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Bone Status (bone + status)
Selected AbstractsAn In Vitro Study of the Ultrasonic Axial Transmission Technique at the Radius: 1-MHz Velocity Measurements Are Sensitive to Both Mineralization and Intracortical Porosity,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2004Emmanuel Bossy Abstract The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Using synchrotron radiation ,CT, we investigated, in vitro, the relationships between 1-MHz axial transmission SOS measurements at the radius and site-matched measurements of C.Th, POR, MIN, and vBMD. Introduction: The ultrasonic axial transmission technique allows for investigating skeletal sites such as the cortical layer of long bones (radius, tibia, phalanges). Materials and Methods:Using synchrotron radiation ,CT, we investigated, in vitro, the relationships between 1-MHz axial transmission speed of sound (SOS) measurements at the radius and site-matched measurements of cortical thickness (C.Th), intracortical porosity (POR), tissue mineralization (MIN), and volumetric BMD (vBMD). SOS measurements were based on bidirectional axial transmission and were performed with a 1-MHz proprietary probe on 39 excised human radii. Results: The highest correlations between SOS values and bone parameters (R2SOS/POR = 0.28, p < 10,3; R2SOS/MIN = 0.38, p < 10,4; R2SOS/vBMD = 0.57, p < 10,3) were found for bone parameters assessed in a 1-mm-thick periosteal region of the cortex rather than throughout the whole cortex. The observed moderate correlation between SOS and C.Th values (R2SOS/C.Th = 0.20, p < 10,2) disappeared when controlled for other variables. The two best multilinear predictive models, including either BMD alone or the pair of dependent variables MIN and POR (all assessed in the periosteal cortex), were equally accurate in predicting SOS values (R2SOS/(POR,MIN) = 0.59, p < 10,5; R2SOS/vBMD = 0.57, p < 10,5). Conclusion: For the first time, the respective adjusted contributions of POR (,24 m/s%,1) and tissue mineralization (+3.5 m/s/mg/cm,3) to SOS values were assessed. These results suggest potential sensitivity of axial transmission SOS values to changes in cortical bone status under different pathological conditions or treatments affecting POR and/or tissue mineralization. [source] Adrenarche and Bone Modeling and Remodeling at the Proximal Radius: Weak Androgens Make Stronger Cortical Bone in Healthy Children,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003Thomas Remer Abstract Adrenarche, the physiological increase in adrenal androgen secretion, may contribute to better bone status. Proximal radial bone and 24-h urinary steroid hormones were analyzed cross-sectionally in 205 healthy children and adolescents. Positive adrenarchal effects on radial diaphyseal bone were observed. Obviously, adrenarche is one determinant of bone mineral status in children. Introduction: Increased bone mass has been reported in several conditions with supraphysiological adrenal androgen secretion during growth. However, no data are available for normal children. Therefore, our aim was to examine whether adrenal androgens within their physiological ranges may be involved in the strengthening of diaphyseal bone during growth. Methods: Periosteal circumference (PC), cortical density, cortical area, bone mineral content, bone strength strain index (SSI), and forearm cross-sectional muscle area were determined with peripheral quantitative computed tomography (pQCT) at the proximal radial diaphysis in healthy children and adolescents. All subjects, aged 6,18 years, who collected a 24-h urine sample around the time of their pQCT analysis (100 boys, 105 girls), were included in the present study, and major urinary glucocorticoid (C21) and androgen (C19) metabolites were quantified using gas chromatography-mass spectrometry. Results and Conclusions: We found a significant influence of muscularity, but not of hormones, on periosteal modeling (PC) before the appearance of pubic hair (prepubarche). Similarly, no influence of total cortisol secretion (C21) was seen on the other bone variables. However, positive effects of C19 on cortical density (p < 0.01), cortical area (p < 0.001), bone mineral content (p < 0.001), and SSI (p < 0.001),reflecting, at least in part, reduction in intracortical remodeling,were observed in prepubarchal children after muscularity or age had been adjusted for. This early adrenarchal contribution to proximal radial diaphyseal bone strength was further confirmed for all cortical variables (except PC) when, instead of C19 and C21, specific dehydroepiandrosterone metabolites were included as independent variables in the multiple regression model. During development of pubic hair (pubarche), muscularity and pubertal stage rather than adrenarchal hormones seemed to influence bone variables. Our study shows that especially the prepubarchal increase in adrenal androgen secretion plays an independent role in the accretion of proximal radial diaphyseal bone strength in healthy children. [source] Total body bone measurements: A cross-sectional study in children with acute lymphoblastic leukemia during and following completion of therapyPEDIATRIC BLOOD & CANCER, Issue 1 2009Kara M. Kelly MD Abstract Background Abnormalities in bone mineral density (BMD) occur in children treated for acute lymphoblastic leukemia (ALL). However, BMD estimates have been performed using varied instruments, reference data, and interpretations. This exploratory cross sectional study to