Anteroposterior versus lateral bone mineral density of spine assessed by dual X-ray absorptiometry

Low bone mineral density of vertebral lateral projections can predict spinal radiographic damage in patients with ankylosing spondylitis

OBJECTIVES

To investigate the association between bone mineral status and spinal radiographic damage in patients with ankylosing spondylitis (AS) and determine whether bone mineral status can predict further spinal radiographic damage after 2 years.

METHODS

Bone mineral density (BMD) of the lumbar spine (anteroposterior and lateral projections), femoral neck, and total hip and trabecular bone score (TBS) of the lumbar spine were measured in AS patients (n = 54) who fulfilled the modified New York criteria. Spinal radiographic damage was scored on cervical and lumbar spine radiographs using modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) at baseline and after 2 years. Simple and multiple linear regression analyses were performed to examine predictors of spinal radiographic damage.

RESULTS

Patients with advanced AS exhibited low BMD on lumbar spine lateral projections, femoral neck, and total hip and low TBS. Low vertebral bone mass at baseline, assessed by BMD of the lateral projections or TBS, was independently associated with baseline mSASSS. After 2 years, mSASSS change from baseline was significantly associated with high baseline mSASSS, high baseline erythrocyte sedimentation rate and C-reactive protein (CRP) levels, and low baseline BMD of the lumbar spine lateral projections. The best predictive model for spinal radiographic progression consisted of baseline mSASSS, baseline CRP, and low BMD of lateral lumbar spine (area under curve = 0.826).

CONCLUSIONS

BMD at vertebral lateral projections and TBS were inversely associated with baseline mSASSS in AS patients. Low BMD at vertebral lateral projections, as well as baseline mSASSS and inflammatory markers, might predict spinal radiographic damage in AS.Key Points• Vertebral bone mineral density of lateral projections and trabecular bone score are inversely associated with baseline mSASSS in patients with ankylosing spondylitis.• Baseline mSASSS, inflammatory markers, and low vertebral bone mineral density might predict spinal radiographic progression in patients with ankylosing spondylitis.

Assessment of the risk of low bone mineral density in premenopausal Japanese female patients with systemic lupus erythematosus

Background

The aim of this study was to assess the relationships between clinical parameters and bone mineral density (BMD) in Japanese female patients with systemic lupus erythematosus (SLE).

Methods

A total of female 136 SLE patients without menopause were retrospectively assessed to identify associations between age, disease duration, body mass index (BMI), glucocorticoid usage and disease activity and BMD based on the treatment with or without bisphosphonate. There were 71 patients treated with bisphosphonate (bisphosphonate group) and 65 patients without (non-bisphosphonate group). We evaluated the impact of age, disease duration, BMI, serologic SLE markers, glucocorticoid use on BMD of the anterior-posterior (AP) and lateral lumbar spine, total hip and femoral neck using univariate and multivariate linear regression analyses of both bisphosphonate and non-bisphosphonate groups.

Results

Multivariate linear regression analyses showed that in non-bisphosphonate group disease duration was negatively associated with BMD of AP spine and femoral neck, whereas in bisphosphonate group these negative associations were not present. However, multivariate linear regression analyses showed a significant relationship between BMI and BMD of the AP spine, femoral neck and total hip, regardless of bisphosphonate treatment.

Conclusions

Bisphosphonate treatment eliminated the negative relationships between disease duration and the BMD of the spine and hip. AP spine and hip BMD in patients with SLE depend on BMI, regardless of bisphosphonate use. SLE serologic markers and glucocorticoid use were not negatively associated with generalized bone loss. SLE patients with low BMI have a high risk of generalized bone loss, and should be assessed and treated to prevent osteoporosis even before menopause.

Vertebral Imaging in the Diagnosis of Osteoporosis: a Clinician's Perspective

PURPOSE OF REVIEW

Vertebral fractures are the most common osteoporotic fracture and result in functional decline and excess mortality. Dual-energy x-ray absorptiometry (DXA) is the gold standard for the diagnosis of osteoporosis to identify patients at risk for fragility fractures; however, advances in imaging have expanded the role of computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating bone health.

RECENT FINDINGS

The utility of CT and MRI in the assessment of bone density is starting to gain traction, particularly when used opportunistically. DXA, conventional radiography, CT, and MRI can all be used to assess for vertebral fractures, and MRI can determine the acuity of fractures. Finally, advances in imaging allow for non-invasive assessment of measures of bone quality, including microarchitecture, bone strength, and bone turnover, to help identify and treat at-risk patients prior to sustaining a vertebral fracture. CT and MRI techniques remain primarily research tools to assess metabolic bone dysfunction, while use of DXA can be clinically expanded beyond measurement of bone density to assess for vertebral fractures and bone architecture to improve fracture risk assessment and guide treatment.

