Pottery dating from thermoluminescence.

For pottery sherds from an arid region, the ratio of natural thermoluminescence to thermoluminescence induced by a standard dose of radiation corresponds closely to the independently assessed archeologic age. Difficulties in age determination, because of variations among sherds, are reduced by averaging results for samples from the same time period.

Differential changes in bone mineral density of the appendicular and axial skeleton with aging: relationship to spinal osteoporosis.

Patterns of bone loss in the axial and the appendicular skeleton were studied in 185 normal volunteers (105 women and 82 men; age range, 20--89 yr) and in 76 women and 9 men with vertebral fractures due to osteoporosis. Bone mineral density was measured in vivo at the lumbar spine (predominantly trabecular bone) by dual photon absorptiometry and at the midradius (greater than 95% cortical bone) and distal radius (75% cortical and 25% trabecular bone) by single photon absorptiometry. In normal women, bone diminution from the vertebrae began in young adulthood and was linear. In the appendicular skeleton, bone diminution did not occur until age 50 yr, was accelerated from aged 51 to 65 yr, and then decelerated somewhat after age 65 yr. Overall bone diminution throughout life was 47% for the vertebrae, 30% for the midradius, and 39% for the distal radius. In normal men, vertebral and appendicular bone diminution with aging was minimal or insignificant. Mean bone mineral density was lower in patients with osteoporosis than in age- and sex-matched normal subjects at all three scanning sites, although spinal measurements discriminated best; however, there was considerable overlap. By age 65 yr, half of the normal women (and by age 85 yr, virtually all of them) had vertebral bone mineral density values below the 90th percentile of women with vertebral fractures and, thus, might be considered to have asymptomatic osteoporosis. For men, the degree of overlap was less. The data suggest that disproportionate loss of trabecular bone from the axial skeleton is a distinguishing characteristic of spinal osteoporosis.

Changes in bone mineral density of the proximal femur and spine with aging. Differences between the postmenopausal and senile osteoporosis syndromes.

We measured bone mineral density (BMD) of the proximal femur, lumbar spine, or both by dual photon absorptiometry in 205 normal volunteers (123 women and 82 men; age range 20 to 92 yr) and in 31 patients with hip fractures (26 women and 5 men; mean age, 78 yr). For normal women, the regression of BMD on age was negative and linear at each site; overall decrease during life was 58% in the femoral neck, 53% in the intertrochanteric region of the femur, and 42% in the lumbar spine. For normal men, the age regression was linear also; the rate of decrease in BMD was two-thirds of that in women for femoral neck and intertrochanteric femur but was only one-fourth of that in women for lumbar spine. This difference may explain why the female/male ratio is 2:1 for hip fractures but 8:1 for vertebral fractures. The standard deviation (Z-score) from the sex-specific age-adjusted normal mean in 26 women with hip fracture averaged -0.31 (P < 0.05) for the femoral neck, -0.53 (P < 0.01) for the intertrochanteric femur, and +0.24 (NS) for the lumbar spine; results were similar for 5 men with hip fractures. By contrast, for 27 additional women, ages 51-65 yr, with only nontraumatic vertebral fractures, the Z-score was -1.92 (P < 0.001) for the lumbar spine. Thus, contrary to the view that osteoporosis is a single age-related entity, our data suggest the existence of two distinct syndromes. One form, "postmenopausal osteoporosis," is characterized by excessive and disproportionate trabecular bone loss, involves a small subset of women in the early postmenopausal period, and is associated mainly with vertebral fractures. The other form, "senile osteoporosis," is characterized by proportionate loss of both cortical and trabecular bone, involves essentially the entire population of aging women and, to a lesser extent, aging men, and is associated with hip fractures or vertebral fractures or both.

Effect of tamoxifen on lumbar spine bone mineral density in postmenopausal women after 5 years.

