Prevention Of Osteopenia Research Articles

Retraction notice to "comparative effects of vitamin K and vitamin D supplementation on prevention of osteopenia in calcium-deficient young rats" [BONE 33(4) (2003) 557-566

Retraction notice to "comparative effects of vitamin K and vitamin D supplementation on prevention of osteopenia in calcium-deficient young rats" [BONE 33(4) (2003) 557-566

Osteoporotic changes in bone and cartilaginous tissue in women with ovarian hypofunction

Annotation. Osteoporosis is the most common disease of the musculoskeletal system, which ranks 4th in the world as a cause of disability and mortality among non-communicable diseases. This is a polyetiological systemic disease of bone tissue, characterized by a decrease in bone mass and deterioration of bone structure and increased fragility. This problem has not only a medical aspect, but also important socio-economic significance in all countries of the world due to the high cost of treatment of such patients and high disability. The aim of the work is to study and analyze the scientific literature and give a generalized description of etiological factors, pathogenesis, primary and secondary methods of prevention of osteoporosis in women with ovarian hypofunction in the pre- and menopausal periods. An analysis of recent research and publications on the problem of osteoporosis and changes in the skeletal system. The main risk factors, etiology and pathogenesis of osteoporosis in the pre- and menopausal period of a woman's life are determined, the main methods of prevention of osteoporosis are described. The most common form of primary osteoporosis is postmenopausal osteoporosis, the trigger of which is hypogonadal states, estrogen deficiency, which causes a sharp acceleration of bone loss. I guarantee healthy bone tissue and prevention of osteopenia and osteoporosis are: accumulation of bone mass in the first 30 years, mechanical stress contributes to the restructuring and remodeling of bone tissue throughout life, timely and early compensation of hypogonadal conditions, improvement of blood flow, improvement of blood flow stability of mineral metabolism and hormonal background. Not all women with hypogonadal condition develop osteoporosis, so studying the use of methods to prevent osteopenia and strengthen bone tissue from a young age is the basis of quality life of modern women at any time in her life in the XXI century, so it needs further study.

A randomized, open-label, controlled trial of monthly oral minodronate or semiannual subcutaneous injection of denosumab for bone loss by androgen deprivation in Asian men with prostate cancer: the PRevention of Osteopenia with Minodronate And DEnosumab (PROMADE) study.

To evaluate whether monthly oral minodronate or semiannual subcutaneous injection of denosumab improves bone mineral density (BMD) in Asian men with prostate cancer (PCa) receiving ADT. A multicenter, open-label, randomized, controlled study including patients with hormone-sensitive PCa without bone metastasis receiving ADT was performed. Patients were randomized (1:1:1) to minodronate, denosumab, or no agent control groups. The primary end point was the mean percentage change in BMD at the lumbar spine at 12months. Secondary end points were the mean percentage change in BMD at the femoral neck and total hip and changes in bone turnover markers. Statistical comparison was performed using analysis of covariance. Of the 147 subjects enrolled in this study, 102 were randomly assigned into the minodronate (n = 36), denosumab (n = 36), and control (n = 30) groups. The percentage change in BMD at the lumbar spine was significantly improved in the minodronate (2.5%, p < 0.05) and denosumab groups (4.0%, p < 0.01) compared with that in the control group (- 0.1%). Denosumab increased BMD at the femoral neck and total hip at 12months, whereas minodronate only increased BMD at the total hip compared with controls (all p< 0.05). The percentage change in bone turnover markers at 12months was significantly lower in the minodronate and denosumab groups compared with that in the control group (both p < 0.01). Minodronate or denosumab can be used for preventing bone loss related to ADT in Asian patients with PCa.