Failure strength of human vertebrae: prediction using bone mineral density measured by DXA and bone volume by micro-CT

Significant relationships exist between areal bone mineral density (BMD) derived from dual energy X-ray absorptiometry (DXA) and bone strength. However, the predictive validity of BMD for osteoporotic vertebral fractures remains suboptimal. The diagnostic sensitivity of DXA in the lumbar spine may be improved by assessing BMD from lateral-projection scans, as these might better approximate the objective of measuring the trabecular-rich bone in the vertebral body, compared to the commonly-used posterior-anterior (PA) projections. Nowadays, X-ray micro-computed tomography (μCT) allows non-destructive three-dimensional structural characterization of entire bone segments at high resolution. In this study, human lumbar cadaver spines were examined ex situ by DXA in lateral and PA projections, as well as by μCT, with the aims (1) to investigate the ability of bone quantity measurements obtained by DXA in the lateral projection and in the PA projection, to predict variations in bone quantity measurements obtained by μCT, and (2) to assess their respective capabilities to predict whole vertebral body strength, determined experimentally. Human cadaver spines were scanned by DXA in PA projections and lateral projections. Bone mineral content (BMC) and BMD for L2 and L3 vertebrae were determined. The L2 and L3 vertebrae were then dissected and entirely scanned by μCT. Total bone volume (BV(tot)=cortical+trabecular), trabecular bone volume (BV), and trabecular bone volume fraction (BV/TV) were calculated over the entire vertebrae. The vertebral bodies were then mechanically tested to failure in compression, to determine ultimate load. The variables BV(tot), BV, and BV/TV measured by μCT were better predicted by BMC and BMD measured by lateral-projection DXA, with higher R(2) values and smaller standard errors of the estimate (R(2)=0.65-0.90, SEE=11%-18%), compared to PA-projection DXA (R(2)=0.33-0.53, SEE=22%-34%). The best predictors of ultimate load were BV(tot) and BV assessed by μCT (R(2)=0.88 and R(2)=0.81, respectively), and BMC and BMD from lateral-projection DXA (R(2)=0.82 and R(2)=0.70, respectively). Conversely, BMC and BMD from PA-projection DXA were lower predictors of ultimate load (R(2)=0.49 and R(2)=0.37, respectively). This ex vivo study highlights greater capabilities of lateral-projection DXA to predict variations in vertebral body bone quantity as measured by μCT, and to predict vertebral strength as assessed experimentally, compared to PA-projection DXA. This provides basis for further exploring the clinical application of lateral-projection DXA analysis.

Follicle-stimulating hormone does not directly regulate bone mass in human beings: evidence from nature

OBJECTIVE

To evaluate the effect of FSH levels in the development of human osteoporosis.

DESIGN

Case-series study.

SETTING

Gynecology department in a teaching hospital.

PATIENT(S)

A total of 8 women diagnosed with Kallman syndrome (KS) were compared with 11 with Turner syndrome and 11 with pure gonadal dysgenesia (GD, karyotype 46,XX).

INTERVENTION(S)

We assessed the pituitary-gonadal axis, bone turnover markers, bone mass, and patient characteristics.

MAIN OUTCOME MEASURE(S)

Bone mineral density as assessed by dual-energy X-ray absorptiometry, plasma FSH, LH, E(2), osteocalcin (BGP), and urinary type I collagen cross-linked N-telopeptide. Other biochemical markers included 25-hydroxyvitamin D, as well as parathyroid hormone and urine concentration of calcium and creatinine.

RESULT(S)

In girls with Turner syndrome and GD, FSH (64.03 +/- 29.2 and 90.08 +/- 22.41 mIU/mL, respectively) and LH (45.29 +/- 11.90 and 48.83 +/- 12.44 mIU/mL, respectively) levels were significantly higher compared with those observed in girls with KS (FSH: 1.87 +/- 0.64 and LH: 1.02 +/- 0.57), whereas no differences were detected in E(2) or bone marker levels. Bone mineral density correlated positively with FSH levels but not with E(2); however, after adjusting for previous growth-hormone therapy, these differences were not found. In addition, bone mineral density in spine and total hip was significantly lower in patients with KS.

CONCLUSION(S)

Follicle-stimulating hormone does not appear to have a major role in the development of bone loss in young women with primary amenorrhea.

