Effects of dairy food supplements on bone mineral density in teenage girls

Summary Background Bone mineral density (BMD) is largely genetically determined and this influence is most powerful in the period of rapid skeletal development in childhood and late adolescence but environmental factors such as exercise and dietary calcium intake may influence up to 20%. Aims of the study The aims of the study were to examine healthy late adolescent females for the effects and benefits of a high calcium intake from dairy product foods on bone mineral density, body composition, lipids and biochemistry. The secondary aim is determine whether a high intake of dairy product foods in the diet is acceptable for this age group long term. Methods Ninety-one teenage girls who participated in a two-year randomised controlled study on the effect of dairy food supplementation on dietary patterns, body composition and bone density in post-pubertal teenage girls were approached one year after the cessation of the study to determine the effects of the cessation of dairy supplements on bone mineral density, dietary habits, biochemical markers, body composition and blood lipids. Bone mineral density and bone mineral content were assessed at the hip, spine and total body. Anthropometric data were collected, and exercise, Tanner, dietary assessment, preference and compliance questionnaires were administered. Lipid profiles, hydroxyproline excretion and urinary calcium and sodium excretion measurements were performed. Results There were no significant differences between the 2 groups for height, weight, lean and fat mass. The supplemented group had significantly higher calcium, phosphorus and protein intake during the supplementation period (p<0.001). No differences were seen between the groups 12 months after supplementation finished. There were no significant differences in exercise level, preference or acceptability of dairy products or in the lipids and bone markers between baseline the end of supplementation and 1 year follow-up. There was a significant increase in trochanter (4.6%), lumbar spine (1.5%) and femoral neck (4.8%) BMD (p<0.05) in the high calcium group at the end of supplementation. There was an increase in bone mineral content at the trochanter (p<0.05) and lumbar spine; however the latter was not statistically significant, in the high calcium group at the end of supplementation. There was no difference in vertebral height or width at any stage of the study, indicating no influence on bone size. Conclusions In this 3 year study (2 years of supplementation, 1 year follow-up), teenage girls, aged 15–18 years, were able to significantly increase their BMD at the trochanter, femoral neck and lumbar spine when supplemented with dairy product foods to a mean calcium intake of 1160 mg/d. There was also an effect seen on the BMC particularly at the trochanter and to a lesser extent at the lumbar spine. The dietary calcium intake achieved did not adversely affect body weight, fat and lean mass or blood lipid profiles. Twelve months after the supplementation finished the girls had returned to their baseline diet, indicating self-selection of a high dairy product diet may be hard to achieve. Received: 5 June 2000, Accepted: 5 September 2000     

Effects of isoflavone supplementation on the bone mineral density of growing female rats

This study was focused on whether or not isoflavones affect the increase in bone mineral density of growing females. Female Sprague-Dawley rats (60 ± 5 g) were randomly assigned to two groups and provided control diets (control group) or isoflavone-supplemented diet (IF group, 57.8 mg isoflavones/100 g diet) for 9 weeks in growing female rats. Measurements of Bone Mineral Density (BMD) and Bone Mineral Content (BMC) on the experimental animals were executed in the 3^rd, 6^th, 9^th weeks. In result, there was no significant difference in spine BMD between the isoflavones supplemented group and the control group. But, the IF group tended to have higher BMD than the control group in between 3 and 9 experimental weeks, and the striking difference could be shown in the 6^th week of feeding. In case of femur BMD, the effects of added isoflavones appeared in the 6^th week of feeding, and it became intensified in the 9^th week of feeding to the extent that the BMD in the IF group was significantly higher than that of the control group (p<0.05). In conclusion, isoflavone supplementation increased spine BMD per weight in the 6^th week of feeding, and affected the increase of femur BMD in the 9^th week. The result of the experiment implies that it affects positively the formation of spine and femur BMD of growing female rats. The study also suggests that the effects of isoflavone on the pattern of BMD formation might differ from the parts of bones.     

