Bone Density Research Papers - Academia.edu (original) (raw)

Objective To determine the effects of menopause on bone-related variables in Indonesian women and to compare them with corresponding data in Caucasian Australian women.Design A study of bone-related variables in women aged 45–55 years... more

Objective To determine the effects of menopause on bone-related variables in Indonesian women and to compare them with corresponding data in Caucasian Australian women.Design A study of bone-related variables in women aged 45–55 years in Jakarta compared with corresponding historical data from Caucasian Australian women.Measurements Dietary intakes, bone mineral density (BMD) and calcium-related variables in blood and urine.Results Dietary calcium, phosphorus and protein intakes were significantly lower in the women from Jakarta than in those from Adelaide (all P < 0·001), probably because of lower milk consumption, but energy intake was similar in the two cities. Indonesian women were shorter and lighter than Australian women (P < 0·001) but had a comparable body mass index (BMI). The Indonesians also had a lower spinal BMD than the Australians but this was accounted for by the differences in height and weight between the two populations. The differences in serum and urinary calcium and phosphate and serum alkaline phosphatase across the menopause were comparable in Indonesian and Australian women but creatinine excretion was 25% lower in Jakarta than in Adelaide (P < 0·001) and this was probably sufficient to account for higher ratios of some urinary solutes to urinary creatinine in the Indonesians. Serum 25-hydroxyvitamin D (25OHD) levels were significantly lower (P < 0·001) and serum PTH levels significantly higher (P = 0·0045) in Jakarta than in Adelaide.Conclusions The differences in bone-related biochemical variables across the menopause were similar in the two populations, but calcium and protein intake and urine creatinine were lower in Indonesian than in Australian women. Serum 25OHD was lower and PTH higher in the Indonesian women, probably because of their darker skin, their practice of avoiding direct sunlight and the heavy atmospheric pollution in Jakarta.

The primary aim of the proposed study is to examine the efficacy of an 8-month supervised, high-intensity progressive resistance training and impact loading programme in comparison with a supervised machine-based isometric exercise... more

The primary aim of the proposed study is to examine the efficacy of an 8-month supervised, high-intensity progressive resistance training and impact loading programme in comparison with a supervised machine-based isometric exercise training programme using the bioDensity system in older men with low bone mass. We will also determine the safety and acceptability of each exercise training mode. Intervention group responses will be compared with those of a self-selected, non-randomised control sample of sex-matched and age-matched men who will follow their usual lifestyle activities for 8 months. Apparently healthy men over 50 years with low bone mass, screened for medical conditions and medications known to adversely affect bone health, will be recruited. Eligible participants will be randomly allocated to 8 months of either exercise programme with block randomisation based on presence or absence of osteoporosis medications. A twice-weekly, 30-minute, supervised exercise programme wil...

The reluctance of physicians to use estrogens in women with hormone responsive disorders is a tragic result of the 2002 WHI study. Although their hostility to estrogen therapy antedated these studies, the flawed data is now used as... more

The reluctance of physicians to use estrogens in women with hormone responsive disorders is a tragic result of the 2002 WHI study. Although their hostility to estrogen therapy antedated these studies, the flawed data is now used as justification for the denial of estrogens for treatment of low bone density and various types of hormone responsive depression in women. Estrogens

The purpose of this study was to analyze, in an animal model, the histologic and biomechanical phenomena at the bone-implant interface of implants inserted with high torque (HT) as compared to low torque (LT) during the first 6 weeks of... more

The purpose of this study was to analyze, in an animal model, the histologic and biomechanical phenomena at the bone-implant interface of implants inserted with high torque (HT) as compared to low torque (LT) during the first 6 weeks of healing. Forty tapered-screw-form implants were placed in five hybrid sheep. The implant sites were placed in the mandible, using an extraoral approach; four were placed with HT (test: mean 110 Ncm) on one side and four were placed with LT (control: mean 10 Ncm) on the contralateral side. After 1, 2, 3, 4, and 6 weeks of healing, removal torque testing and resonance frequency analysis were performed and the animals were sacrificed for histologic examination. Implants from the HT group showed significantly higher bone apposition than implants from the LT group at all examined healing times. Similarly, removal torque was consistently higher for the HT as compared to the LT group. A significant loss of primary stability in the HT group was evident 7 day...

Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related methoxyisoflavones; cajanin and isoformononetin were studied for their effects in osteoblasts. Cajanin had strong mitogenic as well as... more

Following a lead obtained from stem-bark extract of Butea monosperma, two structurally related methoxyisoflavones; cajanin and isoformononetin were studied for their effects in osteoblasts. Cajanin had strong mitogenic as well as differentiation-promoting effects on osteoblasts that involved subsequent activation of MEK-Erk and Akt pathways. On the other hand, isoformononetin exhibited potent anti-apoptotic effect in addition to promoting osteoblast differentiation that involved parallel activation of MEK-Erk and Akt pathways. Unlike genistein or daidzein, none of these two compounds appear to act via estrogen receptors in osteoblast. Once daily oral (by gavage) treatment for 30 consecutive days was given to recently weaned female Sprague–Dawley rats with each of these compounds at 10.0 mg kg−1 day−1 dose. Cajanin increased bone mineral density (BMD) at all skeletal sites studied, bone biomechanical strength, mineral apposition rate (MAR) and bone formation rate (BFR), compared with control. BMD levels at various anatomic positions were also increased with isoformononetin compared with control however, its effect was less potent than cajanin. Isoformononetin had no effect on the parameters of bone biomechanical strength although it enhanced MAR and BFR compared with control. Isoformononetin had very mild uterotrophic effect, whereas cajanin was devoid of any such effect. Our data suggest that cajanin is more potent than isoformononetin in accelerating peak bone mass achievement. To the best of our knowledge, this work represents the first attempt to elucidate structure-activity relationship between the two methoxylated isoflavones regarding their effects in osteoblasts and bone formation. J. Cell. Biochem. 108: 388–399, 2009. © 2009 Wiley-Liss, Inc.

Data are lacking regarding regional morphological changes among women after prolonged physical training. This study employed dual-energy X-ray absorptiometry to assess changes in whole body and regional (i.e., trunk, legs, arms) fat mass,... more

Data are lacking regarding regional morphological changes among women after prolonged physical training. This study employed dual-energy X-ray absorptiometry to assess changes in whole body and regional (i.e., trunk, legs, arms) fat mass, lean mass, and bone mineral content body composition adaptations in 31 healthy women pre-, mid-, and post-6 mo of periodized physical training. These results were compared with those of 1) a control group of women who had not undergone the training program and were assessed pre- and post-6 mo and 2) a group of 18 men that was tested only once. Additionally, magnetic resonance imaging was used to assess changes in muscle morphology of the thigh in a subset of 11 members of the training group. Physical training consisted of a combination of aerobic and resistance exercise in which the subjects engaged for 5 days/wk for 24 wk. Overall, the training group experienced a 2.2% decrease, a 10% decrease, and a 2.2% increase for body mass, fat mass, and soft...

Purpose: To assess the reliability of cone beam computed tomography (CBCT) voxel gray value measurements using Hounsfield units (HU) derived from multislice computed tomography (MSCT) as a clinical reference (gold standard). Materials and... more

Purpose: To assess the reliability of cone beam computed tomography (CBCT) voxel gray value measurements using Hounsfield units (HU) derived from multislice computed tomography (MSCT) as a clinical reference (gold standard). Materials and Methods: Ten partially edentulous human mandibular cadavers were scanned by two types of computed tomography (CT) modalities: multislice CT and cone beam CT. On MSCT scans, eight regions of interest (ROI) designating the site for preoperative implant placement were selected in each mandible. The datasets from both CT systems were matched using a three-dimensional (3D) registration algorithm. The mean voxel gray values of the region around the implant sites were compared between MSCT and CBCT. Results: Significant differences between the mean gray values obtained by CBCT and HU by MSCT were found. In all the selected ROIs, CBCT showed higher mean values than MSCT. A strong correlation (R = 0.968) between mean voxel gray values of CBCT and mean HU of...