In vivo intrarater and interrater precision of measuring apparent bone mineral density in vertebral subregions using supine lateral dual-energy x-ray absorptiometry

Analysis of apparent bone mineral density (BMD) in the lumbar spine is commonly based on anteroposterior (AP) scanning using dual-energy X-ray absorptiometry (DXA). Although not widely used, clinically important information can also be derived from lateral scanning. Vertebral bone density, and therefore strength, can may vary in different subregions of the vertebral body. Therefore, subregional BMD measurements might be informative about fracture risk. However, the intrarater and interrater precision of in vivo subregional BMD assessments from lateral DXA remains unknown. Ten normal, young (mean: 24 yr) and 10 older (mean: 63 yr) individuals with low BMD were scanned on one occasion using an AP/lateral sequence. Each lateral scan was reanalyzed six times at L2 by three raters to determine the intrarater and interrater precision in selecting seven regions of interest (subregions). Precision was expressed using percentage coefficients of variation (% CV) and intraclass correlation coefficients (ICC). Intrarater precision ranged from ICC(1,1) 0.971 to 0.996 (% CV: 0.50-3.68) for the young cohort and ICC(1,1) 0.934 to 0.993 (% CV: 1.46-5.30) for the older cohort. Interrater precision ranged from ICC(2,1) 0.804 to 0.915 (% CV: 1.11-2.35) for the young cohort and ICC(2,1) 0.912 to 0.984 (% CV: 1.85-4.32) for the older cohort. Scanning a subgroup of participants twice with repositioning was used to assess short-term in vivo precision. At L2, short-term in vivo precision ranged from ICC(1,1) 0.867 to 0.962 (% CV: 3.38-9.61), at L3 from ICC(1,1) 0.961 to 0.988 (% CV: 2.02-5.57) and using an L2/L3 combination from ICC(1,1) 0.942 to 0.980 (% CV: 2.04-4.61). This study demonstrated moderate to high precision for subregional analysis of apparent BMD in the lumbar spine using lateral DXA in vivo.

Secreting ovarian tumors may protect women from osteoporosis

OBJECTIVE

It is well known that ovarian steroids modulate bone turnover. Conditions associated with low levels of these hormones, such as menopause, hypogonadism, and others, have been related to osteopenia or osteoporosis. On the other hand, hyperandrogenism in premenopausal women, mainly in polycystic ovarian syndrome, has been reported to have a protective effect on bone mass. However, data regarding how bone mass is affected by neoformative processes in which steroids are increased are not as well documented. Our aim was to study the effect of secreting ovarian tumors on bone mass.

METHODS

A total of 14 patients were referred to our hospital because of endocrine ovarian tumors. Steroid levels were measured prior to and after surgery. Bone mineral density (BMD) by DEXA was assessed at inclusion in all cases. Additionally, in 7 women bone measurement was repeated after 1-year follow-up. The setting was a tertiary hospital.

RESULTS

All patients showed increased levels of testosterone, androstenedione, and free testosterone prior to surgery. BMD was also in the normal-upper range or over normal in all of them. As expected in the subjects with a second DEXA a decrease in bone mass was noted.

CONCLUSION

Steroid secreting ovarian tumors increase bone mass and thus may protect women from later osteoporosis.

Effect of continuous and sequential oral estrogen-progestogen replacement regimens on postmenopausal bone loss: a 2-year prospective study

OBJECTIVE

The aim of the present study was to determine whether assignment to continuous estrogen-progestin therapy is more effective in protecting against bone loss than assignment to a sequential regimen.

STUDY DESIGN

A total of 104 postmenopausal women were randomly assigned to one of two groups of treatment, Conjugated Equine Estrogens and Medroxyprogestin without interruption (continuous group) and Conjugated Equine Estrogens over 25 days with Medroxyprogestin beyond the 14th day (sequential group). Bone mineral density (BMD) was measured at inclusion, 12 and 24 months later by dual energy X-ray absorptiometry.

RESULTS

among women completing the 2-year treatment period, continuous and sequential regimens yielded results significantly different from baseline values, but not significantly different from each other at the 12-month (4.2 and 4%) or 24-month visits (6.6 and 6.3%). In the intention-to-treat analysis, the results with both regimens also differed from baseline values; additionally, the continuous group showed a greater increase in BMD than the sequential group at the 12-month (3.5 and 3%) and at the 24-month visits (5.5 versus 4.6%).

CONCLUSION

assignment to continuous administration seems to be more effective in increasing bone density than the sequential regimen. Thus, combined continuous estrogen therapy would seem to be the most effective regimen for those women requiring long-term hormone replacement therapy.

