Soy isoflavones: no effects on bone mineral content and bone mineral density in healthy,menstruating young adult women after one year

BACKGROUND: The effects of isoflavone-enriched soy protein on human bone mineral content (mass) and density in healthy, menstruating young adult females have not been examined in a comparative prospective investigation. Peri- and post-menopausal women have been reported to show beneficial effects of isoflavones on bone measurements. Therefore, young women may also be able to improve their accrual of peak bone mineral content (BMC) and bone mineral density (BMD) during the early adult years of bone consolidation with an isoflavone-enriched diet. OBJECTIVES: In this controlled, double-blind intervention, we tested the hypothesis that an isoflavone-rich soy protein diet increases BMC and BMD in young adult females over a period of one year in comparison to a control group receiving soy protein that has isoflavones removed. DESIGN: Young healthy women of any ethnic background, 21 to 25 years of age, were divided into two groups, placebo (n = 13) and supplement (n = 15). The soy protein supplement was enriched with isoflavones ( approximately 90 mg of total isoflavones/day), whereas the control protein diet was isoflavone-deficient, even though it contained the same amount of soy protein and other ingredients as the isoflavone-rich diet. Dual-energy x-ray absorptiometric (DXA) measurements of BMC and BMD were made at baseline and at 6 and 12 months. DXA estimates of body composition, including fat mass and lean body mass, were generated from whole-body BMC measurements. BMI was calculated as weight (kg) over height (m) squared. Physical activity was assessed, and three-day dietary records were taken at entry (baseline) and at 6 and 12 months. RESULTS: No changes in BMD after 12 months were found in either the isoflavone-treated (treatment) group or the isoflavone-deficient (control) group. Other variables also remained essentially constant over the 12-month period, including normal menstrual patterns in both the treatment and control groups. CONCLUSIONS: The isoflavone-rich soy preparation had no effects on BMC and BMD over a 12-month period in young healthy adult females with normal menses. An isoflavone-rich supplement appears to have little or no effect on bone in young adult women with normal ovarian function, at least over this 12-month study period.     

Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women

BACKGROUND: No published studies have directly examined the effect of soy protein with isoflavones on bone or bone turnover in perimenopausal women. OBJECTIVE: Our objective was to determine the effects of 24 wk of consumption of soy protein isolate with isoflavones (80.4 mg/d) in attenuating bone loss during the menopausal transition. DESIGN: Perimenopausal subjects were randomly assigned, double blind, to treatment: isoflavone-rich soy (SPI+; n = 24), isoflavone-poor soy (SPI-; n = 24), or whey (control; n = 21) protein. At baseline and posttreatment, lumbar spine bone mineral density (BMD) and bone mineral content (BMC) were measured by using dual-energy X-ray absorptiometry. At baseline, midtreatment, and posttreatment, urinary N:-telopeptides and serum bone-specific alkaline phosphatase (BAP) were measured. RESULTS: The percentage change in lumbar spine BMD and BMC, respectively, did not differ from zero in the SPI+ or SPI- groups, but loss occurred in the control group (-1.28%, P: = 0.0041; -1.73%, P: = 0.0037). By regression analysis, SPI+ treatment had a positive effect on change in BMD (5.6%; P: = 0.023) and BMC (10.1%; P: = 0.0032). Baseline BMD and BMC (P: < or = 0.0001) negatively affected the percentage change in their respective models; baseline body weight (P: = 0.0036) and bone-free lean weight (P: = 0.016) contributed positively to percentage change in BMD and BMC, respectively. Serum BAP posttreatment was negatively related to percentage change in BMD (P: = 0.0016) and BMC (P: = 0.019). Contrast coding using analyses of covariance with BMD or BMC as the outcome showed that isoflavones, not soy protein, exerted the effect. CONCLUSION: Soy isoflavones attenuated bone loss from the lumbar spine in perimenopausal women.     

Association between Dietary Conjugated Linoleic Acid and Bone Mineral Density in Postmenopausal Women

Objective: To determine if dietary conjugated linoleic acid (CLA) is associated with bone mineral density (BMD) of different skeletal sites in postmenopausal women.