Summary Vitamin D deficiency is associated with increased fracture risk. The observational study aimed to investigate vitamin D status and supplementation in ambulatory patients. Only 20% of patients had optimal serum 25-hydroxyvitamin D... more

Summary Vitamin D deficiency is associated with increased fracture risk. The observational study aimed to investigate vitamin D status and supplementation in ambulatory patients. Only 20% of patients had optimal serum 25-hydroxyvitamin D [25(OH)D] levels. Commonly recommended dosages were insufficient to achieve clinically relevant increase of 25(OH)D levels. Higher dosages were safe and effective under clinical practice conditions. Introduction Vitamin D deficiency

During growth the mandible accommodates increases in biomechanical loading resulting from changes in the function of structures of the oral cavity. Biomechanical loads are thought to play an intricate and vital role in the modelling and... more

During growth the mandible accommodates increases in biomechanical loading resulting from changes in the function of structures of the oral cavity. Biomechanical loads are thought to play an intricate and vital role in the modelling and remodelling of bone, with site-specific effects on bone mineral density. It is anticipated that the effects of this loading on bone mineral density are intensified during the functional transition from prenatal to postnatal stages. The aim of this study was thus to evaluate changes in bone mineral density across the body of the immature human mandible during the early stages of dental development. The study sample included 45 human mandibles, subdivided into three age groups: prenatal (30 gestational weeks to birth; n = 15); early postnatal (birth to 12 months; n = 18); and late postnatal (1-5 years; n = 12). Mandibles were scanned using X-ray micro-computed tomography. Eight landmarks were selected along the buccal/labial and lingual surfaces of eac...

Objective: Our aim was to investigate the clinical efficacy and safety of gonadotropin-releasing hormone agonist (GnRH-a) following laparoscopic surgery in the treatment of endometriosis. Methods: A total of 100 patients with... more

Objective: Our aim was to investigate the clinical efficacy and safety of gonadotropin-releasing hormone agonist (GnRH-a) following laparoscopic surgery in the treatment of endometriosis. Methods: A total of 100 patients with endometriosis were randomly divided into a control group (laparoscopic resection only, n=50) and treatment group (laparoscopic resection combined with GnRH-a treatment, n=50). In addition to laparoscopic resection that was performed in the control group, the treatment group also received an additional 3-6 courses of GnRH-a therapy postoperatively (3.75 mg per time, every 28 days). The effective rates, recurrence rates, dysmenorrhea relief rates, dyspareunia relief rates, chronic pelvic pain relief rates, and the total pain relief rates as well as the adverse events were recorded and analyzed. Results: Total effective rates of the treatment and control groups were 86.0% (43/50) and 62.0% (31/50), respectively, with significant inter-group difference (P<0.05)....

Clinical trials have shown that 3-hydoxy-3- methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, known as statins, significantly reduce the risk of both primary and secondary coronary heart disease events. Although these trials have... more

Clinical trials have shown that 3-hydoxy-3- methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, known as statins, significantly reduce the risk of both primary and secondary coronary heart disease events. Although these trials have included few women, the evidence suggests that statins are as effective in women as in men. The addition of hormone replacement therapy to statin therapy augments lowering of low- density lipoprotein cholesterol, but may not increase the favorable effects on clinical events achieved with statins alone. Finally, new data suggest that statins may also reduce the risk of osteoporotic fractures, a provocative finding still in need of verification by clinical trials.

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to... more

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to dual-energy X-ray absorptiometry (DXA) images. Significant correlations between TBS and standard 3-dimensional (3D) parameters of bone microarchitecture have been obtained using a numerical simulation approach. The main objective of this study was to empirically evaluate such correlations in anteroposterior spine DXA images. Thirty dried human cadaver vertebrae were evaluated. Micro-computed tomography acquisitions of the bone pieces were obtained at an isotropic resolution of 93μm. Standard parameters of bone microarchitecture were evaluated in a defined region within the vertebral body, excluding cortical bone. The bone pieces were measured on a Prodigy DXA system (GE Medical-Lunar, Madison, WI), using a custom-made positioning device and experimental setup. Significant correlations were detected between TBS and 3D parameters of bone microarchitecture, mostly independent of any correlation between TBS and bone mineral density (BMD). The greatest correlation was between TBS and connectivity density, with TBS explaining roughly 67.2% of the variance. Based on multivariate linear regression modeling, we have established a model to allow for the interpretation of the relationship between TBS and 3D bone microarchitecture parameters. This model indicates that TBS adds greater value and power of differentiation between samples with similar BMDs but different bone microarchitectures. It has been shown that it is possible to estimate bone microarchitecture status derived from DXA imaging using TBS.