Dual Energy X-ray Absorptionmetry Research Articles

#495 Effect of Vit D supplementation on bone mineral density in haemodialysis patients. A comparative study

Abstract Background and Aims Low serum 25(OH) vit D levels are usually observed in haemodialysis patients. In this population, vit D deficiency is associated with secondary hyperparathyroidism (SHPT) and low bone mineral density (BMD). Although, vit D supplements are routinely prescribed in haemodialysis patients, their exact role in preventing bone loss hasn't been studied thoroughly. The primary aim of this study was to estimate the effect of cholecalciferol (vit D3) use on BMD changes of haemodialysis patients. Secondary aim was to evaluate how parathyroid hormone (PTH), phosphorus and calcium levels are affected by vit D3 supplementation. Method Twelve (12) haemodialysis patients with low levels of serum vit D were included. All of them had their bone density measured with Dual - Energy X-Ray Absorptionmetry (DXA). The study population was then divided in two groups. Half of them (6 patients) received oral cholecarciferol (study group) and the rest continued with their standard treatment (control group). Initial dose of cholecalciferol was 25000 iu weekly and titrated upwards until 25 (OH) vit D levels were reaching 20 ng/ml. Then, cholecarciferol was continued in maintenance dose to keep vit D levels between 20 and 40 ng/ml. Thirty (30) months later, DXA was repeated in all patients. BMD in total hip region was evaluated. During the study period, phosphorus, calcium and PTH levels were measured monthly while 25 (OH) vit D levels were measured every three months. Results Patients’ mean age was 61.9 (±8.8) years. There were no differences in age, initial BMD, PTH or vit D levels between the two groups. Overall, initial mean vit D value was 8.5 ng/ml. At the end of the study, vit D levels had increased to 23.6 ng/ml in the study group while remaining unchanged in the control group. At the beginning of the study, mean BMD in the whole population was 0.742 gr/cm3 and it decreased by 0.042 gr/cm3 after 30 months. No differences in BMD change were observed between the two groups (ΔBMD was −0.057 versus -0.029 gr/cm3 in the study and control group respectively, p = 0.12). PTH levels were reduced in the study group and increased in the control group but the observed difference was not significant (p = 0.11). Phosphorus and calcium levels were not affected by vit D supplementation. Of note, three fractures were observed in the study group and one in the control group during the study period. Conclusion Vit D3 supplementation didn't seem to affect the rate of bone loss in haemodialysis patients, at least in the doses received and levels of 25 (OH) achieved above. Its exact effect in PTH levels as well as in the rate of bone fractures needs to be verified by larger studies.

Application of perfusion bone cement screw in lumbar degenerative disease with osteoporosis

To observe the early clinical effect of perfusion bone cement screw for lumbar degenerative diseases with osteoporosis. The clinical data of 28 patients with lumbar degenerative diseases combined with moderate to severe osteoporosis treated by posterior lateral graft fusion with perfusion of bone cement screws from June 2015 to June 2017 were retrospectively analyzed. There were 9 males and 19 females, aged from 55 to 86 years old with an average of 76 years. Anteroposterior, oblique, and dynamic radiography were performed before operation, and the diagnosis was confirmed by CT, MRI and dual energy X-ray absorptionmetry(DXA). All the patients had moderate to severe lumbar spinal stenosis, including 16 cases with degenerative scoliosis, 12 cases with degenerative lumbar spondylolisthesis, and 16 cases with lumbar disc herniation. According to Jikei grade of osteoporosis, 9 cases were grade II and 19 cases were grade III. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to assess the improvement of lumbar leg pain, and neurological function. Imaging data were used to observe the circumstance of pedicle loosening, prolapse, breakage and bone cement leakage, and comprehensively evaluate the fusion. The hospital stay was from 10 to 14 days with an average of 12 days; the operative time was 100 to 150 min with an average of 120 min;the blood loss was 200 to 600 ml with an average of 350 ml (for operations more than 3 vertebral segments, blood filtration recovery was intraoperatively used);the postoperative drainage volume was 150 to 600 ml with an average of 300 ml, no allogeneic blood was used in all the patients. Bone cement of 2 to 3 ml were injected into each vertebral body, and bone cement leakage occurred in 2 cases during injection, both of which were paravertebral vessel leakage, and there was no evidence of intravertebral leakage. The injection of bone cement was terminated in a timely manner without serious complications such as nerve injury, bone cement toxicity, and vascular embolization and pulmonary embolism. According to the fusion criteria by X-ray, 18 cases achieved strong bone fusion, and 10 cases were inaccurate fusion, but no pseudarthrosis occurred in the fusion segment. No screw loosening, prolapse or fracture were found, and postoperative VAS, JOA scores were significantly improved. Perfusion bone cement screw technique can obtain satisfactory effect in treating lumbar degenerative diseases with osteoporosis.

