Tracking of Bone Mass and Density during Childhood and Adolescence

Abstract Context: Whether a child with low bone mineral density (BMD) at one point in time will continue to have low BMD, despite continued growth and maturation, is important clinically. The stability of a characteristic during growth is referred to as “tracking.” Objective: We examined the degree of tracking in bone mineral content (BMC) and BMD during childhood and adolescence and investigated whether tracking varied according to age, sexual maturation, and changes in growth status. Design: We conducted a longitudinal study with measurements at baseline and annually for 3 yr. Setting: The Bone Mineral Density in Childhood Study was conducted at five clinical centers in the United States. Study Participants: A total of 1554 girls and boys, ages 6–16 yr at baseline, participated in the study. Main Outcome Measures: Whole body, spine, hip, and forearm BMC and BMD were measured by dual-energy x-ray absorptiometry, and age-, sex-, and race-specific Z-scores were calculated. Deviation from tracking was calculated as the Z-score at yr 3 minus baseline. Results: Correlations between Z-scores at baseline and yr 3 ranged from 0.76–0.88. Among children with a Z-score below −1.5 at baseline, 72–87% still had a Z-score below −1 after 3 yr. Age, sexual maturation, and deviations in growth status (P < 0.01) were associated with deviation from tracking; however, tracking was strongly evident even after adjusting for the effects of age, maturation, and growth. Conclusions: Bone density showed a high degree of tracking over 3 yr in children and adolescents. Healthy children with low bone density will likely continue to have low bone density unless effective interventions are instituted.

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EVALUATION OF GLUTATHIONE-S-TRANSFERASE P1 POLYMORPHISM AND ITS RELATION TO BONE MINERAL DENSITY IN EGYPTIAN CHILDREN AND ADOLESCENTS WITH BETA- THALASSEMIA MAJOR

Mediterranean Journal of Hematology and Infectious Diseases ◽

10.4084/mjhid.2016.004 ◽

2016 ◽

Vol 8 ◽

pp. 2016004 ◽

Cited By ~ 3

Author(s):

Seham Ragab

Keyword(s):

Bone Mineral Density ◽

Bone Mineral ◽

Thalassemia Major ◽

Beta Thalassemia ◽

Z Score ◽

Glutathione S Transferase ◽

Mineral Density ◽

Beta Thalassemia Major ◽

Egyptian Children ◽

Z Scores

Background:Osteoporosis is a major problem in beta thalassemia major (TM) patients. Increased oxidative stress and its controlling genes were linked to osteoporosis. Glutathione S-transferase P1 (GSTP1),Ile105 Val variant is a functional mutation with reduced ant-oxidative property .No data are available about this variant or its association with osteoporosis among thalassemia patients yet. Objectives: The aim of this study was to investigate Ile105Val polymorphism and its possible association with bone mineral density (BMD) values in a group of TM children. Methods:Thirty five TM patients and 30 age and sex matched healthy controls were included. Liver and renal functions, serum ferritin, calcium, phosphorous, alkaline phosphatase and osteocalcin were assayed. BMD was determined by DXA with calculation of Z-scores at lumbar spine (Ls) and femoral neck (Fn).Height for age z- score (HAZ) adjusted BMD Z-scores were considered . GSTP1 Ile105Val polymorphism was studied by polymerase chain reaction-restriction fragment length polymorphism. Results:The relative frequency of 105 Val allele was significantly higher in TM patients than the controls (P<0.0001). Significant association between genotype subgroups and BMD parameters was detected. Mutant homozygotes had significant lower BMD , Z –score and haz -adjusted BMD Z-score at both Ls and Fn compared to wild homozygotes ( Ps =0.029, 0.008, 0.011, 0.001,0.02, 0.001) with significant higher osteocalcin level compared to heterozygotes and wild homozygotes (P=0.012 and P=0.013,respectively). Conclusion: The results indicated that 105Val allele was frequent among TM patients and could increase their susceptibility to osteoporosis. Large sample studies are required to confirm these findings.

