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Biomedical subjects

A Gotfredsen

Publications and source records attributed to A Gotfredsen.

At least 37 records · Page 2Linked to original sources
PubMed1990

Does a single local absorptiometric bone measurement indicate the overall skeletal status? Implications for osteoporosis and osteoarthritis of the hip.

Regional bone mineral content (BMC) and density (BMD) (head, arms, chest, spine, pelvis, legs) of a total body dual photon 153Gd absorptiometry (DPA) scan were measured in 20 healthy postmenopausal women, 27 postmenopausal women with hip fracture, and 17 postmenopausal women with osteoarthritis of the hip. In addition, local BMC and BMD were measured in the proximal and distal regions of the distal forearm (BMCprox, BMDprox, BMCdist, BMDdist) by single photon absorptiometry (SPA); and in the lumbar spine (BMCL2-L4 and BMDL2-L4) by 153Gd DPA. The overall impression was a reduction of bone mass in hip fracture patients compared with healthy controls and an increase in the bone mass of osteoarthritic patients. These results were valid using both regional values of the total body scan, and local forearm and lumbar spine measurements, and statistically significant using one-way analysis of variance. There were, however, also significant within-group between-region differences (one-way analysis of variance), showing that the bone mass of the pelvis and legs in hip fracture patients was more reduced than in the remaining skeleton; in osteoarthritic patients it was not increased but rather unchanged or slightly reduced. The differences between the level of the three local measurements (BMDprox BMDdist BMDL2-L4), on the one hand, and the level of the six regional BMD values, on the other hand, were investigated by the two-way analysis of variance: local measurements = rows; regional values = columns. This analysis showed that none of the three local measurements was statistically better than the other two in predicting the overall level of skeletal bone mass as judged by the six regional values. We conclude that serious osteoporotic bone loss has a generalized nature, however, with a tendency towards lower values in the regions affected by fracture (viz: low bone mass in the legs of femoral neck fracture patients). Osteoarthritis may be associated with a high bone mass in most areas, but low values in the affected regions. Local lumbar spine measurement of bone mass by DPA is not superior to local forearm measurement of bone mass by SPA in predicting the nature of overall osteoporotic or osteoarthritic bone change.

Absorptiometry, Photon↗
PubMed1989

Total body bone mineral in light-for-gestational-age infants and appropriate-for-gestational-age infants.

Dual-photon-absorptiometry using 153Gd in a whole body scanner was used to measure total body bone mineral in 51 newborn infants. In preterm light-for-gestational-age infants total body bone mineral was 12.6 g v.s. 25.6 g in preterm appropriate-for-gestational-age infants (p less than 0.05). In term light-for-gestational-age infants total body bone mineral was 41.4 g v. 84.2 g in term appropriate-for-gestational-age infants (p less than 0.001). The correlations between gestational age and total body bone mineral was best described by exponential regression lines.

Bone and Bones↗
PubMed1989

Regional bone mineral in healthy and osteoporotic women: a cross-sectional study.

Regional bone mineral content and density (BMC and BMD) was measured in six regions (head, arms, chest, spine, pelvis, and legs) using dual photon 153Gd absorptiometry (DPA) in 128 healthy women aged 21-77 years, and in 45 women presenting with Colles' fracture (mean age 65 years), 46 women with vertebral crush or wedge fracture (mean age 68 years), and 27 women with femoral neck-fracture (mean age 74 years). The age-related normal bone loss was generalized, uniformly distributed, and best described by a combination of a premenopausal linear and a postmenopausal exponential regression in all six regions. Looking at BMD, the overall expected bone loss from age 20 to age 80 was approximately 20% in all the regions. When the fracture patients were examined, we found also generalized bone deficit as the prominent feature, amounting to about 20% of the premenopausal level for Colles' and spinal fractures, and about 25% for femoral neck-fracture. However, there was a regional bias in the fracture patients, as the Colles' and spinal fracture patients had a preferential reduction in spinal and pelvic BMD, whereas the patients with femoral neck-fracture had a preferential reduction in pelvic and leg BMD. We conclude that age-related and osteoporotic bone loss is generalized. Furthermore, we propose that regional differences in osteoporotic bone loss are brought about by a simple biological variability of the range of (i) relative amount of trabecular and cortical bone, (ii) rate of loss in the two types of bone tissue, and (iii) time of onset of trabecular relative to cortical bone loss.

