Bone mineral density,bone turnover markers,lean mass,and fat mass in Egyptian children with congenital adrenal hyperplasia

Introduction

Aim of this paper is to assess bone mineral density (BMD) and body composition, by dual energy X-ray absorptiometry (DXA), and various markers of bone growth, in a group of children with congenital adrenal hyperplasia (CAH) on long-term glucocorticoid therapy.

Material and methods

A case-control study included thirty patients with CAH with different states of metabolic control. Their mean age was 7.5 ±4.2 years. All patients are subjected to BMD using DXA at the neck of the femur and lumbar spine. A blood sample was taken for assessment of osteocalcin, osteoprotegerin, and procollagen type 1, as markers of bone formation, as well as RANKL and urinary deoxypyridinoline (DPD), as markers of bone resorption.

Results

We found no difference in BMD in patients and control subjects; however, patients showed significantly lower serum osteocalcin (p = 0.008) and osteoprotegerin (p = 0.0001) and significantly higher serum RANKL levels (p = 0.0001). Our results show that patients had significantly lower lean body mass (p = 0.005) and fat/lean ratio (p = 0.008) compared to matched controls. The duration of treatment showed a significant negative correlation with procollagen type 1 (r = –0.49, p = 0.02) and lean mass % (r = –0.43, p = 0.04); however, it showed a significant positive correlation with total fat mass % (r = 0.6, p = 0.0006), and fat/lean ratio (r = 0.43, p = 0.04). Dose of steroid had a significant positive correlation with BMI SDS (r = 0.4, p = 0.02).

Conclusions

Bone mineral density is normal but bone turnover is low in patients with CAH. There is an increase in fat/lean mass in patients with CAH.     

The relationship between body composition and onset of menarche

Background: A late age of menarche in elite adolescent athletes is frequently attributed to low body fat/weight. If a critical body weight/fat is necessary for menarche, a reduction in the variability of these parameters would be observed at menarche compared to times before and after this event.

Aim: The study determined the variability in body mass (BM), per cent body fat (%BF) and total body fat (TBF) of girls between ?2 and +2 years from menarche.

Methods: Participants were part of the Saskatchewan Pediatric Bone Mineral Accrual Study (1991–1998). Body composition was assessed using dual X-ray absorptiometry (DXA). An individual's data was retained for analysis if they had at least four DXA scans between ?3 and +3 years from menarche. Values were interpolated from the cubic spline at whole years between ?2 and +2 years from menarche. Coefficient of variation (CV) was used to assess variability.

Results/Conclusion: Data on 61 girls were retained for analysis. The range in BM, TBF and %BF at menarche was 50.10 kg, 35050.06 g and 31.61%, respectively. Reductions in variability of body fat and weight were not apparent at menarche, which does not provide support for the hypothesis that a critical body weight/fat is required for menarche.     

The influence of exogenous fat and water on lumbar spine bone mineral density in healthy volunteers

Purpose

Changes in human body composition can affect the accuracy of spine bone mineral density (BMD) measurements. The purpose of this study was to evaluate whether fat and water in the soft tissue of the abdomen influence lumbar spine BMD measurements obtained using dual energy X-ray absorptiometry (DXA).

Materials and Methods

Duplicate BMD measurements were carried out on healthy volunteers (10 men and 10 women) and the Hologic anthropomorphic spine phantom had on the same day before and after placement of following 3 materials in the abdominal area: lard 900 g, 1.5 cm thick; oil 1.4 liters in a vinyl bag; and water 1.2 liters in a vinyl bag.

Results

In the case of human participants, following the placement of exogenous water to mimic extracellular fluid (ECF), there was a significant decrease in lumbar spine BMD (-0.012 g/cm², p=0.006), whereas the placement of exogenous lard and oil to mimic abdominal fat produced a slight increase in lumbar spine BMD (0.006 g/cm², p=0.301; 0.008 g/cm², p=0.250, respectively). The average percentage of lumbar spine BMD change with and without exogenous lard, oil, and water showed increase of 0.51%, and 0.67%, and decrease of 1.02%, respectively. Using the phantom, BMD decreased with the placement of both lard (-0.002 g/cm², p=0.699) and water (-0.006 g/cm², p=0.153); however, there was no difference in BMD after oil placement.