Methods: A cross-sectional analysis in 136 Caucasian, healthy, postmenopausal women, mean age 68.6 years. BMD and soft tissue were assessed by dual energy x-ray abosorptiometry (DXA). Energy, calcium, protein, fat, CLA and other relevant nutrients were estimated using 3 day dietary records. Supplement use was recorded as well. Current and past physical activity were determined using the Allied Dunbar National Fitness Survey for older adults.

Results: CLA (63.1 ± 46.8 mg, mean ± SD) was a significant predictor of Ward’s triangle BMD (p = 0.040) in a multiple regression model containing years since menopause (18.5 ± 8.4 y), lean tissue, energy intake (1691 ± 382 kcal/day) dietary calcium (873 ± 365 mg), protein (70.6 ± 18.6 g), fat (57.9 ± 23.9 g), zinc (19.2 ± 13.6 mg), and current and past physical activity, with R²_adj = 0.286. Subjects were also divided into groups below (Group 1) and above (Group 2) the median intake for CLA. Group 2 had higher BMD in the forearm, p = 0.042, and higher BMD in the hip, lumbar spine and whole body, however statistical significance was not reached.

Conclusion: These findings indicate dietary CLA may positively benefit BMD in postmenopausal women. More studies are warranted examining the relationship between dietary CLA and BMD.     

Dietary Protein,Phosphorus and Potassium Are Beneficial to Bone Mineral Density in Adult Men Consuming Adequate Dietary Calcium

Objective: The purpose of this study was to determine relationships of calcium (Ca), protein (Pr), phosphorus (P) and potassium (K) to measures of bone mineral density in adult men.

Methods: Cross-sectional analysis of 57 men ages 39 to 42 years who were participants in an ongoing study. Dietary assessment was conducted using the Block food frequency questionnaire (FFQ). BMD of total body (TB), hip and lumbar spine (LS) were measured with dual X-ray absorptiometry (DXA).

Results: Ca, Pr, P and K, as well as lean body mass (LBM), showed significant correlation with BMD at the total body, hip and lumbar spine. Stepwise forward regression selection method identified LBM, height and fat mass as significant predictors of TB-BMD, LBM and height as significant predictors of hip BMD, and LBM as a significant predictor of LS-BMD. As the nutrients tested correlated significantly with each other, only one nutrient was entered into the regression model at a time to accommodate the potential for multicollinearity. In regression analysis, adjusted for site-specific anthropometric variables and energy intake, K, Pr and P intake accounted for significant (p < 0.05) prediction of TB-BMD and LS-BMD values by 7% to 13%. No bone-related nutrient added significantly to the prediction of hip BMD. Ca intake was not significantly associated with BMD at any site in the adjusted models.

Conclusions: Our analysis provides support that a moderate protein (1.2 g/kg) diet, plentiful in potassium (>100 mmol/day) and phosphorus (1741 ± 535 mg) is beneficial for maintaining bone mineral density in adult men when Ca intake was adequate (1200 ± 515 mg).     

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.     

铁和锌对染铅大鼠股骨矿物质含量和骨密度的影响

目的　以大鼠为模型 ,观察饲料中添加不同铁 (1 0、5 0和 2 5 0mg kg)和锌 (1 0、4 0和 2 0 0mg kg)水平对低剂量铅 (0和 2 0 0mg kg)毒性的拮抗作用。方法　断乳一周Wistar雄性大鼠按体重随机被分成 1 1组 ,每组 1 0只。其中 1 0组饲以不同铁、锌和铅水平的饲料 ,另设 1组为未染铅正常对照 ,饲以基础正常饲料 ,1 2周后处死大鼠测定股骨生长发育有关指标。结果　研究发现 ,铅污染抑制大鼠骨骼的生长发育 ,能降低骨骼中矿物质含量和骨密度 ,补充铁锌后能改善大鼠股骨的重量和长度 ,增加股骨矿物质含量和骨密度 ,同时会增加骨铅含量。提示　需要进一步研究铅影响骨骼生长发育的机制     

A 7-Year Longitudinal Trial of the Safety and Efficacy of a Vitamin/Mineral Enhanced Plant-Sourced Calcium Supplement

Objectives: The objective of this study was to examine the safety and efficacy of a vitamin–mineral enhanced plant-sourced calcium AlgaeCal calcium (AC) in female consumers who had taken the supplement from 1 to 7 years.

