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Bone Mass Gain (bone + mass_gain)
Selected AbstractsChildhood Fractures Are Associated With Decreased Bone Mass Gain During Puberty: An Early Marker of Persistent Bone Fragility?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2006Serge L Ferrari MD Abstract Whether peak bone mass is low among children with fractures remains uncertain. In a cohort of 125 girls followed over 8.5 years, 42 subjects reported 58 fractures. Among those, BMC gain at multiple sites and vertebral bone size at pubertal maturity were significantly decreased. Hence, childhood fractures may be markers of low peak bone mass acquisition and persistent skeletal fragility. Introduction: Fractures in childhood may result from a deficit in bone mass accrual during rapid longitudinal growth. Whether low bone mass persists beyond this period however remains unknown. Materials and Methods: BMC at the spine, radius, hip, and femur diaphysis was prospectively measured over 8.5 years in 125 girls using DXA. Differences in bone mass and size between girls with and without fractures were analyzed using nonparametric tests. The contribution of genetic factors was evaluated by mother-daughter correlations and that of calcium intake by Cox proportional hazard models. Results: Fifty-eight fractures occurred in 42 among 125 girls (cumulative incidence, 46.4%), one-half of all fractures affecting the forearm and wrist. Girls with and without fractures had similar age, height, weight. and calcium intake at all time-points. Before and during early puberty, BMC and width of the radius diaphysis was lower in the fracture compared with no-fracture group (p < 0.05), whereas aBMD and BMAD were similar in the two groups. At pubertal maturity (Tanner's stage 5, mean age ± SD, 16.4 ± 0.5 years), BMC at the ultradistal radius (UD Rad.), femur trochanter, and lumbar spine (LS), and LS projected bone area were all significantly lower in girls with fractures. Throughout puberty, BMC gain at these sites was also decreased in the fracture group (LS, ,8.0%, p = 0.015; UD Rad., ,12.0%, p = 0.004; trochanter, ,8.4%, p = 0.05 versus no fractures). BMC was highly correlated between prepuberty and pubertal maturity (R = 0.54,0.81) and between mature daughters and their mothers (R = 0.32,0.46). Calcium intake was not related to fracture risk. Conclusions: Girls with fractures have decreased bone mass gain in the axial and appendicular skeleton and reduced vertebral bone size when reaching pubertal maturity. Taken together with the evidence of tracking and heritability for BMC, these observations indicate that childhood fractures may be markers for low peak bone mass and persistent bone fragility. [source] Bone Health in Children and Adolescents After Renal Transplantation,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2009Helena Valta MD Abstract The basis for lifelong bone health is established in childhood and adolescence. Whereas pediatric renal transplant (RTx) patients are at risk for impaired bone mass gain and fractures, scarce data on this subject are available. We performed a cross-sectional and longitudinal study of bone health in a national cohort of 106 pediatric RTx patients (median age, 12.6 yr; median follow-up, 5.1 yr after RTx). The patients underwent clinical evaluation, DXA for BMD, and spinal imaging for vertebral fractures. In longitudinal analysis, the median lumbar spine BMD Z-score was lowest (median, ,1.0) at 1 yr postoperatively but increased to a peak value of ,0.2 at 5 yr. In boys, the lumbar spine BMD Z-score increased also during puberty but decreased in girls. In cross-sectional analysis, the lumbar spine, hip, and whole body BMD Z-scores were < ,2 SD in 4%, 6%, and 6% of the patients, respectively. Sixteen percent had sustained peripheral fractures, and 8% had vertebral fractures. Female sex and age >15 yr (OR, 56.26; 95% CI, 5.17,611.82; p = 0.0007) as well as high plasma PTH levels (OR, 4.03; 95% CI, 1.37,11.85; p = 0.009) were significant predictors for low BMD. Three-year cumulative glucocorticoid dose, outside the immediate post-RTx years, was not associated with BMD parameters. The observed BMD results were satisfactory. However, the high (8%) prevalence of vertebral fractures warrants careful evaluation of bone health in these patients. [source] Childhood Fractures Are Associated With Decreased Bone Mass Gain During Puberty: An Early Marker of Persistent Bone Fragility?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2006Serge L Ferrari MD Abstract Whether peak bone mass is low among children with fractures remains uncertain. In a cohort of 125 girls followed over 8.5 years, 42 subjects reported 58 fractures. Among those, BMC gain at multiple sites and vertebral bone size at pubertal maturity were significantly decreased. Hence, childhood fractures may be markers of low peak bone mass acquisition and persistent skeletal fragility. Introduction: Fractures in childhood may result from a deficit in bone mass accrual during rapid longitudinal growth. Whether low bone mass persists beyond this period however remains unknown. Materials and Methods: BMC at the spine, radius, hip, and femur diaphysis was prospectively measured over 8.5 years in 125 girls using DXA. Differences in bone mass and size between girls with and without fractures were analyzed using nonparametric tests. The contribution of