Forearm Bone Density Research Articles

A cross-sectional study of the forearm bone density of long-term users of levonorgestrel-releasing intrauterine system

There are concerns about the effect of hormonal contraceptives on bone mineral density (BMD), but there is currently no information available on the effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) on BMD. The objective of this study was to compare the BMD of LNG-IUS users with that of controls using the TCu380A intrauterine device (IUD). A cross-sectional study paired 53 women, aged 25-51 years, who had been using the LNG-IUS for 7 years, with 53 IUD users, according to age (+/-1 year) and body mass index (BMI; kg/m2) (+/-1). BMD was evaluated at the midshaft of the ulna and the distal radius of the nondominant forearm using double X-ray absorptiometry. Mean age of women was 34 years. BMI was slightly over 25 in both groups. Estradiol was normal. Mean BMD was 0.469 +/- 0.008 and 0.467 +/- 0.009 and 0.409 +/- 0.009 and 0.411 +/- 0.009 at the midshaft of the ulna and distal radius in LNG-IUS and IUD users, respectively, without significant differences. Women aged 25-51 years, using the LNG-IUS for 7 years, had a mean BMD similar to that of the control group of TCu380A IUD users.

Forearm Single X-Ray Absorptiometry in the Identification of Postmenopausal Women With Osteoporosis at the Hip and Spine

The International Society for Clinical Densitometry (ISCD) has stated that forearm bone mineral density (BMD) testing combined with a thorough clinical evaluation may be an option for the diagnosis of osteoporosis when central bone density (CBD) testing is not available. This study assessed the performance of two different forearm sites in identifying subjects with spinal and femoral osteoporosis, and defined the 90% sensitivity point for the DTX-100 bone densitometer in the detection of central osteoporosis. Four hundred and two postmenopausal Bulgarian women between the ages of 50 and 81 yr (mean age 60.24 +/- 10.48 yr) participated in this study. Forearm BMD (distal and ultradistal forearm) was measured with a DTX-100 device (Osteometer Meditech, USA) and central BMD (lumbar spine and proximal femur) with a Hologic QDR 4500 A device. Linear T-score correlations among sites, sensitivity and specificity of the forearm site were analyzed. T-score correlations between the forearm and the central sites ranged from 0.32 to 0.69 (p < or = 0.05 for all correlations in age group 50-59). The forearm site sensitivity increased slightly with advancing age, but specificity decreased. When the distal forearm BMD cut point (0.340 g/cm2) was set to achieve 90% sensitivity to identify total hip osteoporosis, specificity was 40%; when the distal forearm BMD cut point (0.410 g/cm2) was set to achieve 90% sensitivity to identify spinal osteoporosis, specificity was 55.4%; when ultradistal forearm BMD cut points (0.280 and 0.320 g/cm2) were set to achieve 90% sensitivity to identify total hip and spinal osteoporosis, specificity was 40.8 and 59.2%, respectively. Forearm bone density measures may be useful to selectively screen for patients with central osteoporosis.

A prospective study of the forearm bone density of users of etonorgestrel- and levonorgestrel-releasing contraceptive implants

The aim of the study was to compare bone mineral density (BMD) before insertion and at 18 months of use of etonorgestrel- and levonorgestrel-releasing contraceptive implants. One hundred and eleven women, 19-43 years of age, were randomly allocated to two groups: 56 to etonorgestrel and 55 to levonorgestrel. BMD was evaluated at the midshaft of the ulna and at the distal radius of the non-dominant forearm using dual-energy X-ray absorptiometry before insertion and at 18 months of use. There was no difference in baseline demographic or anthropometric characteristics, or in BMD of users of either model of implant. BMD was significantly lower at 18 months of use at the midshaft of the ulna in both groups of users. However, no difference was found at the distal radius. Multiple linear regression analysis showed that the variables associated with BMD at 18 months of use in both implant groups were baseline BMD, body mass index (BMI) and difference in BMI (0 versus 18 months of use). Women of 19-43 years of age using either one of the implants showed lower BMD at 18 months of use at the midshaft of the ulna, however, without a difference at the distal radius.

