characteristics with BMD Z-scores at each site, alkaline phosphatase had a significant negative correlation with BMD Z-scores at LS and femoral neck, but not total body less head (r = -0.441; p = 0.004 and r = -0.351; p = 0.025, respectively). Children and adolescents with newly diagnosed GD had lower bone mass than their healthy peers. These results suggest that BMD measurement at initial evaluation may be necessary in this population.

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.

Reference values for bone mineral density in healthy Mexican children and adolescents

INTRODUCTION

Clinical assessment of bone health by Dual-Energy X-ray Absorptiometry (DXA) in the paediatric population requires robust reference values. The International Society for Clinical Densitometry (ISCD) recommends that country/regional reference values ideally should be used to improve precision in bone health assessment.

OBJECTIVE

The aim of this study was to provide reference values for relevant bone health variables for healthy Mexican children and adolescents aged 5 to 18 years.

METHODS

This was a cross-sectional, stratified and population-based study, that measured a representative sample of healthy Mexican children and adolescents with DXA. We constructed age- and sex-smoothed reference values for areal bone mineral density (aBMD) of total body less head (TBLH), total body (TB), lumbar spine (LS), and bone mineral apparent density (BMAD) for LS, by means of Generalized Additive Models for Location, Scale and Shape (GAMLSS).

RESULTS

Reference data including the 3th, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th centiles, along with lambda (L), mu (M) and sigma (S) values, are given for each variable of interest for each sex at 0.25 years intervals. Reference values relative to height and Tanner-stage for both sexes are also provided. Finally, formulas to enable Z score estimation for clinical use are also presented CONCLUSIONS: The sex, age, height, Tanner-stage and ethnic-specific reference data provided in this study should enable more precise assessment of bone health in the Mexican paediatric population. The data presented may also allow for future evaluation of potential similarities and differences across different ethnic groups.

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.

Bone Mineral Density of Femur and Lumbar and the Relation between Fat Mass and Lean Mass of Adolescents: Based on Korea National Health and Nutrition Examination Survey (KNHNES) from 2008 to 2011

It is most important to reach the maximum bone density in the childhood period to prevent developing osteoporosis; it is widely known that increased body weight has a positive correlation with bone density and that even though both the fat mass and lean mass have a significant impact on bone density, the latter mass has more importance for adults. Therefore, the study analyzed to identify the relationship between bone density and both fat mass and lean mass of Korean adolescents. Subjects were chosen among 21,303 people from the Korea National Health and Nutrition Examination Survey (KNHNES) between 2008 and 2011 that took a bone density checkup; as a result, 1454 teenagers aged between 12 and 18 were selected. Data analysis was performed in SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA) following the KNHNES and the weighted complex sample analysis was conducted; body fat mass and lean mass were divided into quintile groups, and to figure out the differences in bone density that were analyzed in six models adjusted by body weight (kg) and walking (yes/no), muscle strengthening exercises (yes/no), nutrition (intake of ca (g), and serum vitamin D (ng/mL)). Then, the generalized linear model (GLM) and trend test were conducted for each gender with a significance level of 0.05. The bone density differences of fat mass and lean mass were analyzed. The result of Model 6 considering all correction variables is as follows; in the case of male adolescents, the total femur and lumbar spine showed a significant difference (F = 13.120, p < 0.001; F = 12.900, p < 0.001) for fat mass, and the trend test showed that the figures significantly decreased (β = −0.030, p < 0.001; −0.035, p < 0.001). Meanwhile, for lean mass, the total femur and lumbar spine had a significant difference (F = 16.740, p < 0.001; F = 20.590, p < 0.001) too, but the trend test showed a significant increase (β = 0.054, p < 0.001; 0.057, p < 0.001). In the case of female adolescents, the lumbar spine (F = 3.600, p < 0.05) for lean mass showed a significant difference, and it also significantly rose in the trend test too (β = 0.020, p < 0.01). To sum up the results, for male adolescents, the bone density differences for fat mass (FM) and lean mass (LM) all had significant differences, but for female adolescents, only the lumbar spine for LM showed such a result. Meanwhile, both genders showed that LM had a more positive impact on bone density than FM.

