Bone status of Indian women from a low-income group and its relationship to the nutritional status

Indian women from low-income groups consume diets that have inadequate calcium coupled with too few calories, proteins and micronutrients. Hospital-based data suggest that these women have osteoporotic hip fractures at a much earlier age than Western women. Studies reporting bone parameters of the Indian population involving large sample sizes are not available. This study was therefore carried out with 289 women in the 30–60-year age group to estimate the prevalence of osteoporosis and measure the bone parameters by dual energy X-ray absorptiometry (DXA). Their mean (± SD) age was 41.0±8.60 years. Their mean (± SD) height, weight and body mass index (BMI) were 149.1±5.49 cm, 49.2±9.85 kg and 22.1±3.99, respectively. Dietary intake of calcium was estimated to be 270±57 mg/day. The prevalence of osteoporosis at the femoral neck was around 29%. Bone mineral density (BMD) and T scores at all the skeletal sites were much lower than the values reported from the developed countries and were indicative of a high prevalence of osteopenia and osteoporosis. BMD showed a decline after the age of 35 years in cases of the lumbar spine and femoral neck. This was largely due to a decrease of bone mineral content (BMC). The nutritional status of women appears to be an important determinant of bone parameters. BMD and BMC at all the skeletal sites and whole body increased significantly with increasing body weight and BMI of women (P<0.05). However, bone area (BA) did not change with an increase in BMI. In the multiple regression analysis, apart from body weight, age, menopause and calcium intake were the other important determinants of BMD (P<0.05). In addition to these, height was also an important determinant of WB-BMC. This study highlights the urgent need for measures to improve the nutritional status, dietary calcium intake and thus the bone health of this population.All the authors were affiliated with the National Institute of Nutrition during the study period.     

人体瘦组织对骨密度的影响

目的探讨人体瘦组织对骨密度的影响。方法将160例进行DXA(Dual-energy x-ray absorptiometry双能X线骨密度吸收仪)骨密度和身体成分分析的患者作为研究对象,根据瘦组织指数将女性和男性患者平分为高瘦组织指数组和低瘦组织指数组,比较二组的股骨颈、全髋和腰椎骨密度。结果 54例高瘦组织指数组女性瘦组织指数为16.9942±1.2634 kg/m~2,54例低瘦组织指数组女性瘦组织指数为14.2981±0.7956 kg/m~2;26例高瘦组织指数组男性瘦组织指数为19.5200±1.0863 kg/m~2,26例低瘦组织指数组男性瘦组织指数为16.0654±1.4077 kg/m~2。男女高瘦组织指数组的股骨颈、全髋和腰椎骨密度均显著高于低瘦组织指数组(P0.05)。结论高瘦组织指数女性和男性患者均具有较高的股骨颈、全髋和腰椎骨密度。     

Changes in Bone Mineral Density, Body Composition and Adiponectin Levels in Morbidly Obese Patients after Bariatric Surgery

Background  Gastric bypass surgery (GBP) is increasingly used as a treatment option in morbid obesity. Little is known about the effects of this surgery on bone mineral density (BMD) and the underlying mechanisms. To evaluate changes on BMD after GBP and its relation with changes in body composition and serum adiponectin, a longitudinal study in morbid obese subjects was conducted. Methods  Forty-two women (BMI 45.0 ± 4.3 kg/m²; 37.7 ± 9.6 years) were studied before surgery and 6 and 12 months after GBP. Percentage of body fat (%BF), fat-free mass (FFM), and BMD were measured by dual-energy X-ray absorptiometry and serum adiponectin levels by RIA. Results  Twelve months after, GBP weight was decreased by 34.4 ± 6.5% and excess weight loss was 68.2 ± 12.8%. Significant reduction (p < 0.001) in total BMD (−3.0 ± 2.1%), spine BMD (−7.4 ± 6.8%) and hip BMD (−10.5 ± 5.6%) were observed. Adiponectin concentration increased from 11.4 ± 0.7 mg/L before surgery to 15.7 ± 0.7 and 19.8 ± 1.0 at the sixth and twelfth month after GBP, respectively (p < 0.001). Thirty-seven percent of the variation in total BMD could be explained by baseline weight, initial BMD, BF reduction, and adiponectin at the twelfth month (r ² = 0.373; p < 0.001). Adiponectin at the twelfth month had a significant and positive correlation with the reduction of BMD, unrelated to baseline and variation in body composition parameters (adjusted correlation coefficient: r = 0.36). Conclusion  GBP induces a significant BMD loss related with changes in body composition, although some metabolic mediators, such as adiponectin increase, may have an independent action on BMD which deserves further study.     

