Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Dual-energy X-ray absorptiometry ; Lumbar vertebrae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The bone mineral density (BMD) of lumbar vertebrae in the anteroposterior (AP) view may be overestimated in osteoarthritis or with aortic calcification, which are common in elderly. Furthermore, the risk of spinal crush fracture should be more closely related inversely to the BMD of the vertebral body than to that of the posterior arch. Therefore, we measured BMD of lumbar vertebrae in lateral (LAT) view (L2–L3), using a standard dual-energy X-ray absorptiometer (DEXA), thus eliminating most of the posterior spinal elements. The precision of BMD LAT measurement was determined both in vitro and in healthy volunteers. Then, we compared the capability of BMD LAT and BMD AP scans for monitoring bone loss related to age and for discriminating the BMD of postmenopausal women with nontraumatic vertebral fractures from that of young subjects. In vitro, when a spine phantom was placed in lateral position in the middle of 26 cm of water in order to simulate both soft-tissue thickness and X-ray source remoteness, the coefficient of variation (CV) of six repeated determinations of BMD was 1.0%. In vivo, the CV of paired BMD LAT measurements obtained in 20 healthy volunteers after repositioning was 2.8%. The age-related difference between a peak bone mass group estimated in a group of 27 healthy women aged 20 to 35 years and a group of 50 women aged 60 to 75 years, in whom neither vertebral fracture nor osteoporosis risk factors could be detected, were 21.7% and 37.6% in AP and LAT view, respectively. An arbitrary BMD fracture threshold was defined in AP and LAT views as the 90th percentile of the BMD value of a group of 22 osteoporotic women with vertebral fractures. The distribution of BMD AP and LAT above and below this threshold in 169 consecutively screened women without vertebral fracture was then analysed. In both AP and LAT views, 39.1% and 31.3% had BMD values above and below this threshold, respectively. Of the remaining, 16.0% had a BMD below this threshold only in AP and 13.6% only in LAT view. Thus, if BMD LAT was a better reflection of vertebral body bone mass than BMD AP, and thereby a better predictor of the resistance to crush fracture, our results would suggest that only the use of the standard AP view could under- or overestimate spinal fracture risk in about 30% of women screened for osteoporosis. In conclusion, our results indicate that BMD measurement in lateral view is feasible with a standard DEXA instrument. This mode of scanning, besides overcoming artefacts due to osteoarthritis of the posterior arch and aortic calcifications, appears to provide a greater sensitivity for assessing bone mass loss of the vertebral body than the standard anteroposterior scan.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Hip fracture ; Osteoporosis ; Proximal femur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bone mass is an important determinant of resistance to fractures. Whether bone mineral density (BMD) in subjects with a fracture of the proximal femur (hip fracture) is different from that of age-matched controls is still debated. We measured BMD of the femoral neck (FN) on the opposite side to the fracture, as well as femoral shaft (FS) and lumbar spine (LS) BMD by dual-photon absorptiometry in 68 patients (57 women and 11 men, mean age 78.8±1.0) 12.4±0.8 days after hip fracture following a moderate trauma. These values were compared with BMD of 93 non-fractured elderly control subjects (82 women and 11 men), measured during the same period. As compared with the controls, FN BMD was significantly lower in fractured women (0.592±0.013 v. 0.728±0.014 g/cm2,P〈0.001) and in fractured men (0.697±0.029 v. 0.840±0.052,P〈0.05). Expressed as standard deviations above or below the mean BMD of age and sex-matched normal subjects (Z-score), the difference in FN BMD between fractured women and controls was highly significant (−0.6±0.1 v. +0.1±0.1,P〈0.001). As compared with mean BMD of young normal subjects, BMD was decreased by 36.9±1.4 and 22.4±1.5% (P〈0.001) in fractured and control women, respectively. There was no significant difference between FN BMD of 33 women with cervical and 24 with trochanteric hip fractures (0.603±0.017 v. 0.577±0.020). FN BMD was lower than 0.705 g/cm2 in 90% of fractured women. The prevalence of fracture increased with decreasing FN BMD, reaching 100% with values below 0.500 g/cm2. FS and LS BMD were significantly lower in women with hip fracture than in controls (1.388±0.036 v. 1.580±0.030,P〈0.001, for FS, and 0.886±0.027 v. 0.985±0.023,P〈0.01, for LS), but these differences were not significant when expressed as a Z-score. In men with a recent hip fracture, FS BMD was significantly lower than in controls (1.729±0.096 v. 2.069±0.062,P〈0.01), but the difference at the LS level did not reach statistical significance. These results indicate that both women and men with a recent hip fracture had decreased bone mineral density of the femoral neck, femoral shaft and lumbar spine. However, the difference appeared to be of higher magnitude for the femoral neck suggesting a preferential bone loss at this site.