Bone Mass Values Research Articles

Reference values for areal bone mineral density among a healthy Mexican population

Compare the influence of ethnicity in the prevalence of osteopenia and osteoporosis in various Mexican populations using two normal dual X-ray absorptiometry (DXA) reference databases: manufacturer's incorporating US Hispanic population and a normal mestizo Mexican population. MMP included 9 946 subjects participating in an ongoing long-term cohort study focusing on lifestyle and chronic diseases, of which 6 487 MMP males and females aged 7 to 80 years were the normal subjects used to determine bone density T- and Z-scores, following WHO criteria, and peak bone mass values. Abnormal bone mass density values estimated by the manufacturer's and peak bone mass reference values were compared. Our results show that by using the manufacturer's T-score values in the mestizo Mexican population we are underestimating the number of abnormal bone mass BMD populations.

Population-based reference values for bone mineral density in young men

Population-based reference values for peak bone mass density in Danish men. BMD of total hip (1.078 +/- 0,14 g/cm2) differed significantly from values from National Health and Nutrition Examination Survey III and of total lumbar spine ((1.073 +/- 0.125 g/cm2) differed significantly from Hologic values. Geographic, ethnic, and socio-economic factors are known to affect bone mineral density (BMD) and peak bone mass significantly. Reference values for male peak bone mass are scarce, and the diagnosis of male osteoporosis often relies on values provided by producers of dual-energy X-ray absorptiometry (DXA) equipment. The aim of the present study was 1) to establish population-based reference values for BMD in young men and 2) to study subgroups based on variables with suspected impact on bone metabolism. We included 783 young Caucasian men aged 20 to 30 years in the Odense Androgen Study (OAS). Peak BMD was attained within the third decade. Obesity (BMI > 30 kg/m2) was associated with higher BMD. Abuse of anabolic steroids as well as chronic illness was associated with lower BMD. Our population-based reference values for BMD of the total hip (1.078 +/- 0.14 g/cm2) differed significantly from published values from National Health and Nutrition Examination Survey III for non-Hispanic white men, while BMD of total lumbar spine (1.073 +/- 0.125 g/cm2) differed significantly from Hologic reference values. Locally derived reference values are important to avoid false positive or false negative findings during work-up in patients evaluated for osteoporosis.

Timing of Peak Bone Mass: Discrepancies between CT and DXA

The time of life in which peak bone mass in the axial skeleton is attained has been the subject of considerable controversy, with estimates ranging from the time of sexual and skeletal maturity to the fifth decade of life. The objective was to examine whether dual energy x-ray absorptiometry (DXA) and computed tomography (CT) values for bone mass and bone density (BD) in the axial skeleton increase after sexual and skeletal maturity. Measurements of vertebral bone mineral density and bone mineral content (BMC) by DXA and vertebral BD and BMC by CT were obtained in 50 sexually and skeletally mature white females at baseline and 3 yr later. CT BMC values were calculated through analysis of vertebral volume in relation to density (BMC = vertebral volume x BD). Although neither CT BD nor BMC measures changed with time, DXA bone mineral density and BMC values were significantly higher at follow-up (P < 0.0001). Despite strong correlations between DXA and CT bone measures, DXA yielded greater changes in bone values in 47 of 50 subjects. Bone acquisition in the lumbar spine as measured by CT reaches its peak by sexual and skeletal maturity. In contrast, bone values by DXA continue to increase after puberty and cessation of longitudinal growth. Increases in DXA measures are likely a reflection of inhomogeneous changes in soft tissues around the spine or of disproportionate increases in the posterior elements of the vertebrae rather than of changes within the vertebral body.

Peak Bone Mass of Iranian Population: The Iranian Multicenter Osteoporosis Study

Osteoporosis is a major public health problem in the Western countries and is projected to have a similar impact in the Middle East. It has been suggested that peak bone mineral density (BMD), a major determinant of osteoporotic fractures later in life, may be lower in this part of the world compared with the Western world. The purpose of the Iranian Multicenter Osteoporosis Study was to determine peak bone mass in a randomly chosen sample of healthy Iranian subjects. A total of 5201 participants (2340 males, mean age 42.7+/-13.8) were recruited based on randomized clustered sampling from all regions of five major cities across the country. In women, peak lumbar BMD (1.182+/-0.127 g/cm2) occurred in the 29- to 33-yr age group, whereas peak total femur BMD (1.006+/-0.126 g/cm2) occurred in the 32- to 36-yr age group. In men, peak lumbar BMD (1.181+/-0.153 g/cm2) and femoral BMD (1.096+/-0.159 g/cm2) both occurred in the 20- to 24-yr age group. When standardized to mg/cm2 units using established formulas, Iranian peak bone mass values are comparable with that of Western countries and are generally higher than that of Eastern Asian and Middle Eastern countries.

