Race-specific FRAX models are evidence-based and support equitable care: a response to the ASBMR Task Force report on Clinical Algorithms for Fracture Risk.

Task Force on 'Clinical Algorithms for Fracture Risk' commissioned by the American Society for Bone and Mineral Research (ASBMR) Professional Practice Committee has recommended that FRAX® models in the US do not include adjustment for race and ethnicity. This position paper finds that an agnostic model would unfairly discriminate against the Black, Asian and Hispanic communities and recommends the retention of ethnic and race-specific FRAX models for the US, preferably with updated data on fracture and death hazards. In contrast, the use of intervention thresholds based on a fixed bone mineral density unfairly discriminates against the Black, Asian and Hispanic communities in the US. This position of the Working Group on Epidemiology and Quality of Life of the International Osteoporosis Foundation (IOF) is endorsed both by the IOF and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO).

[Actual treatment of osteoporosis].

Basing on European, American and Polish recommendation reviewed are strategy of treatment of osteoporosis. In Poland, rules of reimbursement reinforced general use of antiresorbtive drugs (bisphosponates, demosumab) in the treatment of osteoporosis. For effective therapy the key points are keeping the patient in the treatment and treatment monitoring with potential use of densitometry and bone markers.

A genome-wide copy number association study of osteoporotic fractures points to the 6p25.1 locus.

BACKGROUND: Osteoporosis is a systemic skeletal disease characterised by reduced bone mineral density and increased susceptibility to fracture; these traits are highly heritable. Both common and rare copy number variants (CNVs) potentially affect the function of genes and may influence disease risk. AIM: To identify CNVs associated with osteoporotic bone fracture risk. METHOD: We performed a genome-wide CNV association study in 5178 individuals from a prospective cohort in the Netherlands, including 809 osteoporotic fracture cases, and performed in silico lookups and de novo genotyping to replicate in several independent studies. RESULTS: A rare (population prevalence 0.14%, 95% CI 0.03% to 0.24%) 210 kb deletion located on chromosome 6p25.1 was associated with the risk of fracture (OR 32.58, 95% CI 3.95 to 1488.89; p = 8.69 × 10(-5)). We performed an in silico meta-analysis in four studies with CNV microarray data and the association with fracture risk was replicated (OR 3.11, 95% CI 1.01 to 8.22; p = 0.02). The prevalence of this deletion showed geographic diversity, being absent in additional samples from Australia, Canada, Poland, Iceland, Denmark, and Sweden, but present in the Netherlands (0.34%), Spain (0.33%), USA (0.23%), England (0.15%), Scotland (0.10%), and Ireland (0.06%), with insufficient evidence for association with fracture risk. CONCLUSIONS: These results suggest that deletions in the 6p25.1 locus may predispose to higher risk of fracture in a subset of populations of European origin; larger and geographically restricted studies will be needed to confirm this regional association. This is a first step towards the evaluation of the role of rare CNVs in osteoporosis.

Denosumab significantly increases DXA BMD at both trabecular and cortical sites: results from the FREEDOM study.

Denosumab is an approved therapy for postmenopausal women with osteoporosis at high or increased risk for fracture. In the FREEDOM study, denosumab reduced fracture risk and increased bone mineral density (BMD). We report the spine and hip dual-energy X-ray absorptiometry (DXA) BMD responses from the overall study of 7808 women and from a substudy of 441 participants in which more extensive spine and hip assessments as well as additional skeletal sites were evaluated. Significant BMD improvements were observed as early as 1 mo at the lumbar spine, total hip, and trochanter (all p<0.005 vs placebo and baseline). BMD increased progressively at the lumbar spine, total hip, femoral neck, trochanter, 1/3 radius, and total body from baseline to months 12, 24, and 36 (all p<0.005 vs placebo and baseline). BMD gains above the least significant change of more than 3% at 36 months were observed in 90% of denosumab-treated subjects at the lumbar spine and 74% at the total hip, and gains more than 6% occurred in 77% and 38%, respectively. In conclusion, denosumab treatment resulted in significant, early, and continued BMD increases at both trabecular and cortical sites throughout the skeleton over 36 mo with important gains observed in most subjects.