BACKGROUND: Because adjuvant tamoxifen citrate is given to women with early-stage breast cancer for long periods, it is important to know how it affects risk factors for osteoporotic bone fractures, particularly since rates of bone fracture increase rapidly with age in postmenopausal women. In a 2-year randomized placebo-controlled toxicity study in 140 subjects, we demonstrated that tamoxifen was associated with preservation of bone mineral density (BMD), a major risk factor for fractures, in the lumbar spine. METHODS: Five years after entry on this study we reexamined 62 of the original subjects with lumbar spine BMD and serum osteocalcin measurements. These were women available for study because they had not suffered major illnesses and had continued to receive (1) tamoxifen or (2) the no-tamoxifen regimen that they had originally been randomized to receive for the entire 5 years. RESULTS: For lumbar spine BMD at baseline, the 30 subjects in the long-term tamoxifen group and the 32 subjects in the long-term no-tamoxifen group were not significantly different (P = .26). During the first 2 years of follow-up, the 30 subjects in the long-term tamoxifen group showed the same BMD pattern as the entire 70-patient tamoxifen cohort, and similarly the 32 subjects in the long-term no-tamoxifen group showed the same pattern as the entire 70-patient cohort who received placebo. Five-year mean BMD measurements for each long-term follow-up group showed no significant changes from their respective 2-year levels. However, 5-year BMD measurements between the two groups differed (tamoxifen group, +0.8%; placebo group, -0.7%) (P = .06), and the mean regression lines for the changes in BMD over 5 years differed significantly between the two groups (P = .0005). Adjustment for differences in body mass index, reported exercise, and calcium supplementation between these two groups did not change these results. Osteocalcin levels, also comparable at baseline in the two groups, were significantly lower in tamoxifen-treated subjects at 5 years (P = .0005). CONCLUSIONS: While remodeling of bone may be lower, resorption of lumbar spine bone mineral is also lower, and tamoxifen preserves BMD in the lumbar spine over 5 years of treatment in postmenopausal women. Over longer periods, this preservation of BMD might be expected to be associated with lower fracture rates.

Normalization of spine densitometry.

We investigated several transformations of bone mineral content (BMC) and area density (BMD), in particular volumetric density (BMAD), to ascertain the influence on (1) body size dependence, (2) diagnostic sensitivity, and (3) precision. These transformations were examined in a group of 657 normal postmenopausal women and 327 women with osteoporotic fracture. First, expression of results as BMAD removed some of the slight dependence on body size; 21% of the variation in BMC and 15% of the variation i BMD were associated with body weight, but only 8% with BMAD. Second, the Z scores compared with those for age-matched controls for BMD and BMC were -1.85 and -1.71, respectively; the Z score for BMAD was -1.64. Third, the precision error for BMC was reduced by expressing results as BMD (1.1 versus 0.5%); BMAD degraded precision slightly (0.7%). BMD appeared to be the optimal expression for bone densitometry because it provided the best diagnostic sensitivity and lowest precision error; there was a minimal influence of body size on BMD results. This study also showed that osteoporotic women, even in the first postmenopausal decade, had low spine BMD, small vertebral area, and low body weight. Such women may be particularly at risk of crush fracture.

Bone density of the radius, spine, and proximal femur in osteoporosis.

Bone mineral density (BMD) was measured in 140 normal young women (aged 20 to 39 years) and in 423 consecutive women over age 40 referred for evaluation of osteoporosis. Lumbar spine and proximal femur BMD was measured using dual-photon absorptiometry (153Gd), whereas the radius shaft measurement used single-photon absorptiometry (125I). There were 324 older women with no fractures, of which 278 aged 60 to 80 years served as age-matched controls. There were 99 women with fractures including 32 with vertebral and 22 with hip fractures. Subsequently, another 25 women with hip fractures had BMD measured in another laboratory; their mean BMD was within 2% of that of the original series. The mean age in both the nonfracture and fracture groups was 70 +/- 5 years. The BMD in the age-matched controls was 20% to 25% below that of normal young women for the radius, spine, and femur, but the Ward's triangle region of the femur showed even greater loss (35%). The mean BMD at all sites in the crush fracture cases was about 10% to 15% below that of age-matched controls. Spinal abnormality was best discriminated by spine and femoral measurements (Z score about 0.9). In women with hip fractures, the BMD was 10% below that of age-matched controls for the radius and the spine, and the BMD for the femoral sites was about 25% to 30% below that of age-matched control (Z score about 1.6). Femoral densities gave the best discrimination of hip fracture cases and even reflected spinal osteopenia. In contrast, neither the spine nor the radius reflected the full extent of femoral osteopenia in hip fracture.

