Bone mineral density in adolescent females with recently diagnosed anorexia nervosa

Anorexia nervosa (AN) can lead to osteoporosis and fractures. OBJECTIVE: This study evaluated adolescent females with AN diagnosed within the previous 12 months to determine whether there is bone mass reduction and to investigate relationships between nutritional indices (weight, body mass index [BMI], lean mass, fat mass, and percentage fat) and total body (TB) and lumbar spine (LS) bone mineral densities (BMD) and content (BMC). METHOD: TB and LS BMD and BMC and body composition were measured in 24 adolescent females with AN. RESULTS: There was no significant reduction in TB or LS BMD. Regression analysis shows significant correlation (p < 0.001) between lean mass and TB BMD (r = +0.83), TB BMC (r = +0.92), LS BMD (r = +0.81), and LS BMC (r = +0.92). There was also a significant relationship between weight percentile and LS BMD z score (p < 0.005; r = +0.60). DISCUSSION: Adolescent females with early AN do not appear to have reduced bone mass. Lean mass is correlated to BMD and BMC.     

Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study

BACKGROUND: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear. OBJECTIVE: We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women. DESIGN: We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y. Analyses were performed on 3 data sets: study 1, 83 female twin pairs (21 monozygous and 62 dizygous) aged (x +/- SD) 42.2 +/- 15.5 y who were discordant for ever having been pregnant beyond 20 wk; study 2, 498 twin pairs aged 42.3 +/- 15.0 y; and study 3, 1354 individual twins, their siblings, and family members. RESULTS: In study 1, there were no significant within-pair differences in unadjusted BMD or BMD adjusted for age, height, and fat mass at the lumbar spine or total-hip or in total-body bone mineral content (BMC; kg) (paired t tests). In study 2, there was no significant within-pair difference in measures of bone mineral or body composition related to the within-pair difference in number of pregnancies. In study 3, subjects with 1 or 2 (n = 455) and > or = 3 pregnancies (n = 473) had higher adjusted lumbar spine BMD (2.9% and 3.8%, respectively; P = 0.001) and total-body BMC (2.2% and 3.1%; P < 0.001) than did nulliparous women (n = 426). Parous women who breast-fed had higher adjusted total-body BMC (2.6%; P = 0.005), total-hip BMD (3.2%; P = 0.04), and lower fat mass (10.9%; P = 0.01) than did parous non-breast-feeders. CONCLUSION: We found no long-term detrimental effect of pregnancy or breast-feeding on bone mineral measures.     

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。     

Excess body fat negatively affects bone mass in adolescents

ObjectiveThe aim of this study was to investigate the effects of excess body fat on bone mass in overweight, obese, and extremely obese adolescents.MethodsThis study included 377 adolescents of both sexes, ages 10 to 19 y. Weight, height, body mass index (BMI), bone age, bone mineral content (BMC), and bone mineral density (BMD) were obtained by dual-energy x-ray absorptiometry. The results were adjusted for chronological age and bone age. Comparisons according to nutritional classification were performed by analysis of variance, followed by Tukey test. Linear regression models were used to explain the variation in BMD and BMC in the L1–L4 lumbar spinal region, proximal femur, and whole body in relation to BMI, lean mass, fat mass (FM), and body fat percentage (BF%), considering P < 0.05.ResultsFor all nutritional groups, average bone age was higher than chronological age. In both sexes, weight and BMI values increased from eutrophic to extremely obese groups, except for BMD and BMC, which did not differ among male adolescents, and were smaller in extremely obese than in obese female adolescents (P < 0.01). Significant differences were observed for FM and BF% values among all nutritional groups (P < 0.01). Positive, moderate to strong correlations were detected between BMD and BMC for BMI, lean mass, and FM. A negative and moderate correlation was found between BMC and BF%, and between BMD and BF% at all bone sites analyzed in males and between BF% and spine and femur BMD, in females.ConclusionThe results reveal a negative effect of BF% on bone mass in males and indicate that the higher the BF% among overweight adolescents, the lower the BMD and BMC values.     