Physical rehabilitation of patients with osteoporosis

Osteoporosis is one of the most common diseases, which along with cardiovascular pathology, diabetes mellitus and oncological diseases has a leading place in the structure of morbidity and mortality of the population. The combination of pharmacological and non-pharmacological methods is fundamental for the treatment and prevention of osteopenia and osteoporosis. This article presents rehabilitation methods that are of great importance for improving the functioning of the musculoskeletal system, the quality of life of patients with osteoporosis. Physical rehabilitation is aimed at stopping the destruction of bone tissue, strengthening it, eliminating pain, reducing stress from the affected areas and restoring the normal function of joints and bones. The proposed types of physical activity not only increase bone strength and strengthen muscle mass, but also reduce the risk of falling - a leading cause of osteoporotic fractures. Exercise programs designed for patients with osteoporosis should include strength and exercise exercises, as well as exercises for flexibility, posture correction, coordination of movements and balance. Training should be regular, varied and of a certain duration. The article considers the advantages and disadvantages of each type of activity.

Abstract P-303: EFFICACY OF REFLEX LOCOMOTION TO PREVENT OSTEOPENIA IN PRETERM INFANTS

Aims & Objectives: Preterm infants have a lower level of bone mineralization compared to those born at term. Passive physiotherapy has been effective in the treatment of osteopenia, but active mobilizations can be more effective than passive ones. In this sense, Vojta’s reflex locomotion therapy allows stimulation of central nervous system, causing muscle contraction. The aim of this study is to determine if Vojta therapy is effective in the prevention of osteopenia in preterm infants. Methods 46 premature infants with gestational age (GA) ≤34 weeks were randomly assigned to three groups: experimental group 1 (EGV, N=17), experimental group 2 (EGMP, N=14) and control group (CG, N=15). For 30 days EGV received Vojta therapy, EGMP passive mobilizations with joint pressure and CG massage techniques. A quantitative ultrasound device measured changes in bone density. Two evaluations were carried out: before the treatments and at the end of the treatments. Results There were no significant differences between the groups in GA, birth weight and gender distribution. ANOVA of two partially repeated measures factors was performed, comparing the treatment group and the tibial sound velocity (TSV) results. Our results show that there is no significant interaction of the factor “type of intervention” in the variable TSV, F(2,39)=2.457, p=0.098, n2=0.103; although they show a difference of means between the EGV and the EGMP and CG of 11.3 and 11.9 points respectively Conclusions Although the results do not reveal significant differences between the groups comparing TSV, they show a remarkable tendency, obtaining better results the EGV.

A Natural, Calcium-Rich Marine Multi-mineral Complex Preserves Bone Structure, Composition and Strength in an Ovariectomised Rat Model of Osteoporosis.

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin's efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8weeks post OVX. At the end of the 20-week study, the trabecular architecture was measured using micro computed tomography, bone composition was assessed using Fourier transform infrared spectroscopy and the mechanical properties were assessed using nanoindentation and three-point bend testing. The study demonstrates that oral ingestion of Aquamin results in less deterioration of trabecular bone structure, mineral composition and tissue level biomechanical properties in the tibia of rats following ovariectomy than calcium carbonate. This study has shown that in an animal model of osteoporosis, Aquamin is superior to calcium carbonate at slowing down the onset of bone loss.