Methods: Consumers who had completed at least one dual-energy x-ray absorptiometry (DEXA) bone mineral density (BMD) scan (N = 172) and/or blood chemistry test (N = 30) and purchased AC from 1 to 7 years were contacted and offered complimentary repeat tests. Safety and efficacy were examined by annualized changes in a 45-measurement blood chemistry panel and changes in BMD.

Results: No adverse effects or safety concerns were found in any of the annualized within-group annualized changes in the 45 blood chemistries or in between-group changes in a similar control group (n = 5070) who completed the same measurements. With regard to BMD, consistent and statistically significant within-group increases were found for the 7-year study period and when compared to expected BMD changes in 3 large databases or the combination (N = 25,885) of the 3 databases. Data from this study suggest that AC supplement was associated with a significant annualized and linear increase in BMD of 1.04% per year, 7.3% over the 7-year study period. These results stand in marked contrast to normative or expected changes of ?0.4%/y from 3 different databases or in a combination of all 3 databases (N = 16,289).

Conclusions: No evidence was found in cardiovascular risk as measured by adverse changes in blood lipids, nor was any evidence found of a diminished efficacy over the 7-year study period because gains in BMD were consistent and linear over the 7-year study period, averaging 1.04% per year over the 7-year study. The results are also consistent with earlier short-term studies suggesting that this supplement can facilitate significant increases in total body BMD in contrast to studies suggesting that calcium supplements can only slow down age-related declines in BMD.     

大鼠骨矿物质含量与组织中钙水平的相关性研究

用ＳＤ１０００型单光子骨矿物测定仪研究了９８只１５周龄Ｗｉｓｔａｒ大鼠的股骨矿物质含量（ＢＭＣ）和骨密度（ＢＭＤ，ＢＭＣ／ＢＷ）与组织和血中钙含量的相关性。结果显示：雌、雄动物的身长、体重、骨宽度（ＢＷ）、ＢＭＣ、ＢＭＣ／体重、ＢＭＤ／体重及ＢＭＤ／身长均有显著性差异，活体ＢＭＤ与动物的钙总摄入量、身长、体重、及钙存留率显著相关（Ｐ＜０．０５）；ＢＭＣ与钙总摄入量、身长、体重、性别和肝脏钙含量显著相关（Ｐ＜０．０５）。多元回归分析表明：动物身长、体重、钙总摄入量和心脏钙含量与活体ＢＭＤ呈线性关系，动物身长和血浆钙含量与离体ＢＭＤ呈线性关系。活体测量结果ＢＭＣ、ＢＭＤ由于其与动物的生长发育、钙存留率及肌肉和血浆钙含量具有相关和直线关系，且简便易行、不需要处死动物，因而认为可以反映动物体内钙营养状况和骨质积累情况。     