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.     

膳食钙、磷以及奶制品对绝经后妇女骨密度的影响

目的探讨膳食中钙、磷以及奶制品的摄入量对骨密度及骨盐含量的影响,为研究骨质疏松的预防提供相关线索和依据。方法在广州市越秀区农林街社区发放传单招募调查对象,并采用自编的结构化标准问卷,对320名广州绝经后妇女的膳食习惯进行调查,并测量其全身、股骨全身、股骨颈、股骨干、大粗隆、Ward’s三角以及腰锥1～4的骨密度和骨量,采用多因素逐步回归分析探讨膳食钙、磷及奶制品对骨盐含量及骨密度的影响。结果 320名调查对象平均57.1岁,平均绝经年限7.3年,平均每天摄入钙、磷及奶制品分别为822 mg、949 mg和126 g,平均全身骨密度为1.054 g/cm2,磷与7个部位的骨密度及骨盐含量呈正相关关系（P〈0.05）。随着磷摄入量增加,全身及腰锥1～4骨密度增加,偏回归系数值分别为0.121和0.184 g.（cm2）-1.g-1.d-1。随着奶制品摄入量增加,股骨全身、股骨干骨密度也相应增加,骨密度偏回归系数值分别为0.686、0.841mg.（cm2）-1.g-1.d-1。钙与全身、股骨全身、股骨颈、大粗隆、股骨干和Ward’s三角的BMC具有正相关性,而在钙与BMD关系中,钙只与股骨全身、大粗隆和股骨干呈正相关性,且每日膳食中每增加100 g钙的摄入量,则股骨全身、大粗隆、股骨干的骨密度相应增加5.3、4.8和7.6 g/cm2。结论增加膳食中钙、磷以及奶制品的摄入量有利于绝经后妇女的骨盐含量及骨密度的提高。     

Skeletal and body-composition effects of anorexia nervosa

Eleven female patients (aged 18-46 y) with anorexia nervosa were measured by use of dual-photon absorptiometry for 1) bone mineral content (BMC, in g) and bone mineral density (BMD, in g/cm2) of the total skeleton and its regions, 2) BMD of the lumbar spine and the proximal femur, and 3) total body soft-tissue composition. The patients weighed 44.4 kg, approximately 15 kg less than normal peers (n = 22). The fat mass (3.35 kg) and content of soft tissue (7.8%) were four and three times lower (p less than 0.001) respectively, than those in normal women (15.1 kg and 26%, respectively). The total skeleton mineral (1921 g) was approximately 25% less than that of young normal women. The BMC as a fraction of the lean tissue mass was approximately 4.9% in the patients and 5.9% in normal women. Total body and femoral BMD averaged only 10% and 13% lower than those of normal women, respectively; however, spinal BMD was particularly reduced (approximately 25%, p less than 0.001).     

Blood pressure and calcium intake are related to bone density in adult males

Based on the premise that elevated blood pressure and low bone mass have both been associated with poor Ca nutriture and disturbances in Ca metabolism, a cross-sectional study was employed to determine if blood pressure and dietary Ca intake were significantly related to bone mass. Forty-seven men between 24-77 years of age with blood pressure values ranging from normal to mildly elevated comprised the study group. Blood pressure was measured with a random-zero sphygmomanometer. Bone mineral content (BMC) and density (BMD) of the hip, spine and total body were measured with dual-photon absorptiometry. Dietary intake and physical activity were also assessed. Multiple linear regression analysis was used for statistical analysis. After adjusting for known confounding variables (age, BMI, Ca intake, and others) diastolic blood pressure was negatively related to BMC (P < or = 0.05) and BMD (P < or = 0.01) of the total body, trochanteric region (P < 0.01) and Ward's triangle (P < 0.05), and to BMC of the femoral neck (P < 0.05) and lumbar spine, although the latter was just shy of statistical significance (P = 0.058). Systolic blood pressure was negatively related to trochanteric BMD (P = 0.04) and BMC (P = 0.06). Ca intake was positively related to total body BMD (P = 0.005), and BMC of the lumbar spine (P = 0.05). In this population of men, Ca intake was a positive predictor, and blood pressure was a negative predictor of regional measures of bone mass. These findings support the concept that independent of age, BMI and Ca intake, elevated blood pressure varies indirectly with bone mass and density, known predictors of osteoporotic fractures. Future studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass, and what role dietary Ca plays in that pathway.     