Absorptiometry, Photon↗
PubMed1989

Discriminative ability of total body bone-mineral measured by dual photon absorptiometry.

We investigated the discriminative ability of total body bone-mineral expressed as the total body bone-density (TBBD) measured by dual photon absorptiometry (DPA) in 79 healthy premenopausal women, 27 healthy postmenopausal women, and 120 female osteoporotic fracture patients presenting with either Colles' fracture, vertebral fracture or femoral neck-fracture. TBBD was compared to the bone-mineral density of the lumbar spine (BMDspine) also measured by DPA, and to the bone-mineral content of the forearms (BMCforearm) measured by single photon absorptiometry (SPA). TBBD, BMDspine and BMCforearm showed that all the fracture patient groups had significantly reduced bone-mass. Using receiver operating characteristic (ROC) analysis, we found that TBBD had a tendency towards better discriminative ability than BMDspine or BMCforearm with regard to the discrimination between healthy premenopausal women and the three types of osteoporotic fractures (not significant in spinal fracture patients). BMCforearm had an intermediate position, whereas BMDspine had the smallest discriminative ability. TBBD also discriminated better between healthy postmenopausal women and hip-fracture patients than BMDspine or BMCforearm, whereas there was no significant difference between the three methods regarding the discrimination between the healthy postmenopausal women and the Colles' and spinal fracture patients. We conclude that the TBBD measurement by DPA has a discriminative potential which is better than the local spine or forearm measurements.

Absorptiometry, Photon↗
PubMed1988

Lean body mass in small for gestational age and appropriate for gestational age infants.

Dual photon absorptiometry using 153Gd in a whole-body scanner was used to measure lean body mass (LBM) in 51 newborn infants. LBM% decreased exponentially with increasing gestational age in both small for gestational age (SGA) and appropriate for gestational age (AGA) infants. In preterm SGA and AGA infants LBM was 104% and 103%, respectively, indicating that no fat was detectable. In term SGA infants LBM was 98%, which corresponded to 48 gm fat on average, and in term AGA infants LBM was 87%, which corresponded to 452 gm fat on average. The LBM%, ponderal index, and skinfold thickness were significantly different between AGA and SGA infants. Infants with clinical signs of intrauterine wastage had significantly higher LBM% than did infants without signs of weight loss. Our results on LBM% by dual photon absorptiometry agree with earlier dissection data; the clinically applicable methods of (1) height combined with weight (i.e., ponderal index), (2) skinfold thickness, and (3) scoring by clinical observations are useful for the estimation of lack of fat as an indicator of intrauterine growth retardation.

Adipose Tissue↗
PubMed1988

Age-related bone loss in women evaluated by the single and dual photon technique.

Bone mass and density were measured at two forearm sites (proximal and distal BMC/BMD) and in the spine (spinal BMC/BMD) by respectively single and dual photon absorptiometry in 141 healthy women aged 20-80 years. The proximal forearm site contains approximately 15% trabecular bone and the distal site equal amounts of trabecular and cortical bone. At all three sites linear regression analysis on pre- and postmenopausal women separately revealed accelerated decline in bone density after the menopause. Polynomial regressions in BMC and BMD versus menopause-adjusted age fitted the changes better than a linear regression in the peripheral skeleton, but not in the spine. In both the forearms and the spine the age-related reduction in bone could be described by a combined model, assuming a linear decrease before the menopause and an exponential one thereafter. According to this model, the premenopausal annual changes were 0.067% (proximal site), 0.187% (distal site) and 0.098% (spine). The annual changes during the first postmenopausal year were 3.7, 3.7 and 4.6%. No matter which model was applied to the data, the reduction in the oldest women was lowest in the spine. These data indicate that there are some small differences in the age-related changes in cortical and trabecular bone, but that the reduction of both types of bone accelerates after the menopause.

Adult↗
PubMed1988

Accuracy of lumbar spine bone mineral content by dual photon absorptiometry.