Growth Hormone Changes Bone Geometry and Body Composition in Patients with Juvenile Idiopathic Arthritis Requiring Glucocorticoid Treatment: A Controlled Study Using Peripheral Quantitative Computed Tomography

Osteopenia and growth retardation have been described in children with chronic arthritis. GH has an impact on both. In the present controlled study, we used peripheral quantitative computed tomography to evaluate forearm bone mass, density, and geometry as well as forearm muscle and fat area in 17 patients with juvenile idiopathic arthritis (JIA) receiving treatment with GH for 3.8 +/- 1.1 yr compared with an untreated age- and sex-matched control group (n = 17). All patients had a mean age of 15.3 +/- 2.5 yr and a mean duration of illness of 8.2 +/- 4.4 yr. Height, weight, body mass index, bone parameters, and muscle area were significantly decreased in both groups compared with those in healthy age-matched children. Compared with untreated JIA patients, GH-treated JIA patients had significant higher bone mineral content as well as total cross-sectional area (CSA), cortical CSA, and muscle CSA. Fat CSA was lower in the GH-treated group. A significant difference between groups for height-corrected cortical and muscle areas was only seen in male patients. Cortical CSA relative to muscle CSA was not different between groups. These findings are compatible with an anabolic effect of GH on muscle and bone development.

Environmental cadmium exposure and forearm bone density

Environmental exposure to cadmium may give rise to osteomalacia combined with renal dysfunction, so called 'Itai-Itai disease', which was endemic in the heavily polluted area in Japan. The main focus of this study was to investigate whether environmental exposure to cadmium is associated with low bone mass in a population living near a smelter. A total of 790 persons (302 males and 488 females), who were all over 35 years old and resided in areas near a lead, zinc and cadmium smelter and in a control area in southeast China, completed a questionnaire, and bone mineral density was measured by SPA-4 single photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The present study shows that forearm bone densities were negatively correlated with urinary cadmium excretion (p < 0.001) and forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01), suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was a marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both gender, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.

Cadmium, osteoporosis and calcium metabolism

Occupational exposure to cadmium has for long been associated with renal tubular cell dysfunction, osteomalacia with osteoporosis, hypercalciuria and renal stone formation. High environmental exposure in Japan resulting from a stable diet of cadmium contaminated rice caused itai-itai disease, fractures occurring mainly in elderly multiparous women, with a form of osteomalacia, osteoporosis and renal dysfunction. More recently a population based study in Europe, in the vicinity of zinc smelters has shown that low to moderate exposure to cadmium, with a mean urinary excretion of cadmium of the order of 1 microg/g creatinine has been associated with a decrease in bone density, an increased risk of bone fractures in women and of height loss in men. In a population-based study of residents near a cadmium smelter in China, forearm bone density was shown to decrease linearly with age and urinary cadmium in both sexes, suggesting a dose effect relationship between cadmium dose and bone mineral density. A marked increase in the prevalence of fractures was shown in the cadmium-polluted area in both sexes. Concentrations of cadmium in blood and urine were taken as exposure biomarkers, and beta2-microglobulin, retinol binding protein and albumin as biomarkers of effect. A marked dose response relationship between these indicators of exposure and effect was shown. Hypercalciuria, which may progress to osteoporosis, has been taken as a sensitive renal-tubular biomarker of a low level of cadmium exposure. Cadmium may also act directly on bone. Animal studies have shown cadmium to stimulate the formation and activity of osteoclasts, breaking down the collagen matrix in bone. Osteoporosis is the main cause of fracures in post-menopausal women, a common occurrence worldwide, giving rise to disability and a high cost to health services. The identification of cadmium, an environmental pollutant, as one causal factor is highly significant in helping to control the incidence of this complex condition.

Vitamin D deficiency and secondary hyperparathyroidism and the association with bone mineral density in persons with Pakistani and Norwegian background living in Oslo, Norway: The Oslo Health Study

We studied the prevalence of poor vitamin D status and the association with bone density in men and women born in Norway (quoted as Norwegians, n = 869) and Pakistan (quoted as Pakistanis, n = 177) in the population-based Oslo Health Study, 2000–2001. We measured 25-hydroxyvitamin D, iPTH and ionized calcium in serum and bone mineral density at the forearm site with single energy X-ray absorptiometry. Mean 25-hydroxyvitamin D was 74.8 ± 23.7 nmol/l in the Norwegians and 25.0 ± 13.6 nmol/l in the Pakistanis ( P = 0.000). The prevalence of secondary hyperparathyroidism (iPTH ≥ 8.5 pmol/l, 25-hydroxyvitamin D < 50 nmol/l and Ca 2+ ≤ 1.35 mmol/l) was four times higher in Pakistani compared to Norwegian women. Also in Pakistani men, serious vitamin D deficiency defined as secondary hyperparathyroidism was prevalent, and five times as frequent as in Norwegian men. However, whereas BMD was significantly lower in Norwegian women with, compared to Norwegian women without, secondary hyperparathyroidism, there was no difference in BMD between Pakistani women with and without secondary hyperparathyroidism. In conclusion, vitamin D deficiency was prevalent among Pakistani immigrants, and in great contrast to the vitamin D replete Norwegians. Serious vitamin D deficiency was interestingly not associated with reduced forearm bone density among Pakistani women.

