Impact of weight-cycling history on bone density in obese women

OBJECTIVE: The purpose of this study was to examine the effect of weight cycling (as defined by the frequency and magnitude of intentional weight loss) on bone mineral density and bone mineral content in obese sedentary women. RESEARCH METHODS AND PROCEDURES: Bone mineral content and density measured by DXA, submaximal physical fitness assessment, nutrient intake, oral contraceptive use, and weight-cycling history were assessed in 195 healthy, overweight sedentary women (age, 21 to 45 years; body mass index, 27 to 40 kg/m(2)) before beginning a behavioral weight-loss intervention. RESULTS: After controlling for body weight, multivitamin use, oral contraceptive/estrogen use, and calcium and magnesium intake, women who had a history of weight cycling did not have significantly lower total-body bone mineral content or density or total femur bone mineral density. In addition, 99% of subjects were above or within one SD of age and gender normative data for total femur bone mineral density. DISCUSSION: It does not seem that a history of weight cycling has an adverse affect on total femur and total-body bone mineral density in overweight sedentary premenopausal women.     

Lactation history and bone mineral density among perimenopausal women.

To examine the relation between lactation and bone mineral density, we conducted a cross-sectional study among white, nonsmoking, perimenopausal women age 40-54. Three hundred fifty-two women completed a questionnaire covering medical and reproductive histories, physical activity, and diet. We measured the bone density of lumbar vertebrae 2-4 with dual photon absorptiometry, and the midradius and distal radius with single photon absorptiometry. Women with a history of lactation had 41 mg per cm2 higher lumbar bone mineral density than women with no lactation (95% confidence interval = 8-74 mg per cm2), controlling for parity, body mass, physical activity, and menopausal status. We found no important increase at mid- or distal radius.     

Menstrual cycle and food cravings in young college women

The effect of the menstrual cycle on food cravings was examined in a population of 83 young college women during a 6-week longitudinal study. Food cravings and menstrual symptoms were evaluated by measuring subject responses in weekly questionnaires ("craving sheets"). The women were not told that the central objective of the study was to examine the effects of the menstrual cycle on food cravings. The menstrual cycle was divided into four stages: menstrual flow; the first half of the cycle, excluding menstrual flow; the second half of the cycle, excluding the premenstrual phase; and 1 week premenstrual. Cravings for 32 foods were examined on a weekly basis under controlled environmental conditions. Foods tested were categorized according to common characteristics. The women exhibited a greater preference for chocolate foods during menstrual flow than during the other menstrual stages. Cravings for high-sugar foods, high-starch foods, or lower carbohydrate foods were not significantly affected by the stage of the menstrual cycle.     

Oral contraceptive use and bone density in adolescent and young adult women

Background

Most of the millions of oral contraceptive (OC) users are under 30 years of age and in the critical period for bone mass accrual.

Study Design

This cross-sectional study of 606 women aged 14-30 years examined both OC duration and estrogen dose and their association with bone mineral density (BMD) at the hip, spine, and whole body (dual-energy X-ray absorptiometry).

Results

Of 389 OC users and 217 nonusers enrolled, 50% were adolescents (14-18 years). Of OC users, 38% used “low-dose” OCs [<30 mcg ethinyl estradiol (EE)]. In adolescents, mean BMD differed by neither OC duration nor EE dose. However, 19- to 30-year-old women's mean BMD was lower with longer OC use for spine and whole body (p=.004 and p=.02, respectively) and lowest for >12 months of low-dose OCs for the hip, spine and whole body (p=.02, .003 and .002, respectively).

Conclusions

Prolonged use of today's OCs, particularly <30 mcg EE, may adversely impact young adult women's bone density while using these agents.     

Nutrition, mild hyperparathyroidism, and bone mineral density in young Japanese women