The accuracy of measurement of the bone mineral content (BMC, g) and bone mineral density (BMD, g/cm2) of the lumbar spine by dual photon absorptiometry (DPA) was estimated by means of two different spine scanners (a Nuclear Data 2100 and a Lunar Radiation DP3). The lumbar spines of 13 cadavers were used. BMC and BMD were measured in situ and on the excised vertebrae in a solution of water/ethanol; and covered with ox muscle/porcine muscle/lard. The actual mineral weight and areal density were determined after chemical maceration, fat extraction, drying to a constant weight, ashing for 24 hr at 600 degrees C, and correction for the transverse processes. The true are was measured by parallax free X rays and planimetry. All measurements of BMC or BMD were highly interrelated (r = 0.94-0.99). The standard error of estimate (s.e.e.) of BMC in situ versus BMC in water/ethanol was 5.2%. The agreement between the BMD values of the two scanners was very good (s.e.e. = 2.9%). BMC in situ predicted the actual vertebral mineral mass with an s.e.e. of 8.1%. BMD in situ and BMD in water/ethanol predicted the actual area density with s.e.e.s of 10.3% and 5.0%, respectively. This study discloses the correlation and accuracy error of spinal DPA measurements in situ in whole cadavers versus the actual BMC and BMD. The error, which is underestimated in in vitro studies, amounts to 10%.

Adult↗
PubMed1987

Bone mass, bone structure and vertebral fractures in osteoporotic patients.

The clinical severity of bone disease was studied in 44 post-menopausal osteoporotic women. Spinal x-rays were assessed and compared to objective measurements of bone mass and bone structure; forearm bone mineral content (BMCarm) by single photon absorptiometry, total body bone mineral content (TBBM), and spinal bone mineral content (BMCspine) by dual photon absorptiometry, and corrected cortical width (C Cor W), trabecular bone volume (TBV), and indices of trabecular microstructure by iliac crest biopsy. For comparison data of BMCarm, TBBM and BMCspine in 25 post-menopausal normals are shown. The results showed a reduction in amount of both cortical and trabecular bone in the fracture patients compared to normals. A subdivision of the fracture patients into two groups constituting 26 patients with wedge fractures alone and 18 patients with compression (+wedge) fractures showed that the latter group had a further predominantly trabecular bone loss and a further deteriorated trabecular microstructure. On an individual basis no agreement between clinical severity of bone disease and amount and structure of bone could be demonstrated.

Aged↗
PubMed1987

Bone composition in the distal forearm.

Recent data have indicated that measurements of bone mass in the very distal part of the forearm is superior to more proximal measurements in identifying osteoporosis. Bone slices from the distal part of the forearm were obtained from 16 necropsies and the trabecular fraction of the total dry bone weight was measured in adjacent bone slices, 8 mm thick. Prior to autopsy bone mass at the corresponding sites was measured using a multipath single photon absorptiometric method by which scans are obtained proximal (proximal BMC) and distal (distal BMC) to the site, where the ulna and radius are 8 mm apart. The accuracy of bone measurements at the two sites was virtually similar (r = 0.98 and r = 0.94, respectively). In both areas the amount of trabecular bone increased towards the metaphysis with a trabecular/cortical ratio ranging from 10 to 60% (wt/wt). If bone composition is known it is possible to estimate rates of bone loss from the two compartments.

Adult↗
PubMed1987

Usefulness of regional bone measurements in patients with osteoporotic fractures of the spine and distal forearm.

Bone mineral mass was measured in normal subjects and osteoporotic patients at two forearm sites (proximal and distal of the 8 mm site between the two forearm bones) by single photon absorptiometry and in the spine and whole body by dual photon absorptiometry. There were no signs of preferential low spinal bone mass in 28 patients with vertebral fractures. Their bone mass was at all sites 26% to 37% lower than the premenopausal mean value and 7% to 13% lower than in age-matched normal women. In 45 patients with forearm fractures bone reduction was also universal but only 3% to 6% lower than in healthy women of comparable age. The spinal bone mass in all the patients was significantly related to both forearm measurements with coefficients of correlation of 0.58-0.61 and s.e.e. of 18%. Compared to the premenopausal normal range the distal forearm site had a greater sensitivity in identifying patients with vertebral fractures than had the spinal measurement (chi-square test, p less than 0.01). We thus conclude that patients with vertebral fractures have universal osteoporosis and that measurement of spinal BMC had no predictive advantages over that of the forearm bone mass for population studies.