Evaluation of milk basic protein supplementation on bone density and bone metabolism in Chinese young women

Introduction  Milk is a good source of bioavailable calcium compared with other foods. Recent in vitro and in vivo studies have shown that milk whey protein, especially its basic protein fraction (milk basic protein, MBP), contains several components capable of promoting bone formation and inhibiting bone resorption. The objective of this study was to examine the effects of MBP on bone mineral density (BMD) and bone metabolism of healthy young women. Methods  Eighty-four healthy young women were randomly assigned to three groups: control group, whole milk group or MBP group treated with milk containing 40 mg MBP for 8 months. The bone mineral density of total body, the lumbar vertebrae L2–L4 and the left forearm of each subject were measured by dual-energy X-ray absorptiometry (DEXA) at 0 and 8 months of treatment. Serum indexes of bone metabolism were measured at 0, 3, 6 and 8 months. Eighty-one subjects who completed the study in accordance with the protocol were included in the analysis. Results  Total BMD in all groups significantly increased compared with baseline values. However, no significant difference on the mean rate of gain of total BMD was observed among the MBP group (2.19%), the whole milk group (2.63%) and the control group (1.61%). Serum cross-linked N-teleopeptides of type-I collagen (NTx) in MBP group at 8 months and in whole milk group at 6 months were significantly decreased from baseline. There were no significant differences between whole milk group and MBP group; however, after combining the milk groups, NTx had significantly decreased from baseline. No significant increase was observed in serum bone-specific alkaline phosphatase (BAP) in both whole milk group and MBP group. Conclusion  No significant effect of MBP on bone mineral density and bone metabolism was observed, but milk supplementation was effective in suppressing bone resorption.     

牛乳碱性蛋白对大鼠骨密度的影响

目的探讨牛乳碱性蛋白(MBP)对正常和去卵巢大鼠骨密度、血液生化指标的影响。方法将60只雌性SD大鼠随机分为假手术、去卵巢对照和去卵巢低、中、高5个剂量组;另将44只正常雌性SD大鼠随机分为正常对照、正常低、中、高4个剂量组。分别采用10、20和30mg/(kg.d)MBP给大鼠灌胃连续90天,检测股骨重量,股骨近心端、中段和远心端骨密度与骨矿含量的变化,检测血清总蛋白、胆固醇和血糖等7项血液生化指标。结果正常低剂量组大鼠股骨远心端骨密度和骨矿物质含量显著高于正常对照组;各剂量MBP对去卵巢大鼠骨密度无显著作用;正常低、高剂量组大鼠血清总蛋白和白蛋白显著高于正常对照组。结论10mg/(kg.d)的MBP能显著增加正常大鼠股骨远心端骨密度,对去卵巢大鼠骨密度和骨矿含量无影响,血清总蛋白和白蛋白同时明显升高。     

Effects of taurine supplementation on bone mineral density in ovariectomized rats fed calcium deficient diet

Taurine supplementation has been shown to have a beneficial effect on femur bone mineral content in ovariectomized rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on ovariectomized rats fed calcium deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received sham operation (SHAM), and received either control diet or a taurine supplemented diet for 6 weeks. All rats were fed on calcium deficient diet (AIN-93: 50% level of calcium) and deionized water. Bone mineral density (BMD) and bone mineral content (BMC) were measured in spine and femur. The serum and urine concentrations of calcium and phosphorus were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. Bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Urinary calcium and phosphorus excretion, osteocalcin in blood and cross link value were not significantly different among the groups. Within the OVX group, the taurine supplemented group had not higher femur bone mineral content than the control group. This study established the need for a study on the taurine effect on bone with different calcium levels.     