Measurement Error of DXA: Interpretation of Fat and Lean Mass Changes in Obese and Non-Obese Children

Information on reproducibility of dual-energy X-ray absorptiometry (DXA) measurements is essential because DXA is frequently used by clinicians and researchers to assess body composition changes. We estimated measurement error and absolute and relative smallest detectable differences (SDDs) for fat, lean, and bone mass in children. The SDD is the change necessary to be confident that the change is not a consequence of measurement error. Duplicate whole body DXA (Hologic QDR 4500A, Hologic Inc., Waltham, MA) scans were obtained on 32 obese and 34 non-obese children ages 6-19 yr. Absolute (kg) and relative (coefficient of variation) measurement error and SDD were calculated. Absolute SDDs for fat and lean were higher for obese (1.39 and 1.30 kg, respectively) than for non-obese children (0.42 and 0.47 kg, respectively). The %SDD for fat was lower for obese (3.58%) than non-obese children (5.24%), but for lean the %SDD was higher for obese (2.60%) than non-obese children (1.32%). The SDDs for bone mass were similar for obese and non-obese children. An obese child must lose or gain more absolute fat and lean mass than a non-obese child to be confident that the change is not a reflection of measurement error. Overall, SDD values for fat, lean, and bone mass are low.

Determinants of adherence to osteoporosis treatment in clinical practice

Poor adherence to prescribed treatments is widespread in clinical practice and this can lead to potentially life-threatening events. This problem is apparently very common for osteoporosis treatment but the causes of discontinuation and low compliance are complex and poorly defined. Global adherence to osteoporosis treatment was specifically addressed in a nation-wide survey carried out in 9851 postmenopausal women referred to 141 Italian centres for osteoporosis management for a follow-up assessment, at least one year after having been prescribed a treatment with one of the following drugs: calcium+/-vitamin D supplements alone (CaVitD), hormone replacement therapy (HRT), raloxifene 60 mg (RLX), intramuscular clodronate 100 mg/7-14 days (CLOD), risedronate 5 mg/day (RIS) and alendronate 10mg/daily (ALN10) or 70 mg once weekly (ALN OW). Overall 19.1% of the patients discontinued the prescribed drug before attending the bone mass re-evaluations, more than half of them within the first 6 months. The discontinuation rate was significantly different between the treatments. The medications most frequently interrupted within one year were CLOD (28.7%; p<0.01 versus any other treatment), while by far the least interrupted was ALN-OW (6.9%; p<0.001 versus any other treatment). The most frequent reasons for discontinuation were drug related side effects, insufficient motivation to treatment and fear of side effects. The prevalence of the reasons for discontinuation were different among treatments: safety concerns were very common for HRT, lack of motivation was the most common cause for CaVitD and CLOD, and drug related side effects for RIS, ALN and RLX. Persistence to treatment was significantly higher in patients with previous vertebral fractures, densitometric osteoporosis, on corticosteroid or anti-inflammatory treatments. A significantly increased risk of treatment interruption was found among patients on benzodiazepine or gastro-protective agents and in patients in whom a bone measurement was not readily available. The highest compliance to recommended dosing was observed with ALN OW and HRT (p<0.001 versus any other) and the lowest for CaVitD (p<0.01 versus any other). Poor treatment compliance (<50% drug taken) was significantly related to benzodiazepine and gastroprotective use, while a significantly better compliance was associated with recognized risk factors for osteoporosis: early menopause, low bone mass values values, previous vertebral fractures. The poorest adherence was observed when treatments were prescribed by General practitioners (GPs), and orthopaedic surgeons (p<0.01 versus global mean). The results of this large survey of Italian osteoporotic women indicates that the most important determinant of both persistence and compliance to treatment is the type of drug prescribed with a definite advantage of ALN-OW. Treatment compliance is particularly poor for CaVitD and this emphasizes the need for new ways to supplement at least vitamin D. The main reasons for discontinuation are side effects and lack of motivation while the best treatment adherence was observed in patients with severe and well documented osteoporosis.