Relation between calcium absorption and serum calcitriol in normal men: evidence for age-related intestinal resistance to calcitriol.

To obtain information on the causes of age-related bone loss in men and the concomitant decline in calcium absorption. Cross-sectional study. Adelaide, South Australia, Australia. A total of 95 healthy, Caucasian men (age range 27-87 y). Calcium absorption declined with age (r=-0.46, P<0.0001), as did 24-h urine calcium, phosphate and creatinine (r>-0.21, P<0.05 for all); serum calcitriol and 25 hydroxyvitamin D did not change with age. Calcium absorption was related to serum calcitriol (r=0.20, P=0.05). An inverse relation between the residual deviations in calcium absorption, after allowing for its dependence on calcitriol, and age (F=5.4, P<0.005) was observed. The 24-h urinary calcium, phosphate and creatinine were all related to calcium absorption (r>0.41, P<0.0001). Forearm bone density fell with age (r=-0.45, P<0.0001) but was not related to calcium absorption, or markers of bone turnover. In healthy Caucasian males (i) calcium absorption falls, but serum calcitriol does not change with age, (ii) the relation between calcium absorption and serum calcitriol changes with age, indicative of an intestinal resistance to calcitriol and (iii) calcium absorption is a significant determinant of 24-h urinary calcium excretion.

Influence of environmental cadmium exposure on forearm bone density.

Cadmium may have both direct and indirect effects on bone turnover. It is nephrotoxic and can interfere with vitamin D metabolism. Such perturbation may result in osteoporosis and osteomalacia. In this study, a total of 790 persons (302 males and 488 females) participated; they were all over 35 years old and resided in an area near a cadmium smelter in southeast China. All participants completed a questionnaire, and bone mineral density was measured by SPA-4 single-photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The decline in bone mineral density with age in a heavily polluted area was greater than that in a control area for subjects over 60 years of age of both sexes (p < 0.05). In single regression, forearm bone densities were negatively correlated with urinary cadmium excretion in both males and females (p < 0.001), whereas stepwise regression showed that forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01) in both sexes, suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was the marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both males and females, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.

Paraplegia-related alterations of bone density in forearm and hip in Greek patients after spinal cord injury

Purpose : Paraplegia due to spinal cord injury is related with sublesional bone demineralization with an increased incidence of pathologic fractures in lower extremities. This study was carried out in order to evaluate bone density alterations in forearm and hip in Greek paraplegic patients after spinal cord injury and to correlate the findings with the level of injury, the neurological status, the time interval from injury and the performing of physiotherapy and therapeutic standing. Method : Fifty-seven paraplegic patients (33 men and 24 women, with injuries sustained from 6 months to 27 years) and 36 able-bodied age-matched controls (25 men, 16 women) participated in the study. Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA) in the proximal and distal forearm, the femoral neck, the greater trochanter and Ward's triangle. Results : The measurements revealed a significant reduction of BMD of femoral neck ( p <0.001 in male, p <0.001 in female paraplegics), greater trochanter ( p <0.001 and p =0.001, respectively) and Ward's triangle ( p =0.001 and p =0.005, respectively). Proximal forearm depicted non-significantly decreased BMD values and distal forearm depicted a slight increase in BMD values. The degree of demineralization was independent of factors such as complete or incomplete spinal cord injury, level of the lesion, physiotherapy and performing of standing. In addition to that, BMD values in both hip and forearm showed no statistically significant correlation with time after injury. Conclusions : BMD measurements in Greek paraplegic patients reveal bone loss, which most dramatically occurs in the region of hip with a consequent increase of fracture risk. Forearm measurements depict a non-homogeneous response with limited proximal bone loss and slight distal increase of BMD, the latter being possibly attributed to daily activities.

Assessment of forearm volumetric bone mineral density from standard areal densitometry data.

