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PubMed1988

Measurement of spinal or peripheral bone mass to estimate early postmenopausal bone loss?

This report presents data from 153 healthy, early postmenopausal women who were randomly allocated to two years of treatment with estrogen or placebo. Bone mineral content in the forearms was measured by single-photon absorptiometry, and bone mineral density of the lumbar spine and total-body bone mineral by dual-photon absorptiometry, before and after one and two years of treatment. At the end of the two years, there were highly significant differences of 6 to 7 percent between the estrogen and the placebo groups at all sites measured. The range of the changes of the spine measurement was twice that of the forearm and total-body measurements. It is concluded that measurement of the forearm by single-photon absorptiometry is superior to measurement of the spine by dual-photon absorptiometry both in clinical studies and in the individual patient for detecting estrogen-dependent bone loss and its treatment by estrogen replacement.

Double-Blind Method↗

PubMed1988

The hock as a potential site for non-invasive bone measurement.

An in vitro study on the calcaneus of adult horses (n = 5) and foals (n = 10) was carried out using radiographic photodensitometry, single photon absorptiometry, transmission ultrasound velocity and chemical analysis. Data for trabecular bone content, ash, calcium and phosphorus levels were obtained. As techniques for assessing bone quality, ultrasound velocity was not sufficiently sensitive nor accurate and radiographic photodensitometry was found to be limited value. Photon absorptiometry was both accurate and reproducible, although some variation in bone mineral content and bone mineral density was observed along the length of the calcaneus. Bone mineral content was estimated in a second series of fibular tarsal bones from 23 horses ranging in age from less than six months to 16 years. The photon absorptiometry technique was also applied to the hocks of four hind limbs at post mortem and two horses under general anaesthesia. It was concluded that the calcaneus was a feasible site for photon absorptiometry, but that the present equipment would require considerable modification for use in the standing horse.

Absorptiometry, Photon↗

PubMed2004

[Long-term effects of 7-year growth hormone substitution on bone metabolism, bone density, and bone quality in growth hormone-deficient adults].

BACKGROUND AND PURPOSE: Subnormal bone mineral density (BMD) and increased fracture risk are described in patients with growth hormone deficiency (GHD). Growth hormone (GH) has been reported to have beneficial effects on bone in GHD. The aim of this study was to investigate the long-term effects of GH replacement therapy on bone metabolism, BMD, and bone quality in patients with GHD. PATIENTS AND METHODS: 20 adult patients with GHD (eleven male, nine female, mean age 42.5 years) were included in the study and randomized to either GH or placebo in a dose of 0.25 U/kg body weight/week. After 6 months all patients received GH. After a 1-year double-blind, placebo-controlled study the patients were followed for another 72 months in an open study. The patients were compared to 20 age- und sex-matched healthy controls. Bone turnover was determined by ICTP (type I collagen carboxyterminal cross-linked telopeptide) as parameter of bone resorption and PICP (carboxyterminal propeptide of type I procollagen) as marker of bone formation. BMD was measured at the lumbar spine by dual-photon absorptiometry (DPA) and at the forearm by single-photon absorptiometry (SPA). Apparent phalangeal ultrasound transmission velocity (APU) was assessed as parameter of bone quality independent of BMD. RESULTS: At the beginning of the study BMD at both measuring sites was lower in patients with GHD than in healthy controls. During the 1st year of GH replacement therapy BMD decreased, followed by a continuous increase in BMD (about 12%) up to 60 months which remained unchanged thereafter, building up a plateau. After 72 months no significant difference between the patients and the healthy controls could be detected. Concerning parameters of bone turnover, first ICTP as marker of bone resorption showed a significant increase, later on the marker of bone formation increased as well. APU decreased during the first 6 months of treatment, but had returned to its baseline value after 24 months and remained unchanged throughout the rest of the study. CONCLUSION: BMD is subnormal in adults with GHD. GH replacement therapy stimulates bone turnover in patients with GHD and in the long term such stimulation results in an increased BMD. Thereby, GH shows a triphasic action on BMD: an initial decrease in BMD during the 1st year, followed by a continuous increase in BMD with buildup of a stable plateau after 60 months. The newly formed bone seems to have normal bone elasticity.

Absorptiometry, Photon↗

PubMed1991

Heterogeneity of growth of bone in children at the spine, radius and total skeleton.