Bone morbidity in pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), currently the most common pediatric leukemia, has a high curability rate of up to 90%. Endocrine disorders are highly prevalent in children with ALL, and skeletal morbidity is a major issue induced by multiple factors associated with ALL. Leukemia itself is a predominant risk factor for decreased bone formation, and major bone destruction occurs secondary to chemotherapeutic agents. Glucocorticoids are cornerstone drugs used throughout the course of ALL treatment that exert significant effects on demineralization and osteoclastogenesis. After completion of treatment, ALL survivors are prone to multiple hormone deficiencies that eventually affect bone mineral accrual. Dual-energy X-ray absorptiometry, the most widely used method of measuring bone mineral density, is used to determine the presence of childhood osteoporosis and vertebral fracture. Supplementation with calcium and vitamin D, administration of pyrophosphate analogues, and promotion of mobility and exercise are effective options to prevent further bone resorption and fracture incidence. This review focuses on addressing bone morbidity after pediatric ALL treatment and provides an overview of bone pathology based on skeletal outcomes to increase awareness among pediatric hemato-oncologists and endocrinologists.

A Case of Autosomal Dominant Osteopetrosis Type 2 with a CLCN7 Gene Mutation

Osteopetrosis is a rare genetic disease characterized by increased bone density and bone fractures due to defective osteoclast function. Autosomal dominant osteopetrosis type 2 (ADO-2), Albers-Schonberg disease, is characterized by the sclerosis of bones, predominantly involving the spine, pelvis and the base of the skull. Here, we report a typical case of osteopetrosis in a 17.7-year-old male who carries a heterozygous c.746C>T mutation in exon 9 in the chloride voltage-gated channel 7 (CLCN7) gene. The patient’s spine showed multiple sclerotic changes including sandwich vertebra. His father had the same mutation but his skeletal radiographs were normal. This is the first reported case of ADO-2, confirmed by genetic testing in a Korean patient.

Evaluation of bone mineral status in prepuberal children with newly diagnosed type 1 diabetes

PURPOSE

Many studies have reported that patients with type 1 diabetes have reduced bone mineral density (BMD). We assessed bone status in prepubertal children with type 1 diabetes mellitus (type 1 DM) at initial diagnosis and investigated factors associated with BMD.

METHODS

Prepubertal children (n=29) with newly diagnosed type 1 diabetes from 2006 to 2014 were included. Dual-energy X-ray absorptiometry measured regional and whole-body composition at initial diagnosis. BMD was compared with healthy controls matched for age, sex, and body mass index (BMI).

RESULTS

The mean age of all subjects (16 boys and 13 girls) was 7.58±1.36 years (range, 4.8-11.3 years). Initial mean glycosylated hemoglobin (HbA1c) level was 12.2%±1.9%. The mean BMD z-scores of lumbar spine, femur neck, and total body were not significantly different between patients and controls. Three patients (10.3%) had low bone density (total body BMD standard deviation score [SDS] &lt; -2.0). To identify determinants of lumbar spine BMD z-score, multivariate regression analysis was performed with stepwise variable selection of age, pubertal status, BMI SDS, insulin like growth factor-1, and HbA1c. Only BMI SDS was significantly correlated with lumbar spine BMD z-score (β=0.395, P=0.023).

CONCLUSION

Prepubertal children with newly diagnosed type 1 DM had similar bone mass compared to healthy peers. However, patients with low BMI should be carefully monitored for bone density in type 1 DM.

An atypical case of Noonan syndrome with KRAS mutation diagnosed by targeted exome sequencing

Noonan syndrome (NS) is a genetic disorder caused by autosomal dominant inheritance and is characterized by a distinctive facial appearance, short stature, chest deformity, and congenital heart disease. In individuals with NS, germline mutations have been identified in several genes involved in the RAS/mitogen-activated protein kinase signal transduction pathway. Because of its clinical and genetic heterogeneity, the conventional diagnostic protocol with Sanger sequencing requires a multistep approach. Therefore, molecular genetic diagnosis using targeted exome sequencing (TES) is considered a less expensive and faster method, particularly for patients who do not fulfill the clinical diagnostic criteria of NS. In this case, the patient showed short stature, dysmorphic facial features suggestive of NS, feeding intolerance, cryptorchidism, and intellectual disability in early childhood. At the age of 16, the patient still showed extreme short stature with delayed puberty and characteristic facial features suggestive of NS. Although the patient had no cardiac problems or chest wall deformities, which are commonly present in NS and are major concerns for patients and clinicians, the patient showed several other characteristic clinical features of NS. Considering the possibility of a genetic disorder, including NS, a molecular genetic study with TES was performed. With TES analysis, we detected a pathogenic variant of c.458A > T in KRAS in this patient with atypical NS phenotype and provided appropriate clinical management and genetic counseling. The application of TES enables accurate molecular diagnosis of patients with nonspecific or atypical features in genetic diseases with several responsible genes, such as NS.