Correlations between periodontitis and loss of mandibular bone in relation to systemic bone changes in postmenopausal Japanese women

A new method of measuring mandibular alveolar bone mineral density (BMD) was applied to 40 postmenopausal Japanese women aged 50-69 years exhibiting minimal to mild periodontal diseases. Lumbar spine BMD was measured by dual X-ray absorptiometry (DXA) and calcaneus speed of sound (SOS) by quantitative ultrasound (QUS). There were age-related decreases of alveolar BMD, calcaneus SOS and vertebral BMD. There were significant correlations between two of the respective bone mass values. Correlations between clinical dental findings and bone mass data including alveolar BMD, SOS and lumbar spine BMD were investigated. Significant correlations were demonstrated between alveolar BMD and calcaneus SOS or vertebral BMD. Alveolar BMD showed significant correlation with clinical dental findings including periodontal pocket depth and mobility as well as calcaneus SOS and lumbar spine BMD. Using multivariate analysis combinations of univariate predictors, including deoxypyridinoline (DPD), significantly predicted attachment levels. The SOS value was useful combined with other predictors for predicting attachment level. It was concluded that the new method of evaluating alveolar BMD is useful to predict systemic bone mass and strength as well as dental clinical findings.

Bone mass and bone metabolism in pediatric gastrointestinal disorders.

Bone mass and bone metabolism in pediatric gastrointestinal disorders.

Longitudinal changes in bone metabolism and bone mineral content in children with celiac disease during consumption of a gluten-free diet

A gluten-free diet (GFD) rapidly corrects the bone mineral deficit of children with untreated celiac disease. The mechanisms underlying such changes are still poorly understood. In a longitudinal study, we monitored changes in bone metabolism during consumption of a GFD. We studied 22 white patients with celiac disease (11 girls) aged 10.5 +/- 1.0 y at the time of diagnosis. We compared bone metabolism and bone mass values in these patients with those in 428 healthy white children aged 11.3 +/- 0.2 y. Bone-specific alkaline phosphatase (a bone formation index) and N-terminal telopeptide of type I collagen (NTx; a bone resorption marker) were measured at the time of diagnosis and after 2, 6, and 12 mo of the GFD. Bone mineral content was measured at the lumbar spine and for the whole skeleton. The bone mineral content of patients was significantly lower than that of control subjects at the time of diagnosis but not after 1 y of the GFD. Serum bone-specific alkaline phosphatase concentrations of patients were significantly lower than those of control subjects at the time of diagnosis (P = 0.0064) and increased gradually and significantly during the GFD (ANOVA F = 4.71; P = 0.024). Conversely, patients with untreated disease had significantly higher urinary concentrations of NTx than did healthy control subjects (P < 0.0001). Urinary concentrations of NTx were not significantly affected by treatment (P = 0.37). The rate of bone metabolism is altered in children with untreated celiac disease, and these alterations may be the cause of osteopathy. Remarkable changes occur after the initiation of a GFD, and they result in a more balanced equilibrium.

Definition of a population-specific DXA reference standard in Italian women: the Densitometric Italian Normative Study (DINS).

Osteoporosis is currently defined on the basis of the T-score by dual-energy X-ray absorptiometry (DXA). Despite its limitations, this definition is applied worldwide. However, the normal values provided by manufacturers may not be fully representative of specific local populations. So far, there are no normative data in the Italian population using Hologic densitometers. The Densitometric Italian Normative Study (DINS) is an ongoing multi-center study that aims to establish reference values for bone densitometry with dual-energy X-ray absorptiometry (DXA) in the male and female Italian population. In this paper we report the results of the lumbar vertebrae (L2-L4) and proximal femur in 1,622 women aged 20-79 years. Bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry (DXA) on Hologic bone densitometers (Hologic, Waltham, Mass.). Most of the subjects were examined with a QDR 4500. The BMD of the lumbar vertebrae was virtually constant between 20 and 49 years (test for trend: P=0.66); the BMD values between 20-45 in premenopausal women (mean 1.036; SD 0.109 g/cm(2)) were thus defined as the peak bone mass values, significantly lower compared to the Hologic reference curve (mean 1.079, SD 0.11 g/cm(2)). The mean BMD values of the femoral neck were virtually identical to those of the NHANES study in the first 3 decades; after the age of 50 the BMD values were slightly greater than those of the NHANES subject. The subject classification according to the WHO criteria was similar using the DINS and NHANES reference values for the femur; for the spine, the Hologic reference values classified a larger proportion of women as osteoporotic (21 vs. 16%) or osteopenic (42 vs. 38%) compared to DINS.