Soy isoflavones attenuate bone loss in early postmenopausal Chinese women

Background Previous studies show that daily doses of 40–99 mg soy isoflavones produce inconsistent effects on preventing estrogen-related bone loss in postmenopausal women. Aim of the study To examined the bone-sparing effect of isoflavones at a higher dose in early Chinese postmenopausal women. Methods A total of 90 eligible women aged 45–60 years were randomly assigned to three treatment groups (30 subjects/group) with daily dosages of 0 (placebo), 84 and 126 mg isoflavones for 6 months. Further inclusion criteria included body mass index <30 kg/m² and Kuppermann Climacteric Scale >15. Bone mineral density (BMD) of the spine and hip were measured using dual- energy X-ray absorptiometry at 0 and 6 months. Serum osteocalcin, bone-specific alkaline phosphatase (BAP) and urinary deoxypyridinoline were examined at 0, 3 and 6 months. Results Mean percent changes in BMD at the lumbar spine (p = 0.114) and femoral neck (p = 0.053) increased with the supplementations of soy isoflavones after adjusting for age, years since menopause, body weight and height, dietary intakes of isoflavones, calcium and protein, physical activities and baseline BMD at the relevant sites. We observed significantly dose-dependent linear relationship between the supplemental isoflavones and percent changes of BMD at the spine (p = 0.042) and femoral neck (p = 0.016) post-treatment, and urinary total deoxypyridinoline (p = 0.014) at 12 weeks but not at 24 weeks after adjusting for the above factors. No significant difference in percent changes in serum osteocalcin (p > 0.05) and BAP (p > 0.05) was found among the three treatment groups at 12-week and 24-week post-treatment. Conclusion There is a significantly dose-dependent effect of soy isoflavones on attenuating bone loss at the spine and femoral neck possibly via the inhibition of bone resorption in non-obese postmenopausal Chinese women with high Kuppermann Scale.     

Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats

BACKGROUND/OBJECTIVES

Soy isoflavones are structurally similar to estrogen and bind to estrogen receptors, suggesting that they exhibit estrogenic activities; therefore, they are referred to as phytoestrogens. Fermentation may affect the bioavailability of isoflavones altering soy isoflavone glycosides in the form of aglycones. Thus, this study investigated the effects of fermented soybeans by Rhizopus oligosporus on bone metabolism in both young rats as a pilot test and in ovariectomized (ovx) old rats as a model of menopause.

MATERIALS/METHODS

In the pilot test, a total of 24 seven-week-old female Sprague-Dawley (SD) rats were fed one of three diets for a period of four weeks: casein, unfermented soybean product, or fermented soybean product by R. oligosporus. In the ovx rat model, 20-week-old SD rats weighing 260-290 g underwent either sham-operation (n = 10) or bilateral ovariectomy (n = 30) and were then fed the AIN-93M diet for one week. Thereafter, rats were fed sham-casein, ovx-casein, ovx-soybean, or ovx-fermented soybean diet for five weeks. After decapitation, femoral bones were isolated and preserved in 9% formalin for assessment of bone mineral density (BMD), bone mineral content (BMC), and bone-breaking strength (BBS).

RESULTS

Ovx rats showed significantly increased weight gain and decreased uterine wet weight. Of particular interest, ovx rats fed fermented soybeans showed increased uterine wet weights compared to control rats. Fermented soybean diet caused a significant increase in plasma 17-β estradiol concentrations in young rats, and 17-β estradiol levels were enhanced in ovx rats to match those of sham-operated ones. Significantly lower femoral BMD and BMC were observed in ovx rats compared to sham-operated controls, whereas bone areas did not differ statistically among the groups. In addition, BBS tended to be increased in ovx rats fed soybeans and fermented soybeans.

CONCLUSIONS

Supplementation of fermented soybeans could have preventive and therapeutic effects against osteoporosis in postmenopausal women.     

Early Nutrition during Hospitalization in Relation to Bone Health in Preterm Infants at Term Age and Six Months Corrected Age

Aim: to evaluate the potential association of macronutrient intake in the first postnatal weeks on bone mineral content (BMC) and bone mineral density (BMD) in extremely and very preterm infants. Methods: fifty-eight extremely and very preterm infants were included. Daily macronutrient intake was calculated in g kg⁻¹ day⁻¹ from birth up to 36 weeks postmenstrual age. A dual-energy X-ray absorptiometry whole body scan was used to assess BMC and BMD in preterm infants at term corrected age (TCA) and six months corrected age (CA). Results: fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was positively associated with BMC and BMD at TCA. At six months CA, protein and fat intake (g kg⁻¹ day⁻¹) in the first weeks of life were both individual predictors for BMD. Fat intake (g kg⁻¹ day⁻¹) in the first four postnatal weeks was significantly associated with BMC at six months CA. Conclusion: the association of macronutrient intake in the first postnatal weeks on BMC or BMD, at TCA and six months CA, suggest that early nutritional intervention immediately after birth and during early infancy is important for bone health in the first months of life.     