Changes in Bone Health During the First Year of Cancer Treatment in Children

This study aimed to evaluate longitudinal changes in bone mineral density (BMD) and bone mineral content (BMC) in children with cancer during the first year of treatment. Thirty pediatric cancer patients (median age 11.2 [range 3.8-17.4] yr; 21 boys, 9 girls; 19 hematologic malignancies, 11 solid tumors) and 30 healthy controls were enrolled. Dual energy X-ray absorptiometry was performed at baseline and at 1, 6, and 12 mo for each pediatric cancer patient. There were no significant differences in age, sex, body weight, height, body mass index, serum vitamin D levels, BMD, and BMC among children with hematologic malignancies, those with solid tumors, and the controls at baseline. When the medians of BMD Z-scores were compared between different time intervals, whole-body BMD Z-score significantly decreased during the first year of cancer treatment (p = 0.001) in children with hematologic malignancies, especially during the first month (p = 0.002), and between 1 and 6 mo (p = 0.006). In children with solid tumors, whole-body BMD Z-score changed significantly only between 6 and 12 mo after treatment (p = 0.043). Generalized estimation equations for the analysis of trends in the whole-body BMD Z-scores revealed that there were significant downward trends between BMD Z-scores at baseline and those at 12 mo in children with hematologic malignancies and those with solid tumors. Cancer treatment significantly affects the bone health status at least during the first year, causing a significant decrease in BMD, especially during the first 6 mo for patients with hematologic malignancies and during the last 6 mo for those with solid tumors. Better strategies for treating changes in BMD based on the underlying cancer are necessary during cancer treatment in children.

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)

We established the timing of peak bone mass acquisition and body composition maturation and provide an age- and sex-specific body composition and bone density reference database using dual-energy X-ray absorptiometry in Korean subjects 10-25 years of age. Reference percentiles and curves were developed for bone mineral content (BMC), bone mineral density (BMD) of the whole body, the lumbar spine, and the femoral neck, and for fat mass (FM) and lean mass (LM) of 1969 healthy participants (982 males) who participated in the 2009-2010 Korean National Health and Nutrition Examination Survey. Additionally, bone mineral apparent density (BMAD), FM index, and LM index were calculated to adjust for body size. BMC and BMD at all skeletal sites as well as LM increased with age, reaching plateaus at 17-20 years of age in females and 20-23 years of age in males. The femoral neck was the first to reach a bone mass plateau, followed by the lumbar spine and then the whole body. Spine BMAD increased with age in both sexes, but femoral and whole-body BMAD remained the same over time. Females displayed a dramatic increase in FM during puberty, but the FM of males decreased until mid-puberty. These findings indicate that bone health and body composition should be monitored using a normal reference database until the late second to early third decade of life, when statural growth and somatic maturation are completed.

Efficacy of pamidronate in pediatric osteosarcoma patients with low bone mineral density

PURPOSE

Most surviving pediatric osteosarcoma patients experience osteoporosis, bone pain, and pathologic fracture during and after therapy. The aim of this study was to evaluate the efficacy and side effects of pamidronate therapy in these patients.

METHODS

Nine osteosarcoma patients (12.8±1.6 years of age; 5 boys and 4 girls) who had a history of nontraumatic fracture or severe pain after completing chemotherapy were included. Intravenous pamidronate (1.5 mg/kg) was given every 6 weeks for 4 to 6 cycles. Bone mineral density (BMD) of the lumbar spine was measured by dual-energy x-ray absorptiometry. Clinical outcomes including acute side effects were also evaluated.