A17462 Association of DXA-derived indices of fat distribution with cardiometabolic risk in Chinese children and adolescents

Objectives: Regional fat distribution is an important determinant of cardiometabolic risk in both adult and children and adolescents. The aim of this study was to investigate the association between the indices of fat distribution derived by Dual-energy X-ray Absorptionmetry (DXA) with cardiometabolic risk factors in obese and nonobese children and adolescents. Methods: A total of 1983 children and adolescents aged 6–18 years underwent a comprehensive assessment of cardiometabolic risk factors. Body composition was measured by Dual-energy X-ray Absorptiometry (DXA). Results: After adjusting for age and height, almost indices of fat distribution derived by DXA presented positive relationship with the examined cardimetabolic risk factors, but displayed the negative associations with HDL cholesterol. Moreover, these significant correlations differed with age and sex. VFM was an independent predictor of TG among children aged 6–9 years (P < 0.001), and HDL cholesterol for adolescent boys (P = 0.001). AFM/GFM ratio was an independent predictor of HDL cholesterol and TG for adolescent girls (both P < 0.001). TrFM was the most important determinant of MS in boys (OR = 8.46, 95%CI:3.52–20.32, P < 0.001). For girls, VFM was the most important determinant of MS (OR = 1.01, 95%CI:1.00–1.02, P = 0.017). Conclusion: Among children and adolescents, almost indices of fat distribution derived by DXA presented positive versus negative associations with the examined cardimetabolic risk factors, but with significant differences seen by age and sex. The indices of fat distribution may serve as clinically useful tools for evaluating cardiometabolic risk in children and adolescents, but dependent of age and sex.

Prior administration of vitamin K2 improves the therapeutic effects of zoledronic acid in ovariectomized rats by antagonizing zoledronic acid-induced inhibition of osteoblasts proliferation and mineralization.

Zoledronic acid (ZA) exerts complex influence on bone by suppressing bone resorption, mostly due to the direct osteoclasts inhibition and uncertain influence on osteoblasts. Vitamin K2 (VK2, Menaquinone-4) as an anabolic agent stimulates bone formation via anti-apoptosis in osteoblasts and mild osteoclasts inhibition. Based on these knowledge, the therapeutic effect of the combined or sequential therapy of VK2 and ZA depends on the influence on the osteoblasts, since both cases exert similar inhibitory effect on osteoclasts. In a series of in vitro studies, we confirmed the protective effect of VK2 in osteoblasts culture, especially when followed by exposure to ZA, and the proliferation and mineralization inhibition induced by ZA towards osteoblasts. For mechanism study, expression of bcl-2/bax, Runx2 and Sost in cells were examined. For in vivo studies, an osteoporosis animal model was established in rats via ovariectomy (OVX) and subjected to sequential treatment, namely VK2 followed by ZA. Bone mineral density (BMD) was measured by Dual energy X-ray absorptionmetry (DEXA), morphology and mechanical parameters by micro-computed tomography (micro-CT), mechanical strength by an electro-hydraulic fatigue-testing machine. The bone calcium, hydroxyproline content, blood lipids were evaluated using microplate technique, and the bone surface turnover was evaluated using the fluorescence in corporation method. It was found that VK2 pretreatment partially prevented the inhibition of bone formation caused by ZA, which was reflected by indices like BMD, bone calcium content and bone strength. The underling mechanisms for protection of VK2 pretreatment, mainly demonstrated via in vitro studies, included inhibiting apoptosis and depressing Sost expression in osteoblasts, which in turn improved the osteoporosis therapeutic effects of ZA. These findings suggested that pretreatment with VK2 before ZA therapy might serve a new long-term therapy protocol for osteoporosis.

Stimulation of Wnt/β-catenin signaling pathway is involved in the effect of naringin on the prevention of disuse osteoporosis