BACKGROUND: The adverse effects of poor nutrition on the bones of young Asian women have not been fully elucidated. OBJECTIVE: The purpose of this study was to investigate possible associations of vitamin D nutrition, calcium intake, and other nutrients with bone metabolism and bone mass in young Japanese women. DESIGN: The subjects were 108 female college students aged 19-25 y. Dietary nutrients were measured by using the duplicate sampling method on 3 weekdays. Serum 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone, and bone turnover markers were also measured. Bone mineral density (BMD) of the spine and femur was measured by dual-energy X-ray absorptiometry. RESULTS: The proportions of the subjects with low 25(OH)D (< 30 nmol/L) and high intact parathyroid hormone (> or = 6.9 pmol/L) concentrations were 32.4% and 15.7%, respectively. Serum 25(OH)D concentrations (P = 0.0265) and calcium intake (P = 0.0103) were inversely associated with serum intact parathyroid hormone. In addition to weight and physical activity, the presence of mild hyperparathyroidism was associated with a low BMD of the lumbar spine (P = 0.0062) and the femoral neck (P = 0.0250), and a low calcium intake was associated with a low BMD of the femoral neck (P = 0.0044). CONCLUSIONS: Low calcium intake (based on low BMD of the femoral neck only) and mild hyperparathyroidism (based on low BMD of both the femoral neck and lumbar spine), partly explained by low vitamin D nutrition and a low calcium intake, are important predictors of low BMD in young Japanese women. Effects of poor nutrition and mild hyperparathyroidism on bone peak bone mass in young women should be further investigated in longitudinal studies.     

Previous milk consumption is associated with greater bone density in young women

BACKGROUND: Dietary calcium and milk intakes at specific ages may influence bone mineral measures at specific sites during development of peak bone mass. OBJECTIVE: Relations of previous milk intake and current calcium intake to current bone mineral measures were investigated in young women. DESIGN: A food-frequency interview and recall of previous milk intake from early childhood to 12 y of age and during adolescence (13-19 y) were completed in a cross-sectional analysis in young women (age 18-31 y; n = 224). Three levels of previous milk intake were defined: 1) infrequently or never, 2) sometimes, and 3) at every or almost every meal. Total body (TB), femoral neck, radius (R), and spine (S) bone mineral density (BMD) and bone mineral content (BMC) were determined by using dual-energy X-ray absorptiometry. RESULTS: Childhood and adolescent milk intakes were positively correlated (r = 0.66). Childhood and adolescent milk intakes correlated with current calcium intakes (r = 0.26 and 0.33, respectively). Adolescent milk intake correlated with RBMD (r = 0.16). When weight was controlled for, adolescent milk intake correlated with TBBMD (r = 0.16), TBBMC (r = 0.21), SBMC (r = 0.16), RBMD (r = 0.18), and RBMC (r = 0.15). Current calcium intakes correlated with SBMC (r = 0.17). Regression analyses supported these results. CONCLUSIONS: Results were consistent with the hypothesis that higher milk intake during adolescence is associated with greater total body, spine, and radial bone mineral measures during development of peak bone mass, whereas current calcium intakes may influence SBMC. In addition, milk intake at a younger age may contribute to similar habits of milk intake later in life.     

Menstrual cycle and voluntary food intake in young Chinese women.

The effect of menstrual cycle phase on energy and macronutrients intakes was assessed in 20 university students (21.2+/-1.3 years) all of whom experienced ovulatory cycle as documented by a surge in urinary luteinizing hormone. Three-day food intake records, which consisted of one weekend day, were kept in both mid-follicular and mid-luteal phases. Mean daily energy intake was higher (p=0.02) in the luteal phase (6978+/-1847 kJ) than in the follicular phase (6095+/-1174 kJ). Intakes of carbohydrate and fat were also significantly elevated (by 15 and 21%, respectively) in the luteal phase. The menstrual phase effect on energy intake was attributed to the substantially higher intakes from Thursday through Sunday in the luteal phase. The proportion of energy from the three macronutrients was not affected by menstrual phase nor day of the week.     

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.     

Relationship between vitamin K status, bone mineral density, and hs-CRP in young Korean women

Vitamin K intake has been reported as an essential factor for bone formation. The current study was conducted under the hypothesis that insufficient vitamin K intake would affect inflammatory markers and bone mineral density in young adult women. The study was a cross-sectional design that included 75 women in their 20s. Physical assessments, bone mineral density measurements, 24-hr dietary recalls, and biochemical assessments for high sensitivity C-reactive protein (hs-CRP) and percentages of undercarboxylated osteocalcin (%ucOC) were performed. An analysis of vitamin K nutritional status was performed comparing first, second, and third tertiles of intake based on %ucOC in plasma. Vitamin K intake levels in the first, second, and third tertiles were 94.88 ± 51.48 µg, 73.85 ± 45.15 µg, and 62.58 ± 39.92 µg, respectively (P < 0.05). The T-scores of the first and third tertiles were 1.06 and -0.03, respectively, indicating that bone mineral density was significantly lower in the group with lower vitamin K intake (P < 0.05). There was a tendency for different serum hs-CRP concentrations between the first (0.04 ± 0.02) and third tertiles (0.11 ± 0.18), however this was not statistically significant. Regression analysis was performed to identify the correlations between vitamin K nutritional status, inflammatory markers, and bone mineral density after adjusting for age and BMI. Serum hs-CRP concentrations were positively correlated with vitamin K deficiency status (P < 0.05). And bone mineral density, which was represented by speed, was negatively correlated with vitamin K deficiency status (P < 0.05). In conclusion, status of vitamin K affects inflammatory status and bone formation. Therefore, sufficient intake of vitamin K is required to secure peak bone mass in young adult women.     