The common bone density measurement procedures produce areal bone mineral density data (BMD) alone. Volumetric bone density is thought to offer a different diagnostic perspective and is usually measured by peripheral quantitative computed tomography. We developed a calculation procedure for radial and ulnar volumetric densities based on single X-ray absorptiometry. The study consisted of 418 healthy Bulgarian females (ages 20 83 yr). Forearm bone density was measured on a DTX-100 densitometer at the 8-mm distal site, and the total volumetric bone densities of radius and ulna were calculated. The accuracy error determined on cadaveric bones was 10 14%. The in vivo precision error was 1.0 1.1%. Age-matched reference curves for volumetric BMD (vBMD) were built. Peak values were registered in the age 30 34 group: 0.403 (radius) and 0.469 g/cm(3) (ulna). Ulnar volumetric density exceeded the radial one, representing an interesting finding to be further investigated. For the age 70 74 group, vBMD was reduced by approx 30% compared with the age 30 34 group. Our data confirmed the fact that volumetric density was much less affected by age and menopause. Correlations between forearm vBMD and axial BMD were moderate. The proposed calculation procedure could become an extra option in forearm bone densitometry to be applied in pediatric populations or adults of extremely large or small body size.

Universal standardization of forearm bone densitometry.

As part of an effort to quantify device-dependent differences in forearm bone density, 101 women, aged 20-80 years (approximately 16 women in each age decade), were scanned on six forearm bone densitometers: the Aloka DCS-600EX, the Hologic QDR-4500A, the Lunar PIXI, the Norland pDEXA, the Osteometer DTX-200, and the Pronosco X-posure System. Regression statistics are reported for all similar regions of interest (ROIs). However, comparisons were confounded because of large differences in the ROI size and placement. The number of ROIs reported for a single scan by each device varied from 1 to 12. The correlation coefficients ranged from 0.7 < r < 0.97, with the highest correlation coefficients and lowest SEs for comparisons between the most similar ROIs. Standardized units of bone mineral density are derived for distal (sdBMD), mid-(smBMD), and proximal (spBMD) ROTs that allow for comparable mean bone densities to be derived for patient populations. Five phantoms were scanned and characterized on five of the devices and the precision and mean values were reported. These phantom values will aid in the in vitro cross-calibration between manufacturers to recreate the presented in vivo relationships. Care should be exercised when using these equations for cross-calibrating patient databases or pooling clinical data from different devices because the least significant differences detectable from measurements taken on two different machines can be increased substantially.

Prevalence of low forearm bone density in a Bulgarian female referral population.

Osteoporosis is one of the leading causes of morbidity and mortality in the elderly population. The prevalence of osteoporosis and osteopenia in Bulgaria is unknown except for preliminary data. We tried to determine retrospectively the prevalence of osteopenia and osteoporosis in a referral female population; 8869 consecutive Bulgarian women (age 20-87 years) were included. Information about known risk factors for low bone mass was recorded. Forearm bone mineral density was measured at the distal radius+ulna site by single X-ray absorptiometry (DTX-100 device). T- and Z-scores were calculated from Bulgarian reference data. In the total study sample 15.16% had osteoporosis and 28.8% had osteopenia. In women aged 50 years and over the corresponding prevalence was 20.45% and 32.5%. Age-adjusted prevalence of osteoporosis and osteopenia started rising after age 55 years. Corresponding mean T-scores also declined and the osteoporosis threshold of -2.5 SD was reached in the age group 70-74 years. Z-scores in all age groups were between 0 and -0.6, thus excluding major selection bias. This is the first large-scale Bulgarian study designed to look for the prevalence of osteopenia and osteoporosis in a referral population. It may become the starting point for future screening and intervention strategies in our country.