Bone mineral content (BMC), density (BMD), and size were measured in 202 subjects ranging from 3 to 25 years of age (106 males and 96 females), half of which were children and half young adults. BMC and BMD were measured using single photon absorptiometry at the proximal and distal radius and dual photon absorptiometry at the lumbar spine and the total body. In the pre-pubertal age group (3-9 yrs), no differences were found in BMC nor BMD between males and females at any site. Growth of bone during puberty was characterized by an increase in BMC, bone size and BMD. The percent increase in BMC was greater at the lumbar spine and the total body (+200 to +390 %) than at the radius (+90 to +270 %). The increase in BMC was higher than the increase in BMD (+50 to +90 %). Overall bone growth in the total body was not reflected by changes in BMC of the appendicular skeleton. The increase in BMD was heterogeneous and was higher in the legs than in the arms. In males, the increase in BMC and size during growth was greater than in females resulting in a higher peak bone mass and size in males. The increase in BMD was similar between males and females at the distal radius, the lumbar spine and the total body, but higher at the proximal radius, the arms and the legs in males.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMedDate not supplied

Osteoporosis: radiologic and nuclear medicine procedures.

A number of radiographic and nuclear medicine techniques are available for the assessment of patients suspected of having osteoporosis or at risk for the development of osteoporosis. Spinal radiographs are insensitive indicators of osteoporosis. They can document the presence of metastatic tumors or other lesions that may produce compression fracture. The Singh index assesses the trabecular pattern of the proximal femur. As bone loss occurs, the trabeculae disappear in a definite sequence. Radiogrammetry refers to the measurement of bone and cortical widths in the peripheral skeleton, usually the second metacarpal. The method is low cost and most useful for population studies. It does not reflect early osteoporosis. Photodensitometry entails radiography of a part of a bone with inclusion of a standard reference wedge on the radiograph. The density of the bone is compared with the wedge. In some laboratories, precision is good (1.5 percent) and the radiation dose is low. Peripheral cortical bone is measured primarily, which is a disadvantage. Single photon absorptiometry uses the transmission of 27.5 keV photons emitted from an iodine-125 source to assess bone density. In most instances, measurements of the radial shaft are made, which reflect primarily cortical bone rather than the more reactive trabecular bone. The distal end of the radius and the calcaneus may also be measured; these areas contain primarily trabecular bone. Radiation dose is low (less than 10 mrad), but when cortical bone is evaluated, the results correlate poorly with spinal bone mineral. Thus, the test is an insensitive indicator of spinal osteoporosis. Dual energy photon absorptiometry uses a gadolinium-153 isotope source to emit photons of two different energies. The spine, hip, or total bone mineral can be evaluated. The radiation dose is low(<20 mrem). Although the axial skeleton can be assessed, the scan reflects the density of both the cortical and the trabecular bone and any adjacent calcification.Quantitative computed tomography (QCT) uses a reference phantom that is scanned adjacent to the patient to correct for scanner variations. The study allows the trabecular bone of the spine to be evaluated separately from the cortical bone. Precision is 1-3 percent. Accuracy is decreased by the presence (in older individuals) of vertebral marrow fat that makes the measured values of bone mineral spuriously low.CT scanning, using two X-ray energies, can improve accuracy, but decreases precision.

Absorptiometry, Photon↗

PubMed1993

Reduced creatinine clearance in primary osteoporosis in women.

We determined the relationship between bone mass and age, anthropometric variables, and serum and urine biochemical variables in 77 normal white women and 37 women with primary osteoporosis, 25 of whom had one or more vertebral compression fractures. Skeletal status was assessed by radiography of the hands with measurement of combined cortical thickness of the second metacarpal bones (CCT) or measurement of radial and lumbar bone density, or by both methods. Radial bone mineral content (RBMC) was measured by single-photon absorptiometry (SPA) and lumbar bone mineral density by dual-photon absorptiometry (DPA). Serum and urine biochemical variables were measured on days 6 and 7 of a controlled diet. In this mixed population of normal and osteoporotic women, we confirmed the strong positive correlation between creatinine clearance (Ccr) and bone mass that we previously reported in normal women. Multiple regression analysis showed that the relationship between Ccr and bone mass of the radius and lumbar spine was independent of age and body stature. Ccr was significantly lower in the 25 osteoporotic women with vertebral crush fractures than in age-matched normal women, and Ccr had predictive value for bone mass in individual subjects. The basis for the relationship between Ccr and bone mass has not been established. We excluded diminished production of 1,25-dihydroxyvitamin D as a result of declining renal function as a possible mechanism.