Effects of increasing doses of 1 alpha-hydroxyvitamin D2 on calcium homeostasis in postmenopausal osteopenic women.

This study is the first reported administration of 1 alpha-hydroxyvitamin D2 (1 alpha-OHD2) to human subjects. A total of 15 postmenopausal osteopenic women were given increasing oral doses of 1 alpha-OHD2, beginning with a low dose of 0.5 microgram/day. In 15 subjects, the doses were raised at weekly intervals to 1.0, 2.0, 4.0, and 5.0 micrograms/day, and in 5 of these subjects, the dose was further increased to 8.0 or 10.0 micrograms/day. Mean urine calcium +/- SEM showed a dose-related increase from 134 +/- 17 mg/24 h on 0.5 microgram/day to 198 +/- 21 mg/24 h on 4.0 micrograms/day (p < 0.05) and to 241 +/- 35 mg/24 h on 5.0 micrograms/day (p < 0.05). No subjects had hypercalciuria (> 350 mg/24 h, the upper limit of the laboratory normal range) at doses less than 5.0 micrograms/day; 5 subjects had hypercalciuria at or above 5.0 micrograms/day (3 at 5.0 micrograms/day, 1 at 8.0 micrograms/day, and 1 at 10.0 micrograms/day). Mean serum calcium increased slightly on the 4.0 micrograms dose only (p < 0.05) but remained well within the normal range. Mean creatinine clearance and BUN, used as measures of renal function, showed no significant changes. Routine blood and urine assays also showed no significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Calibration of dual-energy x-ray absorptiometry for bone density.

Bone mineral content (BMC, g) using DEXA (Lunar DPX) was measured on known hydroxyapatite samples in a water bath in the presence of uniform and nonuniform covering of fat-equivalent materials. Selective placement of paraffin over bone had a greater effect than lard in reducing apparent BMC, and polycarbonate plastic had a lesser effect. Measured BMC was 100.1 +/- 1.1% of actual hydroxyapatite weight when (1) fat over bone was about twice the mass of hydroxyapatite, and (2) the surrounding soft tissue was 15-30% fat. There was a linear relationship between observed and expected BMC, area (cm2), and bone mineral density (BMD, g/cm2) measured on an aluminum phantom using either the Lunar DPX or the Hologic QDR-1000. The measured area with the two densitometers was identical, but BMC differed. For both an anthropomorphic phantom and human subjects, use of a constant-threshold (0.2 g/cm2) edge-detection algorithm excluded less low-density bone from the transverse processes than the standard DPX edge-detection algorithm. Differences in edge detection could influence the results obtained with phantoms and in vivo and make system intercomparison difficult.

Bone mineral density in Australia compared with the United States.

Bone density measurements are currently being performed throughout the world in the diagnosis and management of osteoporosis as well as in research into this major health problem. However, it is not clear to what extent bone mineral density (BMD) values determined by dual-photon absorptiometry at one center can be applied to another. This is particularly relevant for the quantitative comparison of results from studies carried out in different laboratories. Furthermore, many centers now acquiring densitometers may not have the resources to determine their own normal range, relying instead on a "normal" range provided by the manufacturer. The question of the comparability of BMD data obtained in different centers was examined by comparing the normal range for the lumbar spine and proximal femur in 203 normal white Australian women and 892 normal white U.S. women, obtained using the same model densitometer. The two populations were compared according to decade. From superimposition of the Australian individual values on the North American normal ranges, only minor differences between the two populations were seen at any of the sites measured at any decade. None of these minor differences were statistically significant. This study shows a close similarity between BMD values in both the proximal femur and lumbar spine in normal white women in Australia and North America, provided the same model densitometer is used. Thus data obtained from different centers in populations with similar ethnic composition may be compared directly. These findings provide for the first time a sound basis for the quantitative comparison of the at times conflicting studies carried out in widely differing settings around the world.

Influence of age and body weight on spine and femur bone mineral density in U.S. white men.