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Vitamin D Status and Its Relationship with Bone Mineral Density and Parathyroid Hormone in Southeast Asian Adults with Low Bone Density

Endocrine Practice ◽

10.4158/ep10202.or ◽

2011 ◽

Vol 17 (2) ◽

pp. 226-234 ◽

Cited By ~ 11

Author(s):

Manju Chandran ◽

Hans Hoeck ◽

Hung Wong ◽

Rong Zhang ◽

Hans Dimai

Keyword(s):

Bone Mineral Density ◽

Vitamin D ◽

Parathyroid Hormone ◽

Bone Density ◽

Bone Mineral ◽

Southeast Asian ◽

Vitamin D Status ◽

Mineral Density ◽

Low Bone Density

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Evaluation of Bone Mineral Density in Children with Sickle Cell Anemia.

Blood ◽

10.1182/blood.v104.11.106.106 ◽

2004 ◽

Vol 104 (11) ◽

pp. 106-106

Author(s):

Ashutosh Lal ◽

Ellen Fung ◽

Bamidele Kammen ◽

Zahra Pakbaz ◽

Nancy Sweeters ◽

...

Keyword(s):

Bone Mineral Density ◽

Lumbar Spine ◽

Sickle Cell ◽

Bone Mineral ◽

Reference Data ◽

Growth Failure ◽

Red Cell ◽

Z Score ◽

Mineral Density ◽

Z Scores

Abstract Background : Reduced bone mineral density (BMD) has been reported in adults and children with sickle cell anemia (SCA). Dual energy x-ray absorptiometry (DXA) is routinely used for measuring BMD because of less radiation exposure and lower cost. However, changes in vertebral body shape, marrow hyperplasia and bone infarction due to SCA may affect the evaluation of BMD with DXA. Hence, we compared DXA with quantitative computerized tomography (QCT), which measures true volumetric density, and may be less influenced by bone changes. Methods : The study enrolled children between 9–19 years of age with SCA, and one or more severe manifestations: >2 hospital admissions/year, growth failure, avascular necrosis, or regular red cell transfusions for sickle cell-related complications. BMD of lumbar spine was determined by performing DXA of lumbar spine (Hologic Delphi-A, Bedford, MA). The apparent volumetric bone mineral density (BMAD) was calculated from bone mineral content, and compared to age, sex and ethnicity-matched reference data. BMD of the lumbar spine was also measured by QCT (Mindways Software, San Francisco, CA), and compared to age and sex-appropriate reference data. Results : The study has enrolled 25 patients (13 females and 12 males), of which 16 were younger than 14 years. In 6 children the height was <10th centile for age. Thirteen patients were on regular transfusions for >6 months, including 10 who had been transfused for >2 years. Calcium intake, assessed by a standardized questionnaire, was less than recommended dietary allowance in 13 patients. The z-score for BMAD determined by DXA was > −1.0 in 8, between −1.0 and −2.0 in 5, and < −2.0 in 12 patients. The z-score for lumbar spine by QCT was > −1.0 in 20, between −1.0 and −2.0 in 1 and < −2.0 in 4 patients. DXA-derived BMD (areal density) and BMAD (apparent volumetric density) z-scores did not differ significantly (p=0.16). On the other hand, the paired values of z-scores by DXA (BMAD) and QCT were significantly different (p=.002). When z-scores were categorized as greater or less than −1.0, the results were concordant in 13 (both DXA and QCT normal in 8, and both DXA and QCT abnormal in 5), and discordant in 12 cases (abnormal DXA with normal QCT in every case). Among patients in discordant group, 9/12 had been on regular red cell transfusions for >6 months, compared to 4/13 with concordant results (p=.047). There was no difference in the serum ferritin values between the two groups (p=.685). No significant difference in the prevalence of low BMAD z-scores was detected between groups based upon age, calcium intake, or growth failure. Five out of the 12 patients with BMAD z-score < −2.0 were not on regular transfusion program. Conclusions : Almost half of the children with SCA had BMD below −2 standard deviations compared to age-matched controls. Low BMD was observed in chronically transfused as well as non-transfused children. In comparison, 16% of the patients were classified as low BMD (z < −2.0) by QCT. The paired DXA/QCT results were discordant in half of the sample, with patients on regular transfusions for >6 months more likely to have normal QCT results. It is likely that the reduction in marrow hyperplasia following initiation of regular transfusions may disproportionately affect the trabecular BMD measured by QCT. Longitudinal evaluation of BMD in patients starting on transfusion program could help to define the effect of transfusions on measures of BMD in SCA.