Effects of inhaled corticosteroid and short courses of oral corticosteroids on bone mineral density in asthmatic patients : a 4-year longitudinal study

BACKGROUND

It is not certain whether inhaled corticosteroid (ICS) therapy reduces bone mineral density (BMD) in asthmatic patients. In addition, the potential risk of osteoporosis associated with the rescue use of short courses of oral corticosteroids (SC-OCS) is unclear.

OBJECTIVE

To evaluate the effect of inhaled beclomethasone dipropionate (BDP) and SC-OCS on BMD in asthmatic patients.

DESIGN

A 4-year longitudinal study.

METHOD

Lumbar BMD was measured twice by dual-energy x-ray absorptiometry at a mean (+/- SD) interval of 4.2 +/- 0.1 years in 35 asthmatic adults (15 men and 20 postmenopausal women; mean age at the second evaluation, 60.6 +/- 11.5 years) who had been treated with BDP and SC-OCS.

RESULTS

The average period of BDP treatment was 7.7 +/- 2.2 years (range, 4.8 to 13.0 years) at the second evaluation. During the study period, the daily dose of BDP was 765 +/- 389 microg (range, 100 to 1,730 microg), and the frequency of SC-OCS was 1.9 +/- 2.7 courses per year (range, 0.0 to 8.9 courses per year). As a whole, lumbar BMD was unchanged during the course of the study, whereas the Z score (ie, the percentage of normal value predicted from age and sex) increased significantly. Changes in BMD and Z scores in patients receiving high doses of BDP (ie, > 1,000 microg/d; n = 9) were not significantly different from those of patients receiving lower doses (ie, <or= 1,000 microg/d; n = 26). However, patients receiving frequent SC-OCS (ie, > 2.5 courses per year; n = 9) showed a significantly greater loss in BMD and Z score compared with those receiving sporadic courses (ie, <or= 2.5 courses per year; n = 26) (p = 0.002 and p = 0.035, respectively).

CONCLUSIONS

ICS therapy per se does not affect BMD, whereas frequent SC-OCS may do so.

Posterior-anterior and lateral dual-energy x-ray absorptiometry for the assessment of vertebral osteoporosis and bone loss among older men

Lateral spine dual-energy x-ray absorptiometry (DXA) selectively measures the trabecular-rich vertebral bodies without the contributions of the cortical-rich posterior elements of the spine and is less affected by spinal degenerative disease than posterior-anterior DXA. We tested whether lateral DXA detects vertebral osteoporosis more often and is more sensitive to age-related bone loss than posterior-anterior DXA in 193 healthy, community-dwelling men aged 51-81 years (mean +/- SD; 67 +/- 8 years). All men had supine lateral, posterior-anterior, and proximal femur DXA scans on a Hologic QDR 2000 densitometer. A subset (n = 102) had repeat scans after 4 years to determine annualized rates of change in bone mineral density (BMD). Age was inversely and significantly associated with BMD in the midlateral (r = -0.27) and lateral (r = -0.24) but not posterior-anterior (r = 0.04) projections. Midlateral (-1.43 +/- 3.48% per year; p = 0.0001), lateral (-0.27 +/- 1.68% per year; p = 0.12), and hip (-0.19 +/- 1.02% per year; p = 0.06) BMD decreased, whereas posterior-anterior BMD increased (0.73 +/- 1.11% per year; p = 0.0001) during follow-up. When compared with normal values in 43 men aged 21-42 years, mean T scores were significantly lower with lateral (-1.47 +/- 1.32) and midlateral (-1.57 +/- 1.36) than posterior-anterior (-0.12 +/- 1.30; p < 0.0001) DXA. Only 2.6% of the older men were considered osteoporotic (T score < or = -2.5) at the posterior-anterior spine, whereas 11.0% were osteoporotic at the femoral neck, 22.5% at the lateral spine, and 24.6% were osteoporotic at the midlateral spine. We conclude that supine lateral DXA identifies considerably more men as osteoporotic and is more sensitive to age-related bone loss than posterior-anterior DXA. Spinal osteoporosis may represent a substantially greater health problem among older men than previously recognized.

Comparative effects of estrogens plus androgens and tibolone on bone, lipid pattern and sexuality in postmenopausal women

BACKGROUND

The main goals of estrogen replacement therapy (ERT) are the prevention of osteoporosis and cardioprotection and the improvement of quality of life (QL). Androgens and tibolone therapy may increase bone mineral density (BMD) to a greater extent than ERT and offer an increase in QL. Lipid and cardiovascular effects, however, are still a major concern.