RESULTS

After pamidronate treatments, all patients experienced decreased pain. Seven of 9 patients could walk without a crutch. The BMD of lumbar spine was increased by 0.108±0.062 mg/cm(2) after 8.4±1.0 months (n=8, P=0.017) and the mean z-score improved from -2.14±0.94 to -1.76±0.95 (P=0.161). Six patients (67%) had an acute-phase reaction, and 2 patients had symptomatic hypocalcemia.

CONCLUSION

Pamidronate appears to be safe and effective for the treatment of osteosarcoma in children with low BMD and bone pain.

Bone mineral density change during adjuvant chemotherapy in pediatric osteosarcoma

PURPOSE

Osteoporosis is currently receiving particular attention as a sequela in survivors of childhood osteosarcoma. The aim of this study was to evaluate bone mineral density (BMD) changes during methotrexate-based chemotherapy in children and adolescents with osteosarcoma.

METHODS

Nine patients with osteosarcoma were included in this retrospective study and compared with eight healthy controls. BMD of the lumbar spine and unaffected femur neck of patients was serially measured by dual-energy x-ray absorptiometry (DXA) before and just after chemotherapy and compared with controls.

RESULTS

Four patients (44%) showed decreased lumbar spine BMD and seven patients (78%) showed decreased femur neck BMD, while all controls showed increased lumbar and femur BMD (P=0.024 and P=0.023). The femur neck BMD z-scores decreased from -0.49±1.14 to -1.63±1.50 (P=0.032). At the end of therapy, five patients (56%) showed femur neck BMD z-scores below -2.0.

CONCLUSION

The bone metabolism is disturbed during therapy in children with osteosarcoma, resulting in a reduced BMD with respect to healthy controls. Since a reduced BMD predisposes to osteoporosis, specific attention and therapeutic interventions should be considered.

Bone mineral density: reference values and correlates for Bangladeshi women aged 16-65 years

BACKGROUND

Studies examining the reference values of bone mineral density (BMD) and their patterns at different ages are largely based on data generated from developed countries. The objective of this study was to estimate reference values of BMD, along with their correlates, for women living in urban and suburban areas of Bangladesh.

METHODS

Dual-energy X-ray absorptiometry scans were performed on 500 women 16-65 years of age. Reference values at the lumbar spine (LS) and femoral neck (FN) were estimated after adjusting for height and weight. In addition, multiple linear regression analysis was used to examine correlates of BMD at the LS and FN.

RESULTS

Mean BMD was highest at the LS and FN in women 16-19 (1.001-1.007 g/cm(2)) and 16-22 years of age (0.880-0.888 g/cm(2)), respectively, and gradually declined with increasing age thereafter. BMD decreased at an annual rate of 0.0027 g/cm(2) at the LS and 0.0046 g/cm(2) at the FN among women aged 16-45 years. For women 46-65 years of age, the respective figures were 0.0073 and 0.0083 g/cm(2). In both age groups, body weight was positively associated with BMD at both sites, and with height only at the LS. In addition, years of pill use was positively associated with BMD at the LS among women aged 16-45 years. BMD levels at both sites began to decline during the early twenties among Bangladeshi women.

CONCLUSIONS

Age-specific BMD data generated in this study could be useful for interpreting bone densitometry data among women in Bangladesh and other South Asian countries.

A phase 2 multi-center, open-label, switch-over trial to evaluate the safety and efficacy of Abcertin® in patients with type 1 Gaucher disease

Gaucher disease is a lysosomal storage disease for which enzyme replacement therapy has proven to be effective. A switch-over clinical trial was performed to evaluate the efficacy and safety of Abcertin® (ISU Abxis, Seoul, Korea) in subjects with type 1 Gaucher disease who were previously treated with imiglucerase. Five Korean patients with type 1 Gaucher disease were enrolled. Previous doses of imiglucerase ranged from 30 to 55 U/kg every other week. The same dose of Abcertin® was administered to all patients for 24 weeks. Primary efficacy endpoints were changes in hemoglobin levels and platelet counts, and the secondary efficacy endpoints included changes in liver and spleen volumes, serum biomarkers, skeletal status and bone mineral density (BMD). During the study period, no statistically significant changes were observed in all parameters including hemoglobin levels and platelet counts, liver and spleen volumes, skeletal status and BMD. Abcertin® administration was continued in three patients for another 24 weeks as an extension of the study. Hemoglobin levels and platelet counts were maintained in all three patients. In conclusion, the efficacy and safety of Abcertin® are similar to those of imiglucerase, and Abcertin® is an effective therapeutic agent for patients with type 1 Gaucher disease (Clinical Trial Registry No. NCT02053896 at www.clinicaltrials.gov).