Absorptiometry, Photon↗

PubMed1992

[Spinal and appendicular osteoporosis in streak gonad syndrome. Photon absorptiometric and roentgen-morphometric studies].

Patterns of bone loss in the axial and the appendicular skeleton were studied in 48 women with streak gonad syndrome (age: between 14-38 years, mean: 25.5 years). Bone mineral content was measured in vivo at the lumbar spine and right femoral neck by dual photon absorptiometry and at the midradius and distal radius by single photon absorptiometry. The bone mineral status of 20 patients was evaluated by radiomorphometrical indices of the metacarpals, femorals and lumbar spine, too. Mean bone mineral content and radiomorphometrical indices were significantly lower in patients with streak gonad syndrome than in age-matched normal subjects at all three scanning sites. The patients lost cortical and trabecular bone mineral content at the same rate, suggesting that bone loss in streak gonad syndrome is a generalized phenomenon. In spite of serious bone loss osteoporotic fractures were not observed in the patients, in contrast to patients with pathological post-menopausal osteoporosis having equal degree of bone deficiency. The authors did not find any relationship between the occurrence of osteoporosis and the karyotype of the patients. It is suggested that the osteoporosis in streak gonad syndrome--at least after puberty--is a consequence of gonadal hormone deficiency.

Absorptiometry, Photon↗

PubMed1993

Bone mass measurement: how, where, when and why?

Low bone mass, by far the major causal factor in osteoporotic fractures, cannot be predicted from the clinical evaluation of risk factors for osteoporosis. Measurement of bone mass is commonly achieved by using dual-energy X-ray absorptiometry (DXA), which has replaced dual-photon absorptiometry (DPA); single-energy X-ray absorptiometry (SXA), which is likely to replace I-125 single-photon absorptiometry; and by using quantitative computed tomography (QCT). Measurement of ultrasound speed and attenuation across the calcaneum is another promising method still under investigation. Each method may have some advantage or disadvantage relating to practical aspects (cost, scanning time, availability) and technical aspects (radiation dose, accuracy, precision). Several clinical situations have been identified in which measurement of bone mass will be useful, including women after the menopause to select those who should receive bone-sparing agents, and patients with x-ray vertebral deformity to confirm the diagnosis of osteoporosis. DXA allows measurement of bone mass at different skeletal sites, including the lumbar spine (by anteroposterior and lateral view), the hip, the forearm, and the total skeleton. The choice of the site to be screened will often be dictated by clinical considerations such as age and associated osteoarthritis, but, in theory, should be oriented by the ability of bone mass measurement at each site to predict osteoporotic fractures. Several prospective studies have shown that a decrease of 1 standard deviation of bone mass is associated with a 1.5- to 3-fold increase of the relative risk of fracture. Measuring any site is probably equally predictive of the risk of all osteoporotic fractures, while measurement of the hip appears to be a better predictor of the risk of hip fracture.

Absorptiometry, Photon↗

PubMed1989

The effects of lactation on bone mineral content in healthy postpartum women.

Bone mineral contents were estimated by dual photon absorptiometry of the lumbar spine (L2-L4) and single photon absorptiometry of the mid- and distal radius in 19 healthy women on their second postpartum day and at 6 months postpartum. All bone mineral measurements were performed by one technician, and the single and dual photon absorptiometry results were read by one observer. Daily oral calcium intakes were estimated from dietary histories obtained by a dietitian. Twelve women who breast-fed exclusively throughout the first 6 months postpartum were compared with seven formula-feeding women who did not breast-feed or who breast-fed for less than 3 months postpartum. No differences were found in age, parity, height, weight, or daily calcium intake between the breast- and formula-feeding women. Breast-feeding women had a significant decrease (averaging 6.5%) in bone mineral of the lumbar spine at 6 months postpartum as compared with 2 days postpartum (1.14 +/- 0.03 versus 1.22 +/- 0.03 g/cm2, mean +/- SEM; P less than .001), whereas no significant change occurred in the formula-feeding women at 6 months (1.24 +/- 0.03 versus 1.26 +/- 0.04 g/cm2). At 6 months postpartum, the breast-feeding women had a significantly lower mean bone mineral content of the lumbar spine than did formula-feeding women (P less than .05). No significant changes were noted in bone mineral content of the mid- or distal radius in either group of women during the period of evaluation. We conclude that during the first 6 months postpartum, breast-feeding is associated with bone mineral loss from the lumbar spine, but not from the mid- or distal radius.