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OR27-04 Risk Factors For Low Baseline Bone Mineral Density In Gender Diverse Youth

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.1296 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Juanita K Hodax ◽

Charles Brady ◽

Sara A DiVall ◽

Kristen Carlin ◽

Hedieh Khalatbari ◽

...

Keyword(s):

Bone Mineral Density ◽

Vitamin D ◽

Hormone Therapy ◽

Bone Mineral ◽

Calcium Intake ◽

Z Score ◽

Mineral Density ◽

Transgender Youth ◽

Z Scores ◽

Dxa Scans

Abstract Background Sex steroids such as testosterone and estrogen are necessary for accumulation of bone mass. Transgender youth treated with gonadotropin releasing hormone analogues (GnRHa) to block natal puberty for gender-affirming care are at risk of low bone mineral density (BMD). Previous studies indicate that transfemale patients assigned male at birth (AMAB) have low BMD at baseline, during and after GnRHa treatment despite cross hormone treatment. Transmales assigned female at birth (AFAB), however, have normal BMD at baseline that decreases upon GnRHa treatment, with normalization upon cross hormone therapy. The reason(s) for the low baseline BMD in transfemales is unclear. We aimed to assess the baseline characteristics of transgender youth at a single multidisciplinary gender clinic prior to medical intervention and determine factors associated with BMD. Methods This is a retrospective chart review of patients <19 years old evaluated in the gender clinic. Dual-energy x-ray absorptiometry (DXA) scans were obtained prior to initiation of GnRHa or cross-hormone therapy per Endocrine Society guidelines for the treatment of gender dysphoria. We included patients with DXA scans completed prior to initiation of treatment with GnRHa or cross gender hormones and excluded those with concurrent medical diagnoses that may affect bone density. Data collected were bone mineral density (BMD) Z-scores, anthropometric data, vitamin D and calcium levels, and calcium intake. Multivariable linear regression models were used to assess the impact of vitamin D levels, height Z-score, weight Z-score, and BMI Z-score on subtotal body BMD Z-score, adjusted for sex assigned at birth and age. Results Sixty-four patients were included in our analysis. Of these, 73% were AMAB and 27% AFAB. Gender identity was male in 14%, female in 44%, and non-binary in 42%. Average height Z-score was 0.12, weight Z-score 0.27, and BMI Z-score 0.22 (using sex assigned at birth). Subtotal body BMD Z-scores were greater than zero in 11%, between zero and greater than -2 in 59%, and less than or equal to -2 in 30% of tested patients. AMAB patients had lower BMD Z-scores compared to those AFAB (p<0.05 for all Z-scores). There was a positive association with BMI, height, and weight Z-scores and increasing BMD Z-scores after adjusting for sex assigned at birth and age (p<0.05 for all Z-scores). Patients who consumed <2 servings of calcium per day had lower BMD Z-scores (p<0.05 for all Z-scores). Average vitamin D level was 24 ng/ml (+/- 9.5 SD) with no significant association with BMD Z-scores (adjusted for sex assigned at birth). Conclusions Patients AMAB and patients with calcium intake of < 2 servings/day are associated with lower baseline BMD in a cohort of adolescents seen in a multidisciplinary gender clinic. Height, weight, and BMI are associated linearly with BMD Z-score, following patterns previously described in other populations.