genetic factors was evaluated by mother-daughter correlations and that of calcium intake by Cox proportional hazard models. Results: Fifty-eight fractures occurred in 42 among 125 girls (cumulative incidence, 46.4%), one-half of all fractures affecting the forearm and wrist. Girls with and without fractures had similar age, height, weight. and calcium intake at all time-points. Before and during early puberty, BMC and width of the radius diaphysis was lower in the fracture compared with no-fracture group (p < 0.05), whereas aBMD and BMAD were similar in the two groups. At pubertal maturity (Tanner's stage 5, mean age ± SD, 16.4 ± 0.5 years), BMC at the ultradistal radius (UD Rad.), femur trochanter, and lumbar spine (LS), and LS projected bone area were all significantly lower in girls with fractures. Throughout puberty, BMC gain at these sites was also decreased in the fracture group (LS, ,8.0%, p = 0.015; UD Rad., ,12.0%, p = 0.004; trochanter, ,8.4%, p = 0.05 versus no fractures). BMC was highly correlated between prepuberty and pubertal maturity (R = 0.54,0.81) and between mature daughters and their mothers (R = 0.32,0.46). Calcium intake was not related to fracture risk. Conclusions: Girls with fractures have decreased bone mass gain in the axial and appendicular skeleton and reduced vertebral bone size when reaching pubertal maturity. Taken together with the evidence of tracking and heritability for BMC, these observations indicate that childhood fractures may be markers for low peak bone mass and persistent bone fragility. [source] Climbing Exercise Increases Bone Mass and Trabecular Bone Turnover Through Transient Regulation of Marrow Osteogenic and Osteoclastogenic Potentials in Mice,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003Toshiharu Mori Abstract To investigate the relationship between the effects of bone turnover and bone marrow cell development in bone cells, we developed a mouse voluntary climbing exercise model. Climbing exercise increased bone volume and transient osteogenic potential of bone marrow. This model would be suitable for investigating the mechanistic roles of mechanical loading. Introduction: The relationship between bone mass gain and local bone formation and resorption in mechanically loaded bone is not well understood. Materials and Methods: Sixty-five C57BL/6J mice, 8 weeks of age, were assigned to five groups: a baseline control and two groups each of ground control and climbing exercise mice for 2 and 4 weeks. Mice were housed in a 100-cm tower and had to climb toward a bottle placed at the top to drink water. Results: Compared with the ground control, bone mineral density of the left femur increased in the climbing mice at 4 weeks. At 2 and 4 weeks, bone formation rate (BFR/BS) of periosteal surface, the cross-sectional area, and moment of inertia were increased in the climbing mice, whereas BFR/BS and eroded surface (ES/BS) of endosteal surface did not differ. The trabecular bone volume (BV/TV) of the proximal tibia increased in climbing mice, and osteoclast surface (Oc.S/BS) and osteoclast number decreased at 2 weeks. At 4 weeks, there were increases in BV/TV and parameters of bone formation, including mineralized surface, mineral apposition rate, and bone formation rate. In marrow cell cultures from the tibia, the number of alkaline phosphatase+ colony forming units-fibroblastic and the area of mineralized nodule formation in climbing mice were increased, and the number of osteoclast-like TRACP+ multinucleated cells was lower at 2 weeks. At 4 weeks, these parameters recovered to the levels of the ground controls. Conclusion: Our results indicate that climbing increased trabecular bone volume and reduced bone resorption, with a subsequent increase in bone formation. Intermittent climbing downregulates marrow osteoclastogenic cells and upregulates osteogenic cells initially, but further exercise seemed to desensitize them. Cortical envelopes were enlarged earlier, but the response seems to differ from trabecular bone. [source] Impaired Bone Health in Adolescents After Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2008H. Valta Long-term complications related to immunosuppressive medication are an important problem after liver transplantation (OLT). This study was carried out to evaluate the bone health and risk factors for osteoporosis and fractures in 40 pediatric liver transplant recipients. The results of 208 longitudinal bone mineral density (BMD) measurements were analyzed retrospectively. In addition, a dual-energy X-ray absorptiometry was performed to assess the bone mineral content more precisely and to detect subclinical vertebral fractures (VF). The median age of the patients was 14 years and mean postoperative follow-up 7.0 years. The results showed that over half (58%) had lumbar spine (LS) Z-score ,,1.0 and one-fifth (18%) had asymptomatic VF. LS Z-score tended to increase from the first year after OLT, but during puberty the bone mass gain was suboptimal and Z-scores decreased in some subjects. Patients with VF were older at the time of OLT (p = 0.002) and their LS Z-score was lower (p = 0.001). Children transplanted before 10 years of age had less VF (p = 0.004) and higher LS Z-score (p = 0.005) than older patients. In conclusion, adolescent liver recipients are prone to osteoporosis and prevention should be targeted especially to this age group. [source] |