Adult↗

PubMed1992

Change in bone mass immediately before menopause.

A group of 75 healthy women nearing menopause were entered into a longitudinal study of bone mass and bone cell function. All were at least 46 years, were still menstruating, and had premenopausal levels of follicle stimulating hormone (FSH) and estradiol (E2). Bone density measurements of the spine (dual-photon absorptiometry, DPA) and total-body (DPA) and forearm (single-photon absorptiometry, SPA) were made at 6 month intervals along with measurements of FSH and E2 over an average of 2.04 +/- 0.45 years. The annual rate of change in bone mass was determined for each individual by regressing the bone mass measurement at each site at the time of observation. The slopes were pooled, and the percentage annual change was calculated as the mean slope divided by the initial mean bone mass value. The mean rates of change in bone mass were calculated with and without weighting by length of observation. No meaningful differences in the results were seen in the weighted values compared to the unweighted values, and none of the sites showed a slope significantly different from zero. Demonstrated reproducibility and sample size provided sufficient power to detect annual weighted rates of change of 0.81% for spine BMC, 0.69% for spine BMD, 1.31% for forearm BMC, 1.55% for forearm BMC/BW, and 1.09% for total body bone mineral. We conclude that if changes in bone mineral are occurring in women at this age, they are substantially less than 1%/year for spine and not much more for the forearm or total skeleton.

Absorptiometry, Photon↗

PubMed2001

The effects of region-specific resistance and aerobic exercises on bone mineral density in premenopausal women.

Epidemiological, cross-sectional, and prospective studies strongly suggest that exercise has beneficial effects on bone mass in premenopausal women. We prospectively compared the effects of resistance or aerobic exercises on regional bone mass in premenopausal active duty military women ranging in age from 19 to 40 years. Subjects were assigned, by preference, to a resistance exercise group or an aerobic exercise group and instructed to exercise at least 30 minutes per day, three times per week, for a period of 1 year. Bone mineral density (BMD) was measured by dual photon absorptiometry at the lumbar spine and femoral neck and by single photon absorptiometry at the mid radius at baseline, 6 months, and 12 months. BMD increments during the study were statistically significant at all sites in both exercise groups. Comparisons between the groups showed that after 12 months, BMD increased similarly in the lumbar spine (2.2% resistance vs. 1.8% aerobics, p = not significant) but more in the resistance group in the femoral neck (5.0% vs. 2.7%, p < 0.001) and the mid radius (7.8% vs. 6.7%, p < 0.05). Both resistance and aerobic exercises increase regional bone mass, particularly cortical bone mass, in premenopausal women. Resistance work appears to have a slightly greater effect on cortical bone than aerobics alone. A combination of aerobics and resistance exercises, therefore, may be a useful strategy for increasing peak bone mass in premenopausal women.

Absorptiometry, Photon↗

PubMed2003

Effects of metal implants on whole-body dual-energy x-ray absorptiometry measurements of bone mineral content and body composition.

OBJECTIVE: The purpose of this study was to evaluate the influence of metal implants on measurements of bone mineral content and body composition by x-ray-based dual-photon absorptiometry. METHODS: Four whole-body dual-photon absorptiometry scans were performed on 13 participants with metal rods either present or absent during the scans. The influence of the amount of metal (50 g, 100 g and 150 g), the proximity of the metal rod to the x-ray source and the reproducibility of any metal-induced effects were evaluated by altering the position or the size of the metal rod used, or both. RESULTS: The presence of metal rods weighing 100 g or 150 g significantly increased reported total body mass and bone mineral content (p < 0.034). Soft-tissue mass was increased when the scan included the 100-g rod (p < 0.003). The proximity of the metal to the x-ray source did not have a significant influence on the body composition changes induced by the metal. The effects of the metal rods on body composition variables were reproducible. CONCLUSION: The presence of metal rods inflated body composition variables measured by dual-photon absorptiometry; however, the effects are reproducible during repeat scans of an individual patient. Metal had the largest impact on whole-body bone mineral content, causing errors of 1.5%-3%.