THE RISK FACTORS AND SPECIFIC FEATURES OF OSTEOPENIC SYNDROME IN PATIENTS WITH CHRONIC NON-INFECTIOUS DISEASES

Objective: to analyze the risk factors (RFs) of osteoporosis (OP), the risk of OP-related fractures, the specific features of osteopenic syndrome in patients with chronic non-infectious diseases (CNID) (coronary heart disease (CHD), hypertension, chronic obstructive pulmonary disease (COPD), and asthma). Materials and methods. The investigation enrolled 377 patients (mean age 55.3 ± 1.6 years) with CNID and 221 persons (mean age, 53.2 ± 1.3 years) who formed a control group. According to the nosological entity, the patients were divided as follows: Group 1 included 84 patients with CHD and hypertension; Group 2 comprised 99 hypertensive patients; Group 3 consisted of 70 patients with COPD; and Group 4 included 124 asthmatic patients. The examinees of all the groups were matched for age, gender, and body mass index. The investigation excluded patients with functional class IV chronic heart failure, continuous atrial fibrillation, heart valve disease, or myocardial noncoronarogenic diseases and those with other diseases and conditions that could have an independent impact on bone metabolism. Prior to the examination, the patients had received no specific therapy for the prevention and treatment of OP. RFs for OP were assessed using the one-minute test recommended by the International OP Foundation (2008); 10-year risk for OP-related fractures were calculated applying the FRAX computer program in accordance with the guidelines of the International OP Association and the World Health Organization (WHO, 2008). To investigate bone mineral density (BMD), bioenergy X-ray densitometry of the lumbar spine and proximal femur was carried out by means of a Lunar DPX apparatus (USA). The results were assessed using the t-test in standard deviations (SD) from the peak bone mass according to the WHO guidelines. Results. The RFs of OP were more frequently recorded in the patients with CNID than in the healthy individuals. RFs, such as smoking, low physical activity, and low-energy fractures, were most common in the patients with cardiovascular disease or COPD. The frequent use of glucocorticoid therapy was also an important RF in the patients with COPD. CHID considerably increased the risk of fractures in the succeeding 10 years after disease onset. The high risk of fractures, those of the proximal femur in particular, provides a rationale for the need for timely antiosteoporotic therapy in the majority of patients with CNID. The performed investigation demonstrated that the BMD values in the patients with CNID corresponded, on the average, to the osteopenia criteria; the lowest BMD values were recorded in the patients with COPD and associated cardiovascular disease. The severe course of osteopenic syndrome (a BMD decrease that was diagnostically significant for OP concurrent with fractures was observed in one-third of patients with CNID. The patients with cardiovascular disease or COPD showed a high incidence and degree of OP, which allows these diseases to be considered as a RF for decreased BMD. The long-term uncontrolled course of disease, the degree of organ and functional disorders in the patients with CNID, and concomitant use of glucocorticoid therapy contribute to a reduction in BMD. Conclusion. RFs for OP were identified in the majority of patients with CNID. The high risk of fractures due to an obvious BMD decrease in patients with CNID requires timely diagnosis, treatment, and prevention of osteopenia.

Prevention of Osteopenia and Dyslipidemia in Rats after Ovariectomy with Combined Aspirin and Low-dose Diethylstilbestrol

ObjectiveTo study whether effect of aspirin plus low-dose diethylstilbestrol is more effective and safer than high diethylstilbestrol dose alone on prevention of ovariectomy-induced osteopenia and dyslipidemia. MethodsThirty-eight 4-month-old female SD rats were divided into baseline (BAS) group (n=6), sham operation group (n=8) and ovariectomy (OVX) group (n=24). The OVX group was further divided into vehicle treatment group (n=8), diethylstilbestrol (30 μg/kg·d) treatment group (OVX+D30 group, n=8), and aspirin (9 mg/kg·d) plus diethylstilbestrol (10 μg/kg·d) treatment group (OVX+A-D10 group, n=8). Their left tibiae were collected for the bone histomorphometric analysis in undecalcified sections. Left femurs were collected for the bone mineral density measurement. ResultsThe body weight and serum cholesterol were increased, while uterine weight and cancellous bone mass were decreased in OVX rats compared with the SHAM group. Cancellous bone mass was significantly increased, while body weight and bone resorption parameters were decreased in both A-D10 and D30 treatment group compared with OVX group. The rats treated with A-D10 showed significantly increased in bone formation parameters and decreased in serum triglyceride compared with the D30-treated rats. ConclusionAspirin plus low-dose diethylstilbestrol can effectively prevent osteopenia by reducing bone resorption, and is thus a better treatment modality for preventing dyslipidemia than high-dose diethylstilbestrol alone.