人体脂肪组织对骨密度的影响

目的探讨人体脂肪对骨密度的影响。方法将160例采用双能X线骨密度吸收仪(dual-energy X-ray absorptiometry,DXA)进行骨密度和身体成分分析的患者作为研究对象,根据脂肪指数将女性和男性患者平分为高脂肪指数组和低脂肪指数组,比较两组的股骨颈、全髋和腰椎骨密度。结果 54例高脂肪指数组女性的脂肪指数为(10.0198±1.6811)kg/m~2,身体脂肪百分比为(36.71±3.06)%;54例低脂肪指数组女性的脂肪指数为(6.7167±1.0130)kg/m~2,身体脂肪百分比为(30.05±3.76)%。26例高脂肪指数组男性的脂肪指数为(6.9240±0.9090)kg/m~2,身体脂肪百分比为(25.72±3.17)%;26例低脂肪指数组男性的脂肪指数为(4.8085±0.7368)kg/m~2;身体脂肪百分比为(21.55±2.39)%。女性高脂肪指数组的股骨颈、全髋和腰椎骨密度均显著高于低脂肪指数组(P0.05);男性高脂肪指数组与低脂肪指数组的各部位骨密度差异无统计学意义(P0.05)。结论女性脂肪量对股骨颈、全髋和腰椎骨密度有正面影响。     

Skeletal Benefits After Long‐Term Retirement in Former Elite Female Gymnasts

Bone strength benefits after long‐term retirement from elite gymnastics in terms of bone geometry and volumetric BMD were studied by comparing retired female gymnasts to moderately active age‐matched women. In a cross‐sectional study, 30 retired female gymnasts were compared with 30 age‐matched moderately active controls. Bone geometric and densitometric parameters were measured by pQCT at the distal epiphyses and shafts of the tibia, femur, radius, and humerus. Muscle cross‐sectional areas were assessed from the shaft scans. Independent t‐tests were conducted on bone and muscle variables to detect differences between the two groups. The gymnasts had retired for a mean of 6.1 ± 0.4 yr and were engaged in ≤2 h of exercise per week since retirement. At the radial and humeral shafts, cortical cross‐sectional area (CSA), total CSA, BMC, and strength strain index (SSIpol) were significantly greater (13–38%, p ≤ 0.01) in the retired gymnasts; likewise, BMC and total CSA were significantly greater at the distal radius (22–25%, p ≤ 0.0001). In the lower limbs, total CSA and BMC at the femur and tibia shaft were greater by 8–11%, and trabecular BMD and BMC were only greater at the tibia (7–8%). Muscle CSA at the forearm and upper arm was greater by 15–17.6% (p ≤ 0.001) but was not different at the upper and lower leg. Past gymnastics training is associated with greater bone mass and bone size in women 6 yr after retirement. Skeletal benefits were site specific, with greater geometric adaptations (greater bone size) in the upper compared with the lower limbs.     

北京郊区12?14岁男女学生骨密度的研究

目的　了解本市郊区 1 2～ 1 4岁少年男女骨密度 (BMD)的变化规律。方法　利用双能X射线骨密度仪对 30 6例健康男女中学生行左前臂、腰椎和全身扫描 ,按性别不同 ,每 1岁分 1个组。结果　该年龄段男女孩各部位BMD每年都有不同程度的增加 ,女孩高于男孩。各部位BMD以腰椎最高 ,全身总的BMD次之 ,前臂BMD最低。 1 2～ 1 3岁女孩身高与各部位BMD呈明显正相关 (P <0 0 1 ,r=0 331～ 0 62 1 ) ,1 3～ 1 4岁男孩身高与各部位BMD呈明显正相关 (P <0 0 1 ,r =0 339～0 662 )。体重与BMD始终相关 ,腰椎与全身总的BMD相关性最后 (P <0 0 0 1 ,r =0 674～ 0 81 1 )。结论　不同部位BMD的增长快慢不一 ,测量腰椎BMD能够较好地反映全身BMD状况 ,体重对BMD的影响比身高对BMD的影响大     