Bone mineral density (BMD) was measured in normal white males using 153 Gd dual-photon absorptiometry. Measurements were made on the lumbar spine (n = 315) and on the proximal femur (n = 282) utilizing three regions of interest. There was a small but significant age-related decrease in spinal BMD (r = -0.11; -0.001 g/cm2 per year) and trochanteric BMD (r = 0.27; -0.002 g/cm2 per year). The BMD of the other femoral sites decreased more rapidly; the femoral neck (r = -0.58; -0.005 g/cm2 per year) and Ward's triangle (r = -0.69; -0.007 g/cm2 per year) declined by about 21 and 34%, respectively, from age 20 to age 70. These femoral BMD decreases were three to four times greater than those usually seen in the peripheral skeleton in males but less than the decreases of 25-30 and 40% in the femoral neck and Ward's triangle of white females. This pattern of aging bone loss may partially explain the paucity of spine fractures and the lower incidence of hip fractures in males versus females.

Bone density in premenopausal women: effects of age, dietary intake, physical activity, smoking, and birth-control pills.

The effects of age, calcium, smoking, and physical activity on appendicular and axial bone mineral density (BMD) were evaluated in a 2-y study of 200-300 healthy young women aged 20-39 y. There was no cross-sectional change of BMD with age or longitudinal change with bone loss. No effect of birth-control pills on BMD was seen. There also was no association of calcium intake with BMD and/or with BMD changes. Current calcium intake was not a significant influence on BMD in this age group. Daily activity had no effect on BMD and there was no apparent additive interaction of activity and calcium intake on BMD. Smokers had significantly lower spine BMD and a tendency for lower BMD at other sites. Body weight was a better predictor of BMD than was any other factor. There was no association of BMD or BMD changes with both urinary calcium and hydroxyproline normalized for creatinine.

Total body composition by dual-photon (153Gd) absorptiometry.

The lean-fat composition (%FATR) of soft tissue and the mineral mass of the skeleton were determined in vivo using dual-photon (153Gd) absorptiometry (dose under 2 mrem). A rectilinear raster scan was made over the entire body in 18 subjects (14 female, 4 male). Single-photon absorptiometry (125I) measured bone mineral content on the radius. Percentage fat (%FATD) was determined in the same subjects using body density (from underwater weighing with correction for residual lung volume). Lean body mass (LBM) was determined using both %FATR and %FATD. Percentage fat from absorptiometry and from underwater density were correlated (r = 0.87). The deviation of %FATD from %FATR was due to the amount of skeletal mineral as a percentage of the LBM (r = 0.90). Therefore, skeletal variability, even in normal subjects, where mineral ranges only from 4 to 8% of the LBM, essentially precludes use of body density as a composition indicator unless skeletal mass is measured. Anthropometry (fatfolds and weight) predicted %FATR and LBM at least as well as did underwater density. The predictive error of %FATR from fatfolds was 5% while the predictive error in predicting LBM from anthropometry was 2 to 3 kg (3%).

Skeletal and body-composition effects of anorexia nervosa.

Eleven female patients (aged 18-46 y) with anorexia nervosa were measured by use of dual-photon absorptiometry for 1) bone mineral content (BMC, in g) and bone mineral density (BMD, in g/cm2) of the total skeleton and its regions, 2) BMD of the lumbar spine and the proximal femur, and 3) total body soft-tissue composition. The patients weighed 44.4 kg, approximately 15 kg less than normal peers (n = 22). The fat mass (3.35 kg) and content of soft tissue (7.8%) were four and three times lower (p less than 0.001) respectively, than those in normal women (15.1 kg and 26%, respectively). The total skeleton mineral (1921 g) was approximately 25% less than that of young normal women. The BMC as a fraction of the lean tissue mass was approximately 4.9% in the patients and 5.9% in normal women. Total body and femoral BMD averaged only 10% and 13% lower than those of normal women, respectively; however, spinal BMD was particularly reduced (approximately 25%, p less than 0.001).

Dual-energy x-ray absorptiometry for total-body and regional bone-mineral and soft-tissue composition.