Fan beam dual energy X-ray absorptiometry body composition measurements in piglets

OBJECTIVES: A piglet model was used to validate and cross validate the fan-beam (FB) dual energy X-ray absorptiometry (DXA) software vKH6 and to determine the predictive values of physiologic parameters (weight, length, age and gender) on body composition. METHODS: Nineteen piglets (Group A: 600 to 21100 g) were used to validate the FB-DXA measurements of body composition based on chemical analysis of the carcass. An additional 22 piglets (Group B: 640 g to 17660 g) had FB-DXA measurements, and these values were compared to the predicted values generated from regression equations computed from group A piglets. Body composition for bone mass, lean mass and fat mass was based on ash weight, nitrogen and fat measured from three aliquots of homogenate from each carcass. Data from all piglets (n = 41) were used to determine the variations in body composition. Data analysis used regression, t test and analysis of variance. RESULTS: Duplicate DXA (total weight TW, bone mineral content BMC, bone area BA, bone mineral density BMD, lean mass LM and fat mass FM) measurements were highly correlated (r = 0.98 to 1.00, p < 0.001 for all comparisons) and were not significantly different. No significant differences were found in the residuals from predicted versus measured DXA values between the larger and the smaller (<1.6 kg) piglets from Group A. For Group B piglets, the DXA measured TW of 5666 +/- 5692 g (mean +/- SD), LM (5063 +/- 5048 g), FM (465 +/- 510 g), BMC (138 +/- 139 g), BA (486 +/- 365 cm(2)) and BMD (0.235 +/- 0.071 g/cm(2)) were highly significantly correlated with (r = 0.94 to 1.00, p < 0.001 for all comparisons) and were not significantly different from the predicted values. Data from all piglets (n = 41) showed that weight is the dominant predictor of whole body and regional body composition. Length, age or gender contributed to <2% of the variability of body composition. CONCLUSION: Body composition measurements using the FB DXA software vKH6 is highly reproducible. The software vKH6 is validated for use in a wide range of body weights and body composition, and cross-validated using a separate group of animals. Body weight is the dominant predictor of body composition in immature piglets.     

Greater fruit and vegetable intake is associated with increased bone mass among postmenopausal Chinese women

Although studies in Caucasian populations have reported the beneficial effects of intakes of fruit and vegetables on bone mass, limited data are available in the Asian populations. We examined the association of the intake of fruits and vegetables with bone mineral density (BMD) in a population-based cross-sectional study of 670 postmenopausal Chinese women aged 48-63 years. Habitual dietary intakes were assessed using a food frequency questionnaire. BMD at the whole body, lumbar spine and left hip were measured with dual-energy X-ray absorptiometry. Univariate regression analyses showed that the total intake of fruits and vegetables was significantly associated with greater BMD at the whole body, lumbar spine (L1-L4), total hip, trochanter and intertrochanter. An independently positive association between fruit and vegetable intake and BMD at the whole body (P = 0.005), lumbar spine (P < 0.001) and total hip (P = 0.024) remained even after adjusting for age, years since menopause, body weight and height, dietary energy, protein and Ca, and physical activities. A daily increase of 100 g fruit and vegetable intake was associated with 0.0062 (95 % CI 0.0019, 0.0105) g/cm2, 0.0098 (95 % CI 0.0041, 0.0155) g/cm2 and 0.0060 (95 % CI 0.0011, 0.0109) g/cm2 increases in BMD at the whole body, lumbar spine and total hip, respectively. In conclusion, greater fruit and vegetable intake is independently associated with better BMD among postmenopausal Chinese women.     