Aged↗
PubMed1987

Total body bone mineral in healthy adults.

Total body bone mineral (TBBM) was measured by dual photon absorptiometry (DPA) using a gadolinium 153 source in 135 healthy women aged 21 to 77 years and 101 healthy men aged 20 to 74 years. Among several predictor variables, including lean body mass measured by DPA, weight, and height, only normalization for the projected skeletal area (i.e., calculation of the total body bone density) had an appreciable effect on reduction of TBBM variation. In regression analysis of TBBM, raw and normalized, vs. age, a menopause-adjusted age was used for interpretation of data in women. Regardless of the normalization procedure, the best fit of TBBM vs. menopause-adjusted age was obtained by a polynomial regression of the third degree or a combined linear (premenopausal)--exponential (postmenopausal) regression. In men bone loss was linear with age (0.2% to 0.3% per year). In women, no significant premenopausal bone loss was found. The postmenopausal exponential loss was 4%, 0.44%, and 0.03% per year from TBBM 1 year, 10 years, and 20 years after the menopause. This amounts to a negative calcium balance of 100 mg calcium per day during the first postmenopausal year, and returning to zero after 20 years of menopause, when about 20% of premenopausal bone is lost.

Adult↗
PubMed1986

Bone changes occurring spontaneously and caused by estrogen in early postmenopausal women: a local or generalised phenomenon?

Regional values of bone mineral content and bone mineral density were calculated from total body dual photon absorptiometry scans of 52 early postmenopausal women treated with oestrogen for one year and of 52 similar women treated with placebo. The six regions were head, arms, chest, spine, pelvis, and legs. In addition, bone mineral density of the lumbar spine was measured by dual photon absorptiometry and bone mineral content of the forearm by single photon absorptiometry, using separate special purpose scanners. All regions were unchanged after one year of treatment with oestrogen, excluding the lumbar spine, for which values rose. Values for all regions except the lumbar spine fell significantly in the placebo group. The rates of loss ranged from 2% to 8%, with no significant differences among the regions. It is concluded that loss of bone in the early menopause is a generalised phenomenon, affecting all parts of the skeleton. Furthermore, oestrogen prophylaxis for loss of bone is effective in all parts of the skeleton. Finally, it is suggested that the measurement of bone mineral content in the forearm should be used for clinical follow up of bone changes, as this method is superior to others in the ratio of change to precision.

Bone and Bones↗
PubMed1986

Is postmenopausal bone loss an age-related phenomenon?

Forearm bone mineral content (BMC), an index of skeletal mineralization, and lean body mass (LBM), an index of the muscle mass in the body, were calculated in 574 healthy, white subjects, aged 20-89 years. In women, there was no significant change in BMC with age until the menopause. Thereafter, a significant decline averaging 15% per decade was found up to the age of 70 years, after which it was 10% per decade. In men, there was a significant overall decline of about 4% per decade from the age of 20. When BMC was corrected for LBM, the age-related fall in men disappeared, while remaining without a significant trend in premenopausal women. This was, however, not the case in women after the menopause, where a significant decline of about 12% per decade was noted. These data clearly demonstrate that the major contribution to the well-known bone loss in postmenopausal women is not a simple age-related phenomenon. The development of osteoporosis must be due to some additional bone-diminishing effect on the female skeleton, most likely the absence of estrogen.

Adult↗
PubMed1986

Prediction of body composition by age, height, weight, and skinfold thickness in normal adults.

In order to establish an easy and reliable method for estimating body composition, the lean body mass (LBM) and the fat mass (FM) were measured in vivo in 228 normal adults (130 women and 98 men) using dual photon (153Gd) absorptiometry. In addition, skinfold thickness was measured at two sites in each subject. Multiple regression equations of LBM and FM based on age, height, and weight were computed (r = .86 to .95, SEE = 2.1 to 2.9 kg). These correlations were only slightly improved in men, but not in women, when the results of the skinfold measurements were included in the calculations. We conclude that LBM and FM can be estimated in normal adults from age, height, and weight with a predictive error below 3 kg.