AIM

To evaluate whether the addition of a weak androgen to ERT may improve postmenopausal bone loss and sexual activity without adverse effects on lipid pattern and to compare these effects with those observed after tibolone therapy.

SUBJECTS AND METHODS

This prospective study enrolled 120 surgical postmenopausal women; of these, 96 completed the 1-year follow-up. Patients were allocated to one of four groups. The first group (A; n = 23) received 4 mg of estradiol valerate plus 200 mg of enanthate of dihydroandrosterone im monthly. The second group (E; n = 26) received 50 microg/day of transdermal 17-b-estradiol continuously; the third (T; n = 23) received 2.5 mg of tibolone every day; and finally, the fourth group (C; n = 24) constituted a treatment-free control group. Bone mass (dual X-ray absorptiometry), serum total cholesterol, HDL, LDL, triglycerides, apolipoproteins A1 and B and sexual activity were evaluated before starting therapy and at the end of follow-up.

RESULTS

All active treatment groups showed an increase in BMD. This increase was higher in the A treatment group (4.08% P < 0.01). Sexuality improved significantly with therapy; however, tibolone and androgens increased scores to a greater extent than ERT. Androgen therapy was associated with significant increases in total cholesterol, LDL and triglycerides. Cholesterol and LDL fall into groups E and T, HDL into groups A and T and triglycerides in group T only.

CONCLUSION

The combined regimen of androgens and ERT increased vertebral bone mass and enhance sexual activity in postmenopausal women equal to that of tibolone and to a greater extent than ERT alone; its effects on lipids, however, are clearly adverse.

Long-term compliance with estrogen replacement therapy in surgical postmenopausal women: benefits to bone and analysis of factors associated with discontinuation

OBJECTIVE

To evaluate prospectively the effects of long-term estrogen replacement therapy (ERT) on bone density in surgical postmenopausal women treated for 5 years with two different modalities and to determine the factors associated with discontinuation of ERT.

DESIGN

We included in the present study 165 women (mean age, 46.8 +/- 4.6 years) who had undergone surgical menopause. ERT was prescribed immediately after surgery, and bone mineral density was measured at the lumbar spine before the women entered the study and at 12, 24, 36, 48, and 60 months after being included. Treated patients were assigned at random to one of two groups. The first group received conjugated equine estrogens 0.625 mg/day continuously, and the second group received transdermal 17beta-estradiol 50 mg/day continuously. Treated groups were compared with a nontreated control group.

RESULTS

Our data showed that although ERT clearly protected against bone loss in women who had experienced surgical menopause, only one third of the treated patients continued ERT at the end of follow-up. The main reason for discontinuation was fear of cancer (36.1 % of cases). In addition, no differences were observed between oral and transdermal groups of treatment.

CONCLUSIONS

Long-term ERT may have a protective effect against bone loss in surgically postmenopausal women; however, two thirds of treated patients discontinued therapy after 5 years and 43% of them presented a negative balance on bone mass in one or more bone density assessments. For this reason, enhancing compliance and monitoring treatment are mandatory.

Age- and gender-related differences in vertebral bone mass, density, and strength

This study was designed to evaluate age- and gender-related differences in vertebral bone mass, density, and strength by dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), ash measurements, and biomechanical testing. The material comprised human lumbar vertebral bodies (L3) from 51 females and 50 males (age-range: 18-96 years). The results showed that females had significantly lower vertebral body bone mass (ash weight) than males at any given age. The decline in bone mass with age was parallel for females and males. The different bone density measurements-cancellous ash density, total vertebral body ash density, DXA bone mineral density, QCT, and pQCT-showed no gender-related difference concerning numeric value or changes with age. Morphometrical measurements showed that females had smaller vertebral bodies (volumes) than males. Hence the females had significantly smaller cross-sectional area (CSA) of L3 than males (11.6 cm2 and 14.4 cm2, respectively). This led to females having lower maximum compressive load (N) than males at all ages, whereas maximum compressive stress (load/CSA) showed no gender-related difference. In conclusion, females have lower vertebral body bone mass than males at any given age, due to smaller vertebral bodies. Hence, maximum compressive load (strength not corrected for size) was lower in females. Vertebral body cancellous bone density and total-vertebral body density were equal when comparing genders, and no gender differences were found in the size-corrected strength: maximum compressive stress. The decrease with age in vertebral body compressive strength decrease was twice as large as the age decrease in density.

Long-term postmenopausal hormone replacement therapy effects on bone mass: differences between surgical and spontaneous patients

BACKGROUND

Hormone Replacement Therapy (HRT) begun soon after spontaneous menopause or oophorectomy minimizes or even reverses the loss of bone that occurs normally during those years. The persistence of this HRT protective effect at long-term on bone density, however, is not well documented.