Conclusion

These results suggest that in cases where changes in fat and ECF volume are similar, ECF exerts a greater influence than fat on DXA lumbar BMD measurements.     

Comparison of bone mineral density and body composition measurements in women obtained from two DXA instruments

Information is lacking regarding the comparison of bone mineral and body composition measurements obtained from the different dual energy X-ray absorptiometry (DXA) systems. The purpose of this study is to compare body composition and whole body bone mineral density (BMD) measurements from the hologic QDR-4500 W (DXA H) and the lunar (DXA L) systems. Seven women older than 40 years of age, were scanned on the same day by using DXA H and DXA L by the same observer. Measured total fat mass, percentage fat, whole body fat free soft tissue mass and BMD were similar between machines, but body mass was significantly higher with DXA L than with DXA H (P=0.0156). This was due to a higher bone mineral content obtained with DXA L. Agreement between the two DXA systems was quantified by using the Bland and Altman method. For each variable, all pairs of measurements were within the 95% confidence limits. These results suggested that we could use the two measurement methods interchangeably. However, due to the bone mineral inter-machine differences, comparisons of DXA measurements from different machines should be interpreted with caution.     

Posterior stabilized component increased femoral bone loss after total knee replacement. 5-year follow-up of 47 knees using dual energy X-ray absorptiometry

After total knee replacement (TKR) bone mineral density (BMD) commonly decreases behind the anterior flange of the femoral component, which may increase the risk for supracondylar fracture. Our aim was to evaluate if changes in femoral design and joint area constraint had any effect on the postoperative bone remodeling in the distal femur.

We used dual-energy X-ray absorptiometry in 47 knees up to 5 years after operation with the AMK (DePuy, Johnson&Johnson Leeds, UK) TKR. The knees had been randomly allocated to receive a flat or a concave tibial insert with retention of the posterior cruciate ligament when preoperative deformity was less severe, and either a concave or a posterior-stabilized (PS) insert with resection of the posterior cruciate ligament when deformity was more pronounced.

The most pronounced relative reduction (15–38%) in bone mineral density (BMD) was seen posterior to the anterior flange. There were no significant differences in relative change in BMD between flat and concave inserts. Knees operated with PS inserts had more reduction posterior to the flange than knees with concave inserts in the subgroup with more advanced preoperative deformity (23% and 38% respectively).

Use of posterior stabilized insert may increase the risk of supracondylar fracture compared to concave insert in knees with advanced preoperative deformity.     

The influence of physical activity on the response of bone mineral density to 5 years tibolone

Objectives: Menopausal hormone replacement therapy (HRT) maintains bone mineral density (BMD) and reduces risk of fracture in postmenopausal women. It has been suggested that sex steroids and loading may have synergistic effects on bone. We therefore investigated whether habitual physical activity influences the response of BMD to tibolone in postmenopausal women. Methods: The subjects were 42 postmenopausal women aged mean (SE) 65.8±6.2 year who had taken tibolone for prevention/ treatment of osteoporosis over 5 years. Bone mineral density was measured annually by dual X-ray absorptiometry and physical activity was assessed using accelerometers after 5 years therapy. Results: Twenty-six women were classified as having low physical activity (LPA; <15 min day⁻¹) and sixteen as high physical activity (HPA; >15 min day⁻¹). Spine BMD did not differ significantly between groups at baseline and increased significantly by 2 years of treatment with further increase to 5 years. The magnitude of increase did not differ between groups. Hip BMD at baseline was 7.3% higher in HPA women (P=0.07). Hip BMD increased over 2 years tibolone treatment in LPA women (+5.6%, P<0.01) whilst no significant change occurred in the HPA group (−0.5%). This difference in response between groups was statistically significant (P=0.002) and persisted after adjustment for age and body mass (P=0.002). Hip BMD was maintained in both groups over the subsequent 3 years of treatment. Conclusions: Spine BMD increased significantly in response to tibolone irrespective of physical activity participation. The more physically active women had higher hip BMD at baseline but the response to tibolone was greater in the less physically active women. The difference in response between groups may be due to physically active women having lower resorption at the hip and hence reduced response to anti-resorptive effects of HRT.     