Influence of polymorphisms in VDR and COLIA1 genes on the risk of osteoporotic fractures in aged men

Osteoporosis in chronic renal failure is a common finding caused by several factors, including age. In the last decade, the likely effect of genetic markers related with the appearance and evolution of osteoporosis has been mainly studied in women, with no categorical results. The aim of this study was to assess the influence of polymorphisms of the vitamin D receptor (VDR) and COLIA1 genes on the risk of osteoporotic fractures in men older than 50 years. The study population comprised 156 men, aged 64 +/- 9 (50-86), randomly selected from the population list of Oviedo, Spain. Prevalent vertebral fractures and incident non-vertebral fractures were identified, as well as several genetic polymorphisms. Prevalent vertebral fractures were considered according to the Genant grade 2 classifications. The analyzed genetic polymorphisms were located on restriction sites BsmI (B,b), ApaI (A,a), and TaqI (T,t) in the VDR and on Sp1 (S,s) in COLIA1. Although none of the VDR gene polymorphisms separately analyzed showed any differences between fractured and non-fractured men, the utilization of haplotypes could be employed in order to find osteoporotic fractures in men. By contrast, the COLIA1 polymorphism was associated with osteoporotic fractures. The percentage of prevalent vertebral fractures was significantly higher in the "ss" genotype with respect to the other genotypes. These results show that in men, the "ss" genotype of COLIA1 polymorphism could be the best osteoporotic fracture risk genetic predictor, independent of bone mass values.

Body composition of 4- and 5-year-old New Zealand girls: a DXA study of initial adiposity and subsequent 4-year fat change.

Dual-energy X-ray information (DXA) quantitating body fat mass and percentage fat in healthy children of preschool age is scarce. To study the initial variability in body composition and subsequent longitudinal changes in absolute fat mass (kg) and relative adiposity (fat percentage) in a sample of contemporary young New Zealand girls. Cross-sectional study with a longitudinal component. University research unit. A total of 89 Caucasian girls aged 4-5 y were recruited by advertisement at baseline and 4-y changes in body composition were evaluated in 23 of these girls. Total body composition was measured by DXA, height and weight by anthropometry. Baseline values for fat mass varied more than values for lean mass or bone mass. Girls from the upper third of our fat percentage distribution (% fat >19.2%) had more than twice the fat mass (5.34 vs 2.31 kg, P<0.001) of those from the lowest third (% fat &<15.4%). The percentage gain in fat mass over 4 y (124 (95% CI 90-163) also exceeded the percentage gain of lean mass (55 (95% CI 51-59). In data adjusted for age and height, 63.5% of the variance in percentage body fat at time 2 was explained by fat mass at time one. In girls, the trajectory of fat gain appears to be established at a young age. Our results support the view that body fatness tracks strongly before puberty. Since preventing the accumulation of excessive fat is preferable to reduction of existing excessive fat stores, it is important to put in place strategies to limit excessive fat gain early in life.

In vitro calibration and validation of a digital subtraction radiography system using scanned images.

To calibrate and validate a digital subtraction radiography system using scanned images for quantification of alveolar bone changes by means of computer-assisted densitometric image analysis (CADIA) in vitro. Noise levels were determined using 10 standardized periapical radiographs of the same lower molar region in a human dry skull. For validation of the system, radiographs were taken before and after bovine bone particles in measures with increments of 2 mg weighing from 2 to 20 mg were added into each socket of three dry skulls. Radiographs were developed and scanned into a computer with a flatbed scanner. After digitization, the images were subjected to alignment, normalization and subtraction. Appropriate regions of interest (ROIs) were selected and their CADIA values were calculated for the determination of noise levels, and correlations between the CADIA values and the actual bone mass were performed. When the threshold value was 7, the percentage of pixels deviating from the set threshold value was small (0-11.3%). There were statistically significant correlations between the actual bone mass and the CADIA value for anterior sockets (p<0.001, r2=0.89) and posterior sockets (p<0.001, r2=0.9). For pooled data of both anterior and posterior sockets, the correlation was also statistically significant (p<0.001, r2=0.88). A high and statistically significant correlation between the actual bone mass and CADIA value was obtained, which suggests that the system could be suitable for the detection of small alveolar bone changes.

Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations?

Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.