AIM

to evaluate the effects of 5 years of HRT in postmenopausal women on bone mineral density of the lumbar spine.

SUBJECTS AND METHODS

The 5-year prospective study enrolled 154 postmenopausal women, of them 136 completed the first year and were considered electible to continue the follow-up. These 136 postmenopausal women were allocated to two groups according their origin: surgical (n=68) and spontaneous (n=68). HRT was prescribed and bone mineral density (BMD) was measured at the lumbar spine prior to commencement of therapy, and then yearly for the duration of the study. All patients received a continuous therapy with standard dose (0.625 mg/day) of conjugated equine estrogen (CEE) or 50 microg/day of 17-beta-Estradiol in transdermal therapeutic systems (TTS). Subjects who experienced natural menopause also received 5 mg/day of medroxyprogesterone acetate sequentially added to the last 12 days of estrogen therapy. Treated groups were compared with two non-treated control groups (surgical n=77; spontaneous n=53).

RESULTS

Our data showed that HRT increased the BMD of women who had experienced spontaneous menopause. Comparison with a control group revealed that HRT also protected against bone loss in women who had undergone surgical menopause.

CONCLUSION

Long term hormone replacement therapy increases bone mineral density in women who have experienced natural menopause, and protects against bone loss in surgically postmenopausal women.

Vertebral bone density evaluated by dual-energy X-ray absorptiometry and quantitative computed tomography in vitro

Vertebral bone density is evaluated mainly by dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). Densitometry is used as an estimator of bone strength and forms the basis for choice of treatment. DXA expresses bone density in grams per square centimeter (area density) and QCT expresses bone density in milligrams per cubic centimeter (volumetric density). The aim of this study was to identify the differences between the two techniques, DXA and QCT, when applied to a group of female and male subjects over a wide age range. The data consisted of 221 lumbar vertebral bodies (L3 and L4) excised at autopsy. There were 90 females with a mean age of 65.6 (range 18-94) years and 131 males with a mean age of 62.0 (range 21-94) years. The vertebrae were scanned en bloc in demineralized water in Plexiglas containers with both DXA and QCT. DXA was performed using posteroanterior (PA) and lateral projection. QCT was performed in the center of each vertebra with 1 cm slice thickness. Both methods showed decreasing bone density with age. Lateral DXA showed a decrease in bone density with age from approximately 0.8 g/cm2 to approximately 0.4 g/cm2. QCT showed a decrease in bone density with age from approximately 180 mg/cm3 to approximately 30 mg/cm3. Lateral DXA bone mineral densities (BMD) were correlated with QCT densities in both females (r2 = 0.68, p < 0.00001) and males (r2 = 0.53, p < 0.00001), but females had constantly lower DXA BMDs than males at a given QCT density. QCT and width-adjusted midlateral DXA (g/cm3) were significantly correlated, with r2 = 0.64 (p < 0.00001) for females and r2 = 0.61 (p < 0.00001) for males. In conclusion, age- and gender-related differences in human vertebral bone density were shown to be dependent on the scanning method used. DXA bone mineral content (BMC) and BMD showed that females had lower values than males at all ages. When the "volumetric" DXA measurements and QCT were used, the females had the highest densities in the younger decades and males had the highest densities in the oldest decades. Finally, the area density (BMD) measured by DXA was lower in females than in males with identical QCT volumetric bone densities.

Effects on bone mass of two oral contraceptives containing ethinylestradiol and cyproterone acetate or desogestrel: results of a 2-year follow-up

BACKGROUND

There are conflicting data about the effects of oral contraceptives on bone mass in young women. Moreover, amenorrheic women may also be affected to varying degrees by osteopenia. Both conditions (oral contraceptive use and amenorrhea) are not infrequent in women during their reproductive years.

AIM

To evaluate the safety for bone mass of two oral contraceptives, one containing cyproterone acetate and the other containing desogestrel.

METHODS

A total of 67 women between 19 and 29 years of age were studied. Of these women, 35 were selected to receive an oral contraceptive containing 35 mg ethinylestradiol and 2 mg cyproterone acetate. A second group of 32 women received an oral contraceptive containing 30 mg ethinylestradiol and 150 mg desogestrel for 2 years. Immediately before and after the 12th and 24th months of therapy, bone mineral density was assessed by dual X-ray absorptiometry, and hormonal profiles and Ferriman-Gallwey scores were evaluated.