6～9岁骨龄男童体脂率测量方法的比较及公式推算

目的:通过对6~9岁骨龄男童体脂率的不同测量方法进行比较分析,寻找并建立最适用于小学生的体脂率测量方法。方法:随机从万泉小学等学校抽取130名正常健康男童,进行骨龄拍摄,挑取其中骨龄为6~9岁男童为研究对象,分为正常组、超重组和肥胖组。分别采用皮褶厚度法、生物电阻抗法(BIA)、双能量X线吸收法(DEXA)在同一时间段对研究对象进行测量。结果:6~9岁骨龄男童BIA与DEXA测量结果均值比较无差异,除正常组外,超重组和肥胖组BIA测量结果均与DEXA高度相关,且在该骨龄组男童中两者测量结果的一致性较高。通过与DEXA对比,皮褶厚度法推算体脂率,无论是均值比较,相关性分析,还是一致性分析,姚兴家公式在推测受试者的体脂率时都存在显著低估现象,而元田恒公式在推测受试者的体脂率时则存在显著性的高估现象,相比较而言,长岭公式虽然也存在误差,但其结果与DEXA结果最为接近。以DEXA为校标,通过皮褶厚度法推算全身体脂率公式为全身体脂率=9.103+1.033×腹部皮褶。结论:通过与DEXA对比显示,在6~9岁骨龄段男童,BIA检测体脂率的准确度要明显优于皮褶厚度推测法。应用皮褶厚度法推算6~9岁骨龄男童全身体脂率,其公式为全身体脂率=9.103+1.033×腹部皮褶,经检验,结果可靠有效。     

Dual X-ray absorptiometry detects disease- and treatment-related alterations of bone density in prostate cancer patients

Metastatic bone disease is an important clinical problem which has proven difficult to study because of a lack of noninvasive investigative modalities. Here we show that dual-energy X-ray absorptiometry (DXA) scanning provides clinically useful information about the status of metastatic bone lesions in cancer patients undergoing palliative treatment. In the study group of 21 patients, a significant increase in metastatic bone mineral density (BMD) was confirmed in prostate (n=14) relative to breast (n=7) cancer patients. With respect to the prostate cancer cohort, further increases in lesional BMD were evident in all evaluable patients in whom biochemical progression occurred; conversely, lesional BMD declined in patients who had a partial response to therapy. BMD of uninvolved bone decreased with all types of androgen-deprivation therapy regardless of whether patients responded or relapsed. We conclude that BMD changes in both lesional and uninvolved bone are readily detectable in metastatic prostate cancer, and propose that DXA scanning represents a promising new approach to monitoring the natural history and therapeutic course of this disease. This revised version was published online in July 2006 with corrections to the Cover Date.     

Decreased bone mineral density in experimental myasthenia gravis in C57BL/6 mice

Experimental autoimmune myasthenia gravis (EAMG), an animal model of myasthenia gravis (MG), can be induced in C57BL/6 (B6, H-2?^b) mice by 2?3 injections with Torpedo californica AChR (tAChR) in complete Freund’s adjuvant. Some EAMG mice exhibit weight loss with muscle weakness. The loss in body weight, which is closely associated with bone structure, is particularly evident in EAMG mice with severe muscle weakness. However, the relationship between muscle weakness and bone loss in EAMG has not been studied before. Recent investigations on bone have shed light on association of bone health and immunological states. It is possible that muscle weakness in EAMG developed by anti-tAChR immune responses might accompany bone loss. We determined whether reduced muscle strength associates with decreased bone mineral density (BMD) in EAMG mice. EAMG was induced by two injections at 4-week interval of tAChR and adjuvants in two different age groups. The first tAChR injection was either at age 8 weeks or at 15 weeks. We measured BMD at three skeletal sites, including femur, tibia, and lumbar vertebrae, using dual energy X-ray absorptiometry. Among these bone areas, femur of EAMG mice in both age groups showed a significant decrease in BMD compared to control adjuvant-injected and to non-immunized mice. Reduction in BMD in induced EAMG at a later-age appears to parallel the severity of the disease. The results indicate that anti-tAChR autoimmune response alone can reduce bone density in EAMG mice. BMD reduction was also observed in adjuvant-injected mice in comparison to normal un-injected mice, suggesting that BMD decrease can occur even when muscle activity is normal. Decreased BMD observed in both tAChR-injected and adjuvant-injected mice groups were discussed in relation to innate immunity and bone-related immunology involving activated T cells and tumour necrosis factor-related cytokines that trigger osteoclastogenesis and bone loss.     