evaluate bone mass in children with ALL, uses an algorithm that serially adjusts for variables known to affect pediatric bone measures by dual energy X-ray absorptiometry (DXA), based on models developed in 1,218 healthy children and adolescents. Procedure Anthropometry, DXA scans, and factors with possible influence on bone mass were evaluated in 21 ALL patients receiving chemotherapy and 20 in the follow-up phase. Main outcome was treatment group differences in Z -scores for total body bone mineral content (BMC), bone area (Area), and areal BMD (aBMD). Results Mean Z -scores for the entire study population for BMC, Area, and aBMD were significantly less than zero. Among possible contributing factors, only calcium intake was a significant co-variate. Comparison between treatment groups showed that least-square mean Z -scores for patients on-therapy for at least 12 months were significantly lower than those off therapy for at least 12 months (P: 0.0008,0.044), except for BMC at last step of the algorithm (adjusted for sex, age, ethnicity, height, weight, and bone area). Conclusions Evaluation of total body DXA by this algorithm is consistent with better general bone status in those off-therapy. However, in this small exploratory study, the lack of significant difference between Z -scores for fully adjusted BMC in on- versus off-therapy groups suggests possible risk of low peak bone mass. Additional longitudinal evaluation is warranted. Pediatr Blood Cancer 2009;52:33,38. © 2008 Wiley-Liss, Inc. [source] The relationship between circulating osteoprotegerin levels and bone mineral metabolism in healthy womenCLINICAL ENDOCRINOLOGY, Issue 2 2004Ki Won Oh Summary objective, Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the RANK ligand. Moreover, OPG has been shown to be an important inhibitor of osteoclastogenesis in animal models. However, the relationship between circulating OPG levels and female bone status in human populations is unclear. In this study we undertook to investigate the relationship between circulating OPG levels and bone mineral metabolism in healthy women. patients and measurements, Our subjects were 287 women aged 37,73 years (mean age 51·5 years). The serum concentrations of OPG were determined by enzyme-linked immunosorbent assay (ELISA). The biochemical markers of bone turnover and FSH were measured using standard methods. Bone mineral densities at the lumbar spine and femoral neck were measured by dual-energy X-ray absorptiometry. results, Postmenopausal women had a significantly higher mean value of serum OPG than premenopausal women (1358·5 ± 32·5 pg/ml vs. 1228·8 ± 33·3 pg/ml, P < 0·01). Serum OPG levels were positively correlated with age (r = 0·169, P < 0·01), as were urine deoxypyridinoline levels (r = 0·133, P < 0·05) and serum FSH levels (r = 0·187, P < 0·01) in a bivariate correlation analyses. In a multiple regression analysis, only urine calcium excretion was identified as a significant predictor for serum OPG levels. conclusions, Circulating OPG levels were found to be associated with urine calcium excretion and menopause in healthy women. Our observations suggest that circulating OPG levels reflect an antiresorptive activity in bone, and they are related to endogenous oestrogen levels. [source] Refinement of an osteoporosis risk-assessment questionnaire for use in community pharmacyINTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 5 2008Lee Ser Poh pharmacy practice advanced student Objective To explore the influence of bone mineral density (BMD) tests in osteoporosis risk categorisation in community pharmacies, and to develop a simple tool for pharmacists to use as a pre-BMD test screen. Method A secondary data analysis was conducted on the responses of 193 participants to a risk-assessment questionnaire, used in previous osteoporosis research that included a BMD test. To explore the impact of the BMD test on pharmacists' categorisation of risk, the researchers made an independent assessment based on responses of the questionnaire. The influence of risk factors on BMD scores/bone status was explored using multiple and logistic regression respectively. Key findings A total of responses of 193 participants were available for study, with 113 in the BMD group and 80 from the non-BMD group. In the BMD group, both researchers and pharmacists identified a similar proportion of patients in the moderate/high-risk category when BMD results were incorporated in the risk assessments (X2 = 0.78, degrees of freedom (df) = 1, 0.3 < P < 0.5). A statistically significant difference in risk categorisation was found between the pharmacists and researchers in the non-BMD group (X2 = 23.9, df = 1, P < 0.001). Risk factors identified to be significantly affecting BMD and of use for identifying patients at high risk for osteopenia/osteoporosis were age, weight, postmenopause and absence of hormone replacement therapy (HRT). These four factors were used to construct a simple risk index to guide pharmacists' initial risk categorisation. Conclusion The findings of this study suggested that BMD testing may increase the effectiveness of risk assessments and enhance the screening procedures in the community pharmacy. The simple risk index could serve as a pre-BMD test screen, with a BMD test recommended when necessary. A refined risk-assessment questionnaire could serve to guide pharmacists in directing individualised counselling and advice for at-risk patients, through identification of modifiable risk factors and conditions. [source] | ||||||||||