Familial interactions and physical, lifestyle, and dietary factors to affect bone mineral density of children in the KNHANES 2009-2010

We examined familial bone mineral density (BMD) interactions between parents and children and lifestyle factors affecting BMD in the Korean general population of children under 20 and parents under 50 years of age. This cross-sectional study included 2,453 participants (667 daughters, 705 sons, 719 mothers, and 362 fathers) in the 2009-2010 Korean National Health and Nutrition Examination Survey. We calculated prevalence ratios and 95 % confidence intervals for BMD values of whole femur, femur neck, lumbar spine, and whole body excluding the head being in the low tertile in adolescents according to parental BMD tertile after adjusting for physical, lifestyle, and dietary factors. For daughters and sons, there were significant differences in BMD at the four bone sites according to age group, body fat percentage, regular walking and exercise, and milk consumption compared to the reference value for each classification category. Surprisingly, there were no differences in BMD according to serum 25-OH-D levels. Birth order affected BMD of only whole body except head, but its impact was less than that of lifestyle factors. The mean differences in BMD between daughters and sons in the first and third parental BMD tertiles were statistically significant. Notably, the prevalence ratio of whole body without head BMD being in the low tertile increased eight and ten-folds in adolescent daughters and sons, respectively, when parents were in the low BMD tertile. In specific bone regions, parental BMD had a greater effect on total femur in daughters but in the lumbar spine in sons. In conclusion, parental BMD positively influences BMD in daughters and sons after adjustment for environmental parameters. This suggests that the children from parents with low BMD need to make an extra effort to increase BMD through dietary and lifestyle changes.

Reference values for bone mineral density according to age with body size adjustment in Korean children and adolescents

Bone acquisition failure during growth or low bone mineral density (BMD) in childhood and adolescence might increase future osteoporosis risk. To identify these children and adolescents, appropriate reference values are necessary. The robust reference values must be community based as well as sex-, age-, and ethnicity specific. In addition, body size adjustment is necessary because individuals demonstrate different body sizes and different tempos of growth, which affect measured BMD. We aimed to provide reference data with body size adjustment of Korean children and adolescents. We used dual-energy X-ray absorptiometry data of 1,650 subjects (aged 10-20 years; 788 female) from the Korea National Health and Nutrition Examination Survey (2009-2010). The BMD of each region of interest (ROI), including the lumbar spine, total body less head, total body, and femoral neck, were obtained. We calculated the mean and percentiles for each ROI. Because height and weight variations were high and correlated independently with BMD within the same age group, we developed equations to calculate the "predicted BMD Z score." Although 12.8-17.9 % of subjects with short stature showed a low measured BMD Z score depending on the measured site, only 2.6 % of those of short stature had a low adjusted BMD Z score after applying the predicted BMD Z score. We also compared the BMD of children and adolescents of other ethnicities using the same device. This study provided robust reference values for the assessment and monitoring of bone health in Korean children and adolescents. Additionally, it extended the knowledge of bone acquisition in Asian children and adolescents.

Additive association of vitamin D insufficiency and sarcopenia with low femoral bone mineral density in noninstitutionalized elderly population: the Korea National Health and Nutrition Examination Surveys 2009-2010

Vitamin D insufficiency and sarcopenia are crucial risk factors for osteoporosis. In a study of noninstitutionalized elderly subjects, we investigated the simultaneous effect of vitamin D and sarcopenia on bone mineral density (BMD) and found that sarcopenia was associated with low BMD in the femur, especially in those with suboptimal vitamin D levels.

INTRODUCTION

Although vitamin D insufficiency and sarcopenia are prevalent in the elderly population worldwide, their possible influence on BMD has not been determined. We aimed to investigate the different effect of vitamin D insufficiency and sarcopenia on BMD in the elderly Korean population.