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Older age at Initiation of Antiretroviral Therapy Predicts Low Bone Mineral Density in Children with perinatally-infected HIV in Zimbabwe

10.1101/565143 ◽

2019 ◽

Author(s):

Celia L Gregson ◽

April Hartley ◽

Edith Majonga ◽

Grace Mchugh ◽

Nicola Crabtree ◽

...

Keyword(s):

Antiretroviral Therapy ◽

Bone Density ◽

Bone Mineral ◽

Lean Mass ◽

Muscle Development ◽

Z Score ◽

Mineral Density ◽

Bone Mineral Apparent Density ◽

Art Initiation ◽

Z Scores

AbstractBackgroundPerinatally-acquired HIV infection commonly causes stunting in children, but how this affects bone and muscle development is unclear. We investigated differences in bone and muscle mass and muscle function between children with HIV (CWH) and uninfected children.SettingCross-sectional study of CWH (6–16 years) receiving antiretroviral therapy (ART) for >6 months and children in the same age-group testing HIV-negative at primary health clinics in Zimbabwe.MethodsFrom Dual-energy X-ray Absorptiometry (DXA) we calculated total-body less-head (TBLH) Bone Mineral Content (BMC) for lean mass adjusted-for-height (TBLH-BMCLBM) Z-scores, and lumbar spine (LS) Bone Mineral Apparent Density (BMAD) Z-scores.ResultsThe 97 CWH were older (mean age 12.7 vs. 10.0 years) and therefore taller (mean height 142cm vs. 134cm) than those 77 uninfected. However, stunting (height-for-age Z-score≤-2) was more prevalent in CWH (35% vs. 5%, p<0.001). Amongst CWH, 15% had low LS-BMAD (Z-score ≤-2) and 13% had low TBLH-BMCLBM, vs. 1% and 3% respectively in those uninfected (both p≤0.02). After age, sex, height and puberty adjustment, LS-BMAD was 0.33 SDs (95%CI −0.01, 0.67; p=0.06) lower in CWH, with no differences in TBLH-BMCLBM, lean mass or grip strength by HIV status. However, there was a strong relationship between age at ART initiation and both LS-BMAD Z-score (r=-0.33, p=0.001) and TBLH-BMCLBM Z-score (r=-0.23, p=0.027); for each year ART initiation was delayed a 0.13 SD reduction in LS-BMAD was seen.ConclusionSize-adjusted low bone density is common in CWH. Delay in initiating ART adversely affects bone density. Findings support immediate ART initiation at HIV diagnosis.

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D-vitamin-anyagcsere és osteoporosis szisztémás sclerosisban

Orvosi Hetilap ◽

10.1556/650.2017.30816 ◽

2017 ◽

Vol 158 (32) ◽

pp. 1252-1258 ◽

Cited By ~ 2

Author(s):

Szilvia Szamosi ◽

Ágnes Horváth ◽

Zoltán Szekanecz ◽

Gabriella Szűcs

Keyword(s):