不同锻炼水平对大学生骨密度和体成分的影响及其相关性分析

目的探讨不同锻炼水平对大学生骨密度和体成分的影响,同时分析骨密度和体成分之间的相关性。方法选取中国矿业大学在校本科大学生120名,根据参与运动情况分为缺乏运动组、普通运动组和大运动量组,每组40名,男女各20名,采用超声法和生物电阻法分别检测其跟骨密度和体成分各项指标,测试所得数据采用Spss16.0软件进行统计分析。结果普通运动组大学生的骨密度明显高于缺乏运动组和大运动量组大学生的骨密度(P0.05),与缺乏运动组相比,普通运动组和大运动量组的体脂百分比均显著降低(P0.05),而去脂体重和肌肉量却明显升高(P0.05),与缺乏运动组和大运动量组相比,普通运动组矿物质含量明显升高(P0.05),各组去脂体重/体重、肌肉量/体重、矿物质含量与骨密度呈高度正相关(P0.01)。结论适量运动使大学生骨密度增加,大强度长时间的大量运动使骨密度下降,不利于骨骼的生长,运动锻炼可以有效改善大学生身体成分,降低脂肪含量,增加去脂体重,预防肥胖。     

600例学龄少女前臂骨密度的研究

目的了解少女(10～11岁)前臂骨密度(BMD)年增长情况以及BMD与身高、体重的关系.方法对600例健康少女行左前臂扫描,按首次平均体重指数(BMI)分组,正常组(BMI=14.2～19.6),超重组(BMI＞19.6),偏轻组(BMI＜14.2).一年后,采用同台双能X线骨密度仪再次扫描,追踪观察一年中BMD的变化.结果600例少女前臂远端1/10、1/3处BMD年均增长率分别为3.9%和10.6%,年增长率以正常组最快,超重组次之,偏轻组最慢.前后两次前臂远端1/10、1/3处BMD与身高、体重均呈明显正相关(r=0.307～0.649,P＜0.001).结论该年龄段发育正常者身高、体重和BMD的年增长均最快.     

Bone gained from physical activity and lost through detraining: a longitudinal study in young males

The aim of this study was to investigate the effect of training and detraining on bone mineral density of both weight-bearing and non-weight-bearing bone in a cohort of young males who participated in ice hockey training. Forty-three healthy adolescent ice hockey players (16.7±0.6 years) training for a mean of 9.7±2.4 h/week and 25 control subjects (16.8±0.3 years) training for 2.1±2.7 h/week, were included in this longitudinal study. Bone mineral density (BMD, g/cm²) of the arms, the dominant and non-dominant humerus, dominant and non-dominant femur, and the right femoral neck, total hip, and bone area of the femur, humerus and hip were measured at baseline and again after 30 and 70 months using dual-energy X-ray absorptiometry. From baseline to the first follow-up, athletes gained significantly more BMD in the femoral neck (0.07 versus 0.03 g/cm²) and arms (0.09 versus 0.06 g/cm²) compared with the controls (P=0.04 for both). Between the first and the second follow-up, 21 ice hockey players stopped their active sports career. These men lost significantly more BMD at the femoral neck (–0.02 versus –0.10 g/cm², P<0.001), total hip (–0.05 versus –0.09, P=0.04), dominant (0.02 versus –0.03 g/cm², P=0.009) and non-dominant humerus (0.03 versus –0.01 g/cm², P=0.03) than the still active ice hockey players (n=22). At the second follow-up examination, at 22 years of age, the former ice hockey players still had significantly higher BMD at the non-dominant humerus than the controls (P<0.01). During the total study period, the still active athletes (n=22) gained significantly more BMD compared with the controls at the femoral neck (0.09 g/cm²; P=0.008), total hip (0.05 g/cm², P=0.04) and arms (0.07 g/cm²; P=0.01). No differences were seen in bone areas when comparing the different groups. In conclusion, training associated with ice hockey is related to continuous accumulation of BMD after puberty in males. Reduced activity is followed by BMD loss within 3 years of cessation of sports career at predominantly weight-bearing sites. The effects are confined to bone density and not bone size.     