METHODS

Individuals aged 60 or older were selected from those who participated in the Fourth and Fifth Korea National Health and Nutrition Examination Surveys conducted in 2009 and 2010; 1,596 males and 1,886 females were analyzed. Appendicular skeletal muscle mass (ASM) and BMD were assessed by dual-energy X-ray absorptiometry; serum 25-hydroxyvitamin D [25(OH)D] and a panel of clinical and laboratory parameters were also measured.

RESULTS

The study population was divided into four groups according to their vitamin D and sarcopenic status. BMD in total femur and in the femoral neck but not the lumbar spine was markedly decreased in sarcopenic subjects with vitamin D insufficiency [25(OH)D < 20 ng/ml] comparing to other groups, regardless of gender. Multivariable linear regression models showed that BMD was significantly associated with ASM and high daily calcium intake as well as conventional risk factors such as age, body mass index (BMI), and history of fracture. Independent predictors for low femur BMD included sarcopenia, low daily calcium intake, low 25(OH)D levels, age, and BMI.

CONCLUSIONS

These data showed that an association between vitamin D insufficiency and low BMD was more prominent in elderly subjects with sarcopenia.

Changes in bone mineral density and body composition of children with well-controlled homocystinuria caused by CBS deficiency

Homocystinuria due to cystathionine β-synthase (CBS) deficiency is an inherited disorder of the metabolism of methionine. Clinical manifestations include mental retardation, dislocation of the optic lens, vascular lesions, arterial and venous thromboembolism, skeletal abnormalities, and osteoporosis. Most homocystinuria patients diagnosed in adulthood have severe osteoporosis, and homocystinuria is frequently mentioned as a cause of osteoporosis. Good control of plasma homocysteine may prevent or delay some of these complications. However, the effectiveness of bone mineral density (BMD) gain or fracture prevention has not been addressed. Here, we describe changes in BMD and body composition in 5 CBS deficiency patients who were diagnosed at young age and were managed with good metabolic control. We found that the BMD of each region was within the normal range. BMD gain was adequate and the patients had no significant change in skeletal morphology.

Adequate vitamin D status and adiposity contribute to bone health in peripubertal nonobese children

The dietary reference intake (DRI) of vitamin D for Korean children was reduced from 400 IU/day in 2005 to 200 IU/day in 2010. We evaluated the risk factors for low 25-hydroxyvitamin D [25(OH)D] status and its relationships with bone health in peripubertal nonobese children living in Seoul or Gyeonggi-do. One hundred children (9.3 ± 1.9 years, 71 prepubertal, 45 boys) participated in the winter (n = 38, December through March) and summer (June through September). Bone mineral content (Z_BMC), fat mass (Z_FM), lean mass (Z_LM), and bone mineral density for the total body (Z_TB) and lumbar spine (Z_L1-4) were measured using dual-energy X-ray absorptiometry. Twenty-nine percent of children (47.4 % in winter, 17.7 % in summer) were vitamin D deficient (25(OH)D level of <20 ng/mL). The winter season (P = 0.008) and low vitamin D intake (P = 0.044) were associated with low 25(OH)D level. The 25(OH)D level correlated positively with Z_BMC (P = 0.040), Z_TB (P = 0.027), and Z_L1-4 (P = 0.045) independently of sex, puberty, Z_FM, Z_LM, physical activity level, and calcium intake. Z_FM correlated independently with Z_BMC (P < 0.001), Z_TB (P = 0.037), and Z_L1-4 (P < 0.001). In conclusion, almost half of peripubertal nonobese children were vitamin D deficient in winter. Adequate vitamin D status and adiposity contributed to good bone health in nonobese children. Considering the beneficial effects of adequate vitamin D status on bone health, the current DRI may be insufficient for preventing vitamin D deficiency in winter among Korean children.

Bone mineral density deficits in childhood cancer survivors: Pathophysiology, prevalence, screening, and management

As chemotherapy and other sophisticated treatment strategies evolve and the number of survivors of long-term childhood cancer grows, the long-term complications of treatment and the cancer itself are becoming ever more important. One of the most important but often neglected complications is osteoporosis and increased risk of fracture during and after cancer treatment. Acquisition of optimal peak bone mass and strength during childhood and adolescence is critical to preventing osteoporosis later in life. However, most childhood cancer patients have multiple risk factors for bone mineral loss. Cancer itself, malnutrition, decreased physical activity during treatment, chemotherapeutic agents such as steroids, and radiotherapy cause bone mineral deficit. Furthermore, complications such as growth hormone deficiency and musculoskeletal deformity have negative effects on bone metabolism. Low bone mineral density is associated with fractures, skeletal deformity, pain, and substantial financial burden not only for childhood cancer survivors but also for public health care systems. Thus, it is important to monitor bone health in these patients and minimize their risk of developing osteoporosis and fragility fractures later in life.