Chocolate consumption and bone density in older women

BACKGROUND: Nutrition is important for the development and maintenance of bone structure and for the prevention of osteoporosis and fracture. The relation of chocolate intake with bone has yet to be investigated. OBJECTIVE: We investigated the relation of chocolate consumption with measurements of whole-body and regional bone density and strength. DESIGN: Randomly selected women aged 70-85 y (n=1460) were recruited from the general population to a randomized controlled trial of calcium supplementation and fracture risk. We present here a cross-sectional analysis of 1001 of these women. Bone density and strength were measured with the use of dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and quantitative ultrasonography. Frequency of chocolate intake was assessed with the use of a questionnaire and condensed into 3 categories: <1 time/wk, 1-6 times/wk, >or=1 time/d. RESULTS: Higher frequency of chocolate consumption was linearly related to lower bone density and strength (P<0.05). Daily (>or=1 times/d) consumption of chocolate, in comparison to <1 time/wk, was associated with a 3.1% lower whole-body bone density; with similarly lower bone density of the total hip, femoral neck, tibia, and heel; and with lower bone strength in the tibia and the heel (P<0.05, for all). Adjustment for covariates did not influence interpretation of the results. CONCLUSIONS: Older women who consume chocolate daily had lower bone density and strength. Additional cross-sectional and longitudinal studies are needed to confirm these observations. Confirmation of these findings could have important implications for prevention of osteoporotic fracture.     

Influence of smoking and oral contraceptives on bone mineral density and bone remodeling in young women: a 2-year study

The objective of the study was to explore the influence of menstrual irregularities, oral contraceptives and smoking on bone mineral density (BMD) development and bone turnover with time. Healthy young women (n = 118) were divided into four categories: (a) women neither smoking nor using oral contraceptives; (b) women who were smokers; (c) women using oral contraceptives; (d) women who were smoking and using oral contraceptives. They responded to a validated questionnaire with 34 questions concerning lifestyle and the Sense of Coherence scale (SOC). BMD was measured by dual energy x-ray absorptiometry (DEXA). Deoxypyridinoline (DPD) was measured in urine. Data were analyzed by multiple linear regression analysis. Among smokers, BMD level decreased during a 2-year period and smoking was associated with a larger negative change in BMD. Use of oral contraceptives moderated the negative impact of smoking. Women using oral contraceptives at baseline and with regular bleeding induced by contraceptive pills had a significantly higher BMD at baseline and at follow-up. They also had lower SOC than women who had natural regular bleedings. Use of oral contraceptives in combination with smoking was linked to high alcohol consumption and higher frequency of self-reported body weight reduction, which reduced the negative BMD change in this category. DPD level and difference were strongly associated with estrogen influence. It is concluded that smokers without OCs had a negative BMD development and BMD in young women with irregular menstruations seems to be improved by OC.     

Factors affecting bone density in young adults.

A 14-y follow-up of 581 children who took part in a randomized controlled trial of the effect of a milk supplement on growth of children was conducted to investigate the supplement's effect on adult bone mineral content (BMC) and density (BMD). BMC and BMD of the nondominant forearm were measured by single-photon absorptiometry in 371 subjects (64%) aged 20-23 y, at a proximal site (shaft of radius and ulna) and at a distal site near the wrist. BMCs and BMDs tended to be higher in the intervention group (NS). Cross-sectionally, BMD was positively associated with body weight (P less than 0.01) in both sexes; inversely associated with alcohol consumption (P less than 0.05), and positively with manual occupation (NS) in men; positively associated with current intakes of calcium (P less than 0.05), vitamin D (P less than 0.01), and sports activity during adolescence (P less than 0.01), and inversely with parity (NS) in women. In multiple linear-regression analysis body weight and sports activity during adolescence were stronger determinants of female BMD than was diet.     