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Calcium ; Elderly ; Femoral neck ; Fracture ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The efficacy of calcium (Ca) in reducing bone loss is debated. In a randomized placebo-controlled double-masked study, we investigated the effects of oral Ca supplements on femoral shaft (FS), femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD), and on the incidence of vertebral fracture in vitamin-D-replete elderly. Ninety-three healthy subjects (72.1±0.6 years) were randomly allocated to three groups receiving 800 mg/day Ca in two different forms or a placebo for 18 months. Sixty-three patients (78.4±1.0 years) with a recent hip fracture were allocated to two groups receiving the two forms of Ca without placebo. FS BMD changes in Ca-supplemented non-fractured women were significantly different from those in the placebo group (+0.6±0.5% v −1.2±0.7%,p〈0.05). There was no difference in effect between the two forms of Ca. The changes of +0.7±0.8% v −1.7±1.6% in FN BMD of Ca-supplemented women and the placebo group did not reach statistical significance. In fractured patients, FS, FN and LS BMD changes were −1.3±0.8, +0.3±1.6 and +3.1±1.2% (p〈0.05 for the last). The rate of new vertebral fractures was 74.3 and 106.2 fractures per 1000 patient-years in Ca-supplemented non-fractured subjects and in the placebo group, respectively, and 144.0 in Ca-supplemented fractured patients. Thus, oral Ca supplements prevented a femoral BMD decrease and lowered vertebral fracture rate in the elderly.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Dual X-ray absorptiometry ; Sex difference ; Vertebral arch ; Vertebral body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Peak bone mass (PBM) is an important reference value in the diagnosis of osteoporosis. It is usually established by determining the areal bone mineral density (BMD in g/cm2) for a given site of the skeleton in young healthy adults. This measurement takes into account both the thickness and the integrated mineral density of the bone scanned. It should therefore be a major determinant of the resistance to mechanical stress. However, in lumbar spine the mean BMD as determined by dual-energy either isotopic or X-ray (DXA) absorptiometry in antero-posterior (ap) view was repeatedly found not to be different between male and female young healthy adults despite the greater volume of lumbar vertebral bodies in males. A greater contribution of the posterior vertebral arch to areal BMD-ap in females than in males could account for such an apparent discrepancy. In order to clarify this issue we have determined in 65 (32 male and 33 female) young healthy adults aged 20–35 years the relative contribution of the vertebral body (VB) and posterior vertebral arch (VA) to BMD and bone mineral content (BMC) of L2–3 measured by both antero-posterior and lateral (lat) scanning using DXA. In young healthy adults mean BMC in antero-posterior view was found not to be significantly different from the total BMC determined by lateral scanning including both VB and VA. This allowed us then to calculate the VA BMC by substracting VB BMC-lat from BMC-ap. The results indicated that the mean value for males was significantly greater than that for females for BMC-ap (male/female ratio (mean±SEM): 1.16±0.05,p〈0.01), BMC-lat (1.38±0.07,p〈0.001) and VB BMD-lat (1.16±0.04,p〈0.001). In sharp contrast, no sex difference was found in BMD-ap (male/female ratio: 0.99±0.03) and VA BMC (male/female ratio: 0.97±0.06). VA BMC represented 44% and 53% (p〈0.001) of BMC-ap in males and females, respectively. Furthermore, in neither sex was any correlation between VA BMC and VB BMC found. In summary, this study indicates that the relative contribution of the posterior vertebral arch to the bone mineral content of L2–3 is significantly smaller in males than in females. This difference could partly explain the absence of a sex difference in areal BMD as measured in antero-posterior view. In agreement with lumbar anthropomorphometric data this study further shows that the sex difference in vertebral body size, an important component in mechanical resistance, is expressed when areal BMD is measured in lateral but not in antero-posterior scanning. Finally, the data analysis underlines the quantitative importance of the vertebral arch in the value of areal BMD as measured by DXA in the classical antero-posterior view, and demonstrates the absence of a significant quantitative relationship between the bone mineral content of the vertebral body and that of the posterior vertebral arch.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Dual X-ray absorptiometry ; Peak bone mass ; Reference ranges