Young age at diagnosis, male sex, and decreased lean mass are risk factors of osteoporosis in long-term survivors of osteosarcoma

BACKGROUND

Long-term survival of children with osteosarcoma has increased, but most suffer from osteoporosis in adulthood. The aim of this study was to investigate the prevalence and identify the risk factors of osteoporosis.

METHODS

Forty long-term survivors of osteosarcoma and 55 controls were enrolled. The mean age of the survivors was 21.8 ± 5.2 years. They were diagnosed at younger than 23 years of age (mean, 14.9 + 5.0 y). Bone mineral densities (BMD) and body compositions were measured by dual-energy x-ray absorptiometry.

RESULTS

Nineteen (47.5%) subjects had osteoporosis and 12 (30.0%) had osteopenia. The regions affected by osteoporosis were: femur neck of osteosarcoma site (47.5%), unaffected femur neck (12.5%), lumbar spine (12.5%), and total body (15.0%). Twelve subjects (30.0%) had 14 episodes of fractures. The identified risk factors of osteoporosis were young age at diagnosis, male sex, and low lean mass. Subjects diagnosed before attainment of puberty (male ≤ 16 y, female ≤ 14 y) were found to have a higher prevalence of osteoporosis (37.5% vs. 10.0%, P < 0.01). Males had a higher prevalence of osteopenia or osteoporosis than females (86.4% vs. 66.7%, P < 0.01). Total lean mass was positively correlated with unaffected femur neck BMD. Regional lean mass in affected limb was significantly reduced along with affected femur neck BMD.

CONCLUSIONS

In long-term survivors of osteosarcoma, prevalence of osteoporosis and fracture was higher than expected. Initial evaluation and regular follow-up of BMD should be performed in all osteosarcoma patients, especially in those who did not attain puberty, males, and those with a low lean mass.

A milk and cereal dietary pattern is associated with a reduced likelihood of having a low bone mineral density of the lumbar spine in Korean adolescents

The traditional rice-based Korean diet has been changing toward a Western-style diet. This change has been especially rapid among adolescents. The purpose of this study was to investigate the association between dietary patterns and bone health among Korean adolescents. This cross-sectional study was conducted on 196 adolescents aged 12 to 15 years. Information on the general characteristics of the subjects was obtained through a questionnaire, and dietary intake was assessed with 6-day food records. Bone mineral densities (BMDs) of the lumbar spine and femur were measured by dual-energy x-ray absorptiometry. Dietary patterns were derived from 24 food groups using factor analysis. Four distinct dietary patterns-traditional Korean, fast food, milk and cereal, and snacks-were identified and accounted for 28.4% of the total variance. After adjusting for sex, age, body mass index percentiles, weight loss attempts, pubertal status, and regular exercise, the adolescents in the highest tertile of the "milk and cereal" dietary pattern score had significantly a reduced likelihood of having low BMD compared with those in the lowest tertile of this diet at the lumbar spine (odds ratio, 0.36; 95% confidence interval, 0.14-0.93; P = .0461). The other dietary patterns were not associated with the BMD of Korean adolescents. These results indicate that the intake of milk and cereal is important for the bone health of Korean adolescents, whose diets are composed mainly of grains and vegetables.

The effect of gonadotrophin-releasing hormone agonist treatment over 3 years on bone mineral density and body composition in girls with central precocious puberty

OBJECTIVE

Puberty is a period characterized by growth spurt and rapid change in body composition. The effect of GnRH agonist therapy for central precocious puberty on bone mineral density is unclear. We demonstrated changes in bone mineral density in subjects with central precocious puberty, who were treated with GnRH agonist for more than 3 years.

DESIGN

The changes in bone mineral density and body compositions were tested with analysis of variance with repeated measures to identify statistical significance over the treatment period.