Objective To investigate whether naringin has a role in the prevention of disuse osteoporosis and the mechanisms that may be involved. Methods Disuse osteoporosis in male SD rats was induced by tail suspension, which were then randomly divided into four groups as following: the Hindlimb Suspension group(HLS), 30 mg·kg-1·d-1, 100 mg·kg-1·d-1 and 300 mg· kg-1·d-1 Naringin-treating group. Rats in the control group and suspension only group received equivalent saline as vehicle. Another equal amount of rats was selected as the Control group. Four weeks following the operation, all rats were sacrificed. Dual energy X-ray absorptionmetry(DXA)was used to analyze the distal femoral BMD, Micro-CT was used to test the trabecular microstructure in distal femur, biomechanical tests were used to analyze femoral mechanical properties and bone turnover markers in serum were tested by ELISA. The expressions of periostin, sclerostin and nucleus β-catenin in tibias were evaluated by qRT-PCR and Western-blot. The femurs were immunohistochemical stained for periostin and sclerostin. Results Four weeks after operation, BMD of distal femurs in HLS group decreased significantly compared with the control group, together with the dramatical deterioration of distal femoral trabecular microstructure and femur mechanical properties. The serum level of CTX-1 increased significantly while that of P1NP decreased. PCR and Western-blot indicated that the expression of periostin and nucleus β-catenin in tibias decreased dramatically, while sclerostin increased. The periostin secreted by periosteal osteoblasts decreased significantly while the intensity of positive immunostaining with sclerostin in osteocytes increased. Naringin at 100 mg·kg-1·d-1 and 300 mg·kg-1·d-1 significantly inhibited hindlimb suspension-induced decreasing of BMD in distal femur, together with the deterioration of trabecular microstructure and femur mechanical properties, increased serum P1NP level and decreased CTX-1. Naringin increased the expression of periostin and nucleus β-catenin and decreased the level of sclerositn. Conclusion Naringin could prevent the progress of disuse osteoporosis in rats, which may be mediated by the increased expression of periostin and subsequently inhibition of sclerostin and activation of Wnt/β-catenin signaling pathways. Key words: Osteoporosis; Drynaria fortunei; beta Catenin; Wnt signaling pathway

Insulin resistance, body composition, and fat distribution in obese children with nonalcoholic fatty liver disease.

The aim of this study was to evaluate the influence of body composition, especially distribution of body fat, and insulin resistance on nonalcoholic fatty liver disease (NAFLD) in obese children. One hundred obese children (66 boys, 34 girls) with (n=60) and without NAFLD (n=40) were assessed. Anthropometry, laboratory tests, abdominal ultrasonography, and dual energy x-ray absorption metry (DXA) were evaluated in all subjects. Subject age and measurements of liver enzymes, γ- glutamyl transpeptidase (γGT), uric acid, high-density lipoprotein cholesterol, and insulin resistance were significantly different between the non-NAFLD group and NAFLD group. Body fat and trunk fat percentage were significantly different between the two groups (p<0.001 and p=0.003), whereas extremity fat percentage was not (p=0.683). Insulin resistance correlated significantly with body fat and trunk fat percentages, age, liver enzymes, γGT, and uric acid in obese children. Multiple logistic regression analysis indicated that insulin resistance and trunk fat percentage significantly affected the development of NAFLD in obese children. Body fat, especially abdominal fat, influences the development of insulin resistance and subsequent NAFLD in obese children. Therefore, body composition measurement using DXA, in conjunction with biochemical tests, may be beneficial in evaluating obese children with NAFLD.

Effects of atorvastatin on bone mineral density (BMD) and bone metabolism in elderly males with osteopenia and mild dyslipidemia: A 1-year randomized trial

We explored the effects of atorvastatin on BMD and biochemical markers of bone metabolism in a 1-year, prospective, randomized controlled study. 64 male patients with osteopenia and mild dyslipidemia (mean age 80.1±6.6 years) were randomized to a 1-year atorvastatin treatment or control. BMD of hip and lumbar spine was measured with dual-energy X-ray absorptionmetry (DXA). Bone metabolic markers including resorption markers β-c-terminal telopeptide of type I collagen (CTx), formative markers osteocalcin (OC), 25-hydroxyvitamin D (25(OH)D) were measured with electrochemiluminescence immunoassay (ECLIA). Other bone metabolism markers including intact parathyroid hormone (iPTH) and testosterone were measured with chemiluminescence enzyme immunoassay (CLEIA). Levels of serum lipid and biochemical parameters were measured with automatic biochemical analyzer. All the parameters were recorded at baseline, and at 6 and 12 months, respectively. Compared with the control group, the atorvastatin treatment group showed significant reduction of triglyceride (TG, P<0.01) and low-density lipoprotein cholesterol (LDL-C, P<0.01). At 12 month, total hip BMD in atorvastatin group was significantly higher (P<0.01) compared with the control group, while there were no similar effect on femoral neck or lumbar spine between the two groups (P=0.48 and 0.53 respectively). Meanwhile, CTx significantly reduced in atorvastatin treatment group (P<0.001) compared with baseline. Our findings suggest that in elderly male patients with osteopenia and mild dyslipidemia, therapeutic doses of atorvastatin were associated with positive effects on BMD, probably mediated by suppressed bone resorption.