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The so-called peak bone mass (PBM) represents the highest amount of bony tissue achieved during life at a given site of the skeleton. It has been suggested that PBM might be achieved as late as the fourth decade, but recent data have indicated that PBM is already achieved by the end of sexual maturation, namely at the end of the second decade. The solving of this apparent controversy is of interest for a better understanding of bone homeostasis and for defining the cohort of normal subjects to be evaluated in order to establish a PBM reference range — necessary for the diagnosis of osteoporosis and evaluation of the fracture risk. To study bone mass evolution in young healthy adults and to determine whether such a cohort can be used to establish PBM reference values, we measured bone mineral density (BMD) in sixty 20- to 35-year-old young healthy adults by dual-energy X-ray absorptiometry at the levels of the lumbar spine (in both anteroposterior and lateral views), femoral neck, trochanter region, total hip and of Ward's triangle, as well as whole-body BMD and bone mineral content (BMC) in cross-sectional and longitudinal studies. In the cross-sectional analysis, none of the bone mass variables was dependent on age using linear regression analysis. The longitudinal study indicated that the mean changes in lumbar spine, proximal femur and whole body BMD or BMC determined after a 1-year interval were not statistically different from zero in either females or males aged 20–35 years. In conclusion, the present results confirm that at the levels of lumbar spine and proximal femur, two sites particularly at risk of osteoporotic fractures, PBM can be achieved before the third and fourth decades in both male and female normal subjects.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Osteoporosis international 4 (1994), S. S7 
    ISSN: 1433-2965
    Keywords: Bone fragility ; Bone mineral density ; Bone size ; Cortical bone ; Osteoporosis ; Puberty ; Sex difference ; Statural height ; Trabecular bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Peak bone mass, which can be defined as the amount of bony tissue present at the end of the skeletal maturation, is an important determinant of osteoporotic fracture risk.Measurement of bone mass development. The bone mass of a given part of the skeleton is directly dependent upon both its volume or size and the density of the mineralized tissue contained within the periosteal envelope. The techniques of single-1 and dual-energy photon or X-ray absorptiometry measure the so-called ‘areal’ or ‘surface’ bone mineral density (BMD), a variable which has been shown to be directly related to bone strength.Bone mass gain during puberty. During puberty the gender difference in bone mass becomes expressed. This difference appears to be essentially due to a more prolonged bone maturation period in males than in females, with a larger increase in bone size and cortical thickness. Puberty affects bone size much more than the volumetric mineral density. There is no significant sex difference in the volumetric trabecular density at the end of pubertal maturation. During puberty, the accumulation rate in areal BMD at both the lumbar spine and femoral neck levels increases to four- to sixfold over a 3-and 4-year period in females and males, respectively. Change in bone mass accumulation rate is less marked in long bone diaphyses. There is an asynchrony between the gain in statural height and bone mass growth. This phenomenon may be responsible for the occurrence of a transient period of a relative increase in bone fragility that may account for the pattern of fracture incidence during adolescence.Variance in peak bone mass. At the beginning of the third decade there is a large variability in the normal values of areal BMD in the axial and appendicular skeleton. This large variance, which is observed at sites particularly susceptible to osteoporotic fractures such as lumbar spine and femoral neck, is barely reduced after correction for statural height, and does not appear to increase substantially during adult life. The height-independent broad variance in bone mass develops during puberty at sites such as lumbar spine and femoral neck, where the accretion rate is markedly increased.Time of peak bone mass attainment. Despite the fact that a majority of studies did not indicate that bone mass continues to accumulate significantly during the third and fourth decades, it has been generally accepted that peak bone mass at any skeletal site is attained in both sexes during the mid-thirties. However, recent studies indicate that in healthy Caucasian females with apparently adequate intakes of energy and calcium, bone mass accumulation can virtually be completed before the end of the second decade, for both lumbar spine and femoral neck. It is possible that both genetic and environmental factors could influence the time of peak bone mass achievement.Determinants of peaks bone mass. Several variables, more or less independent, are supposed to influence bone mass accumulation during growth; heredity, sex, dietary components, endocrine factors, mechanical forces, and exposure to risk factors. Quantitatively, the most prominent factor appears to be the genetic determinant, as estimated by studies comparing monozygotic and dizygotic twins. That heredity is not to be the only determinant of peak bone mass is of practical interest, since environmental factors can be modified. With respect to nutrition, the quantitative importance of calcium intake in bone mass accumulation during growth, particularly at sites prone to osteoporotic fractures, remains to be clearly determined. The same can be said for the impact of physical activity. Finally, the crucial years when these external factors will be particularly effective on bone mass accumulation remain to be determined by longitudinal prospective studies in order to produce credible and well targeted recommendations for the setting up of osteoporosis prevention programs aimed at maximizing peak bone mass.