广西瑶族中老年人骨密度与体成分的相关性分析

目的:分析探讨广西瑶族中老年人身高、体质量、脂肪率、脂肪、体质量指数与骨密度的规律及其相关性。方法:随机抽取343名(男性123名,女性220名)广西瑶族健康中老年人作为研究对象,检测受试者的体质量、脂肪率、脂肪量、体质量指数、身高和右足跟骨密度。结果:广西瑶族中老年人身高、体质量、脂肪率、脂肪量、体质量指数与骨密度均随着年龄的增长逐渐降低,不同性别间身高、脂肪率和骨密度差异明显。男性的身高、脂肪率和骨密度均大于同龄段女性,男性骨密度减少的幅度小于女性。男、女性的身高、体质量、体质量指数与骨密度均显著相关。结论:广西瑶族中老年人身高、体质量、体质量指数和骨密度随年龄的增长逐渐降低,且身高、体质量、体质量指数对骨密度起决定性作用。     

体脂对DXA骨密度测量结果及骨质疏松诊断的影响

随着社会老龄化和生活水平提高,制约老年人健康长寿的骨质疏松症受到越来越多的重视。双能Ｘ线吸收测量法(dual energy X-ray absorptiometer,DXA)测量骨密度是诊断骨质疏松的金标准,但它的精确性受身体脂肪含量的影响。体脂可以干扰DXA测量骨密度的结果,这可能会导致体脂分布改变显著者（如绝经后体脂分布变化较大的女性）骨质疏松诊断的偏倚,造成此类人群骨质疏松时误诊或漏诊的发生。本文就脂肪对骨密度测量结果及骨质疏松诊断的影响作一综述。     

特纳综合征患者早期雌激素替代治疗改善骨密度

目的探讨早期雌激素替代治疗对特纳综合征(TS)患者骨密度(BMD)改善的效果。方法选取2005年8月到2015年8月就诊于北京协和医院内分泌科矮小门诊的27例TS患者,全部测量身高、体质量,雌激素治疗前后的骨密度由LUNAR-PRODGIY型骨密度仪进行测量。比较TS患者雌激素替代治疗前后骨密度的差异,治疗起始年龄对骨密度的影响。结果应用雌激素治疗后1年内、1~3年、3年L2-4的骨密度分别为(0.96±0.13)g/cm~2、(0.92±0.13)g/cm~2、(0.93±0.14)g/cm~2,显著高于基线水平分别为(0.73±0.08)g/cm~2、(0.70±0.13)g/cm~2、(0.75±0.07)g/cm~2;治疗起始年龄18岁组L2-4骨密度(0.96±0.14)g/cm2显著高于治疗起始年龄≥18岁组(0.90±0.10)g/cm~2。结论早期雌激素替代治疗可更有效地改善TS患者骨密度,但影响骨密度的其他因素仍需进一步深入探究。     

Treatment of subclinical hypothyroidism does not affect bone mass as determined by dual-energy X-ray absorptiometry,peripheral quantitative computed tomography and quantitative bone ultrasound in Spanish women

Introduction

The results of studies examining the influence of subclinical hypothyroidism (SCH) and levothyroxine (L-T₄) replacement therapy on bone have generated considerable interest but also controversy. The present research aims to evaluate the effects of L-T₄ treatment on different skeletal sites in women.