中国成人吸烟与骨密度相关性的Meta分析

摘要:目的　探讨吸烟是否影响中国成人骨密度（BMD）。方法　检索研究中国成人吸烟与骨密度关系的文献,采用Meta分析方法进行分析。结果　11篇文献共5122名观察对象纳入分析:吸烟者腰椎、股骨颈及Ward's区BMD低于非吸烟者,差异有统计学意义（P＜0.0001）;亚组分析显示男性与女性吸烟者的股骨颈BMD低于非吸烟者,50岁及以上吸烟者股骨颈BMD低于非吸烟者,生态学与病例-对照亚组吸烟者的股骨颈BMD低于非吸烟者,病例-对照亚组吸烟者的腰椎BMD低于非吸烟者,以上差异均有统计学意义（P＜0.0001）。结论　吸烟与中国人群的腰椎、股骨颈和Ward's区的骨密度降低相关,特别是50岁及以上的成人,同时,吸烟女性的股骨颈骨密度比男性降低更显著。     

补充钙剂对青春期骨矿含量的影响

为研究补充钙剂对青少年骨矿含量以及体格发育的影响 ,选取 1 61例 9～ 2 0岁健康青少年 ,按性别和性发育程度分为补钙组和对照组。实验前后评价两组膳食钙摄入量、运动量水平、性发育程度 ,并测定两组青少年身高、体重和桡骨远端 1 3处骨矿含量、骨宽和血清总碱性磷酸酶水平。结果表明本组青少年膳食钙摄入量低于每日膳食钙参考摄入量的适宜摄入量水平 ,补充钙剂对青少年身高、体重无明显影响 ;骨矿含量增长除女性青春期后期有显著性差异外 ,其余各组增长与对照组比较无显著性。结果提示 ,青春期存在体格快速发育和骨量迅速积累的特点 ,补充钙剂对骨矿含量的增长作用有限 ,对体格发育也无明显影响 ;在女性骨量增长较少阶段补充钙剂则可能有助于骨矿含量的增加 ,且这种作用可能通过降低骨代谢率实现     

Vitamin D supplementation and bone mineral density in early postmenopausal women

BACKGROUND: Increased vitamin D intake may preserve or increase bone mineral density (BMD) in older persons. OBJECTIVE: A 2-y double-blind study was undertaken to determine whether weekly administration of 10 000 units of vitamin D(2) maintained or increased BMD in younger postmenopausal women more efficiently than did calcium supplements alone. DESIGN: One hundred eighty-seven women who were >or= 1 y postmenopausal were randomly assigned to take either 1000 mg Ca/d after the evening meal or 1000 mg Ca/d plus 10 000 U vitamin D(2)/wk in a double-blind, placebo-controlled format. The BMD of the proximal forearm, lumbar spine, femoral neck, Ward's triangle, and femoral trochanter was measured at 6-mo intervals by osteodensitometry. RESULTS: During the 2-y period, there was no significant difference in the change in BMD at any site between the subjects taking calcium supplements and those taking calcium plus vitamin D(2). Both groups significantly (P < 0.005) gained BMD in Ward's triangle and the femoral trochanter but significantly (P < 0.005) lost bone in the proximal radius. There was no significant change in the lumbar spine or femoral neck BMD. CONCLUSION: In younger postmenopausal women ( age: 56 y) whose average baseline serum 25-hydroxyvitamin D concentration was well within the normal range, the addition of 10 000 U vitamin D(2)/wk to calcium supplementation at 1000 mg/d did not confer benefits on BMD beyond those achieved with calcium supplementation alone.     