Adolescent Anorexia Nervosa: The Catch-up Effect in Bone Mineral Density After Recovery

To determine whether bone mineral density (BMD) loss can be reversed in adolescent anorexic patients. A prospective study with 108 anorexia nervosa patients (DSM-IV) from 12 to 17 years of age at the Eating Disorders Unit in the Hospital Clinic of Barcelona (Spain). They were first evaluated by dual-energy x-ray absorptiometry in lumbar spine and femoral neck consecutively from 1997 until 1999 and reexamined after 6 to 30 months. Results were compared with normative values of bone mass. Patients with poor outcome (n = 44) had a bone mass loss. Patients with good short-term outcome were divided in two groups. The group with normal BMD at first evaluation (n = 41) had a bone mass gain per year of 3.0% at lumbar spine and 0.5% at femoral neck. The group with low BMD at first evaluation (n = 23) had an increase per year of 9.1% at lumbar spine and 4.5% at femoral neck. In a multiple linear regression analysis with the variables body mass index, age, months with menstruation, and BMD zscore at first evaluation, the only predictor of BMD increase was the first z score both at the lumbar spine (coefficient R = 0.64; p < .001) and at the femoral neck (coefficient R = 0.5; p < .001). There is a catch-up effect in adolescent patients with low BMD but good short-term outcome.

Quantitative phalangeal bone ultrasound is normal after long-term gluten-free diet in young coeliac patients.

To determine bone mass using quantitative phalangeal bone ultrasound in young coeliac patients after a long-term gluten-free diet. A total of 99 patients with coeliac disease (CD) (52 girls, mean age 15.5 +/- 9.7 years; 47 boys, mean age 14.4 +/- 8.4 years) and 44 healthy subjects matched for age, weight and height (26 girls, mean age 18.4 +/- 9.9 years; 18 boys, mean age 16.3 +/- 11.2 years) were included in the study. Bone status was assessed using an ultrasound device that measures amplitude-dependent speed of sound (Ad-SoS) in metres per second. Measurements were made on the phalanges (II-V) of the non-dominant hand, and an average value was computed. Nutrient intake was assessed using a 7-day record. Analysis of variance (ANOVA) and the unpaired t-test showed that the intake of phosphates (P < 0.05), proteins, fat and carbohydrates (P < 0.005 in all) was higher in patients than in controls. No significant difference in Ad-SoS was found between patients and controls (95% CI -10.9 to 60.6) in the overall group, in girls or boys, or in patients following a gluten-free diet strictly or partially. In the patients, only age (beta 4.01, 95% CI 1.84-6.16, P < 0.0005) and weight (beta 2.62, 95% CI 1.53-3.70, P < 0.0001) showed a significant positive relation with Ad-SoS. In patients with CD, gluten-free diet and increased nutritional intake were accompanied by normal bone mass values as determined by ultrasound on phalanges.

Changes in bone density of the femur after cement-free implantation of a modular hip prosthesis with a long shaft

Until now, no reports exist on the existence of femoral bone loss after hip arthroplasty using long-stem cementless prostheses in elderly patients. In a prospective evaluation the amount of bone loss (stress-shielding) after implantation of a long stem hip prosthesis in patients with femoral neck fractures (group A) or pertrochanteric femoral fractures (group B) was examined. Eleven patients (five from group A and six from group B) were treated with a long-stem modular hip prosthesis (MHP). Change of bone mass was evaluated using quantitative computed tomographie (QCT) immediately following and at six months (group A and B) and twelve months (group A) after implantation of the prosthesis. Clinical results, expressed with the modified Harris Hip Score, and relative changes of bone mass were compared with mean periprosthetic bone mass of the femur after operation. After implantation of the MHP, the maximum decrease of mean femoral bone mass was 19.1% at six months and 20.2% at twelve months for group A and 29.5% at six months for group B. Bone loss in the proximal periprosthetic area was higher than in the distal part. There was no correlation between baseline values of bone mass and the amount of stress-shielding or clinical outcome.