Material and methods

A group of 45 premenopausal (mean age: 43.62 ±6.65 years) and 180 postmenopausal (mean age: 59.51 ±7.90 years) women with SCH who were undergoing L-T₄ replacement therapy for at least 6 months were compared to 58 pre- and 180 postmenopausal women with SCH (untreated) matched for age. The mean doses of L-T₄ were 90.88 ±42.59 µg/day in the premenopausal women and 86.35 ±34.11 µg/day in the postmenopausal women. Bone measurements were obtained using quantitative bone ultrasound (QUS) for the phalanx, dual-energy X-ray absorptiometry (DXA) for the lumbar spine and hip, and peripheral quantitative computed tomography (pQCT) for the non-dominant distal forearm.

Results

No differences were observed between patients and untreated controls in these bone measurements except in the bone mineral density (BMD) of the spine (p = 0.0214) in postmenopausal women, which was greater in treated women than in untreated controls.

Conclusions

Our results indicate that adequate metabolic control through replacement treatment with L-T₄ in pre- and postmenopausal women does not affect bone mass.     

健康绝经妇女体成分差异对跟骨骨密度的影响

目的探讨锦州市健康绝经妇女身体质量指数(BMI)、左下肢肌肉含量及脂肪含量等身体组成成分与左侧跟骨骨密度(BMD)的关系。方法使用体成分仪及骨密度仪测量421例健康绝经妇女的体成分和左侧跟骨骨密度。结论左侧跟骨BMD与年龄呈负相关,与左下肢肌肉量、BMI呈正相关关系,而与左下肢脂肪量没有相关性。结论 BMI是影响绝经妇女BMD的重要因素,加强运动、增加身体肌肉含量对预防骨质疏松有重要作用。     

Vitamin D status and bone density in steroid-treated children with glomerulopathies: effect of cholecalciferol and calcium supplementation

PurposeThe aim of this study was to assess vitamin D status and bone density in steroid-treated children with glomerulopathies and to evaluate the effect of prophylactic vitamin D and calcium supplementation.Material and MethodsRetrospective analysis was performed on 55 children aged 4–18 yrs with glomerulopathies. The following data were analyzed: antropometrical parameters, bone densitometries, parathormone, 25-hydroxyvitamin D (25-OHD), urinary calcium excretion and medications received for prevention of low bone mass.ResultsA significant number of children (38%) had decreased spinal bone mineral density (BMD z-score < ?2.0) and the majority of them (89%) had hypovitaminosis D (25-OHD < 30ng/ml), 75% were vitamin D insufficient (25-OHD < 20ng/ml) and 16% were vitamin D deficient (25-OHD < 10ng/ml). The mean serum 25-OHD concentration was comparable to that of controls (19.32±12.87 vs. 15.05±8.52 ng/ml). Nearly all patients (82%) were receiving preparations of calcium and/or vitamin D to improve bone health. Patients on cholecalciferol had higher mean concentration of 25-OHD compared to those who were not receiving it (p=0.027) and to the controls (p=0.047). In 23 children on vitamin D and calcium supplementation for an average 6-month time, we observed an increase in the mean BMD values (p=0.004), however, mean BMD z-score and 25-OHD concentrations did not significantly change over time.ConclusionsVitamin D and bone density deficits are remarkably common in steroid-treated children with glomerulopathies, despite vitamin D and calcium repletion. In order to enhance the effectiveness of vitamin D supplementation for improvement of bone density, we suggest regular assessment of serum concentration of 25-OHD that can guide subsequent dose adjustment of vitamin D.     