青春前期女童钙感应受体基因多态性与骨量关系

目的了解我国青春前期女童钙感应受体（CASR）A986S基因多态性分布并探讨其对骨量的影响。方法选择153名9～11．5岁未月经初潮的健康女童，采用双能X线骨密度仪（DXEA）检测对象全身、L1—L4腰椎、左侧近端股骨的骨矿含量、骨密度以及体成分。采用等位基因特异性突变扩增PCR技术检测CASRA986S多态性。结果152名对象CASR基因A986S多态性基因型的分布频率分别为：野生型纯合子（AA）91．44％，杂合子（AS）7，89％，突变型纯合子（SS）为0．67％，研究对象基因型中含有s等位基因者TBBMD、TBBMC，L1-L4LSBMD均显著低于基因型中不含S等位基因者（P〈0．05）。其中含S等位基因者TBBMD比无S等位基因者低5％，TBBMC下降了约10％。结论CASRA986S基因多态性与骨量有关。有S等位基因者TBBMC、TBBMD显著低于无S基因者。     

口服碳酸钙制剂对孕产妇骨密度的影响

目的探讨孕产妇补充碳酸钙制剂对其骨密度的影响。方法36例孕第一胎妇女从孕20周开始通过膳食、膳食干预及碳酸钙补充摄入不同剂量的钙至产后45天。监测并比较孕中、孕末及产后期的血钙、碱性磷酸酶、尿羟脯氨酸、骨钙素及产后骨密度的差异。结果(1)传统膳食加40g／d奶粉补充的孕产妇产后骨密度虽优于传统膳食组,但明显低于奶粉加碳酸钙组;(2)奶粉加碳酸钙补充组的产妇腰椎骨密度明显高于奶粉组和传统膳食组,并维持至正常非常非孕同龄妇女的水平;(3)奶粉加碳酸钙补充组在孕末期、产后期的碱性磷酸酶活性、尿羟脯氨酸水均明显低于传统膳食组而骨钙素含量明显高于传统膳食组。结论(1)我国传统膳食钙摄入量约450mg／d,孕期的低钙摄入可导致产后骨密度下降;(2)孕期在传统膳食基础上补充40g奶粉／d,可使其产后骨密度优于传统膳食组,但不能维持骨密度至正常的水平;(3)奶粉加碳酸钙的联合补充,可使孕产妇产后骨密度明显高于传统膳食组和奶粉补充组,并维持其骨密度至正常水平。     

Effects of dietary protein deficiency on mineral metabolism and bone mineral density.

The effects of dietary protein restriction on mineral and bone metabolism are uncharacterized. We studied growing rats fed a diet low in protein (5%) for 4, 6, and 8 wks (n = 10 animals/group) and compared them with animals pair-fed with a protein-replete (18%) diet. The low-protein diet rapidly induced a profound hypocalciuria that persisted for greater than or equal to 8 wk. Serum calcium and phosphorus concentrations were not affected but serum total and free 25-dihydroxyvitamin D concentrations as well as gastrointestinal calcium absorption were lower in the low-protein animals. Skeletal dimensions were reduced in the protein-deprived rats but there were no significant differences in bone mineral content between control and low-protein animals at 4, 6, and 8 wks. Hence, dietary protein deprivation resulted in slower growth but bone mineral density was maintained when there was a marked reduction in urinary calcium excretion.     

Growth, bone mass, and vitamin D status of Chinese adolescent girls 3 y after withdrawal of milk supplementation

BACKGROUND: A 2-y school milk intervention trial showed that 330 mL of a dietary milk supplement (fortified with calcium alone or with both calcium and vitamin D) enhanced the growth and bone mineral accretion of Chinese girls aged 10 y at baseline. Girls who received milk fortified with both calcium and vitamin D also had better vitamin D status than did girls who received nothing or girls who received milk fortified only with calcium. OBJECTIVE: The aim was to evaluate whether these effects were sustained 3 y after supplement withdrawal. DESIGN: Anthropometric measures and dietary intake were reassessed in 501 of the 698 girls whose data had been studied at the end of the intervention. As in the intervention phase, total-body bone mineral content and bone mineral density and serum 25-hydroxyvitamin D concentrations were measured in half of these subjects. RESULTS: At follow-up, 99% of girls had reached menarche, at a mean (+/-SD) menarcheal age of 12.1 +/- 1.1 y. No significant differences in the timing of menarche were observed between the 3 groups (P = 0.6). No significant differences in the changes of total-body bone mineral content and bone mineral density since baseline were observed between the groups. The group receiving calcium-fortified milk had significantly greater gains in sitting height (0.9 +/- 0.3%; P = 0.02) than did the control group. The group that received calcium- and vitamin D-fortified milk had 17.1 +/- 6.7% lower serum 25-hydroxyvitamin D concentrations than did the control group (P = 0.04), but the difference was attenuated by additional adjustment for physical activity level (14.2 +/- 6.7%; P = 0.08). CONCLUSION: Milk supplementation during early puberty does not have long-lasting effects on bone mineral accretion.     