234 ESTIMATION OF SKELETAL MUSCLE MASS BY DUAL-ENERGY X-RAY ABSORPTIONMETRY APPENDICULAR LEAN SOFT MASS IN CHINESE ADULT

Objective: We studied whether total body skeletal muscle (SM) mass could be accurately estimated from appendicular lean soft tissue (ALST) mass measured by dual-energy X-ray absorptionmetry (DXA), and investigated the validity of equations of prediction reported previously and derived from the data of the present study. Methods: We measured body composition by magnetic resonance imaging (MRI) and DXA in 194 Chinese stratified for sex, age and body mass index. The equation of prediction was generated by linear regression. The agreement between measured and predicted SM mass was assessed by the use of intraclass correlation analysis, paired t test, Bland-Altman plot.Results: The total body SM mass measured by MRI (18.1±4.8 kg) was closely correlated with ALST mass (19.4±4.7 kg), with a correlation coefficient of 0.95, 0.84 and 0.89 in all subjects, men and women, respectively. If the previously published equations were used, the difference of SM mass measured by MRI and estimated from ALST was 3.37±1.75 kg and 3.25±1.70 kg in the absence and presence of age in the equation, respectively. On the basis of our own data, we generated 2 equations without or with age: SM=0.98*ALST-0.99 (R2=0.91, P<0.0001) and SM=0.97 * ALST-0.03*Age+0.66 (R2=0.92, P<0.0001). By the application of these equations, the difference between measured and estimated SM mass decreased to -0.05±1.46 kg and -0.03±1.39 kg, respectively.Conclusions: Estimation of SM mass by ALST is plausible, but requires population-specific equations of prediction. Our equations should be validated in other studies in Chinese.

폐금속광산 지역주민의 요중 카드뮴 수준 및 골밀도와의 관련성

Objectives: The objective of this study was to investigate the possible effects of environmental cadmium (Cd) exposure on of bone mineral density (BMD) levels. Methods: A total of 171 residents around abandoned mines in Chungcheongnam-do were surveyed in 2008-2011. Urinary Cd and BMD were analyzed by atomic absorption spectrometry and Dual-Energy X-ray absorptionmetry , respectively. Osteoporosis and osteopenia were defined by T-scores set by the WHO; Tscore ≥ ?1.0, normal; ?1.0 ＞ T-score ＞ ?2.5, osteopenia; and T-score ≤ ?2.5, osteoporosis. Logistic and multiple linear regressions were applied to estimate the association between U-Cd levels and BMD. Results: The U-Cd geometric mean of 171 Koreans was 2.79 ㎍/g·cr. The U-Cd concentration was significantly higher among women (2.98 ㎍/g·cr) than men (2.39 ㎍/g·cr). With the multiple regression model, the BMD was influenced by U-Cd, BMI, and monthly income. With the logistic regression model, osteoporosis was associated with U-Cd levels (OR = 3.239, 95% CI = 1.770-5.927). Conclusions: We conclude that exposure to cadmium is associated with an increased risk of osteoporosis.

Female College Students' Knowledge, Self-efficacy and Health Behaviors related to Bone Health.

This study described female college students' knowledge, self-efficacy and health behaviors related to bone health. A descriptive cross-sectional survey design was used. A total of 214 students were conveniently recruited from a school of nursing in Korea. Participants (mean age=21.2, SD=1.9 years) bone mineral density (BMD) was measured using dual energy x-ray absorptionmetry. Participants also completed a questionnaire consisting of knowledge test, self-efficacy scale and health behaviors related to bone health. Data were analyzed using SPSS/WIN 17.0 program. The mean BMD at left femoral neck site was 0.86 g/cm2 and 6.1~12.6%. Results showed that participants were below the expected range of BMD. Level of knowledge (correct rate=54%) and self-efficacy were moderate (mean 54.8 out of 84). More than 84% of subjects drank alcohol more than once a month and 58.4% did participate in regular exercise. Only 7.9% participants took calcium and vitamin-D rich foods every day. There were significant positive correlations between knowledge and self-efficacy (r=.17), health behaviors (r=.14) and self-efficacy and health behaviors (r=.28, all p<.05). These results suggest that health care professionals need to provide effective interventions for young women in order to enhance knowledge, self-efficacy and health behaviors related to bone health.