Guidelines for the diagnosis and management of osteoporosis in Poland. Update 2022.

Guidelines to provide an update of the previously published Polish recommendations for the management of women and men with osteoporosis have been developed in line with advances in medical knowledge, evidence-based data, and new concepts in diagnostic and therapeutic strategies. A Working Group of experts from the Multidisciplinary Osteoporosis Forum and from the National Institute of Geriatrics, Rheumatology, and Rehabilitation in Warsaw performed a thorough comprehensive review of current relevant publications in the field (including all age groups of people and management of secondary osteoporosis), and they evaluated epidemiological data on osteoporosis in Poland and the existing standards of care and costs. A voting panel of all co-authors assessed and discussed the quality of evidence to formulate 29 specific recommendations and voted independently the strength of each recommendation. This updated practice guidance highlights a new algorithm of the diagnostic and therapeutic procedures for individuals at high and very high fracture risk and presents a spectrum of general management and the use of medication including anabolic therapy. Furthermore, the paper discusses the strategy of primary and secondary fracture prevention, detection of fragility fractures in the population, and points to vital elements for improving management of osteoporosis in Poland.

Bone metabolism in cholestatic children before and after living-related liver transplantation--a long-term prospective study.

Bone disorders are common in children with end-stage liver diseases, especially those associated with cholestasis. Abnormal hepatocyte function, disordered vitamin D metabolism and calcium-phosphorous homeostasis, malnutrition, and immunosuppressive treatment are potential risk factors of bone tissue pathology before and after transplantation. The aim of the study was to analyze the long-term effect of successful living-related liver transplantation (LRLTx) on skeletal status and bone metabolism in cholestatic children. Eighteen cholestatic children (1.4±0.5yr old; 12 females [F]/6 males [M]) qualified for LRLTx were analyzed; 16 (5F/11M) of them participated in long-term observation (V4). Serum levels of osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), cross-linked telopeptide of type 1 collagen (CTx), insulin-like growth factor I (IGF-I), IGF-I binding protein 3 (IGFBP-3), parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), and 1,25-dihydroxyvitamin D (1,25(OH)(2)D) were assayed before (V0) and 6mo (V1), 12mo (V2), 18mo (V3), and 4.4yr (V4) after LRLTx. Total body bone mineral content (TBBMC) and total body bone mineral density (TBBMD) were measured by dual-energy X-ray absorptiometry (DXA) at the same pattern. Before LRLTx, the OC, P1NP, CTx, IGF-I, and IGFBP-3 levels as well as TBBMC and TBBMD were decreased compared with age-matched control group. The mean serum levels of 25(OH)D and 1,25(OH)(2)D were within reference ranges from V0 to V4. After LRLTx, the OC, P1NP, CTx, IGF-I, and IGFBP-3 as well as TBBMC and TBBMD reached the age-matched reference values. At V4, the level of P1NP decreased below and the PTH increased above the reference range that coincided with reduced Z-scores of both TBBMC (-1.11±1.24) and TBBMD (-1.00±1.19). P1NP and CTx, both measured at V3, correlated with IGF-I at V2 (R=0.86, p=0.014 and R=0.78, p=0.021, respectively) and PTH at V3 for P1NP and V1 for CTx (R=0.64, p=0.048 and R=0.54, p=0.038, respectively). The TBBMC changes between V0 and V4 correlated with IGF-I (R=0.68, p=0.015) and 1,25(OH)(2)D (R=0.54, p=0.025), both assayed at V1. The change of TBBMC Z-scores between V0 and V4 correlated with P1NP at V1 (R=0.69, p=0.002). The TBBMD changes between V0 and V4 correlated with CTx at V1 (R=0.54, p=0.027) and P1NP change between V0 and V1 (R=0.51, p=0.038). In short-term observation, successful LRLTx led to bone metabolism normalization triggered by probable anabolic action of IGF-I and PTH and manifested by TBBMC and TBBMD increases. In long-term horizon, moderately impaired DXA assessed bone status coincided with disturbances in bone metabolism. Bone metabolism markers, especially P1NP and CTx, appeared to be good predictors of changes in bone status evaluated by DXA.