Effect of a Nutritional Supplementation on Bone Health in Chilean Elderly Subjects with Femoral Osteoporosis

Objective: To study the effects of a special nutritional supplement on bone mineral density and bone turnover markers in Chilean elderly subjects with femoral osteoporosis.

Setting: Public primary health care clinics in Chile.

Subjects: Free living elderly subjects with femoral osteoporosis.

Interventions: Subjects were randomized to receive the usual nutritional supplement provided by the Chilean Ministry of Health or a special nutritional supplement providing, among other nutrients, 90 mg isoflavones, 800 mg calcium, 400 IU vitamin D, 60 ug vitamin K and 31 g proteins per day.

Measures of Outcome: At baseline, and after six and twelve months of supplementation, body composition, bone mineral density, serum 25 OH vitamin D, intact parathyroid hormone (iPTH), osteocalcin, decarboxylated osteocalcin, urinary aminoterminal telopeptide of type I collagen (NTX), deoxypyridoline cross links (Dpd) and equol were measured. Every month, urinary daidzein was measured in a morning urine sample.

Results: No differences between treatment groups were observed in body composition or bone mineral density changes. The group receiving the special supplement had a significant increase in serum 25 OH vitamin D and a significant decrease in serum iPTH and decarboxylated osteocalcin. No association between daidzein or equol excretion and changes in bone mineralization was observed.

Conclusions: A special supplement delivered to elderly subjects with osteoporosis improved serum vitamin D and reduced serum iPTH and undercarboxylated osteocalcin levels but did not affect BMD.     

Bone Mineral Density and Metabolism at an Early Stage of Menopause When Estrogen and Calcium Supplement Are Not Used and without the Interference of Major Confounding Variables

Objectives: To measure bone mineral density (BMD) and to screen for early biochemical abnormalities in bone mineral metabolism in the first five years of natural menopause when estrogen and calcium supplement are not used and in the absence of major confounding variables.

Setting: Two homogeneous and comparable groups (n = 30) of healthy pre- and postmenopausal Caucasian women living in a northern region (latitude 46° N) were recruited during the mid-Spring/Summer season in a cross-sectional design.

Methods: Volumetric apparent BMAD (g/cm³) was calculated from areal BMD (g/cm²) which was evaluated by dual energy X-ray absorptiometry (Lunar®) at both axial and peripheric (femur) sites using two sets of reference values (WHO criterion expressed as T-score and absolute values of areal density) in combination to bone specific biochemical measurements.

Results: BMD and BM(A)D were significantly lower in postmenopausal women for all lumbar sites, but not for Ward’s triangle and any other femoral sites whereas free deoxypyridinoline (Dpd), urinary biochemical marker of bone resorption, was markedly (p < 0.0001) greater. Their serum calcium and phosphate were significantly higher without a difference in 1,25(OH)₂D₃ and PTH. The prevalence of osteopenia in pre- and postmenopausal women was about 2-fold lower in both groups (26.6 and 46.9%, respectively) when lumbar (L) spine and femur neck were combined and using the criteria based on reference values of areal density instead of T-scores.

Conclusions: The present study showed that the negative effects of estrogen deficiency on BMD and bone metabolism in early menopause occurred independently of the effect of major calcitropic hormones. Bone loss affects a non negligible proportion of premenopausal women. The prevalence of osteopenia in pre- and postmenopausal women varied according to the criterion used and anatomic site.     

Soybean Isoflavones Reduce Postmenopausal Bone Resorption in Female Japanese Immigrants in Brazil: A Ten-Week Study

Objective: Some human studies and animal models of experimental osteoporosis have shown that soy isoflavones may be effective on bone health. In this study, we carried out an intervention study to explore the effects of dietary isoflavone on bone metabolism.

Methods: Forty healthy female postmenopausal Japanese immigrants living in Brazil were divided into two groups: isoflavone-administered (n = 20) or placebo (n = 20). Subjects in the isoflavone-administered group ingested 37.3 mg per day for 10 weeks. The collection of 24-hour urine and the measurement of bone stiffness were performed at 0 and 10 weeks. Urinary excretion of isoflavones and bone resorption markers were analyzed.