이중에너지 X선 흡수계측법을 이용한 폐경 전 여성의 골감소증 관련요인

이중에너지 X-ray 골밀도 측정기를 이용하여 폐경 전 여성들을 대상으로 골밀도에 영향을 규명하기 위하여 폐경기 이후에 증가하는 골다공증의 예방에 기여하고자 수행하였다. 연구 대상자의 골감소증은 20.2%였으며, 골밀도 수치를 예측할 수 있는 가장 중요한 인자는 연령 이었다. 연령이 높을수록 유의하게 낮은 골밀도를 보였다. 운동에 있어서는 운동을 안하는 것보다 운동을 하는 것이 골밀도에 더 좋은 영향을 미치며, 적정한 운동을 하는 것이 골밀도에 좋은 영향을 미치는 것으로 나타났다. 식생활에 따른 골밀도는 채식 위주의 식사보다는 육식위주의 식사를 선호하는 경우 골밀도에 유의한 영향을 미치는 것으로 나타났고, 생리주기가 짧을수록 골밀도가 유의하게 높았다. 골밀도와 관련요인에 대한 다중회귀분석에서는 연령이 증가할 유의하게 골밀도가 낮게 나타나 연령이 골다공증의 위험요인으로 나타났다. The purpose of this study is to examine factors that affect the bone mineral density of pre-menopause women by using the dual energy x-ray absorptionmetry, ultimately contributing to preventing women's osteoporosis that tends to be aggravated since menopause. Out of the subjects, 20.2% were suffering osteopenia. Age was found most important in estimating the level of bone mineral density. Meanwhile, the older women were, the significantly lower their bone mineral density was. It was found that taking exercise has a more positive effect on boss mineral density than not taking. Exercising in a suitable amount was helping women keep their bone mineral density better. Preferring meat to vegetarian diets were significantly affecting women's bone mineral density. Meanwhile, it was found that the shorter menstrual cycle is, the significantly lower bone mineral density is. A multi=regression analysis of bone mineral density and its related factors showed that the older women were, the significantly lower their bone mineral density was. In other words, age was found as the most risk factor of osteoporosis.

Risk factors for metabolic bone disease in Crohnʼs disease patients

The aim was to evaluate the presence of metabolic bone disease (MBD) in patients with Crohn's disease (CD) and to identify potential etiologic factors. The case-control study included 99 patients with CD and 56 controls with a similar age and gender distribution. Both groups had dual-energy x-ray absorptionmetry and a nutritional evaluation. Single nucleotide polymorphisms at the IL1, TNF-α, LTα, and IL-6 genes were analyzed in patients only. Statistical analysis was performed using SPSS software. The prevalence of MBD was significantly higher in patients (P = 0.006). CD patients with osteoporosis were older (P < 0.005), small bowel involvement and surgical resections were more frequent (P < 0.005), they more often exhibited a penetrating or stricturing phenotype (P < 0.05), duration of disease over 15 years (P < 0.005), and body mass index (BMI) under 18.5 kg/m(2) (P < 0.01) were more often found. No association was found with steroid use. Patients with a Z-score < -2.0 more frequently had chronic active disease (P < 0.05). With regard to diet, low vitamin K intake was more frequent (P = 0.03) and intake of total, monounsaturated, and polyunsaturated fat was higher in patients with Z-score < -2.0 (P < 0.05). With respect to genetics, carriage of the polymorphic allele for LTα252 A/G was associated with a higher risk of osteoporosis (P = 0.02). Regression analysis showed that age over 40 years, chronic active disease, and previous colonic resections were independently associated with the risk of developing MBD. The prevalence of MBD was significantly higher in CD patients. Besides the usual risk factors, we observed that factors related to chronic active and long-lasting disease increased the risk of MBD.

Abstract 1885: Dietary stearate reduces abdominal fat, serum leptin and glucose and increases MCP-1

Abstract Stearate is a dietary, long-chain saturated fatty acid (C18:0) that has been shown to decrease breast cancer cell proliferation, migration, and invasion in vitro and reduce tumor growth and metastasis in vivo. Obesity, or excess adipose tissue, is a risk factor for breast cancer. Our overall hypothesis is that dietary stearate inhibits breast cancer by decreasing body fat. Our goal was to determine whether there was an association between dietary stearate and adipose tissue. Four groups of 10 athymic nude mice each were each fed one of four different diets for 18 weeks (6% corn oil - low fat diet, 17% stearate diet, 17% corn oil diet, or 17% safflower oil diet). Body composition was assessed by nuclear magnetic resonance (NMR) and dual energy X-ray absorptionmetry (DXA). Serum concentrations of glucose, insulin, leptin, adiponectin, interleukin-6, and monocyte chemoattractant protein-1 (MCP-1) were also determined. In a repeated measures model assessing the relationship between groups, for fat and lean mass over time the following differences were found: the stearate group had significantly reduced body fat compared to the low fat and the corn oil groups (p&amp;lt;0.001); mice on the high fat diets (stearate, corn oil, and safflower oil) had a significantly increased lean body mass compared to the low fat group (p=0.009, 0.012, and 0.022 respectively). Postmortem measurement revealed no significant changes in organ weight (brain, heart/lungs, liver, and kidney) among the four diet groups. However dietary stearate had less abdominal fat than the other diets although only the low fat - stearate difference was significant (low fat-stearate *p= 0.0043. corn oil-stearate p= 0.0565, and safflower-stearate p= 0.0636). Serum glucose and leptin concentrations were significantly reduced in the stearate diet mice (glucose, p&amp;lt;0.039, stearate vs all other diets, leptin, p&amp;lt;0.015, stearate vs low fat and corn oil diets). Serum MCP-1 was increased in stearate diet mice compared to either the low fat or safflower oil mice (p&amp;lt;0.019). Significant differences were not observed with the other analytes. Studies have suggested that glucose and leptin have cancer promoting effects, while MCP-1 may promote or inhibit breast cancer. Overall these data support our hypothesis that dietary stearate decreases body fat and that this decrease in body fat may be related to stearate inhibition of breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1885.