Relationships Among Bone Mineral Density,Body Composition,and Isokinetic Strength in Young Women

The purpose of this study was to examine the relationships among bone mineral density (BMD), body composition, and isokinetic strength in young women. Subjects were 76 women (age: 20 ± 2 yr, height: 164 ± 6 cm, weight: 57 ± 6 kg, body fat: 27 ± 4%) with a normal body mass index (18–25 kg/m²). Total body, nondominant proximal femur, and nondominant distal forearm BMD were measured with dual-energy x-ray absorptiometry. Isokinetic concentric (CON) and eccentric (ECC) strength of the nondominant thigh and upper arm were measured at 60 deg/sec. Fat-free mass (FFM) correlated (P < 0.001) with BMD of the total body (r = 0.56) and femoral neck (r = 0.52), whereas fat mass (FM) did not relate to BMD at any site. Leg FFM, but not FM, correlated with BMD in all regions of interest at the proximal femur. Weak associations were observed between arm FFM and forearm BMD. Isokinetic strength did not relate to BMD at any site after correcting for regional FFM. In conclusion, strong, independent associations exist between BMD and FFM, but not FM or isokinetic strength, in young women.     

Amifostine and Dexrazoxane Enhance the Rapid Loss of Bone Mass and Further Deterioration of Vertebrae Architecture in Female Rats

Doxorubicin (DOX) is widely used in combination cocktails for treatment of childhood hematologic cancers and solid tumors. A major factor limiting DOX usage is DOX-induced cardiotoxicity. Dexrazoxane (DXR) is an iron-binding compound and the only approved cardioprotectant for use with DOX. Amifostine (AMF) is a free radical scavenger and approved as a broad-spectrum cytoprotectant. We have shown that when female rats are treated with AMF, AMF + DOX, or AMF + DXR + DOX there is a significant decrease in the right femoral and lumbar vertebral bone mineral density (BMD) (P < 0.05) but not in the left femoral BMD. Furthermore, the relative bone volume (BV/TV) was significantly smaller in the lumbar vertebral bodies of rats treated with AMF (21.1%), AMF + DOX (34.4%), and AMF + DXR + DOX (38.4%), as was the trabecular number (Tb.N) with AMF (15.5%), AMF + DOX (29.9%), and AMF + DXR + DOX (32.3%). AMF + DOX– and AMF + DXR + DOX–treated vertebrae also exhibited deterioration in the microarchitecture of the trabecular bone and spinous processes as ascertained by microcomputerized tomography (micro CT). This information will be useful in designing better cancer combination therapies that do not lead to bone deterioration. Grant Sponsor: Heart and Stroke Foundation of Quebec; Grant Sponsor: Canadian Institutes of Health Research; Grant Sponsor: Canadian Orthopaedic Foundation; Grant Sponsor: Rx&D Health Research Foundation.     

北京城区10?12岁女孩骨密度的研究

目的 观察10－12岁女孩骨密度（BMD）的变化。方法 对375例健康女孩行全身扫描和左前臂扫描，按首位（10岁）平均体重指数（BMI）分组为超重组（BMMI＞19．6）、正常组（BMI＝14．2－19．6）、偏轻组（BMI＜14．2）。1年和2年后，利用同台双能X线骨密度仪再次扫描，连续3年追踪观察该年龄段女孩每年BMD的变化。结果 全身各部位的BMD值和全身总的骨矿含量（BMC）值第2年明显高于第1年（P＜0．01－0．001）。第3年（12岁）与第2年（11岁）相比：仅前臂远端1／10处BMD值有明显增加（P＜0．001），前臂远端1／3处BMD值和全身总的BMD值无增加，且全身总的BMD值略有下降（P＞0．05）；但全身总的BMC值有明显增加（P＜0．001）。BMD、BMC值均以超重组最高，正常组次之，偏轻组最低。结论 青春期女孩不同部位的BMD值年增长率快慢不一，但全身总的BMC值总是随着年龄增长而增加。     

早孕期骨密度正常妇女产褥期骨密度分析

目的分析早孕期骨密度正常妇女产褥期骨密度情况,分析产前、产时、产后各种因素对产褥期骨密度的影响。方法对210名在海淀妇幼保健院建档并住院分娩的早孕期桡骨骨密度正常的妇女在产褥期进行超声骨密度测定,分析孕前体重指数、孕期体重增长、分娩方式、胎儿体重、产后出血、产后喂养方式、产后补钙情况、产后户外活动等对产褥期骨密度的影响。结果早孕期骨密度正常的妇女在产褥期骨密度正常者占90.5%,骨量减少占9.5%,骨质疏松0%。210名妇女产褥期骨密度较早孕期减少,差异有统计学意义(P0.05)。产后出血量多于500m L,孕期体重增加超过12.5kg,产后未补钙及产后户外活动少的产妇,产褥期骨密度较低,差异有统计学意义(P0.05)。而孕前体重指数、分娩方式、胎儿体重、产后喂养方式对产褥期骨密度无影响(P0.05)。结论产褥期骨密度较早孕期下降,孕期控制体重增长、产褥期补钙、适当户外活动,可减少骨量流失。     