[Pathologies of calcium-phosphate homeostasis]. / Patologie zwiazane z gospodarka wapniowo-fosforanowa.

The colossal progress in understanding of vitamin D and phosphate metabolism introduces new perspectives in chronic kidney disease (CKD) therapy. Increasing demand for phosphate excretion per nephron triggers the vicious cycle that leads to increase in FGF-23 and PTH and decrease in vitamin D and Klotho. Restriction of dietary phosphate intake (low phosphate diet) and administration of phosphate binder can be regarded as the most important interventions in this case. Because the vicious cycle is likely activated long before hyperphosphatemia occurs during CKD progression, phosphate restriction would have been more effective if started before serum phosphate levels increased, perhaps as soon as serum FGF-23 levels rose. Phosphate restriction alleviates phosphate overload per nephron and can disrupt the vicious cycle: phosphate restriction can reduce serum FGF-23 levels and increase vitamin D, which in turn increase Klotho expression in kidney and parathyroid glands. Inhibitors of rennin-angiotensin system (rosiglitazone, angiotensin-converting enzyme inhibitors) and proper vitamin D supplementation may also up-regulate Klotho expression. Increased Klotho in the kidney may improve FGF-23 sensitivity, which further reduce the amount of FGF-23 required for excreting a given amount of phosphate. Increased Klotho in parathyroid may improve the ability of FGF-23 to suppress PTH. Proper supplementation with vitamin D increase the concentration of substrate for local 1,25(OH)2D synthesis 25(OH)D, which directly suppress PTH, increase Klotho, and decrease FGF-23 by proanabolic action on bone. Improving vitamin D status by inhibition of CYP24A is also under evaluation, as well as antibodies against FGF-23, as modern therapies in CKD.

Vitamin D supplementation and status in infants: a prospective cohort observational study.

OBJECTIVE: Vitamin D status in infants depends on supplementation. We examined the vitamin D status in relation to supplementation dose and scheme in infants. PATIENTS AND METHODS: One hundred thirty-four infants age 6 months and 98 infants age 12 months (drop out 27%) were investigated. Vitamin D intake (diet, supplements), anthropometry, and 25-hydroxyvitamin D (25-OHD) serum concentration at the 6th and 12th months were assessed. RESULTS: Vitamin D intake of 1062 ± 694 IU at the 6th month was not different from that at the 12th month (937 ± 618 IU). Vitamin D intake expressed in international units per kilogram of body weight decreased from 141 ± 80 IU/kg at the 6th month to 93 ± 62 IU/kg at the 12th month (P < 0.0001), which was associated with a reduction in 25-OHD from 43 ± 20 ng/mL to 29 ± 12 ng/mL, respectively (P < 0.0001). In the subgroup of everyday supplemented infants (n = 43), vitamin D intake decreased from 143 ± 88 IU/kg at the 6th month to 118 ± 60 IU/kg at the 12th month (P < 0.05), which coincided with a reduction of 25-OHD from 40 ± 19 ng/mL to 32 ± 13 ng/mL (P < 0.01). In the subgroup with variable supplementation habits (n = 32), vitamin D intake decreased from 146 ± 79 IU/kg to 77 ± 56 IU/kg (P < 0.001), which was associated with a reduction of 25-OHD from 42 ± 21 ng/mL to 25 ± 8 ng/mL (P < 0.0001). 25-OHD concentration change between the 6th and the 12th months negatively correlated with the 25-OHD level assessed at the 6th month (r = -0.82; P < 0.0001). CONCLUSIONS: Vitamin D supplementation of infants should consider their rapid body weight increment. We postulate vitamin D daily dose close to 100 IU/kg body weight as favorable for infants up to age 12 months.

The evaluation of consistency between body composition assessments in pediatric population using pencil beam and fan beam dual-energy x-ray absorptiometers.