Medial peg position of cementless porous tantalum tibial component affects bone mineral density around the prosthesis after total knee arthroplasty: 2-year follow-up study

BackgroundUse of a porous tantalum tibial component for total knee arthroplasty (TKA) was reported to have beneficial effects on periprosthetic bone mineral density (BMD). In some cases, hexagonal peg is placed close to or in contact with the tibial cortex, which may result in stress-shielding around the peg. However, no studies have analyzed the relationship between peg position and BMD. The aim of this study was to compare the peg position and BMD around the peg in a porous tantalum tibial component after TKA.MethodsTwenty-seven patients (27 knees) who underwent primary TKA with a cementless porous tantalum tibial component were investigated. BMD was measured by dual-energy X-ray absorptiometry for 2 years after the operation. The distance between the peg and the tibial cortex (peg distance) was measured on the medial and lateral sides.ResultsBMD was decreased in the medial region after the operation (p < 0.01). Relative change in BMD was lower in the medial region than in the central and lateral regions (p < 0.01). Multiple regression analysis showed that medial peg distance was negatively correlated with relative change of BMD in the medial part of the tibia (p = 0.04, R = 0.402).ConclusionsThe medial peg position affected the postoperative relative change of BMD in the medial part of the tibia, but did not affect the longevity of the implant. As the tibial medial peg became closer to the medial tibial cortex, the BMD loss became larger in the medial part of the tibia at 2 years postoperatively.     

Difference in the effects of body composition on bone mineral density between pre- and postmenopausal women

Objective: This study was to investigate whether the effect of lean and fat mass component on bone mineral density (BMD) differs between pre- and postmenopausal women. Materials and methods: Subjects were 360 pre- and 193 postmenopausal Japanese women with right side dominance. Age, height, and years since menopause (YSM, in postmenopausal women) were recorded. Body fat and lean body mass were measured by whole body scanning with dual-energy X-ray absorptiometry (DEXA). BMD of the vertical axis (L2-4 of the lumbar spine, pelvis, bilateral legs, and total body) and horizontal axis (arms) were also measured by DEXA. Results: In premenopausal women, lean body mass was independently correlated with BMD of the left arm (partial correlation COEFFICIENT=0.417), right arm (0.430), L2-4 (0.285), pelvis (0.276), left leg (0.403), right leg (0.412), and total body (0.377) (P<0.001). However, body fat mass was not correlated with several BMD sites except for pelvis BMD (0.187, P<0.01). In postmenopausal women, body fat mass was independently correlated with BMD of the left arm (0.248, P<0.01), L2-4 (0.188, P<0.05), pelvis (0.263, P<0.01), left leg (0.228, P<0.01), right leg (0.319, P<0.001), and total body (0.188, P<0.01)). However, lean body mass was correlated with BMD in only three segmental regions including left arm (0.175), right arm (0.217), and left leg (0.210; P<0.05). Conclusion: Lean body mass is a significant determinant of BMD in premenopausal women, while body fat mass is a significant determinant in postmenopausal women.     

Relationship between blood pressure levels and bone mineral density in postmenopausal Turkish women

Introduction

We investigated the association between bone mineral density (BMD) detected by dual-energy X-ray absorptiometric (DXA) method and blood pressure (BP) in a large sample of postmenopausal women.

Material and methods

The current study was based on a retrospective analysis of 586 postmenopausal women with a mean age of 60.8 ±8.8 years, who were screened for osteopenia or osteoporosis by DXA. Patients with hypertension (HT, n= 306) were compared with normotensive (NT, n = 290) individuals. Bone mineral density results for the femur neck and spine were classified into 3 groups according to World Health Organization criteria: normal (T score > –1.0 SD), osteopenia (T score –1.0 to –2.5 SD) and osteoporosis (T score < –2.5 SD). Patients with osteopenia or osteoporosis (T score < –1.0 SD) were grouped as having low bone mass (LBM).

Results

There were no significant differences in femur T score, femur BMD, femur Z score, spinal T score, spinal BMD and spinal Z score between hypertensive and normotensive groups. The group of patients with low bone mass calculated from femur T scores had higher age, systolic BP, duration of hypertension and duration of menopause, but lower BMI. Similarly, patients with low spine BMD had higher age and duration of menopause, but lower BMI. Linear regression analysis showed a significant correlation between systolic BP and femur BMD and T score values. Furthermore, logistic regression analysis revealed that hypertension is an independent predictor of spinal osteopenia and osteoporosis.

Conclusions

The presence of hypertension is an independent predictor of spinal low bone density in Turkish women after menopause.