Lifetime milk consumption and bone mineral density in older women.

This study examined the relationship between lifetime milk consumption both axial and appendicular bone mineral density in 581 postmenopausal White women. Positive significant, graded associations between milk consumption in adulthood and bone mineral density at the spine, total hip, trochanter, intertrochanter, and midradius, but not the ultradistal wrist or femoral neck, were observed. Adolescent milk consumption showed similar, statistically significant associations (spine and midradius). Associations were independent of age, body mass index, years postmenopausal, thiazide, estrogen and alcohol use, smoking, and exercise. Regular milk consumption in youth and adulthood is associated with better bone mineral density at cortical and trabecular sites in elderly women.     

婴儿活动水平对骨密度的影响

【目的】探讨婴儿活动水平与骨密度的关系,了解家庭环境及养育方式和观念对婴儿活动水平的影响。【方法】根据DDST筛查结果,共有31名婴儿在大动作和精细动作能区出现迟缓,作为可疑者入选研究组,同时选择31名测试正常的婴儿作为对照组。此外,进一步对受试婴儿进行骨密度检测,并通过问卷调查影响其活动的相关因素。【结果】骨密度值在研究组和对照组中分别为0.40±0.02,0.44±0.02,差异有显著性(t=10.34,P<0.005)。在研究组中,婴儿受2人以上照料、母亲照料时间≤3h、老人照料时间≥3h、家住古城区、小区无公共活动场所、婴儿每天俯卧位时间≤1h、不训练抓握与翻身、育儿理念错误者、婴儿每天被搂抱时间≥3h、不做被动体操、开始训练婴儿活动时间≥2个月龄者多于对照组,差异有显著性(P均<0.05)。经多元线性回归分析,影响婴儿骨密度的主要因素依次为俯卧位时间、照料人数、育儿理念、做婴儿被动体操、老人照料婴儿时间、搂抱时间(P均<0.05)。【结论】婴儿活动水平低阻碍动作发展,并导致骨密度下降,而家庭环境、养育方式和观念是影响婴儿活动的重要因素。     

Familial aggregation of forearm bone mineral density in Chinese

Osteoporosis is a major public health concern and its prevalence can be predicted based on forearm bone mineral density (BMD). This study is to investigate the familial aggregation of forearm BMD in a population-based, cross-sectional study in Anhui, China. Information on sociodemographic and environmental variables was obtained from 1,636 subjects from 409 nuclear families (including mother, father, and their first two children) by a standardized questionnaire. The forearm BMD was measured by peripheral dual-energy X-ray absorptiometry (pDXA). Using generalized additive models with a sequential adjustment for covariates, it was clearly indicated that the forearm BMD of the mother, the father, and the first sibling each had a significant and independent relation to the forearm BMD of the second sibling. Furthermore, using multiple logistic regression, the second sibling had an odds ratio (OR) of 5.3 (95%CI: 2.0–14.5) of having an extremely low (bottom 10th percentile) proximal forearm BMD and an OR of 4.3 (95%CI: 1.6–12.0) of having an extremely low distal forearm BMD when the parental mean forearm BMD was low and the first sibling’s forearm BMD was low. Our findings showing strong familial aggregation of both proximal and distal forearm BMD values suggest that genetic factors play a significant role in determining both traits.     