Bone mineral density (BMD) and soft-tissue composition of the total body and major subregions were measured with dual-energy x-ray absorptiometry (DEXA). Total body scans were made in 12 young adults (6 male, 6 female) on five occasions at both a medium speed (20 min) and a fast speed (10 min). There were no significant differences in mean results or in precision errors between the two speeds. The precision errors (1 SD) for total body BMD, percent fat in soft tissue (% Fat), fat mass, and lean tissue mass were less than 0.01 g/cm2, 1.4%, 1.0 kg, and 0.8 kg, respectively. These results corresponded to a relative error of 0.8% for total body BMD and 1.5% for lean body mass. Regional BMD and soft-tissue values (arms, legs, trunk) were determined with slightly higher precision errors. Skeletal mineral was 5.8 +/- 0.5% of lean tissue mass (r = 0.96, p less than 0.001). DEXA provides precise composition analysis with a low radiation exposure (less than 0.1 microGy).

Bone mineral and vitamin D in Aleutian Islanders.

Serum concentrations of vitamin D metabolites (chromatography) and bone mineral status (125I absorptiometry) were examined in a group of Aleutian Islanders age 40-75 from St Paul Island, Alaska. Based on 25-(OH)D (16.6 ng/ml) vitamin D status appeared adequate. However, high concentrations of 1,25-(OH)2D (44.3 pg/ml) and very low concentrations of 24,25-(OH)2D3 (0.6 ng/ml) were found. Among females, low bone mineral levels were associated with high concentrations of 1,25-(OH)2D. A low calcium intake in these Aleutians may be responsible for high concentrations of 1,25-(OH)2D and resorption of calcium from bone.

Rapid determination of total hydroxyproline (HYP) in human urine by HPLC analysis of the phenylisothiocyonate (PITC)-derivative.

A recent development in the preparation for amino acid analysis is the use of phenylisothiocyanate (PITC) as a precolumn derivatizing agent prior to analysis to form a stable derivative. These derivatives can then be separated by reversed phase high pressure liquid chromatography (HPLC). Because of interest in the accurate measurement of urinary hydroxyproline (HYP), PITC was used for derivatization followed by HPLC analysis. Using an automated computer-controlled sampler system, up to 75 samples can be analyzed each 24 h. Technical details, specificity, and reliability of this method are provided. Duplicate measurements of HYP had a coefficient of variation (CV) of 5.5% and with a recovery of HYP in spiked urine samples of 94 to 104%. A sample frozen and thawed 10 times showed no change in the concentration of HYP. When total HYP was measured in 230 healthy women between 20 and 39 years of age, it was found to be 236.62 +/- 146.41 mumoles/L. These samples were researched in 3.5 days using this technique.

Persistence of diminished bone mineral content following renal transplantation in childhood.

Bone mineral content (BMC) was measured in the nondominant arm of 18 children (aged 3 7/12 to 17 1/2 years) for a total 783 months after renal transplantation. Using photon absorptiometry, 89 measurements were made; 17 of the 18 patients had a functioning graft and one patient died. Significant demineralization, a BMC greater than -2 SD below appropriate control volumes, was found in 11 of 18 patients (62%) and 55 of 89 measurements (61%). Bone loss was progressive; among the 16 patients followed for more than 6 months, ten showed a decline of more than 0.5 SD in BMC, five had no change, and only one showed improvement. No relationship was found between BMC and the use of furosemide, type of transplant (15 living, seven cadaver), prior renal disease (six with glomerulonephritis, 11 tubulointerstitial), need for a second graft (five patients), chronic anticonvulsant therapy, or serum calcium and phosphate values. BMC was slightly correlated (P less than .05) with alkaline phosphatase values. BMC was more strongly correlated with serum creatinine (y = -0.48x + 1.25, r = -.042, P less than .001) and prednisone dose (mg/kg/d) (y = -0.65x + 0.481, r = -.543, P less than .001) in an inverse relationship. Patients whose serum creatinine value was less than 1 mg/dL had a BMC of -0.71 +/- 0.34 SD; those with serum creatinine value greater than 2 mg/dL had BMC of -3.32 +/- 0.31 SD, different at P less than .001. Patients receiving daily prednisone therapy had a significantly lower BMC than those receiving alternate-day therapy (-3.11 +/- 1.23 SD v -1.72 +/- 1.29 SD, P less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Bone mineral status measured by direct photon absorptiometry in childhood renal disease.