女性人群骨密度分布描述及其预测模型的研究

目的通过了解农村地区成年女性人群骨矿物质密度随年龄的变化趋势及年龄、身高、体重、绝经年限对骨密度的独立作用,建立骨密度的预测模型。方法根据统一的问卷收集了3008对农村女性双生子的人口学特征及环境资料,利用美国Norland公司生产的外周双能X光吸收骨密度仪(pDXA)测定腰椎、髋部及前臂近端桡骨骨密度。采用SAS6·12软件包及SPLUS进行数据分析。结果研究的结局变量为腰椎、股骨颈、股骨三角区、大转子、手臂骨及全身骨6个部位的骨密度。不同部位的骨密度值在年龄上的分布趋势类似,但它们达到骨峰值的年龄及骨丢失上存在着区别:以小梁骨为主要成份的骨密度达骨峰值年龄较早,并先出现骨丢失,骨丢失率较高;年龄、绝经年限、身高、体重在整个年龄段中对骨密度的独立作用不呈线性关系;将人群分成3个年龄段,建立年龄、绝经年限、身高及体重对各部位的预测模型,经检验,这些预测模型所获得的估计值与实际值较为接近。结论预测模型能较好地利用一些易测量的指标来预测个体的骨密度值,为中国农村地区女性人群的骨质疏松症诊断提供了简便的手段。     

绝经后妇女体力活动水平与骨密度的关系

目的检验绝经后妇女体力活动(PA)总量及不同强度PA与骨密度(BMD)和骨盐含量(BMC)的关联。方法从广州市社区招募315名50～70岁停经妇女。通过面对面访问调查其日常PA情况及一般情况和膳食情况等相关协变量。采用双能X-光骨密度仪检测全身、腰椎(L1-L4)及左侧股骨(总股骨、股骨颈、大粗隆、股骨干和Wards区)的BMD和BMC。结果以PA能量代谢当量(MET值)进行三等分位法分组,协方差分析结果显示总体上各部位BMD和BMC随PA总量增加而呈增高的趋势。PA总量低、中、高水平组全身BMD的均值(SE)分别为(1.045±0.008),(1.043±0.008),(1.068±0.008)g/cm2,高PA组显著高于低和中PA组(P=0.049和0.028)。其他部位BMD在三组间无统计学差异意义(P>0.05)。高PA组总股骨、股骨颈、股骨干和Wards区的BMC显著高于低PA组(P=0.004～0.042)。不同强度PA对BMD影响不同,低强度PA越少、中等强度PA越多以及适量的高强度PA均增加BMD。结论较高的PA水平,尤其是增加中等强度和适量的高强度PA更有利于绝经后妇女的骨质健康。     

Eating restraint is negatively associated with biomarkers of bone turnover but not measurements of bone mineral density in young women

Relationships among bone mineral density (BMD), bone turnover markers, cortisol, calcium and vitamin D intakes, and cognitive eating restraint score were examined. Sixty-five healthy women, ages 18 to 25 years, had total body, spine, hip, and forearm BMD measured by dual-energy x-ray absorptiometry. Serum osteocalcin, urinary cross-linked N-telopeptide of type I collagen (NTx), and salivary cortisol were measured, and intakes of calcium and vitamin D were estimated from questionnaires. Cognitive eating restraint scores were determined from the Eating Inventory. Associations between measures were analyzed by Pearson correlations; predictors of BMD and bone turnover markers were tested using stepwise regression. Serum osteocalcin (P<0.01) and urinary NTx (P<0.05) were negatively related to cognitive eating restraint score. Intakes of calcium (P<0.05) and vitamin D (P<0.05) were associated with forearm BMD. Regression analyses indicated that vitamin D intake predicted total body (P<0.08) and forearm (P<0.01) BMD. Negative associations between cognitive eating restraint score and bone biomarkers suggest a reduction in bone remodeling, not reflected in current BMD.     