The Effect of Chronic Long-Term Intermittent Hypobaric Hypoxia on Bone Mineral Density in Rats: Role of Nitric Oxide

Intermittent hypoxia is the most common pattern of hypoxic exposure in humans. The effect of chronic long-term intermittent hypobaric hypoxia (CLTIHH) on bone metabolism is not investigated. We examined the effect of CLTIHH on bone metabolism and the role of nitric oxide (NO) in this process. The rats were divided into three groups in this study. The animals in groups I and II have been exposed to CLTIHH. The animals in group II were also treated with nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester. To obtain CLTIHH, rats were placed in a hypobaric chamber (430 mm Hg; 5 h/day, 5 days/week, 5 weeks). The group III (control) rats breathed room air in the same environment. At the begining of the experiments, bone mineral density (BMD) of the animals were measured, and blood samples were collected from the tail vein. After the 5-week CLTIHH period, the same measurements were repeated. Parathyroid hormone, calcium, phosphate, bone alkaline phosphatase (b-ALP), NO, interleukin 1 beta, interleukin 6, and tumor necrosis factor alpha levels were determined. The cytokines, NO levels, and BMD in CLTIHH-induced rats were higher compared with baseline and control values. The cytokines, b-ALP, and BMD increased while NO levels decreased in the group II compared with baseline values. BMD values of group II were lower than group I but higher than control group. Our results suggested that CLTIHH has positive effects on bone density. Intermittent hypoxia protocols may be developed for treatment and prevention of osteopenia and osteoporosis.

1354 Evaluation and Comparison of Calcium and Phosphorus in the Improvement of Metabolic Bone Disorder in Premature Infants

BackgroundMetabolic bone disease is a common condition among premature Neonates. The aim of this study was to determine the impact of calcium and phosphorus on radiological and biochemical character osteopenia...

Androgen prevents hypogonadal bone loss via inhibition of resorption mediated by mature osteoblasts/osteocytes

Androgen receptor (AR) is expressed throughout the osteoblast lineage. Two different AR transgenic families (AR2.3-tg and AR3.6-tg mice) demonstrating overlapping and distinct expression profiles were employed to assess the effects of enhanced androgen sensitivity to ameliorate hypogonadal loss. Two different paradigms of steroid replacement following orchidectomy (ORX) were used as either preventative or therapeutic therapy. ORX was performed in male wild-type (WT), AR2.3-tg and AR3.6-tg mice at 5months with immediate DHT replacement (prevention, higher turnover) or at 3months with DHT treatment delayed for 2months (therapeutic, lower turnover), both with treatment for the last 6weeks. Dual energy X-ray absorptiometry (DXA), micro-computed tomography (μCT), and histomorphometry were performed. In the prevention model, ORX significantly reduced BMD and BMC in all genotypes compared to sham and DHT was effective at prevention of osteopenia. In the therapeutic model, all genotypes became osteopenic compared to sham, but after a prolonged hypogonadal period, delayed DHT treatment provided little benefit. μCT analysis of mid-shaft total bone in all genotypes generally showed reductions after ORX. Delayed DHT was ineffective at restoring bone volume in any genotype whereas immediate treatment prevented loss only in AR transgenic mice. Cortical thickness also decreased with ORX but immediate DHT treatment was effective to increase thickness only in WT mice, likely due to expansion of marrow volume in both AR-tg lines. In metabolically highly active cancellous bone, ORX resulted in lower bone volume/tissue volume (BV/TV) in all genotypes, consistent among 3 sites measured. Again with delayed treatment, there was little effect of DHT to restore BV/TV, but when administered at the time of ORX, DHT completely prevented the decrease in cancellous bone in all genotypes. Improvement in cancellous bone architecture was seen with immediate DHT replacement that was enhanced in AR transgenic lines compared to WT. In contrast, there were only modest changes in all genotypes using the delayed treatment paradigm. With ORX in both paradigms, trabecular number was decreased while spacing increased. Thus, androgen therapy is effective for the prevention of endosteal and cancellous osteopenia primarily through its anti-resorptive properties, but shows little anabolic action as a therapeutic strategy to restore bone. Given the similarity in response to androgen treatment in both AR transgenic lines, overlapping expression profiles suggest that the target cells mediating androgen action in vivo are mature osteoblast/osteocytes. Combined, these results demonstrate that in the adult mouse, androgen treatment can reduce bone resorption but has little overall anabolic activity.