The replacement of the old dual-energy X-ray absorptiometry system with a novel one should be preceded by a cross-calibration procedure. Therefore, the study was aimed at investigating the consistency of bone and body composition measures performed in pediatric population using pencil beam (DPX-L; GE Healthcare, GE Healthcare, Madison, WI) and fan beam (Prodigy; GE Healthcare, GE Healthcare, Madison, WI) densitometers. The study group consisted of 212 healthy children aged 4-18yr. Total body (TB) and lumbar spine (S) (L2-L4) measurements were performed using DPX-L and Prodigy during the same visit. Bland-Altman analysis, linear regressions, and paired t-test were performed to evaluate the consistency of measurements and to establish a cross-calibration equation. The average Prodigy values for TB and lumbar spine bone mineral density (BMD) and content (BMC) were 2.7%, 2.4% and 1.6%, 1.6% higher than those of DPX-L, respectively (p<0.0001). Prodigy-assessed bone area (BA) was lower by 1.4% for TBBA (p<0.0001) and 1.1% for SBA (p<0.001). Lean body mass (LBM) from Prodigy was higher by 6.9% (p<0.0001), whereas fat mass (FM) was lower by 8.4% compared with those from DPX-L (p<0.0001). Bland-Altman analyses revealed the effect of magnitude that was nonlinear (2nd degree polynomial) for TBBMD (r=0.32, p=0.001), TBBMC (r=0.51, p<0.0001), TBBA (r=0.34, p<0.0001), and LBM (r=0.56, p<0.0001), but not for FM (r=0.14, not significant [n.s.]). In contrast, in lumbar spine, the magnitude dependence was linear and significant for SBMC (r=0.46, p<0.0001) and SBA (r=0.34, p<0.0001) but not for SBMD (r=0.12, n.s.). Both skeletal and body composition variables assessed by DPX-L and Prodigy devices were highly correlated, showing R(2) values ranging from 0.976 for FM to 0.994 for SBMC. The results of this study document a necessity for implementation of calculated cross-calibration equations to transform DPX-L-based local pediatric references into a novel Prodigy system.

[Prophylaxis of vitamin D deficiency--Polish recommendation 2009]. / Stanowisko Zespolu Ekspertów. Polskie zalecenia dotyczace profilaktyki niedoborów witaminy D - 2009.

Adequate vitamin D intake and its status are important not only for bone health and Ca-P metabolism, but for optimal function of many organs and tissues throughout the body. Due to documented changes in dietary habits and physical activity level, both observed in growing children and adults, the prevalence of vitamin D insufficiency is continuously increasing. Basing on current literature review and opinions of National Consultants and experts in the field, polish recommendations for prophylactic vitamin D supplementation in infants, toddlers, children and adolescents as well as in adults, including pregnant and lactating women have been established.

[Prophylaxis of vitamin D deficiency--Polish recommendations 2009]. / Polskie zalecenia dotyczace profilaktyki niedoborów witaminy D--2009.

Appropriate state procurement system for vitamin D is important not only for the proper functioning of the skeletal, maintaining calcium and phosphorus homeostasis, but also for a number of other organs and tissues in our body. In connection with the change in lifestyle including dietary habits change, the widespread use of UV filters and less outdoor activity, observed an increase in the percentage of vitamin D deficiency, both in population and developmental age and adults. Based on the results of recent scientific research team of experts provides recommendations for preventive Polish supply of vitamin D in infants, children, adolescents and adults, including pregnant women and nursing mothers.

[Mechanisms of action of anticatabolic drugs used in osteoporosis therapy]. / Mechanizmy dzialania leków antykatabolicznych stosowanych w osteoporozie.

Bone remodeling is essential for skeletal and the whole body health. Imbalance in skeletal turnover, so that bone resorption exceeds bone formation, may lead to reduction in bone strength and increase fractures risk. The main target of anticatabolic therapy is to normalize increased osteoclasts activity and bone turnover. Molecular mechanisms of action of this class of drugs are related with different points in cellular signaling pathways that control osteoclasts differentiation and resorbing activity. These mechanisms are briefly described in our review.

Critical points in strategies for the diagnosis and treatment of osteoporosis.