Bone Mineral Density ◽

Vitamin D ◽

Systemic Sclerosis ◽

Bone Density ◽

Vitamin D Deficiency ◽

Bone Mineral ◽

Mineral Density ◽

Low Bone Mineral Density ◽

Low Bone Density

Abstract: In the past few years more and more data have become available on the important role of vitamin D in immunological processes and inflammation. The role of vitamin D deficiency in the pathogenesis as well as in disease progression of different autoimmune and inflammatory conditions is suspected. Vitamin D deficiency is prevalent in several autoimmune diseases, including systemic sclerosis. Hypovitaminosis has been found to be associated with low bone mineral density and higher prevalence of osteoporosis in this group of patients. Determinants of low bone density in SSc are poorly understood. Studies have shown the importance of both traditional osteoporotic as well as disease-specific factors (extent of skin involvement, presence of internal organ manifestation, malabsorption, systemic sclerosis subtype, serological profile, medication) in the development of low bone mineral density. The relationship between low bone density in systemic sclerosis patients and the above mentioned risk factors may be more complex and the real role of each factor is unclear. Yet very few studies reported clinically relevant low bone mass outcomes such as fracture risk assessment and fracture associated mortality in scleroderma. This review aims to synthesize data about the essential role of vitamin D in immune homeostasis as well as the prevalence of hypovitaminosis, low bone density, changes in bone turnover markers and presence of osteoporosis in scleroderma patients. Orv Hetil. 2017; 158(32): 1252–1258.

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Bone Mineral Density in Transfusion Independent Thalassemia Patients.

Blood ◽

10.1182/blood.v108.11.3353.3353 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3353-3353

Author(s):

Zahra Pakbaz ◽

Zhe Zhang ◽

Ellen Fung ◽

Nancy Sweeters ◽

Sylvia Singer ◽

...

Keyword(s):

Bone Mineral Density ◽

Family History ◽

Bone Mineral ◽

Z Score ◽

Low Bone Mass ◽

Mineral Density ◽

Patients Âgés ◽

Z Scores ◽

History Of ◽

The Mean

Abstract Low bone mineral density (BMD) is commonly seen in regularly transfused thalassemia patients; however, there have been few reports for bone mineral density assessment in transfusion independent thalassemia patients. The present report includes the results of BMD assessments in patients with transfusion independent thalassemia who were referred to the bone density clinic through 2002–2006. BMD was evaluated by dual energy x-ray absorptiometry (DXA, Hologic Delphi A). A convenience sample of 24 patients (Females=15) with transfusion independent thalassemia were measured with a mean age of 22.1 ± 13.8 years. Subjects younger than 10 yrs old (n = 7) underwent scans for Lumbar spine (LS; L1-L4) and whole body (WB), patients ages 10–20 (n = 5) were assessed for LS, WB, and non-dominant hip, and for patients older than 20 (n = 12), LS and hip scans were completed. Z-scores specific for age and gender were generated using Zemel BS et al.(J. Bone Min Res 2004) database. Z-scores less than −2.0 were considered as low bone density. Calcium intake was assessed by a brief food frequency questionnaire. Past medical history, medications, history of fractures, and family history of osteoporosis were obtained by chart review and patient interview. Data is presented as Mean ± SD. T-test was used to assess differences in continuous variables. The mean LS Z-score (n = 24) was −1.5 ± 1.0 and the mean hip Z-score (n = 17) was −0.5 ± 1.1. Mean WB Z-score (n = 10) was −2.0 ± 1.2. There was a significant (p<0.001) difference between spine and hip Z-scores. Overall 46% had a Z-score less than −2.0. Thirty-three percent of patients have spine Z-scores of less than −2.0 and 25% spine Z-scores between −2.0 and −1.0. Average spine Z-score in patients younger than 10 years old (n=7) was −1.6 ± 0.5. In WB scans, 50% of the patients had WB Z-scores worse than −2.0. None of the young patients (5–9 yrs; n = 7) consumed inadequate intake of calcium (< 2/3 of RDA age specific) while 75% of patients ages 10–20 (n = 4) years old consumed inadequate intake of calcium (dietary + supplement). Neither spine nor hip Z-score was related to patients’ gender, age, and calcium intake. Two patients reported fractures in the past and two reported family history of osteoporosis. Six patients had delayed puberty and one has hypogonadism. Seven patients have short stature. This data suggests that low bone mass is not only a problem in transfused thalassemia patients, but is also observed in non-transfused patients. The significance and pathophysiology of low bone mass should be studied further in non-transfused patient population, especially in younger children.

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