绝经后女性的体成分与年龄和绝经的关系及其对不同部位骨密度的影响

目的 调查绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD之间的关系.方法 用双能X线骨密度仪测量919例绝经后女性的体成分、正位腰椎和髋部BMD.结果 下身脂肪量、全身脂肪量和全身瘦组织量与年龄、绝经年龄和绝经年限都相关(P＜0.05～0.01),但只有绝经年限进入体成分的多元逐步回归方程,采用复合或三次回归模型拟合优度最佳.体成分随绝经年限的延长有下降趋势.绝经10年以上女性的下身脂肪量和全身瘦组织量显著减少,分别较绝经年限5年以内女性下降8.6%和3.1%.所有部位的体成分与所测区域的BMD 均呈正相关(P＜0.05～0.01),控制体重变量后,仅有全身脂肪量与腰椎BMD 呈正相关(P＜0.05),而全身瘦组织量与髋部BMD 呈正相关(P＜0.05).多元逐步回归分析发现体成分是影响腰椎和髋部BMD的一个重要因素,但对腰椎BMD影响最大的是全身脂肪量,而对髋部BMD影响最大的是全身瘦组织量.BMD 越低者,全身脂肪量和全身瘦组织量也越低,组间比较有显著性差异.结论 绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD相关,其中,绝经年限对体成分的影响最大,体成分组分对BMD的影响存在部位差异.     

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1?±?7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolutionperipheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect.     

Quantitative Trait Locus on Chromosome 1q Influences Bone Loss in Young Mexican American Adults

Bone loss occurs as early as the third decade and its cumulative effect throughout adulthood may impact risk for osteoporosis in later life, however, the genes and environmental factors influencing early bone loss are largely unknown. We investigated the role of genes in the change in bone mineral density (BMD) in participants in the San Antonio Family Osteoporosis Study. BMD change in 327 Mexican Americans (ages 25–45 years) from 32 extended pedigrees was calculated from DXA measurements at baseline and follow-up (3.5 to 8.9 years later). Family-based likelihood methods were used to estimate heritability (h ²) and perform autosome-wide linkage analysis for BMD change of the proximal femur and forearm and to estimate heritability for BMD change of lumbar spine. BMD change was significantly heritable for total hip, ultradistal radius, and 33% radius (h ² = 0.34, 0.34, and 0.27, respectively; p < 0.03 for all), modestly heritable for femoral neck (h ² = 0.22; p = 0.06) and not heritable for spine BMD. Covariates associated with BMD change included age, sex, baseline BMD, menopause, body mass index, and interim BMI change, and accounted for 6% to 24% of phenotype variation. A significant quantitative trait locus (LOD = 3.6) for femoral neck BMD change was observed on chromosome 1q23. In conclusion, we observed that change in BMD in young adults is heritable and performed one of the first linkage studies for BMD change. Linkage to chromosome 1q23 suggests that this region may harbor one or more genes involved in regulating early BMD change of the femoral neck.     

体重体成分与骨密度的关系

为了研究体成分与骨密度（ＢＭＤ）之间的关系，因体重与ＢＭＤ显著相关，体成分各个组成相加等于体重，而体成分与ＢＭＤ的关系仍不清楚。方法随机选取２０６名１６～５２岁健康的男女性汉族人，用双能Ｘ射线吸收法（ＤＸＡ）测量ＢＭＤ与体成分，进行ＢＭＤ与体重，体成分的多元线性回归分析。结果体重，瘦组织（ＬＴＭ）与男女性的ＢＭＤ显著正相关，脂肪组织（ＦＴＭ）仅对女性全身，腰椎ＢＭＤ起显著性作用。结论影响男女性ＢＭＤ的体成分中，ＬＴＭ是主要因素，ＦＴＭ仅对女性ＢＭＤ有影响。本文较全面地研究了体成分与ＢＭＤ的关系。     

Disruption of Four-and-a-Half LIM 2 Decreases Bone Mineral Content and Bone Mineral Density in Femur and Tibia Bones of Female Mice