Forearm bone density in long-term users of oral combined contraceptives and depot medroxyprogesterone acetate

Objective: To compare the bone mineral density of users of combined oral contraceptives (OC) or depot medroxyprogesterone acetate (depot-MPA) with women who have never used a hormonal contraceptive method. Design: Cross-sectional study. Setting: Academic tertiary-care hospital. Patient(s): A total of 189 women, aged 30 to 34 years old, were allocated to three groups: 63 who had used OC for at least 2 years; 63 who had used depot-MPA for at least 2 years; and 63 control women who had never used hormonal contraceptives. Intervention(s): Each woman’s bone mineral density (BMD) was evaluated at the distal and ultradistal section of the radius of the nondominant forearm by the use of single x-ray absorptiometry. Main Outcome Measure(s): We obtained BMD measurements for each participant. Result(s): Independent of the period of use and the section of the forearm studied, we found no difference in BMD for OC or depot-MPA users when compared to women who had never used hormonal contraceptive methods. In addition, BMD was similar between OC users and depot-MPA users. The multiple linear regression analysis showed that the variables associated with BMD were weight, number of pregnancies, and the woman’s occupation. Conclusion(s): Women aged 30 to 34 years who have used OC or depot-MPA have similar BMD as control women. These findings suggest that the use of OC or depot-MPA does not affect the BMD of women in this age group.

Separate assessment of forearm cortical and trabecular bone density from standard densitometry data

BACKGROUND. Cortical and trabecular bone are different bone components. Their mineral density cannot be measured directly by areal bone densitometry.AIM. To introduce a method for assessment of pure radial cortical and trabecular bone density based on standard densitometry data.METHOD. The study included 418 healthy females (aged 20–83 years, body mass index between 19 and 30) free of previous fractures and conditions or drugs affecting bone metabolism: as well as a group of 64 age-matched females with early menopause. Forearm bone density was measured by single X-ray absorptiometry and calculated separately for cortical and trabecular bone. Age-adjusted bone density curves were built.RESULTS. Peak bone density was found to occur between 30 and 34 years of age and was 0.561 g/cm2 for cortical and 0.281 g/cm2 for trabecular bone. In comparison, lowest values were registered between 70 and 74 years of age: cortical bone density reduced by 26% and trabecular density by 44%. Both bone density profiles through life reflected the earlier peri- and postmenopausal (mainly trabecular) and later senile (cortical bone also involved) changes in bone mass. A step-wise pattern of trabecular bone reduction was registered with acceleration around 45, 55 and 65 years. The effects of early menopause on trabecular and cortical bone were tested in the prematurely menopausal women.CONCLUSIONS. The ability of our model to discriminate between natural and premature menopause was moderate. Although hypothetical (based on calculations from integral densitometry data rather than on direct measurements), our method could differentiate between cortical and trabecular osteopenia and may prove helpful in assessing the type of osteoporosis, in making therapy choices and monitoring response to therapy based on forearm bone density.

Unique Co-Operative Worksite-Based Osteoporosis Project

Osteoporosis is considered a disease that affects elderly women. Younger, working-aged women are seldom considered to be at risk, although low bone mass may occur at menopause or even earlier. Bone density testing for working women may therefore be considered of low priority for both women and their employers, especially if they perceive that there is a low risk of having low bone density at this age. We have designed a project to test bone density of women at their worksites. To: (i) create a method to detect silent bone loss in an employed population of women at their worksite; (ii) create a service to provide education and assist in compliance with management of low bone density for those affected; (iii) measure the effectiveness of these interventions. This study is a collaboration of an employer, the managed care organization, which provides healthcare coverage for this employer, and a pharmaceutical company which has long been involved in bone density research. We performed bone density screening of working women at their worksites who, based on a risk assessment, were potentially at risk of osteopenia or osteoporosis. Forearm bone density was assessed for each woman. For those women found to have low bone mass, a series of interventions, including worksite counseling and periodic telephonic follow-up, was provided to help them understand more fully their screening results and the need for interventions, including lifestyle changes, and follow-up with their primary care physicians for diagnosis and treatment. Data were collected before and after the interventions for each woman to measure outcomes, compliance and satisfaction with the screenings and interventions. 52 women employed by Sara Lee Corporation who participated in the healthcare trial and were found to have low bone density. All agreed to participate in the year-long interventions. We found that these women reported increased knowledge about low bone density, compliance with their medications, and lifestyle habits following screening, counseling and periodic telephonic follow-up. In addition, as a result of the screenings performed, a significant proportion of these women (with low bone mass) were confirmed to have osteopenia or osteoporosis by their physicians, and started on therapy. Satisfaction with the screening process and telephonic management was uniformly high, with >95% of the women rating the services of the project as ‘good’ or ‘excellent’. A worksite-based bone density testing method such as this was well received by those who participated. It led to improved detection and treatment of a group of younger, working-aged women who may have otherwise not undergone such testing until a much later age, if at all. This earlier detection and treatment may prevent further loss of bone mass and likelihood of clinical fracture. The collaboration between an employer, a managed care organization, and a pharmaceutical company enhanced the design and delivery of a functional project for a worksite-based bone density screening and contributed largely to its success.