Relationship between body composition, body mass index and bone mineral density in a large population of normal, osteopenic and osteoporotic women

The knowledge of factors modulating the behaviour of bone mass is crucial for preventing and treating osteoporotic disease; among these factors, body weight (BW) has been shown to be of primary importance in postmenopausal women. Nevertheless, the relative effects of body composition indices are still being debated. Our aim was to analyze the relationship between body mass index (BMI), fat and lean mass and bone mineral density (BMD) in a large population of women. Moreover, this study represents a first important report on reference standard values for body composition in Italian women. Between 2005 and 2008, weight and height of 6,249 Italian women (aged 30-80 years) were measured and BMI was calculated; furthermore BMD, bone mineral content, fat and lean mass were measured by dual-energy X-ray absorptiometry. Individuals were divided into five groups by decades (group 1, 30.0-39.9; group 2, 40.0-49.9; group 3, 50.0-59.9; group 4, 60.0-69.9; group 5, 70.0-79.9). Differences among decades for all variables were calculated using a one-way analysis of variance (ANOVA) and Bonferroni test by the SPSS programme. Mean BW was 66.8±12.1 kg, mean height 159.1±6.3 cm and mean BMI 26.4±4.7 kg/m(2). According to BW and BMI, there was an increase of obesity with age, especially in women older than 50 years (p<0.001). Lean mass increased until 50 years of age but significantly decreased after this age (p<0.001). The percentage of osteopenia and osteoporosis in the examined population was 43.0% and 16.7%, respectively. Our data show that obesity significantly decreased the risk for osteoporosis but did not decrease the risk for osteopenia. It is strongly recommended that a strong policy regarding prevention of osteopenia and osteoporosis be commenced. An overall examination of our results suggests that both fat and lean body mass can influence bone mass and that their relative effect on bone could be modulated by their absolute amount and ratio to total BW.

AO-32. The impact of total body massage and kangaroo care on prevention of osteopenia of prematurity in VLBW infants in the northwest Iran

AO-32. The impact of total body massage and kangaroo care on prevention of osteopenia of prematurity in VLBW infants in the northwest Iran

Changes in bone and mineral metabolism in kidney transplant patients with chronic kidney disease

Recently, the Foundation has proposed new definitions KDIGO to refer to the alterations of bone - mineral metabolism in patients with chronic renal disease (CRD), relegating the traditional term of renal osteodystrophy (ODR). RECOMMEND: The term ODR exclusively to define alterations in bone morphology and architecture characteristic of the ERC. - And the term of bone-mineral alteration associated with the CRD to describe biochemical changes, and skeletal calcifications that occur as a result of alterations in mineral metabolism in the CRD. The different metabolic abnormalities are secondary to the progressive loss of renal mass and renal function that leads to retention of phosphorus and a decrease in the levels of calcitriol which are responsible for the skeletal resistance to the action of PTH. The main clinical manifestations of abnormal bone mineral metabolism are posttransplantation osteoporosis and osteopenia producing an increase in fractures, osteonecrosis, and bone pain. Biochemical parameters (calcium, phosphorus, PTH, 25 hydroxyvitamin D), X-ray bone densitometry and bone biopsy. (Evidence B). THERAPEUTIC ALTERNATIVES: It is recommended for the treatment and prevention of osteopenia - osteoporosis in transplant patients based on data from clinical evidence available from other study populations, such as in patients with chronic kidney disease. In addition to specific treatment, we must take into account the preventive measures to reduce the risk of fractures. Treatment includes specific measures for the prevention of bone loss (active metabolite of vitamin D analogues and bisphosphonates) and the treatment of persistent hyperparathyroidism (calcimiméticos). (Evidence B).