Absorptiometry, Photon↗

PubMed1991

Bone mineral density in patients with cervical and trochanteric fractures of the proximal femur.

The bone mineral density (BMD) of the proximal femur, spine and radius shaft was determined in 75 women with atraumatic fractures of the proximal femur (FXf) (average age: 70.1 +/- 9.6 years) and 51 controls of similar age. Fractures were classified as either cervical (n = 36) or trochanteric (n = 39) on the basis of radiographic and surgical finding. The BMD of spine and proximal femur was determined by dual-photon absorptiometry (Lunar DP3) and the BMD of the radius shaft by single photon absorptiometry. The BMD of patients with FXf was significantly decreased over all skeletal sites compared to controls of similar age. No significant correlation was found between age and the BMD of the femoral neck in patients with FXf. Patients with trochanteric FXf were older and thinner (average: age, 72.9 +/- 9.4 years; weight, 53.1 +/- 7.8 kg) compared with patients with cervical fractures (age, 67.2 +/- 8.9 years; weight, 59.3 +/- 8.3 kg). Likewise the BMD of trochanteric FXf was lower at all measured sites: femoral neck, 0.548 +/- 0.066 g/cm2 vs 0.624 +/- 0.055 g/cm2 (P less than 0.001); L2-L4, 0.799 +/- 0.115 g/cm2 vs 0.925 +/- 0.106 g/cm2 (P less than 0.001); radius shaft, 0.454 +/- 0.057 g/cm2 vs 0.502 +/- 0.083 g/cm2 (P less than 0.05). Of the patients with trochanteric fractures 66% had concomitant vertebral fractures, while this occurred in only 28% of the patients with cervical fractures (P (Fisher) = 0.0007). In summary, females with trochanteric FXf are older, thinner, have less bone mass in all measured sites and suffer with a significantly greater frequency of vertebral fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed2000

Ultrasonographic, axial, and peripheral measurements in female patients with benign hypermobility syndrome.

Twenty-five female Caucasians, aged 19-57 years, with the hypermobility syndrome had bone density measurements using established noninvasive techniques such as dual X-ray absorptiometry (DXA), single photon absorptiometry (SPA), heel ultrasound (US), and peripheral computed tomography (pQCT) acquisitions of the radius. As a group, comparisons of the different bone indices with the corresponding age-matched reference population resulted in normal z-scores for the arial densities, however, values for the volumetric total and cortical bone at the radius measured by pQCT were significantly lower than expected (P < 0.0001). Spinal and femoral bone density results were significant after correction for body mass index (BMI). This cross-sectional study shows that the benign hypermobility syndrome patients have lowered t-scores for data reflecting bone structure and bone strength as measured with US and the tomographic technique.

Absorptiometry, Photon↗

PubMed1991

Glucocorticoid-induced osteoporosis: a cross-sectional study.

We studied 70 patients (48 women and 22 men) with either rheumatic disease (n = 25) or lung disease (n = 45) who had been treated with glucocorticoids for at least 6 months (mean cumulative dose, 24.2 +/- 27.1 g of prednisone; mean current dose, 11.0 +/- 8.6 mg/d, mean duration of therapy, 8.1 years. We measured bone mineral density (BMD) of the hip (femoral neck) and spine (L2-L4) using dual-photon absorptiometry and BMD of the distal one third radius using single-photon absorptiometry. Compared with age-matched controls, the study population had decreased BMD of the spine (87.0%), hip (87.2%), and radius (90.6%). Current dose, cumulative dose, and duration of therapy were not correlated with BMD in the spine or hip in the total study population. The most significant correlations with low bone mass at the hip and spine were short height and low weight. There was a high incidence of hypercalciuria (30%) as compared with an age- and sex-matched control group (6.4%). Glucocorticoids are known to decrease vertebral and radial bone density. We conclude that glucocorticoids also decrease hip bone density as measured at the femoral neck. The high incidence of hypercalciuria may have implications for therapy of glucocorticoid-induced osteoporosis.

Absorptiometry, Photon↗

PubMed1992

Bone mass status in different degrees of chronic renal failure.