Results: Urinary isoflavone excretion in the isoflavone-administered group was significantly increased at weeks 3 and 10. Urinary excretion of bone resorption markers was reduced in the isoflavone-administered group, while the placebo group did not show any significant reduction. Differences in levels of urinary isoflavones and bone resorption markers between the two groups were significant.

Conclusion: This study demonstrated that the bone resorption was associated with the intake of soy isoflavones in postmenopausal women, and continuous dietary intake of isoflavone may inhibit postmenopausal osteoporosis.     

补钙对青年女性全身各部位骨密度的影响

目的探讨不同钙摄入量对我国青年女性全身及各部位骨密度的影响,为进一步研究制定我国居民钙的适宜摄入量提供科学依据。方法为期13个月设有对照的双盲干预研究。将某军校平均年龄19.8岁女学员179人,以基线调查的全身骨密度及膳食钙摄入量为指标,随机分为4组,每天给予不同剂量碳酸钙片,使总钙摄入量分别达到400、800、1000及1200mg/d,每片钙片中均强化60IU的维生素D。干预前后分别使用食堂记帐法、称重法和24小时记录法了解膳食摄入,体力活动问卷了解体力活动情况,双能X线骨密度仪测定全身、腰椎和前臂的骨密度。结果4组平均摄入的膳食钙加上补充钙的中位数分别是517mg/d(1组)、810mg/d(2组)、964mg/d(3组)、1185mg/d(4组)。实验前后各部位骨密度增加值的组间比较分析显示,3组和4组的全身、下肢和尺骨远端1/3处骨密度增加值均显著高于1组和2组(P<0.05);3组和4组的3处骨密度增加值差异均无显著性。结论随着钙摄入量的增加,青年女性全身各部位骨密度增加,当钙摄入量达到约1000mg/d时,全身、下肢和尺骨远端1/3处骨密度增加值达到最大,再增加钙摄入至1200mg/d时,骨密度不再显著增加。提示我国青年女性钙的适宜摄入量可能在1000mg/d左右。     

硒锌水平对染铅大鼠股骨中微量元素及矿物质含量的影响

目的　以大鼠为模型 ,观察饲料中添加不同亚硒酸钠 (Se 0 1、0 5和 1 0mg kg)、乳酸锌 (Zn 10、5 0和 2 0 0mg kg)对醋酸铅 (Pb 0、2 0 0mg kg)所致骨骼毒性的拮抗作用。方法　断乳一周Wistar雄性大鼠按体重随机被分成 10组 ,每组 10只。其中 10组添加了不同铁、锌和铅水平的饲料 ,12周后处死大鼠测定股骨生长发育有关指标 ,结果　染铅抑制大鼠骨骼的生长发育 ,降低骨骼中矿物质含量和骨密度 ,补充硒锌后能改善大鼠股骨的重量和长度 ,增加股骨矿物质含量和骨密度 ,同时降低骨铅含量。结论　需要进一步研究铅影响骨骼生长发育的机制     

The Association of Dietary and Urinary Sodium With Bone Mineral Density and Risk of Osteoporosis: A Systematic Review and Meta-Analysis

Objective: Although some earlier studies have indicated an association between dietary/urinary sodium and bone mass density (BMD), bone mass content (BMC), and the risk of osteoporosis (OS), findings are still conflicting. The aim of this study was to summarize the relation of dietary/urinary sodium with BMD, BMC, and the risk of OS.

Methods: We conducted a systematic search up to April 2017 in PubMed/MEDLINE, SCOPUS, and Web of Science to find relevant studies. Articles with cross-sectional and cohort designs in which odds ratios (ORs), correlations (r), or beta coefficients were reported for the association between dietary/urinary sodium and OS, BMD, or BMC were included.