Osteopenia and Osteoporosis in Pediatric Patients After Stem Cell Transplant

As more patients are surviving the transplant experience, more children are coping with long-term side effects. Long-term side effects, such as osteopenia and osteoporosis, are not as well acknowledged in pediatric stem cell transplant survivors. Osteopenia and osteoporosis can lead to fractures, deformities, pain, and financial burden. There are many factors during and after a stem cell transplant that cause patients to be at an increased risk for osteopenia or osteoporosis. Nurses have the ability to prevent these potentially debilitating and progressive diseases and to provide adequate treatment to prevent further complications. Key features of the history, physical examination, and diagnostic imaging can assist with making a diagnosis of osteoporosis or osteopenia. Prevention of osteopenia and osteoporosis involves both lifestyle modifications and medical management. Measures to prevent and treat bone loss are crucial. Transplant nurses must be knowledgeable regarding the risk factors and prevention and treatment strategies for osteopenia and osteoporosis.

Use of Bone Health Protocol to Identify and Prevent Bone Disease in Kidney and Pancreas Transplant Recipients

Posttransplant bone disease is a well recognized and undertreated problem. The use of protocols within other populations has been shown to improve recognition and treatment of common disease states, but outcome studies involving the use of protocols within transplant patients are lacking. To compare the appropriate screening for and the prevention and treatment of osteopenia and osteoporosis in transplant patients before and after a bone health protocol was implemented. A retrospective analysis in a single institution was designed to determine whether the development and implementation of a comprehensive bone health protocol impacted disease outcomes in posttransplant kidney and simultaneous kidney-pancreas patients. There were 132 patients in the historical control group and 76 in the treatment group. The groups were well matched, with no statistically significant differences noted for any of the baseline characteristics that were compared, including the modifiable and nonmodifiable risk factors known to put a patient at increased risk for osteopenia or osteoporosis. Significantly more patients in the treatment group received proper screening and prevention compared with the historical control group (p < 0.001). Although more patients in the treatment group received proper bone disease treatment, this did not reach statistical significance (81% vs 66%; p < 0.22). Additionally, the dual energy X-ray absorptiometry scans were performed, on average, 19 days earlier in the treatment group, although this also did not achieve statistical significance (p = 0.149). The multidisciplinary development and implementation of a comprehensive bone health protocol improves the screening and prevention of osteopenia and osteoporosis within kidney and pancreas transplant recipients.

Is deoxypyridinoline a good resorption marker to detect osteopenia in phenylketonuria?

Objectives: To evaluate deoxypyridinoline as a resorption marker in phenylketonuria (PKU) and to search for a relationship between deoxypyridinoline, calcium/creatinine index (Ca/Cr I), osteocalcin and bone alkaline phosphatase (BAP). Methods: This was a transversal analytical study of 46 PKU patients [17.5 (4–38) years]. Deoxypyridinoline and osteocalcin were measured with a chemiluminescent assay and BAP was measured with an immunoradiometric assay. Results: Deoxypyridinoline was significantly increased in patients aged 7–14 and >18 years old, being associated with age ( r = −0.724, P < 0.001). Adult patients showed significantly higher Ca/Cr I, which correlates with Phe values for the year prior to the study ( P = 0.014). Serum BAP was significantly increased in pediatric patients (9–13 years), while it was decreased in adult patients ( P = 0.003). Decreased osteocalcin levels were found in patients >15 years ( P = 0.028). Altered deoxypyridinoline and BAP values were related ( P = 0.042). Conclusion: PKU patients excreted increased D-Pyr, suggesting high bone resorption. Bone formation seems active in childhood but deteriorates in adult PKU patients. Periodic measurement of D-Pyr and BAP may be useful in the prevention of osteopenia in PKU patients.