Bone mineral density (BMD) was evaluated in 69 patients with chronic renal failure (CRF) and in healthy controls matched for age, sex, and, for women, menopausal status. Both appendicular (predominantly cortical) and axial (predominantly trabecular) bone mass were measured. Appendicular BMD was measured by single photon absorptiometry on the distal forearm and axial BMD was measured by dual photon absorptiometry on the lumbar spine. Patients were divided into three groups on the basis of creatinine clearance: group 1, 58 to 36 ml/min; group 2, 30 to 18 ml/min; group 3, 15 to 9 ml/min. Both appendicular and axial BMD decreased with the worsening of renal failure. Parathyroid hormone levels were inversely correlated with the values of appendicular BMD. BMD values were significantly lower in postmenopausal than in premenopausal women. Months of menopause were inversely correlated with axial BMD values. Appendicular BMD was lower in CRF patients than in controls, and both appendicular and axial BMD were significantly lower in postmenopausal uremic women than in postmenopausal healthy women.

Absorptiometry, Photon↗

PubMed1998

Effect of long-term treatment with GH on bone metabolism, bone mineral density and bone elasticity in GH-deficient adults.

OBJECTIVE: Adults with GH deficiency (GHD) commonly have subnormal bone mineral density (BMD), and have been reported to have an increased risk of fractures. It has been suggested that GH replacement therapy may have beneficial effects on bone in such patients. The aim of this study was to investigate the effects of long-term GH replacement therapy on bone metabolism, BMD and bone elasticity in adults with GHD. DESIGN: At the start of the study, 20 adults with GHD were randomized to receive either GH, 0.25 IU/kg/week (the 'GH group') or placebo (the 'placebo group'). After 6 months, patients in the placebo group were switched to GH therapy, and all patients received GH for a further 42 months. PATIENTS: Of the 20 patients included in the study, 11 were male and nine were female. Mean age at the start of the study was 42.5 +/- 10.1 years. All patients had been GH-deficient for at least 2 years before the start of the study. MEASUREMENTS: Rates of bone resorption and formation were assessed by measuring serum levels of type I collagen carboxyterminal cross-linked telopeptide (ICTP) and carboxyterminal propeptide of type I procollagen (PICP), respectively. BMD was measured at the lumbar spine by dual-photon absorptiometry (DPA) and at the non-dominant forearm by single-photon absorptiometry (SPA). Bone elasticity was assessed by measuring apparent phalangeal ultrasound transmission velocity (APU). RESULTS: The main results in the GH group were as follows. The rate of bone resorption increased significantly during the first 6 months of treatment and remained significantly elevated above its baseline level thereafter. The rate of bone formation also rose during the first 6 months of treatment and remained elevated thereafter, but was significantly higher than at baseline only after 24 months of treatment. At both sites measured, BMD was subnormal at baseline, decreased during the first 6 months of treatment, and increased progressively for the rest of the study, eventually rising well above its baseline level. Bone elasticity decreased during the first 6 months of treatment, but had returned to its baseline level after 24 months. CONCLUSIONS: Our results support previous findings that BMD is subnormal in adults with GHD, that GH replacement therapy can stimulate bone turnover in such adults and that, in the long term, such stimulation results in a significant increase in BMD. In addition they show, for the first time, that BMD may continue to rise even after GH replacement therapy has been administered for 4 years, and indicate that bone elasticity is not adversely affected by long-term GH therapy.

Absorptiometry, Photon↗

PubMed1989

Chemical determination of human body density in vivo: relevance to hydrodensitometry.

A chemical approach to establishing human body density in vivo was developed by combining recently developed noninvasive methods. Four compartments were measured: protein (P; prompt-gamma neutron activation), water (A; 3H2O dilution), mineral (M; dual-photon absorptiometry and delayed-gamma neutron activation), and fat (F; dual-photon absorptiometry). By this model body weight is equal to P + A + M + F. This approach was applied to 13 healthy adults (8 females and 5 males). The four compartments accounted for greater than 97% actual body weight. Calculated density based upon composition agreed within 0.6 +/- 0.4% (mean +/- SD) with density (D) measured by hydrodensitometry [calculated D (g/cc) = 0.86 measured D +0.15; r = 0.94, p less than 0.001]. The average calculated lean (P + A + M) density of 1.096 +/- 0.007 g/cc agreed closely with three classic human cadaver studies (1.100 g/cc). This multicompartment approach provides a new opportunity to estimate human body density in vivo and to refine body composition methods based upon an assumed but inadequately validated constant lean density.

Absorptiometry, Photon↗