Results: Pooling 11 effect sizes with a total of 39,065 people showed that higher sodium consumption significantly increased the risk of OS (OR = 1.20; 95% confidence interval [CI], 1.02–1.41; p = 0.026), with high heterogeneity among studies (I² = 68.0%; p = 0.001). Subgroup analyses showed significantly higher risk of OS in premenopausal women (OR = 1.31; 95% CI, 1.01–1.69; p = 0.036), in participants with a mean age older than 50 years (OR = 1.15; 95% CI, 1.04–1.28; p = 0.005), in dietary sodium intake subgroup (OR = 1.45; 95% CI, 1.19–1.77; p < 0.001), and in individuals with adjustment for energy (OR = 1.77; 95% CI, 1.38–2.27; p < 0.001). The correlation coefficients showed no significant association between urinary sodium and BMD (r = ?0.46; 95% CI, ?0.74 to ?0.18; p = 0.02).

Conclusions: We found a positive association between sodium intake and the risk of OS, while no association was found with urinary sodium. Furthermore, there was no significant correlation between sodium intake and BMD. Due to high heterogeneity in this research, more studies are suggested.     

大豆异黄酮减缓绝经后妇女骨丢失的临床效应

目的:确定大豆异黄酮减缓绝经后雌激素缺失状态下骨丢失的生理效应及其有效剂量。方法:以骨量正常或低减的绝经后妇女87人为研究对象,随机单盲分为大豆异黄酮84 mg/d和126 mg/d两个剂量组及安慰剂对照组,另以绝经后妇女10人给予7-炔诺酮2.5 mg/d作为阳性对照组,追踪24 w,测定腰椎、股骨颈和Ward,s三角区试验前后的骨密度值。结果:试验后安慰剂对照组腰椎骨密度较试验前显著下降(P<0.05), 大豆异黄酮两组及雌激素对照组各部位骨密度试验前后无显著变化 (P>0.05);协方差分析表明,试验后大豆异黄酮126 mg/d组、和雌激素对照组腰椎部位骨密度均值及其变化率显著高于安慰剂组(P<0.05),回归分析表明大豆异黄酮对各部位的骨密度变化率均有显著的正向作用(P<0.05)。结论:大豆异黄酮84～126 mg/d可减缓绝经后妇女骨的丢失,维持骨密度的相对稳定,其显效剂量是126 mg/d。     

Soymilk or progesterone for prevention of bone loss

BACKGROUND: Given concerns over the use of hormone replacement therapy (HRT), women are seeking natural alternatives to cope with the symptoms and effects of menopause. The bone sparing effects of soy protein and its isoflavones is well established in animal studies, while 5 previous human studies on soy and bone have yielded variable outcomes due in part to their short duration of study. Progesterone has been suggested as a bone-trophic hormone, but the effect of long-term, low dose transdermal progesterone is unknown. AIM: The aim of the study was to compare for the first time the long-term effects of soymilk, with or without isoflavones with natural transdermal progesterone, or the combination, on bone mineral density in the lumbar spine and hip. METHODS: Postmenopausal, Caucasian women with established osteoporosis or at least 3 risk-factors for osteoporosis, were randomly assigned, double-blind to one of four treatment-groups: soymilk containing isoflavones (soy+, n = 23), transdermal progesterone (TPD+, n = 22), or the combination of soy+ and TDP+,(n = 22) or placebo (isoflavone-poor soymilk, soy/ and progesterone-free-cream TDP/, n = 22). All subjects received comparable intakes of calcium, minerals and vitamins. Bone mineral content (BMC) and density (BMD) were measured in lumbar spine and hip by using dual-energy X-ray absorptiometry (DEXA) at baseline and after 2 years. FINDINGS: The percentage change in lumbar spine BMD and BMC respectively, did not differ from zero in the soy+ group (+1.1%, +2.0%) and TDP+ group (/1.1%, +0.4 %) but significant bone loss occurred in the control group (/4.2%,/4.3 %) and the combined treatment group (/2.8%, /2.4 %). No significant changes occurred for femoral neck BMD or BMC. INTERPRETATION: Daily intake of two glasses of soymilk containing 76 mg isoflavones prevents lumbar spine bone loss in postmenopausal women. Transdermal progesterone had bone-sparing effects but when combined with soy milk a negative interaction between the two treatments occurs resulting in bone-loss to a greater extent than either treatment alone.