Four-and-a-half LIM 2 (FHL2) is a member of a family of LIM domain proteins which mediate protein-protein interactions. FHL2 acts as a coactivator and binds to important regulators of bone formation such as insulin-like growth factor binding protein (IGFBP)-5, androgen receptor, and β-catenin. We hypothesized that FHL2 is an important regulator of bone formation. We evaluated growth and skeletal parameters in FHL2 knockout (KO) and wild-type (WT) mice at 4, 8, and 12 weeks of age. At 4 weeks of age, lack of FHL2 reduced femur, tibia, and total bone mineral content (BMC) and body weight in all mice. A gender-by-treatment interaction (P ≤ 0.05) was observed for several parameters due to a greater reduction in females. Specifically, femur BMC was reduced 11–27% at 8 and 12 weeks of age and BMD was reduced 7–13% at all ages in female KO mice (P < 0.05). A similar reduction was observed in the tibias at 8 weeks of age. A 6% reduction (P = 0.07) in femur cortical thickness was observed at 12 weeks of age in female KO mice. Interestingly, a gender-specific reduction in IGFBP-5 expression was observed in the femurs of female KO mice. During differentiation of bone marrow stromal cells into osteoblasts, expression of osteocalcin, alkaline phosphatase, and bone sialoprotein was reduced 47–96% in FHL2 KO cells (P < 0.001). In conclusion, FHL2 is an important regulator of peak bone mass, lack of FHL2 produces gender- and site-specific effects on bone accretion and IGFBP-5 expression, and FHL2 is important for optimal osteoblast differentiation in vitro. The information contained in this publication does not necessarily reflect the position or the policy of the government, and no official endorsement should be inferred. All work was performed in facilities provided by the Department of Veterans Affairs.     

老年女性腰椎骨密度与年龄及椎旁体质成分相关性分析

目的探讨不同腰椎椎体骨密度(bone mineral density,BMD)与年龄及同层面椎旁腰大肌、竖脊肌、腹部脂肪、血管钙化情况的关系。方法收集体检中心行腰椎检查的老年女性90名,采用定量CT(quantitative CT,QCT)及后处理软件测量L2-L4椎体骨密度及三椎体同层面椎旁体质成分。统计学处理应用配对t检验、Pearson相关分析和多元逐步回归分析等。结果①3组椎体BMD均与年龄均呈负相关(P0.05),L2BMD、L3BMD均与双侧腰大肌、竖脊肌密度成正相关(r=0.233~0.301,P均0.05)。而L4BMD显示与双侧竖脊肌密度及腹部脂肪面积有良好的相关性,均呈正相关。②多元逐步回归分析显示除年龄外,肌肉是影响BMD的重要因素。年龄是唯一全部进入3组腰椎BMD回归方程,并呈负相关,是影响腰椎BMD的重要因素。结论老年女性的腰椎骨密度与椎旁腰大肌、竖脊肌密度,腹部脂肪面积及年龄密切相关,除年龄外椎旁肌肉密度对骨密度影响最大。QCT扫描更加直观、精确显示椎骨与椎旁体质成分情况,可作为测量诊断骨质疏松、体质成分的新手段。     

Changes in bone mineral density, body composition and biochemical markers of bone turnover during weight gain in adolescents with severe anorexia nervosa: a 1-year prospective study

Osteoporosis is a serious complication of anorexia nervosa and in affected adolescents may result in a permanent deficit in bone mass. The pathophysiology of this bone disease has not been clearly defined. In this prospective study of 26 young women with anorexia nervosa aged 13–20 years (mean 16.5) we have measured changes in bone mineral density, total body composition and biochemical indices of bone turnover over 1 year. Over this period there was a mean weight gain of 10 kg and significant height gain with baseline and final values for body mass index of 14.2±1.7 and 17.6±2.3 kg/m² (P<0.001). However, no significant changes were seen in bone mineral density in the spine or proximal femur during the study; total body bone mineral content was significantly higher than baseline at 3 months and 12 months (P=0.001 and P<0.0001), but total body bone mineral density at 3 months was significantly lower than baseline (P=0.003). Serum osteocalcin and bone-specific alkaline phosphatase values increased significantly and remained higher than baseline at all time points whereas urinary NTX/creatinine excretion showed a non-significant increase over the first 6 months of the study, but at 12 months, the mean value was significantly lower than baseline. Mean serum 25-hydroxyvitamin D levels showed a significant decrease at 6 months (P<0.05), but returned towards baseline thereafter. There was a significant increase in serum parathyroid hormone levels at all time points compared to baseline, these occurring within the normal range. These results indicate that although weight gain in young anorexics is associated with linear growth, bone mineral density does not increase. Whether this deficit can be corrected subsequently requires longer-term prospective studies.