Current treatment decisions for osteoporosis depend on the fracture risk calculated based on the results of comprehensive diagnostic procedures [clinical risk factors (CRF), densitometry (BMD), morphometry, and bone turnover markers (BTM)]. Recently developed fracture risk assessment tool (FRAX) represents an important new achievement as a 10-year fracture risk calculation based on femoral neck densitometry and age combined with independent clinical fracture risk factors. FRAX presents several options: FRAX BMI (body mass index) is advocated as a helpful screening tool to identify the group of patients with high fracture risk, independently of access to densitometry and FRAX, utilizing hip densitometry. In both cases, the probability of major fractures or hip fractures are calculated during performed diagnostic evaluations. Operating FRAX algorithm does not include spinal bone mineral density, which is its main limitation. With the aim of improvement of anti-fracture efficacy of therapeutic management of osteoporosis, we have extended our discussion to three integral elements of existent strategy: 1) screening outlines, 2) principles of drug selection, and 3) treatment benefit evaluation. Since osteoporosis is a chronic disease, long-term adherence to the treatment is important. The suitability of the drug, the patient's preference, tolerability, and convenience should all be considered. Anti-catabolic drugs are most appropriate in patients with high bone turnover, while anabolic drugs demonstrate efficacy irrespective of bone turnover. BMD measurement is most widely used for long-term assessment of the efficacy of osteoporosis treatment. The measurements of bone turnover markers (BTMs) can be considered a useful shortterm (at 3 months) monitoring tool in selected patients. In both BTM and BMD, the least significant change (LSC) method should be used for interpretation of the results. Fractures are not a reliable clinical endpoint for evaluating the effectiveness of therapy in individual patients because of their stochastic nature. If fractures occur, however, the need for drug change and additional non-pharmacological treatment (fall prevention, balance training, muscle strengthening) should always be considered.

Dual energy X-ray absorptiometry interpretation and reporting in children and adolescents: the 2007 ISCD Pediatric Official Positions.

The International Society for Clinical Densitometry Official Positions on reporting of densitometry results in children represent an effort to consolidate opinions to assist healthcare providers determine which skeletal sites should be assessed, which adjustments should be made in these assessments, appropriate pediatric reference databases, and elements to include in a dual energy X-ray absorptiometry (DXA) report. Skeletal sites recommended for assessment are the lumbar spine and total body less head, the latter being valuable as it provides information on soft tissue, as well as bone. Interpretation of DXA findings in children with growth or maturational delay requires special consideration; adjustments are required to prevent erroneous interpretation. Normative databases used as a reference should be based on a large sample of healthy children that characterizes the variability in bone measures relative to gender, age, and race/ethnicity, and should be specific for each manufacturer and model of densitometer and software. Pediatric DXA reports should provide relevant demographic and health information, technical details of the scan, Z-scores, and should not include T-scores. The rationale and evidence for development of the Official Positions are provided. Given the sparse data currently available in many of these areas, it is likely that these positions will change over time as new data become available.

Feasibility of simultaneous measurement of bone formation and bone resorption markers to assess bone turnover rate in postmenopausal women: an EPOLOS study.

BACKGROUND: One of the most important risk factors for osteoporotic fractures in postmenopausal women is elevated bone turnover (EBT), occurring in 25-30% of this population. This study's aim was to find a correlation between bone resorption and bone formation markers to assess bone turnover rate and qualify an individual postmenopausal woman as a possible EBT subject. MATERIAL/METHODS: Three hundred twenty postmenopausal women (> or = one year after the last menstruation, < or = 70 years old) were enrolled at seven clinical sites in this cross-sectional observational study conducted within the EPOLOS. The group was a random sample of the population. The study was performed in a referral center involved in the diagnosis and treatment of osteoporosis. The exclusion criteria included pregnancy, cancer, fracture in the last year, and overweight (> 100 kg). Bone mineral density (BMD) measurements of the lumbar spine, total hip, trochanter, and femoral neck regions were performed. Bone resorption and formation rates were evaluated by serum levels of C-terminal telopeptide of type I collagen (CTX) and osteocalcin (OC), respectively. RESULTS: Using logistic regression to correlate the concentrations of CTX and OC it was possible not only to distinguish the EBT subgroup, but also to construct a simple nomogram for easy classification of individual patients as possible EBT subjects. EBT patients showed generally decreased BMD values and increased bone formation and resorption rates. CONCLUSIONS: Evaluation of both CTX and OC levels enables a more proper indication for EBT. The proposed nomogram may assist in evaluating outcome from the two markers of bone turnover.