Adult↗
PubMed1986

Measurement of lean body mass and total body fat using dual photon absorptiometry.

We describe a method for measuring the lean body mass (LBM) and total body fat (FAT) by dual photon absorptiometry (DPA). A total body rectilinear scan was employed with a radiation source of 1 Ci 153Gd. The reliability of estimating the lean percent was assessed in vitro using limb phantoms consisting of ox muscle, lard, and human bone. The precision and accuracy in vitro of the lean percent determination were 1.5% and 1.9%, respectively. The accuracy error in vivo of measuring the total mass of soft tissues (TMST) was approximately 1.4%, thus yielding an overall accuracy error of the LBM of about 2.5%. The precision in vivo of the lean percent and the LBM in kg of duplicate measurements on five healthy subjects was 2.5% and 2.2%, respectively. Other estimates of the LBM and FAT, ie, the calculation according to Boddy et al6 and the skinfold thickness measurement (triceps and subscapular), were compared to the DPA measurement in 100 healthy subjects. High correlations were found between the FAT or FAT% by DPA versus (1) the FAT or FAT% calculated according to the formulae of Boddy et al, and (2) the skinfold thickness. The correlations between the FAT and FAT% by Boddy et al and the skinfold thickness were, however, moderate. The correlation between LBM by DPA and LBM by Boddy et al was highly significant (r = 0.96, SEE = 4.4%). We conclude that LBM and FAT measurements using DPA have precision and accuracy errors that are commensurate with a reliable estimation of the gross body composition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1986

Iliac crest biopsy: representativity for the amount of mineralized bone.

The aim of the study was to evaluate the representativity of iliac crest biopsy for the amount of mineralized trabecular and cortical bone in the skeleton. The following data were obtained on bone from 14 necropsies: right sided iliac crest biopsy, lumbar spine biopsy, dry fat free weight of lumbar spine, bone mineral density (BMD) in the lumbar spine and dry fat free weight of cortical and trabecular bone from the left distal forearm. The amount of mineralized cortical and trabecular bone from various sites was compared by linear regression analysis. The results confirm iliac crest biopsy as a good predictor of the amount of trabecular bone, but not of cortical bone. Furthermore, iliac crest biopsy is a better estimate of the amount of trabecular bone in the lumbar spine than spinal BMD.

Adult↗
PubMed1986

The diagnostic validity of local and total bone mineral measurements in postmenopausal osteoporosis and osteoarthritis.

Assessment of different forms of prevention and treatment of bone mineral loss depends upon valid and precise methods to assess bone mass. We have here studied four groups of women: 45 healthy premenopausal women, 37 healthy postmenopausal women, 21 women with osteoarthritis and 20 with hip fractures. Bone mass was measured in the spine and total body by dual photon absorptiometry and in two forearm sites (proximal and distal bone mineral content (BMC) by single photon absorptiometry. The long-term (1 year) reproducibility was 1.2% for proximal BMC, 1.6% for distal BMC, 5.5% for spinal BMC, and 2.1% for total body bone mass (TBBM). In the early postmenopausal years bone mass was mainly reduced in areas with a high content of trabecular bone. In elderly postmenopausal women and women with hip fractures bone mass was almost identical in all four sites studied. The osteoarthritic patients had an 18% reduction of bone mass in the forearms and in TBBM, whereas the spinal bone mass was only reduced by 6%. In all subgroups TBBM could be predicted from the forearm measurements with standard errors of estimates of 9-13%. When the osteoarthritic women were excluded spinal bone mass could be predicted from both forearm measurements with a standard error of 15% (r = 0.74). The distal forearm BMC seems to be a more accurate estimate of spinal bone mass than does the proximal measurement. Of the 20 patients with hip fracture 16 had a distal forearm value below the premenopausal normal range, whereas spinal bone mass was subnormal in only eight (P less than 0.05). We conclude that bone loss is universal in patients with hip fracture and measurements of forearm bone mass will meet most clinical and research demands.

Adult↗