The differences in bone mineral content between female dancers and controls aged 15 - 17 years old and its relationship with physical activity level

To assess bone mineral content (BMC) of 15 - 17 year-old dancers and high school females and analyze the relationship between physical activity status and BMC. Sixty dancers and 77 healthy controls aged 15 - 17 years old were enrolled in our study. BMC in the total body and forearm were measured by dual-energy X-ray absorptiometry (DEXA) while body weight and height were also measured. Physical activity information was collected by "one-year physical activity questionnaire". The physical activity level (PAL) and the average daily energy expenditure (EE) of dancers were all higher than controls (PAL: 2.17 +/- 0.34 vs 1.63 +/- 0.34, t = 7.283; EE: (6876.43 +/- 1036.72) kJ vs (5388.43 +/- 920.83) kJ, t = 7.214, both P values < 0.01). The dancers showed lower BMC/height at total body and arms compared with the controls (the total body BMC/height was (13.896 +/- 1.308) vs (14.494 +/- 1.272) g/cm, F = -2.563); and the BMC/height of left and right arm were (0.779 +/- 0.088) vs (0.829 +/- 0.101) g/cm (F = -2.892) and (0.766 +/- 0.093) vs (0.829 +/- 0.097) g/cm (F = -3.650) respectively, all these P values were < 0.01.Yet after adjusting age and BMI, the dancers showed higher BMC/height at total body and legs, the corresponding values were (14.550 +/- 0.146) vs (13.947 +/- 0.131) g/cm (F = 7.868), (2.681 +/- 0.033) vs (2.389 +/- 0.030) g/cm (F = 36.520), (2.821 +/- 0.031) vs (2.450 +/- 0.028) g/cm (F = 65.279), all these P values were < 0.01. While no differences were found with controls at non-weight bearing sites (arms). Daily period (h) of training was significantly related to BMC/height of legs, total body (r value were 0.618, 0.448 and 0.554 respectively, all the P values < 0.01), while the history of training was also correlated with BMC/height of two legs (r value were 0.38 and 0.304 respectively, both P values < 0.05). The adolescent dancers showed higher BMC after adjusting age and BMI, which was attributed to the long-term high level weight-bearing physical activity.

Bone Mineral Density at 45 Years of Age, Before Menopause

The objectives of this study were to investigate variations in bone mineral density values in 45-year-old women from a community sample in the City of Rio de Janeiro, in the same-name Brazilian state, and to compare them with US norms and international standards. In this cohort study, the age of 45 years is significant for the design, since clinical observation in this community indicates that it is approximately 5 years before menopause can be confirmed, thus preceding the typical postmenopause acceleration of the rate of bone loss. Nine hundred fifty-nine such women volunteered to participate in the investigation, conducted in 2 Rio de Janeiro teaching hospitals. Informed of procedures, potential risks, and benefits, they were screened for the inclusion criteria: (a) being 45-years-old: (b) being healthy (without obvious or diagnosed systemic disease, metabolic disease, endocrine disease, liver disease, cardiac disease, infectious disease, pulmonary disease, neurologic disease, dermatologic disease, inflammatory bowel disease, kidney disease, hereditary, or congenital conditions); (c) having regular and intact menstrual cycles; (d) having had normal healthy development to date; (e) having had high protein intake from birth to date; (f) having at least completed high school; (g) living in a dwelling equipped with running water, electricity, and public sewer; (h) being nonsmoking and non-drug abusing. Racial distinction was not among the inclusion criteria. After further informed consent, the 146 women who met all inclusion criteria had bone mineral density quantified--using the dual energy x-ray absorptionmetry method--and compared with US-born density norms for L2-L4 and the neck of the femur for young adults and the sample age group, which are endorsed by the World Health Organization and by the International Osteoporosis Foundation. About three-quarters of the sample had normal bone mineral density values, 22.61% had osteopenia, and 2.73% had osteoporosis. These findings, obtained from women whose regular and intact menstrual cycles demonstrated premenopausal hormonal levels, seem to attest to the importance of genetic predisposition, yet they warrant the authors' recommendation that interventions be instituted before age 45, specifically aimed at increasing the chances of all women, especially those genetically predisposed, of avoiding osteoporosis and its deleterious consequences.