Effect of milk and milk products consumption on physical growth and bone mineral density in Korean adolescents

This study was conducted to investigate the relationship among the current status of calcium intake from milk and milk products, physical growth and bone mineral density in 664 male and female middle school and high school students aged 15-17 years. In the study, the current status of calcium intake from milk and milk products was analyzed, and the height, body composition, and bone mineral density of the right heel bone (calcaneus) were measured. The daily calcium intake of milk and milk products was calculated as the ''dairy equivalent of calcium'', which is the calcium content in 200 mL of white milk. The cutoffs of tertiles of the dairy equivalent of calcium were calculated and then the subjects were categorized into 3 groups according to the tertiles, Q1 group (lower intake group), Q2 group (middle intake group) and Q3 group (upper intake group). The daily calcium intake of milk and milk products in Q1, Q2 and Q3 groups was 16.2 mg, 99.7 mg, and 284.0 mg, respectively, and the ratio of milk and milk product consumption to the daily total calcium intake was 5.4%, 27.4%, and 49.7%, respectively. The ratio of total calcium intake to the daily recommended intake in study subjects was 30.5% in Q1, 42.3% in Q2, and 60.7% in Q3, with significant differences (P < 0.05). Height, body weight, BMI, and % of body fat in three tertile groups (Q1, Q2 and Q3) were not significantly different. However, the T scores for bone mineral density in female students in three tertile groups (Q1, Q2 and Q3) was significantly different (P < 0.05). The study showed that the intake of milk and milk products in adolescents, particularly in girls, can improve the bone mineral density without increasing body weight, and thus confirmed that milk intake is important in adolescence.     

Effects of body mass index on bone mineral density in men

INTRODUCTION: A strong positive association between body mass index and bone mineral density is well defined in postmenopausal osteoporosis, but not in men. AIMS: The primary goal of the current research was to investigate this association in case of men. METHODS: According to WHO criteria (T-score below -1.0 at all measure site) seventy-two (mean age 55.7 +/- 0.99, range 38-78 yr normal density) healthy male with normal density were recruited. Exclusion criteria were the absence of any risk factors or signs of metabolic disease. Bone mineral measurements at the lumbar spine (L2-4) and femoral neck were performed by the dual-energy X-ray absorptiometry (DEXA, Lunar DPX-L, USA), bone mineral content of the non-dominant radius was measured with single photon absorptiometry (SPA, NK-364, Hungary). Participants were divided into three groups according to body mass index normal weight (18.5-24.9 kg/m2), moderate overweight (25-29.9 kg/m2) and obese subjects (> 30 kg/m2). RESULTS: Femur neck density was significantly lower in the normal weight than in the overweight counterparts (0.969 +/- 0.03 vs 1.062 +/- 0.02 p = 0.01). There was a strong positive association between BMI and femur neck BMD (r = 0.412 p < 0.001). Body mass was an independent predictor of femur neck bone mineral density (regression coefficients 0.382, p = 0.001). There was not correlation at the lumbar spine and the radius sites. CONCLUSION: Bone density at femur neck sites is lower in the normal weight men than in obese subjects, therefore the risk factors for proximal femur osteoporosis are higher in these cases. Prevention strategy is needed for men in the lowest quintile of body mass to prevent further decrease in BMD and reduce the risk of hip fracture.     

青春期女性应用孕激素避孕药对骨健康的影响

单纯孕激素避孕药醋酸甲羟基孕酮因高效、长效而被广泛应用,这种避孕方法 明显降低了青春期女性的妊娠率.但是,醋酸甲羟基孕酮也有许多副作用,尤其是对骨矿物质密度的影响,因此人们担心青春期女性应用醋酸甲羟基孕酮对骨健康产生不利影响.该文就近年来有关青春期女性应用醋酸甲羟基孕酮对骨矿物质密度影响的研究进行综述.