RESULTS

After the 2-year follow-up, all subjects showed regular cycles, no pregnancies, and no changes in bone mass density. In addition, hirsute subjects showed a decrease of almost 42% in hirsutism scores.

CONCLUSION

Oral contraceptives containing cyproterone acetate or desogestrel in the studied doses have no deleterious effects on bone marrow.

How often does lateral spine DXA detect low bone mass in patients with both normal PA spine and hip?

The clinical utility of lateral bone mineral density (BMD) measurement for the diagnosis of osteoporosis remains controversial. Since both posterior-anterior (PA) spine and hip scans are universally performed, the true clinical utility of lateral dual-energy X-ray absorptiometry (DXA) should lie in its ability to detect low bone mass independent of both PA spine and hip. We examined lateral, PA and hip BMDs in 2134 referred Caucasian females aged 25-89 using the Hologic 2000. Compared only to PA scans, the additional percentages of women with very low BMD (T-score below -2.5 utilizing the National Health and Nutrition Examination Survey [NHANES] III normative database) on lateral were 7.3, 16.4, 28.2, 33.7, and 26.2% for age groups 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. When the results from both PA and total hip measurements were combined, lower but still significant percentages were found: 5.4, 14.9, 24.4, 26.6, and 17.8% for age groups 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. Utilizing the original Hologic normative database, the additional yield in women with a nonosteoporotic PA spine and femoral neck was quite low: 4.6, 8.5, 13.3, 10.0, and 2.5% for women age 25-49, 50-59, 60-69, 70-79, and 80-89, respectively. Thus, the lateral scans now add more additional patients into the very low BMD category. Whether the relationship to future fracture risk of low BMD and T-scores on lateral is similar to that of PA spine remains to be established.

Technical principles of dual energy x-ray absorptiometry

Since its introduction nearly ten years ago, dual-energy x-ray absorptiometry (DXA) has become the single most widely used technique for performing bone densitometry studies. One reason for its popularity is the ability of DXA systems to measure bone mineral density (BMD) in the spine and proximal femur, the two most common sites for osteoporotic fractures. Other advantages of DXA include the exceptionally low radiation dose to patients, short scan times, high resolution images, good precision and inherent stability of calibration. For these reasons DXA scans are widely used to diagnose osteoporosis, assist making decisions in treatment, and as a follow-up response to therapy. Another important application has been the use of DXA in many clinical trials of new treatments for osteoporosis. Since the first generation pencil beam DXA systems became available, the most significant technical innovation has been the introduction of fan beam systems with shorter scan times, increased patient throughput, and improved image quality. New clinical applications include the measurement of lateral spine and total body BMD, body composition, and vertebral morphometry. Despite these advances, posteroanterior (PA) spine and proximal femur scans remain the most widely used application because of their utility in treatment decisions and monitoring response to therapy.

Menstrual history as a determinant of current bone density in young hirsute women

There is evidence that bone mass is influenced by estrogen, declining in situations characterized by a decrease in the production of this hormone. Usually, amenorrhea and oligomenorrhea are associated with a state of hypoestrogenism, and both situations are frequent in hirsute patients. The aim of the present study was to analyze the relationship between bone mass and menstrual cyclicity in hirsute women. A total of 52 nulliparous women complaining of hirsutism in various degrees with associated oligomenorrhea/amenorrhea (OA) in 27 cases and eumenorrhea in 25 were included in this study. Basal serum levels of follicle-stimulating hormone (FSH), luteinzing hormone (LH), estradiol-17beta (E2), prolactin (PRL), testosterone (T), androstenedione (A4) dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone (OHP), and SHBG were determined, and the area under the curve (AUC) for E2 was plotted. Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry (DEXA). The mean age for eumenorrheic patients was 26 years (range, 17 to 31), and for OA patients, 24 (range, 16 to 29). Both groups had similar Ferriman-Gallwey scores. Basal levels of PRL, LH, FSH, E2, T, A4, OHP, and DHEAS were similar for eumenorrheic and OA patients. The AUC for E2 was significantly higher for eumenorrheic patients, and DEXA at the lumbar spine demonstrated a significant difference between eumenorrheic (1.222 +/- 0.240 g/cm2) and OA (1.016 +/- 0.108 g/cm2) hirsute women (P < .01). In conclusion, OA, due to a relative hypoestrogenism, may be correlated with osteopenia in young hirsute women.