Visceral adiposity and leptin are independently associated with C-reactive protein in Korean type 2 diabetic patients

The inflammatory marker, C-reactive protein (CRP) is associated with long-term cardiovascular events. The aim of the study was to investigate the factors contributing to serum CRP, assess the relationship between CRP level and the parameters of visceral obesity, and examine the association between leptin and CRP level in type 2 diabetic patients. 150 patients with type 2 diabetes were enrolled. These patients were recently diagnosed (< or =3 years) with type 2 diabetes and were drug naive or taking sulfonylureas only. BMI, WC, and serum concentration of CRP, glycosylated hemoglobin (HbA1c), glucose, lipids, plasminogen activator-1 (PAI-1) and leptin were measured. Insulin resistance was estimated by the insulin resistance index of homeostasis model assessment (HOMA-IR). We measured the carotid intima-media thickness (IMT). Fat mass assessed by dual-energy X-ray absorptionmetry and abdominal fat distribution was determined by CT scan. Serum concentration of CRP was significantly correlated with BMI (gamma = 0.257, P < 0.01), WC (gamma = 0.293, P < 0.01), fat mass (gamma = 0.213, P < 0.01), total adipose tissue (gamma = 0.263, P < 0.01), visceral adipose tissue (gamma = 0.296, P < 0.01), insulin (gamma = 0.189, P = 0.047), PAI-1 (gamma = 0.206, P < 0.01), leptin (gamma = 0.322, P < 0.01), mean IMT (gamma = 0.132, P = 0.042), and HOMA-IR (gamma = 0.172, P = 0.045). After adjustment for age and gender, multiple regression analysis showed that serum CRP was significantly associated with leptin (beta = 0.326, P = 0.01) and visceral adipose tissue (beta = 0.265, P = 0.035). In conclusion, serum CRP level is significantly associated with obesity, especially the visceral adipose tissue, and serum leptin is another important independent factor associated with CRP in Korean type 2 diabetic patients.

Evaluation of Osteoporosis Self-Assessment Tool Usefulness as a Screening Test for Osteoporosis in Korean Men

Background: This study was done to determine whether the Osteoporosis Self-assessment Tool (OST) can predict central bone mineral density in Korean men above 50 years, as defi ned by dual energy X-ray absorptionmetry (DXA). Methods: We applied the OST index to Korean men aged over 50 in Health Promotion Center of Konkuk University Hospital from September 2005 to September 2008. The calculated OST risk index was based on weight and age, truncated to an integer. Results: The study population was 276 men. The mean age, height and weight of the men were 59.7 ± 6.69 years, 167.6 ± 6.14 cm and 67.5 ± 8.93 kg respectively. By DXA, 4.7% of the men had a T score of -2.5 or less, and 46.4% had a T score of -2 or less at the spine, total hip, or femoral neck. The OST index ranged from -4 to 7. Using a cutoff score of 0, we predicted osteoporosis with a sensitivity of 85% and a specifi city of 62%. The receiver operating characteristic curve showed an area under the curve of 0.77. When the subjects were analyzed by age and smoking status, the predictive value of the OST was maintained. Conclusion: The OST is a simple and useful method to predict osteoporosis in Korean men.

Biochemical Markers and Health Behavior Related with Bone Mineral Density in Adult Men

Background: More than half of the causes of male osteoporosis is due to secondary osteoporosis. Therefore, it is important to detect and modify its related factors. The aim of this study was to fi nd related lifestyle factors and biochemical markers with low bone mineral density (BMD) in Korean men. Methods: A cross-sectional analysis was performed in men aged 40-69 years who visited a hospital for health checkup from January to March 2007. BMD was measured at proximal femur and lumbar spine by dual energy x-ray absorptionmetry. Lifestyle factors were estimated by a self-administered questionnaire and fasting glucose, uric acid, gamma glutamyltransferase, alkaline phosphatase, creatinine, free testosterone, 25-OH vitamin D, urine deoxypyridinoline, osteocalcin were measured. Multivariate logistic regression was used to fi the association to the lowest tertile of BMD. Results: A total of 152 subjects were included. After multivariate analysis adjusted with age, BMI, smoking, alcohol and exercise, different factors were correlated with low bone density in each site of femoral neck and lumbar spine. Factors correlated at both sites were BMI and exercise; lower BMI and doing no exercise increased risks of low bone density. Increasing age and alcohol intake ≥ 14 drinks/week were associated with lower BMD at femoral neck. The factors associated with lower lumbar spine BMD only were lower level of uric acid and higher level of urine deoxypyridinoline. Conclusion: Different factors were associated with low bone density at femoral neck and lumbar spine in men. BMI and exercise were related in both sites; age, alcohol intake, uric acid and deoxypyridinoline were related on either site.