深圳市20～30岁健康女性超声骨密度测定

目的:了解深圳地区20～30岁正常年轻女性超声骨密度状况,确定该年龄段女性超声骨密度正常参考值,为骨质疏松症的超声诊断标准提供科学依据。方法:选择20～30岁深圳居住的正常女性280例为检测对象,以每周岁分组共分为11组,用定量超声骨密度仪(QUS)测定受检者足跟部骨密度(BMD)值,同时测量受检者身高、体重、体重指数(BMI)。结果:20～30岁健康女性BMD值随年龄增长变化不大,骨峰值年龄出现在25岁组和26岁组,但除了与29岁组比较有统计学意义外,与其它各组之间比较无统计学意义。身高、体重、BMI和BMD变化无相关性(分别r=0.098,P>0.05;r=0.004,P>0.05;r=-0.062,P>0.05),差异均无显著性意义。结论:20～30岁正常女性体重、身高、BMI和足跟部BMD值之间均无显著相关性,本研究获得的BMD值将为确定我国正常女性超声骨密度的参考值和骨质疏松症的超声诊断标准提供重要的参考依据。     

Tea drinking and bone mineral density in older women

BACKGROUND: High caffeine intake is reportedly a risk factor for reduced bone mineral density (BMD) in women. Most studies, however, are from populations in which coffee drinking predominates and is the major caffeine source. Tea contains caffeine but also has other nutrients, such as flavonoids, that may influence bone mass in different ways. OBJECTIVE: We examined the relation between tea drinking and BMD in older women in Britain, where tea drinking is common. METHODS: We measured BMD at the lumbar spine, femoral neck, greater trochanter, and Ward's triangle in 1256 free-living women aged 65-76 y in Cambridge, United Kingdom. Tea drinking was assessed by self-completed questionnaire and women were categorized as tea drinkers or non-tea drinkers. RESULTS: There were 1134 tea drinkers (90.3%) and 122 non-tea drinkers (9.7%). Compared with non-tea drinkers, tea drinkers had significantly greater ( approximately 5%) mean BMD measurements, adjusted for age and body mass index, at the lumbar spine (0.033 g/cm(2); P = 0.03), greater trochanter (0.028 g/cm(2); P = 0.004), and Ward's triangle (0.025 g/cm(2); P = 0.02). Differences at the femoral neck (0.013 g/cm(2)) were not significant. These findings were independent of smoking status, use of hormone replacement therapy, coffee drinking, and whether milk was added to tea. CONCLUSIONS: Older women who drank tea had higher BMD measurements than did those who did not drink tea. Nutrients found in tea, such as flavonoids, may influence BMD. Tea drinking may protect against osteoporosis in older women.     

Menstrual history and risk of hip fractures in postmenopausal women. The Iowa Women's Health Study

The authors examined prospectively between 1986 and 1997 the relation of irregular menstrual cycles and irregular menstrual bleeding duration earlier in life with risk of hip fracture in 33,434 postmenopausal Iowa women. Over the 318,522 person-years of follow-up, 523 hip fractures were reported. Adjusted for age, smoking, body mass index, waist/hip ratio, and estrogen use, the relative risk of hip fracture in women who reported always having irregular menstrual cycles, compared with women who never had irregular cycles, was 1.36 (95% confidence interval (CI): 1.03, 1.78). Women who reported having irregular menstrual bleeding duration had a 1.40-fold (95% CI: 1.10, 1.78) increased risk of hip fracture compared with women with regular bleeding duration. In addition, women who reported having both irregular menstrual cycles and irregular menstrual bleeding had a 1.82-fold (95% CI: 1.55, 2.15) higher risk of hip fracture than did women who reported neither irregularity. Women who reported only one menstrual disturbance did not have a risk of hip fracture that was significantly different from women who reported no menstrual disturbances. The authors conclude that women with menstrual irregularities are at increased risk of hip fracture, probably because they are estrogen or progesterone deficient.     

An exploratory study of depot-medroxyprogesterone acetate and bone mineral density in adolescent and young adult women with cerebral palsy

ObjectiveTo explore whether use of depot-medroxyprogesterone acetate (DMPA) in adolescent and young adult females with cerebral palsy is associated with lower bone mineral density (BMD).MethodsA chart review of adolescent and young adult females with cerebral palsy who had undergone dual-energy X-ray absorptiometry, comparing BMD among those with (n = 19) and without DMPA (n = 84) exposure.ResultsBMD was similar in patients with and without DMPA exposure. All patients had low BMD, with average Z-scores of less than −2 at most sites.ConclusionResults suggest that DMPA is not associated with lower BMD in non-ambulatory adolescent and young adult females with cerebral palsy.