Skeletal and muscular status in juveniles with GFD treated clinical and newly diagnosed atypical celiac disease--preliminary data.

Undiagnosed and untreated celiac disease (CD) constitutes an increasing skeletal health problem due to its association with low bone density and fractures. Examinations of skeletal status in children using dual-energy X-ray absorptiometry (DXA) are prone to size-related misinterpretation. In contrary, the analysis of muscle-bone relationship seems to limit a possibility of misdiagnosis because skeletal status is evaluated from the functional perspective. The study was aimed to assess skeletal status of children suffering from CD with the use of muscle-bone functional algorithm. The study group comprised 29 celiac patients (13.7yr+/-2.9) on gluten-free diet (GFD), and 24 newly diagnosed atypical celiac patients, including subgroup with normal height (n=14; 12.6yr+/-3.9) and subgroup with short stature (n=10; 12.2yr+/-2.9). Muscular and skeletal status was evaluated by DXA (DPX-L, GE). Anthropometry, total body bone mineral density (TBBMD, g/cm(2)). and total body bone mineral content (TBBMC, g) as well as lean body mass (LBM, g) were evaluated. Muscle-bone interactions were estimated using TBBMC/LBM ratio. Previously established references for healthy controls were used for the calculation of Z-scores (age-matched) and SD-scores (height-matched). GFD treated celiacs and atypical celiacs with normal body height had TBBMD, TBBMC, LBM, and TBBMC/LBM ratio Z-scores and SD-scores within normal range for healthy controls. In contrary, atypical celiacs with short stature had significantly lower Z-scores for TBBMD (-2.3+/-0.4), TBBMC (-2.1+/-0.3), LBM (-1.4+/-0.3). and TBBMC/LBM ratio (-2.3+/-0.6) when compared to respective values observed in GFD treated celiacs (p<0.001, p<0.001, p<0.05, p<0.01) and atypical celiacs with normal height (p<0.01, p<0.01, p<0.05, p<0.01). When body-height matching of DXA data was used to limit the influence of body size, the atypical celiacs with short stature had SD-scores for TBBMD (-1.3+/-0.7), TBBMC (-1.3+/-0.6), and LBM (+0.8+/-0.3) not significantly different from the corresponding SD-scores obtained in the remaining 2 groups. Nevertheless, short stature in atypical celiacs still coincided with significantly lower TBBMC/LBM ratio SD-score of -1.9+/-0.7 when compared to values observed in GFD treated celiacs (+0.04+/-0.2; p<0.05) and atypical celiacs with normal height (-0.4+/-0.2; p<0.05). GFD regime in classic celiacs corresponded with physiological values of DXA assessed indicators of bone and muscle status as well as normal muscle-bone interactions. Untreated atypical celiacs may present a broad spectrum of heterogeneous abnormalities from normal to markedly depressed TBBMC/LBM ratio values pointing on the marked imbalance between TBBMC and LBM.

Metabolic bone disease in children : etiology and treatment options.

Metabolic bone disease in children includes many hereditary and acquired conditions of diverse etiology that lead to disturbed metabolism of the bone tissue. Some of these processes primarily affect bone; others are secondary to nutritional deficiencies, a variety of chronic disorders, and/or treatment with some drugs. Some of these disorders are rare, but some present public health concerns (for instance, rickets) that have been well known for many years but still persist. The most important clinical consequences of bone metabolic diseases in the pediatric population include reduced linear growth, bone deformations, and non-traumatic fractures leading to bone pain, deterioration of motor development and disability. In this article, we analyze primary and secondary osteoporosis, rickets, osteomalacia (nutritional and hereditary vitamin D-dependent, hypophosphatemic and that due to renal tubular abnormalities), renal osteodystrophy, sclerosing bony disorders, and some genetic bone diseases (hypophosphatasia, fibrous dysplasia, skeletal dysplasia, juvenile Paget disease, familial expansile osteolysis, and osteoporosis pseudoglioma syndrome). Early identification and treatment of potential risk factors is essential for skeletal health in adulthood. In most conditions it is necessary to ensure an appropriate diet, with calcium and vitamin D, and an adequate amount of physical activity as a means of prevention. In secondary bone diseases, treatment of the primary disorder is crucial. Most genetic disorders await prospective gene therapies, while bone marrow transplantation has been attempted in other disorders. At present, affected patients are treated symptomatically, frequently by interdisciplinary teams. The role of exercise and pharmacologic therapy with calcium, vitamin D, phosphate, bisphosphonates, calcitonin, sex hormones, growth hormone, and thiazides is discussed. The perspectives on future therapy with insulin-like growth factor-1, new analogs of vitamin D, strontium, osteoprotegerin, and calcimimetics are presented.