The effect of hormone replacement therapy on bone mass in patients with ovarian failure due to bone marrow transplantation

BACKGROUND

Long permanent remissions in malignant hematopoietic disorders can often be achieved by autologous bone marrow transplantation (ABMT) or by allogenic bone marrow transplantation (BMT). Previous studies have shown that such therapies may induce osteoporosis due to iatrogenic ovarian failure. The administration of hormone replacement therapy (HRT) in these women could prevent the adverse effects of long-term ovarian failure without remarkable side effects. The aim of this study was to evaluate how the bone mass is affected by HRT in patients undergoing ABMT or BMT adjusting the results for age, weight, and height.

SUBJECTS AND METHODS

Thirteen women with previous ABMT/BMT were treated with a standard dose (0.625 mg/day) of conjugated equine estrogen (CEE) or with 50 micrograms/day of 17-beta-estradiol in transdermal therapeutic systems (TTS) plus 5 mg/day of medroxyprogesterone acetate sequentially added to the last 12 days of estrogen therapy. Bone mass was measured prior to and 12 months following HRT. Blood samples were collected before therapy and during the 6th and 12th treatment months.

RESULTS

The mean time elapsed between bone transplantation and HRT initiation was 13.0 months (range 3-26 months). Before treatment nine patients were osteopenic and after HRT bone mass increased in all cases. Following ABMT/BMT, hepatic hyperenzymemia was detected in three patients. After 6 and 12 months of treatment no significant changes were observed in hepatic enzymes.

CONCLUSION

Although hepatic hyperenzymemia is commonly considered as a contraindication for HRT, our results suggest that HRT is safe for these patients and that such therapy should be initiated after transplantation in women to prevent adverse effects of long-term ovarian failure.

Lateral bone density measurements in osteoarthritis of the lumbar spine

OBJECTIVE

To investigate whether spinal osteoarthritis (OA) is responsible for the common finding that lumbar spine bone mineral density (BMD) is greater when measured in the anteroposterior plane than when measured in the lateral plane.

METHODS

We studied lateral spine radiographs from 63 women who attended a hospital outpatient department for bone density measurement and who also underwent lumbar spine radiography. Osteoarthritis was assessed using both the Kellgren and Lawrence scale and a scoring system for osteophytosis. Bone density was measured in the anteroposterior and lateral planes using a Hologic QDR-2000 instrument.

RESULTS

The mean anteroposterior BMD (0.92 g/cm2) was significantly greater than the lateral BMD (0.59 g/cm2) (p < 0.01), and the difference between antero-posterior and lateral measurements was significantly associated with both increasing Kellgren and Lawrence score and osteophyte score, even after adjustment for age.

CONCLUSION

These data suggest that spinal OA is a major cause of the difference between anteroposterior and lateral BMD and that lateral BMD may provide a more accurate representation of true vertebral body bone density in patients with OA of the lumbar spine.

A longitudinal study of supine lateral DXA of the lumbar spine: a comparison with posteroanterior spine, hip and total-body DXA

We report a study to assess whether supine lateral dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine provide better data for monitoring response to treatment than alternative measurement sites such as the posteroanterior (PA) spine, hip and total body. The study population was 152 women enrolled in a placebo-controlled clinical trial of cyclical etidronate therapy. All subjects were 1-10 years after the menopause with bone mineral density (BMD) between 0 and -2 SD of age-matched normal women. Paired PA and lateral spine, left hip and total-body DXA scans were performed at baseline, 1 year and 2 years on a Hologic QDR-2000. One hundred and thirty-one subjects completed the study. Mean percentage change from baseline at 2 years in the treated (n = 61) and control (n = 70) groups was calculated for vertebral body, width-adjusted (WA) vertebral body, mid-vertebral body and WA mid-vertebral body BMD measurement on the lateral scans and compared with the percentage changes in PA spine, femoral neck, trochanter, Ward's triangle and total-body BMD. The long-term precision for each BMD measurement site was obtained by linear regression analysis in subjects taking placebo. Overall treatment effect, defined as the difference in the percentage change in BMD in the two treatment groups at 2 years, was divided by long-term precision to give an index of the ability of each site to monitor response to treatment. Results (and standard errors) normalized to the ratio of treatment effect/ precision for PA spine BMD were as follows: PA spine, 1.00; vertebral body, 0.89 (0.14); WA vertebral body, 0.78 (0.14); mid-vertebral body, 0.65 (0.14); WA mid-vertebral body, 0.60 (0.13); femoral neck, 0.35 (0.15); trochanter, 0.45 (0.15); Ward's triangle, 0.59 (0.22); total body, 0.52 (0.19). Although treatment effect was larger for lateral than for PA spine BMD, this advantage was offset by the greater precision errors. PA spine BMD remains the optimum measurement for longitudinal studies in recently postmenopausal women.