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Calcium ; Corticosteroid ; Fluoride ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Corticosteroid-induced osteoporosis, which particularly affects the axial skeleton and the proximal femur, is characterized by a state of low bone remodelling. Fluoride is a potent stimulator of trabecular bone formation which could potentially be useful in the treatment of corticosteroid-induced osteoporosis. We investigated the effects of sodium monofluorophosphate (26 mg/day of fluoride) combined with 1000 mg of calcium (MFP-calcium-treated group), or of calcium alone (control), given for 18 months, on bone mineral density (BMD) of lumbar spine (LS), femoral neck (FN) and midfemoral shaft (FS) in 48 patients with corticosteroid-induced osteoporosis. Mean ages were 49.4±3.1 and 51.6±3.0 years (mean± SEM), duration of corticosteroid therapy 7.5±1.8 and 9.3±1.7 years, and mean daily dose of prednisone 18.2±2.3 and 12.1±1.1 mg in the MFP-calcium-treated group and controls, respectively. Initial BMDs (expressed as theZ-score, i.e. the difference in standard deviations from age- and sex-matched normal subjects) were −1.5±0.2 and −1.2±0.2 for LS, −1.4± 0.2 and −1.3±0.2 for FN, and −0.8±0.3 and −0.6±0.3 for FS, in the MFP-calcium-treated group and controls, respectively. Analysis by linear regression of 6-monthly measurement values revealed BMD changes of +7.8 ±2.2 versus + 3.6±1.3% (p〈0.02) for LS, −1.5±1.8 versus +0.9 ±1.8% for FN, and −1.1±1.1 versus −0.5±1.4% for FS after 18 months of follow-up in the MFP-calcium-treated group and controls, respectively. For comparison, 17 patients with idiopathic osteoporosis (mean age 63.9±2.0 years), with initial BMDs of −1.3±0.4, −1.6±0.3 and −0.8±0.4 (Z-score for LS, FN and FS, respectively), received MFP and calcium for 22.1±1.7 months. BMD changes in idiopathic osteoporosis were +9.3±2.7% (p〈0.005), −1.3±2.0% and +0.6± 0.9% for LS, FN and FS, respectively. These results indicate that the combination sodium monofluorophosphate and calcium was more efficient than calcium alone in increasing lumbar spine BMD in patients with corticosteroid-induced osteoporosis; neither femoral neck nor femoral shaft BMD was affected. Moreover, these effects were similar in patients with corticosteroid-induced and idiopathic osteoporosis.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Elderly ; Osteoporosis ; Protein ; Under nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dietary protein and/or calorie insufficiencies represent an important problem in elderly patients. The biological and clinical implications, and particularly the influence on bone mass of undernutrition in the elderly, have not been completely defined, although several studies have demonstrated a high prevalence of dietary insufficiencies in patients with a recent fracture of the proximal femur. In the present study the relationship between dietary intakes, physical performance and bone mineral density (BMD) was examined in hospitalized elderly patients. The study comprised 74 patients (48 women, mean age 82 years; and 26 men, mean age 80 years) who were hospitalized for various medical indications. They were divided into two groups according to their dietary protein intakes, evaluated during the first 28 days in hospital while on a regular diet. The first group consisted of 26 patients (14 women and 12 men) whose protein intake was equal to or greater than 1 g per kilogram of ideal body weight. The second group consisted of 48 patients (34 women and 14 men) who consumed less than 1 g of protein per kilogram of ideal body weight. The two groups differed also in their energy, carbohydrate, lipid and calcium intakes. Patients in the group with the higher protein intake displayed higher BMD at the level of the femoral neck as measured by dual-photon absorptiometry. The men in this group also had higher lumbar spine BMD. After 4 weeks in hospital the women with a higher protein intake had significantly enhanced bicipital and quadricipital muscle strength and better performance as indicated by the increased capacity to climb stairs. These results indicate that lower dietary intakes in hospitalized elderly patients without fractures are associated with lower physical performance and lower femoral neck BMD. Thus, the role of dietary factors, including protein, in the risk of proximal femoral fractures deserves further investigation.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1433-2965
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of nuclear medicine 14 (1988), S. 639-639 
    ISSN: 1619-7089
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...