Effects of two intermittent alendronate regimens in the prevention or treatment of postmenopausal osteoporosis

In clinical practice, a large proportion of patients have bone mass values for which a therapeutic intervention is considered necessary, but the accepted aim might be the sole preservation or marginal increases of the actual bone mass. These goals might be achieved with lower or intermittent doses of a powerful agent for the purpose of fewer side effects and improved compliance. The aim of this study was to assess the effects of two intermittent alendronate regimens in the treatment of postmenopausal osteoporosis. One hundred twenty-four postmenopausal women (age range 52–75 years, at least 7 years since last menopause) with a bone mineral density (BMD) at either the femoral neck or lumbar spine of 2 SD below the mean values of young healthy individuals, and without a history of previous osteoporotic fracture, were randomly assigned either to calcium/vitamin D supplements, alone or associated with two different intermittent oral alendronate regimens: 20 mg once a week (weekly alendronate group) or 10 mg daily (orally) for 1 month out of 3 (cyclical alendronate group). After 1 year, in both groups given intermittent alendronate, we observed significant increases in BMD at both the spine (+2.2 ± 2.6 and +2.5 ± 2.9) and femoral neck (+1.6 ± 4.8 and +1.5 ± 2.2) for the weekly and cyclical regimens, respectively. This was associated with a significant diminution of both serum bone-specific alkaline phosphatase and urinary N-telopeptides of collagen type I excretion. In the patients in the control group BMD decreased significantly at the lumbar spine, with a slight decline of serum bone-specific alkaline phosphatase. Compliance with treatment and drug tolerability were good in both alendronate groups. In conclusion, intermittent alendronate administration at cumulative doses (and costs) three times lower than those currently recommended for osteoporosis treatment is very well accepted, and is able to significantly increase BMD at the spine and femoral neck and to decrease the markers of bone turnover. These regimens can be clinically useful in the long-term treatment of postmenopausal osteoporosis without prevalent osteoporotic fractures, particularly in women with lower compliance for continuous administration.

The prevalence of osteoporosis in the Hong Kong Chinese female population

Objectives: This paper aims to present population-based age-related bone mass values in the Hong Kong Chinese female population, and to assess the number and proportion of Chinese women considered osteoporotic according to the WHO diagnostic guidelines. Methods: A total of 769 community-based female subjects were recruited. Social demographic characteristics of these subjects were similar to the Hong Kong general population. All bone mass measurements were performed by means of a dual energy X-ray densitometry (Norland XR 26) at two sites: lumbar vertebrae L2–L4 and left hip. These values were expressed as T-scores, with reference to the mean bone mineral density (BMD) values of the group aged 21–40 years. Results: The study revealed that, in women aged 60 years and above, their mean BMD values are 30% lower than the young normal mean. The prevalence of osteoporosis at the spine increased dramatically from about 10% in the age group 50–59 to 45% in the group aged 60–69. In women aged 70 onwards, over half have osteoporosis at the hip. The prevalence of osteoporosis at the spine is relatively stable in the age groups above 60, while that for osteoporosis at the hip increased exponentially with age. Conclusions: The prevalence of osteoporosis in Hong Kong women is comparable to that found in Caucasian populations. Prevention of osteoporosis, involving both immediate and long-term measures, and targeting at different age groups, are required to combat this serious public health problem in Hong Kong.

Analysis of trabecular microarchitecture of human iliac bone using microcomputed tomography in patients with hip arthrosis with or without vertebral fracture

Iliac bone samples were obtained from 50 women with osteoarthrosis of the hip (50–80 years of age) during hip surgery for total hip joint replacement. After determining the resolution and threshold for the binary image, the two-dimensional (2D) and three-dimensional (3D) data of the trabecular structure were obtained in these iliac bone samples using microcomputed tomography (micro-CT). Conventional histomorphometry was then performed. Both 2D and 3D parameters of the trabecular structure were significantly correlated with the parameters of conventional histomorphometry ( r = 0.63–0.86 in 2D analysis, and r = 0.60–0.77 in 3D analysis). The patients were classified into the non-spinal-fracture group (n = 36) and the spinal fracture group (n = 14). There was no significant difference in patient age between the two groups. The parameter values of bone mass, such as 2D fractional trabecular bone area and 3D fractional bone volume, and the values of trabecular number (Tb.N) in terms of both 2D and 3D analyses were significantly smaller, and those of trabecular separation (Tb.Sp) were significantly higher in the spinal fracture group than in the non-spinal-fracture group. Trabecular thickness (Tb.Th) values did not significantly differ between the two groups. There was no significant difference between 2D and 3D parameters in discriminating the spinal fracture group from the non-spinal-fracture group. However, 3D analysis demonstrated that the value of the bone surface to bone volume (BS/BV) ratio could discriminate between these two groups. These data demonstrated that micro-CT can evaluate the 3D structure of the human iliac bone, and that decreases in the parameters of the 3D-structure-related bone surface density as well as decreases in trabecular bone volume are related to osteoporotic fracture.