Calorie restriction accelerates the catabolism of lean body mass during 2 wk of bed rest

Background: Muscle inactivity and low energy intake commonly occur in persons with acute or chronic disease, in astronauts during space flight, and during aging.Objective: We used a crossover design to investigate the effects of the interactions of inactivity and calorie restriction on whole-body composition and protein kinetic regulation in 9 healthy volunteers.Design: Lean body mass (LBM) was measured by using dual-energy X-ray absorptionmetry before and at the end of 14-d periods of bed rest (B) and controlled ambulation (A) in patients receiving eucaloric (E) or hypocaloric (H) (≈80% of total energy expenditure) diets. Whole-body leucine kinetics were determined at the end of the 4 study periods by using a standard stable-isotope technique in the postabsorptive state and during a 3-h infusion of a 0.13 g · kg LBM−1 · h−1 amino acid mixture.Results: In the postabsorptive state, we found a significant (P = 0.04) bed rest × hypocaloric diet interaction for the rate of leucine oxidation, an index of net protein catabolism (A+E: 0.23 ± 0.01; B+E: 25 ± 0.01; A+H: 0.23 ± 0.01; B+H: 0.28 ± 0.01 μmol · min−1 · kg LBM−1). Bed rest significantly (P < 0.01) decreased amino acid–mediated stimulation of nonoxidative leucine disappearance, an index of protein synthesis (A+E: 35 ± 2%; B+E: 30 ± 2%; A+H: 41 ± 3%; B+H: 32 ± 2%). B+H decreased LBM by 1.10 ± 0.1 kg, which is significantly (P < 0.01) greater than the decrease seen with A+E, A+H, or B+E.Conclusion: Calorie restriction enhanced the catabolic response to inactivity by combining greater protein catabolism in the postabsorptive state with an impaired postprandial anabolic utilization of free amino acids.

A review of the use of isotopic and nuclear techniques in animal production

Isotopic and nuclear techniques play an important role in food and agriculture, health and industry. This paper discusses the use of these techniques and highlights potential for their use in the area of Animal Production. These techniques are discussed in two parts: (1) Isotopic methods and (2) non-isotopic nuclear methods. The isotopic techniques discussed are: stable- ( 15N) and radio-isotope ( 35S or 32P) incorporation methods for measuring microbial mass in vitro and in vivo; 125I-labelled bovine serum albumin and 14C-labelled polyethylene glycol assays for measuring tannin in feeds; a method based on the feeding of isotope-labelled protein ( 15N or 125I) complexed with tannin for ranking different tannins for their abilities to release protein for digestion in vivo; 14C-uric acid and 14C-allantoin infusion methods for development of models describing excretion of purine derivatives in urine and microbial protein supply to ruminants, which permit assessment of nutritional status of animals and determination of nutritional quality of feed resources; a 15N isotope dilution technique using 15N-leucine to distinguish feed and endogenous secretions at the ileum, for determination of true digestibility of protein-rich tree leaves and aquatic plants in pigs; progesterone radioimmunoassay (RIA) for enhancing reproductive efficiency of ruminants, and RIA based leptin and insulin like growth factor assays for assessing the nutritional status of animals; feeding of 15N enriched plant material to generate 15N-labelled excreta for research on the fate of excreta N in the environment; 15N, 13C and 34S isotopic methods for nutrient budgeting and for following the nutrient pathways in the soil–plant–animal continuum; 32P- or 33P-labelled fertilizers for estimating the efficiency of P utilization in legume leaf production used for livestock feeding; double labelled water ( 18O and 2H labelled) method for estimating energy expenditures of grazing animals, body composition, basal metabolic rate, and milk output in cows with calves; NaH 13CO 3/NaH 14CO 3 infusion for estimation of the carbon dioxide production, which in turn is used to estimate energy expenditure in free-ranging animals; 3H- or 14C-labelled methane and 14C-labelled volatile fatty acids dilution technique for direct and indirect (using stoichiometry of carbohydrate fermentation) for determination of methane emission from livestock; 15N dilution technique requiring labeling the soil with 15N fertilizer ( 15N-ammonium sulphate or 15N-urea) for estimation of nitrogen fixation by leguminous trees and pastures. The non-isotopic nuclear techniques that have been used or have the potential for use are: dual energy X-ray absorptionmetry and computer tomography for body composition determination; nuclear magnetic resonance techniques, fast atom bombardment mass spectroscopy, and mass ionisation spectroscopy for identification and structure determination of bioactive moieties of plant origin having potential for rumen manipulation or controlling internal parasites; gamma irradiation for inactivating antinutrients such as protease inhibitors, lectin, phytic acid, non-starch polysaccharides and oligosaccharides in feeds; induced mutations with gamma radiation, electron beam and fast neutrons for producing useful mutants of forage plants with improved yield, nutrient profiles and uptake.