Association of osteopenia with curve severity in adolescent idiopathic scoliosis: a study of 919 girls

Generalized osteopenia and spinal deformity occur concomitantly in adolescent idiopathic scoliosis (AIS) during the peripubertal period. No large-scale study has been performed to reveal the link between scoliotic deformity and bone-mineral status in AIS. In a cross-sectional study, the extent of scoliotic-curve severity in relation to bone-mineral status was examined for 619 AIS girls and compared with those of 300 healthy non-AIS counterparts aged 11-16 years. Curve severity was categorized into a moderate (10-39 degrees) and a severe group (> or = 40 degrees) based on Cobb angle. Anthropometric parameters, bone mineral-density (BMD) and bone mineral-content (BMC) of lumbar spine, proximal femur and distal tibia were determined by dual-energy X-ray absorptiometry and peripheral QCT. Differences in anthropometric parameters and bone mass among control and the AIS-moderate and AIS-severe groups were tested by one-way ANOVA. Association between Cobb angle and bone mass was determined by univariate and multivariate analyses. Mean Cobb angle of the moderate and severe groups were 25+/-6.3 degrees and 50.2+/-11.3 degrees, respectively. Arm span and leg length among the moderate and severe AIS subjects were almost all longer than for the controls from age 13 years. Age-adjusted arm span and leg length were significantly correlated with curve severity (p < 0.015). Starting from age 13 years, most axial and peripheral BMD and BMC of the moderate or severe AIS group was significantly lower than for the controls (p < 0.029). Age-adjusted Cobb angle was inversely correlated with BMD and BMC of the distal tibia and lumbar spine among AIS subjects (p < or = 0.042). The proportion of osteopenic AIS girls in the severe group was significantly higher than that in the moderate group (p < or = 0.033). Multivariate analysis indicated that Cobb angle was inversely and independently associated with axial and peripheral BMD and BMC (p < or = 0.042). To conclude, curve severity was an inverse and independent associated factor on bone mineral mass of AIS during peripuberty. The study implied that prevention of osteopenia could be as important as controlling spinal progression in the management of AIS.

Inhibition of HSP70 and a collagen-specific molecular chaperone (HSP47) expression in rat osteoblasts by microgravity.

Rat osteoblasts were cultured aboard a space shuttle for 4 or 5 days. Cells were exposed to 1alpha, 25 dihydroxyvitamin D(3) during the last 20 h and then solubilized by guanidine solution. The mRNA levels for molecular chaperones were analyzed by semi-quantitative RT-PCR. ELISA was used to quantify TGF-beta1 in the conditioned medium. The HSP70 mRNA levels in the flight cultures were almost completely suppressed, as compared to the ground (1 x g) controls. The inducible HSP70 is known as the major heat shock protein that prevents stress-induced apoptosis. The mean mRNA levels for the constitutive HSC73 in the flight cultures were reduced to 69%, approximately 60% of the ground controls. HSC73 is reported to prevent the pathological state that is induced by disruption of microtubule network. The mean HSP47 mRNA levels in the flight cultures were decreased to 50% and 19% of the ground controls on the 4th and 5th days. Concomitantly, the concentration of TGF-beta1 in the conditioned medium of the flight cultures was reduced to 37% and 19% of the ground controls on the 4th and 5th days. HSP47 is the collagen-specific molecular chaperone that controls collagen processing and quality and is regulated by TGF-beta1. Microgravity differentially modulated the expression of molecular chaperones in osteoblasts, which might be involved in induction and/or prevention of osteopenia in space.

Anorexie mentale : conséquences sur la croissance et la minéralisation osseuse

Anorexia nervosa (AN) concerns 1% of adolescent girls and happens at a time of intense bone growth. Adolescents who develop AN before or during puberty have growth retardation and may not achieve their genetic height potential. Osteopenia, as evidenced by dual-energy X-ray absorptiometry, is also frequent. The degree of osteopenia depends on the age of onset and the duration of AN. The role of estrogen deficiency is no more considered paramount with regards to other factors like the fall of growth factor IGF1. The prevention of osteopenia in AN relies mostly on early nutritional intervention. Hormone replacement therapy or calcium/vit D supplements are not sufficient to improve bone density in undernourished patients. New therapeutic strategies combining anabolic and antiresorptive agents are being developed.