Bone width (BW), bone mineral content (BMC), and their ration (BMC/BW ratio) were measured in renal patients using direct photon absorptiometry. Serial measurements were made on the radius and ulna in 74 children with renal diseases. Values were compared to age-, sex-, height-, and weight-matched controls. The SD from the mean in normal subjects is +/- 10%. Significant demineralization (greater than -2 SD) was found in 42% of all patients and in 75% with tubulointerstitial disease. Twelve patients with nephrotic syndrome and two with systemic lupus erythematosus, all of whom were receiving prednisone therapy and had a serum creatinine level less than 1.0 mg/dl, and three treated with anticonvulsants had significant demineralization. Severe demineralization (greater than -3 SD) was found in four rachitic patients with tubulointerstitial disease. Normal mineralization was present in 32 patients with various primary glomerular diseases, seven of whom had a serum creatinine level greater than 1.5 mg/dl. BMC declined with daily prednisone therapy but increased with alternate-day dosage in seven patients. This study suggests that demineralization is more common in patients with tubulointerstitial disease and in patients with primary glomerular disease who are receiving prednisone (16 patients) or anticonvulsants. Photon absorptiometry appeared more useful than conventional radiographic evaluation in assessing skeletal involvement in childhood renal disease.

Long-term influence of calcitriol (1,25-dihydroxyvitamin D) and supplemental phosphate in X-linked hypophosphatemic rickets.

Ten patients with hypophosphatemic rickets (eight with X-linked familial form) were treated with vitamin D2 (10,000 to 75,000 units per day) and oral phosphate (1.5 to 3.6 gm) for a total of 438 treatment months. Therapy was then changed to calcitriol (17 to 34 ng/kg/day) and the same phosphate dose. Patients served as their own controls, and significant biochemical changes noted were an increase in immunoreactive parathyroid hormone from 29 +/- 9 (SD) microliters Eq/ml (pre-phosphate) to 62 +/- 34 on vitamin D2 plus PO4, then decreasing to 40 +/- 20 on a regimen of 1,25-dihydroxyvitamin D (1,25(OH)2D) plus PO4; serum PO4 rose from 2.44 +/- 0.45 (SD) mg/100 ml to 3.06 +/- 0.79 and then to 3.43 +/- 0.76; alkaline phosphatase activity decreased from 677 +/- 298 (SD) IU/liter to 457 +/- 183 to 290 +/- 176. Serum calcium and creatinine levels were unchanged. Both urinary calcium excretion and calcium-creatinine ratio decreased after therapy with 1,25(OH)2D. Urinary phosphate excretion was higher after calcitriol administration. Serum 1,25(OH)2D levels were low in these vitamin D2-treated patients, and an inverse relationship between serum 25(OH)D and 1,25(OH)2D was found. Improved bone mineralization was evident from serial assessment by photon absorptiometry, and radial bone mineral content rose from 75.3% +/- 2.2% of expected to 82.2% +/- 1.4% (P less than .005). Stature was improved when assessed by standard deviation for chronologic age but did not reach statistical significance. Long-term 1,25(OH)2D plus phosphate therapy appears to be more efficacious than vitamin D2 in this form of rickets, particularly in improving phosphate homeostasis.

Does bone measurement on the radius indicate skeletal status? Concise communication.

Single-photon (I-125) absorptiometry was used to measure bone mineral content (BMC) of the distal third of the radius, and dual-photon absorptiometry (Gd-153) was used to measure total-body bone mineral (TBBM), as well as the BMC of major skeletal regions. Measurements were done in normal females, normal males, osteoporotic females, osteoporotic males, and renal patients. The BMC of the radius predicted TBBM well in normal subjects, but was less satisfactory in the patient groups. The spinal BMC was predicted with even lower accuracy from radius measurement. The error in predicting areal density (bone mass per unit projected skeletal area) of the lumbar and thoracic spine from the radius BMC divided by its width was smaller, but the regressions differed significantly among normals, osteoporotics, and renal patients. There was a preferential spinal osteopenia in the osteoporotic group and in about half of the renal patients. Bone measurements on the radius can indicate overall skeletal status in normal subjects and to a lesser degree in patients, but these radius measurements are inaccurate, even on the average, as an indicator of spinal state.