PATIENTS

One hundred ninety-five Korean girls with central precocious puberty were treated with GnRH agonist, and among these subjects, 39 patients were treated for more than 3 years.

MEASUREMENTS

Dual-energy X-ray absorptiometry was performed on the subjects at the initial evaluation and once yearly thereafter while on the treatment.

RESULTS

The bone mineral density parameters for chronological age tended to decrease near the mean for the treatment period; however, they increased significantly for bone age excluding bone mineral apparent density. An increment of the BMI was not significant for the chronological age.

CONCLUSIONS

Three-year treatment with GnRH agonist in central precocious puberty patients did not impair bone maturation. GnRH agonist could be effectively commenced in girls with precocious puberty from an early age.

Effect of bisphosphonates on bone mineral density and fracture prevention in gastric cancer patients after gastrectomy

GOAL

To evaluate the effectiveness of bisphosphonates in preventing fractures in gastric cancer patients by increasing bone mineral density (BMD).

BACKGROUND

The effectiveness of bisphosphonates is questionable in gastric cancer patients who have undergone gastrectomy, although they display a high prevalence of osteoporosis.

STUDY

Forty-seven gastric cancer patients with osteoporosis were retrospectively analyzed. All patients were supplemented with calcium and vitamin D. Twenty-four patients were treated with bisphosphonate (bisphosphonate group) and 23 patients were untreated (control group). Fractures, severe bone pain, and adverse effects of bisphosphonates were monitored. BMD of the lumbar spine and femoral neck were measured before and 1-year treatment with bisphosphonates by dual-energy X-ray absorptiometry.

RESULTS

During a 1-year follow-up, 7 of the 47 (15%) patients developed new fractures. The bisphosphonate-treated group had a significantly lower fracture rate than the control group (n=1 vs. 6, P<0.05). Lumbar spine BMD increased in both groups (0.047 ± 0.03 vs. 0.021 ± 0.03 g/cm², respectively), whereas femoral neck BMD increased only in the bisphosphonate group (0.032 ± 0.03 vs. -0.004 ± 0.02 g/cm², respectively). Furthermore, the bisphosphonate group showed greater increases in lumbar spine and femoral neck BMDs than the controls (P<0.05). No difference was found between alendronate and risedronate in terms of BMD at follow-up.

CONCLUSIONS

Therapy using bisphosphonates might be effective at increasing BMD and reducing fracture risk in gastric cancer patients after gastrectomy. Further well-designed randomized controlled trials are needed for confirmation.

Risk factors for osteoporosis in long-term survivors of intracranial germ cell tumors

SUMMARY

We measured bone mineral densities in 28 intracranial germ cell tumor long-term survivors. There was the high prevalence of osteoporosis and osteopenia, 25.0% and 42.9%, respectively, and three additional risk factors, male sex, a low lean mass, and adult growth hormone replacement, were identified.

INTRODUCTION

Intracranial germ cell tumor long-term survivors (iGCTLS) have many risk factors for osteoporosis, including irradiation from cancer therapy and multiple hormone deficiencies. However, no study of bone mineral density (BMD) has been conducted in iGCTLS because these tumors are rare. The aims of this study were to evaluate the prevalence of osteoporosis and to identify risk factors associated with reduced bone mass in iGCTLS.

METHODS

We evaluated BMD and body composition of 28 iGCTLS (10.9 ± 5.2 years after cancer treatment; 13 males) using dual-energy X-ray absorptiometry. To determine risk factors, we analyzed the medical history, including the nature of the tumor, treatment modality, endocrine status, hormone replacement therapy, lifestyle, and biochemical parameters.

RESULTS

Twenty-five percent of iGCTLS were diagnosed with osteoporosis and 42.9% with osteopenia. Most males (92.3%) had low BMD. Lean mass (LM) was positively correlated with BMD in all regions of interest, and the starting age of adult growth hormone (GH) replacement was negatively correlated with the BMD Z-score at the femur neck. In logistic regression analysis, male sex and low LM were related to low BMD.

CONCLUSIONS

The iGCTLS had a high prevalence of low BMD. We found that male sex, low LM, and delayed start of adult GH replacement were risk factors for osteoporosis. Therefore, the BMD of all iGCTLS should be evaluated, and if it is low, proper management should be started early.