The worldwide controversy about the polymorphism of the vitamin D receptor gene and bone mineral density

Bone density has been reported to be strongly genetically determined. Smith et al. found that forearm bone density was more similar in monozygotic twin (MZ) pairs than in dizygotic twin (DZ) pairs (1). In another study, Takeshita et al. measured bone mineral density (BMD) in the total body, the lumbar spine and in the femoral neck in Japanese twins. They observed highly significant intraclass correlation coefficients at several sites in a study of MZ twins between the ages of 20 and 49. These data suggested a considerable contribution of genetic factors to BMD (2). Osteocalcin is an abundant bone protein of uncertain function. It is derived exclusively from osteoblasts. In studies of twins, variation in serum osteocalcin levels has been shown to have a major genetic component (3) and to be closely correlated with the known genetic diversity in bone density (4). Vitamin D is known to be a potent regulator of bone and calcium homeostasis. The vitamin D receptor (VDR) activates osteocalcin gene expression through the vitamin D response element in the promoter

Forearm bone density in users of Depo-Provera as a contraceptive method

Objective: To determine the influence of depot medroxyprogesterone acetate (MPA) on bone mineral density when used as a contraceptive method. Design: Cross-sectional study. Setting: Academic tertiary-care hospital. Patient(s): Fifty premenopausal women who had used depot MPA as a contraceptive method for ≥1 year and 50 women who had never used hormonal contraceptive methods. Intervention(s): Bone mineral density was evaluated at the midshaft and at the distal radius of the nondominant forearm using single x-ray absorptiometry. Main Outcome Measure(s): Bone mineral density. Result(s): Bone mineral density at the midshaft of the forearm was lower in depot MPA users than in women who had never used hormonal contraceptive methods, but the difference was not statistically significant. At the distal portion, bone mineral density was significantly lower in the study group. The duration of depot MPA use was not related to bone mineral density. Conclusion(s): Women ≥35 years of age presented with a lower bone mineral density only at the distal portion of the forearm after the use of depot MPA for ≥1 year. However, this decrease was not related to the duration of depot MPA use. It is not possible to conclude that women who use depot MPA are at risk of osteoporosis.

Environmental exposure to cadmium, forearm bone density, and risk of fractures: prospective population study

Chronic low-level exposure to cadmium may promote calcium loss via urinary excretion. We undertook a prospective population study to investigate whether environmental exposure to cadmium lowers bone density and increases risk of fractures. We measured urinary cadmium excretion, a biomarker of lifetime exposure, in people from ten districts of Belgium, of which six districts bordered on three zinc smelters. We also measured cadmium in soil and in vegetables from the districts, and collected data on incidence of fractures and height loss. Bone density was measured at the forearm just above the wrist by single photon absorptiometry, and calculated as the mean of six proximal and four distal scans. Mean cadmium excretion at baseline was 8.7 nmol daily. Across the ten districts, mean cadmium concentration in soil ranged from 0.8 to 14.7 mg/kg, and from 0.1 to 4.0 mg/kg dry weight in vegetables. Median follow-up was 6.6 years. Mean forearm bone density in proximal and distal scans was 0.54 g/cm2 and 0.43 g/cm2 in men, and 0.44 g/cm2 and 0.34 g/cm2 in women. In postmenopausal women, a twofold increase in urinary cadmium correlated with 0.01 g/cm2 decrease in bone density (p<0.02). The relative risks associated with doubled urinary cadmium were 1.73 (95% CI 1.16-2.57; p=0.007) for fractures in women and 1.60 (0.94-2.72, p=0.08) for height loss in men. Cadmium excretion in districts near smelters was 22.8% higher (p=0.001) than in other districts, with fracture rates of 16.0 and 10.3 cases per 1000 person-years, respectively, and a population-attributable risk of 35.0%. Even at a low degree of environmental exposure, cadmium may promote skeletal demineralisation, which may lead to increased bone fragility and raised risk of fractures.

The Effect of an Isoflavone Dietary Supplement (P-081) on Serum Lipids, Forearm Bone Density and Endometrial Thickness in Postmenopausal Women

The Effect of an Isoflavone Dietary Supplement (P-081) on Serum Lipids, Forearm Bone Density and Endometrial Thickness in Postmenopausal Women