Evaluation of practical use of bone age assessments based on DXA-derived hand scans in diagnosis of skeletal status in healthy and diseased children.

The assessment of bone age is an important factor for the analysis of skeletal maturity, growth, and its aberrations. The classical method of bone age estimations is based on the recognition of changes in the radiographic appearance of the maturity indicators in hand-wrist radiographs by comparison with reference atlas. To apply bone age assessments, based on dual-energy X-ray absorptiometry (DXA)-derived hand scans, in the evaluation of skeletal status, 151 healthy children (4-18 yr old) and 61 with bone disorders (5-20 yr old) were investigated. All measurements were performed using Expert-XL and DPX-L densitometers (GE Lunar). Hand densitometry performed by the Expert-XL machine was used for the evaluation of bone age. Total-body measurements were performed using DPXL to calculate total-body bone mineral density (BMD) Z-score values as standard diagnostic parameters in pediatric densitometry and to verify diagnosis by taking into account assessed bone age. Strong correlations were found between BMD (g/cm2) and bone age in healthy children of both genders. We noted in several cases that low values of Z-scores (<-1) corresponded to delayed bone age in comparison to chronological age. After recalculation of BMD data according to bone age, a marked increase in Z-scores was noted, mainly in multihormonal pituitary-deficient subjects. It can be concluded that the use of hand densitometry in parallel with BMD measurements provide valuable information about skeletal maturation that leads to the improved diagnosis of skeletal status, especially in subjects with constitutional delay in growth.

Reference values for the indicators of skeletal and muscular status of healthy Polish children.

Dual-energy X-ray absorptiometry (DXA) results are affected by the growth- and maturation-based anthropometric variances during childhood and adolescence. To address this issue, anthropometric variables were implemented to normative DXA values for the total body (TB) and lumbar spine (S) data obtained from a cross-sectional sample of 562 healthy Caucasian children (278 females) aged 5 to 18 yr who were measured using a pencil-beam DXA device (DPX-L; GE Lunar). Across age or body height (BH) groups, female and male values for TB bone mineral content (TBBMC) (g), TB bone mineral density (TTBMD) (g/cm(2)), SBMC (g), SBMD (g/cm(2)), lean body mass (LBM) (g), TBBMD/LBM (g/g), and SBMC/LBM [(g/g) x 100)] were assessed and compared using ANOVA and t-tests. There was no gender difference in TBBMC until age 16 and in TBBMD until age 17; thereafter, male values were significantly higher. At 12 to 13 yr of age, female SBMD values were significantly higher than male. The BH matching revealed lack of major gender-related differences in TBBMC or TBBMD values across whole height range, whereas at heights of 150 to 175 cm, females had generally higher values of SBMC and SBMD than male counterparts. Further, the LBM values and calculated TBBMC/LBM and SBMC/LBM ratios were considered as the muscle and muscle-bone indicators, respectively. The muscle-bone relationship analysis using LBM and TBBMC/LBM and SBMC/LBM values revealed age- and BH-related differences between genders. At LBM values of 32 kg and above and ages 14 yr and above for the whole skeleton as well as 12 yr and above for spine segment, females accrued significantly more BMC for the LBM unit than males. In order to properly assess children who might be at risk for low bone mass, we provide reference values for BMC and BMD of usually studied sites, expanded by muscle-bone relationship indicators owing to reduced diagnostic errors and distinguished bone disorders.