Dose response of bone mass to dietary arachidonic acid in piglets fed cow milk-based formula

BACKGROUND: The addition of arachidonic acid (AA) and docosahexaenoic acid (DHA) to infant formula was recently approved in North America. In piglets, dietary AA is linked to elevations in bone mass. OBJECTIVE: The objective was to investigate the effects of varied amounts of dietary AA on bone modeling and bone mass with the use of the piglet model for infant nutrition. DESIGN: Male piglets (n = 32) were randomly assigned to receive 1 of 4 formulas supplemented with AA (0.30%, 0.45%, 0.60%, or 0.75% of fat) plus DHA (0.1% of fat) from days 5 to 20 of life. Measurements included biomarkers of bone modeling, fatty acid status, and whole-body and femur bone mineral content; bone area was measured by dual-energy X-ray absorptiometry. Differences among groups were detected with two-factor analysis of variance. Regression analyses were used to determine factors responsible for bone mineral content after dietary AA was accounted for. RESULTS: Proportions of AA in plasma, liver, and adipose were modified by the dietary treatments, but bone modeling was not affected. Liver AA was positively related to plasma insulin-like growth factor 1 and calcitriol and urinary N-telopeptide. Whole-body bone mineral content was elevated in the piglets fed 0.60% and 0.75% AA and was best predicted by dietary AA and bone resorption. CONCLUSIONS: This study confirms that dietary AA alters bone mass and clarifies the best amount of AA to add to the diet of pigs born at term. Because the amount of dietary DHA was held constant, whether other amounts of DHA are related to bone mass requires investigation.     

膳食钙摄入量与青春前期女童骨量关系的研究

目的:研究青春前期女童膳食钙摄入量与骨量的关系,为指导合理钙营养提供科学依据。方法:采用双能X线骨密度测量仪测量年龄在10±1岁的194名青春前期女童全身及多位点骨密度和骨矿物质含量,采用食物频数及3d膳食询问法调查膳食钙摄入量,问卷法调查体力活动。结果:日均钙摄入量与所测各位点骨矿物质含量及骨密度均呈显著正相关;日均钙摄入量平均从257mg增加到759mg,不同位点的骨矿物质含量和骨密度分别增加13%～22%和3.6%～16%。结论:增加青春前期女童膳食钙摄入量有助于获得较高骨量和骨密度。     

Modulation of essential (n-6):(n-3) fatty acid ratios alters fatty acid status but not bone mass in piglets

Dietary (n-6) and (n-3) fatty acids have been implicated as important regulators of bone metabolism. The main objective of this research was to define the response of whole-body growth, fatty acid status and bone mass to a reduced dietary (n-6):(n-3) fatty acid ratio. A secondary objective was to determine whether there is an amount of fat x fatty acid ratio interaction for these outcomes. Piglets (n = 32) were randomized to 1 of 4 diets: group 1: [30 g fat/L + (n-6):(n-3) ratio 4.5:1]; group 2: [30 g fat/L + (n-6):(n-3) ratio 9.0:1]; group 3: [60 g fat/L + (n-6):(n-3) ratio 4.5:1]; and group 4: [60 g fat/L + (n-6):(n-3) ratio 9.0:1]. After 21 d, outcomes assessed included growth, fatty acid status and bone mass and metabolism. Growth and bone mass did not differ among the four groups nor did arachidonic acid (AA as g/100 g fatty acids) in plasma, adipose and brain. Piglets fed diets 1 and 3 with the lower (n-6):(n-3) ratio had lower liver AA (P < 0.001). Those fed diets 1 and 2 containing 30 g fat/L had lower docosahexaenoic acid (DHA as g/100 g fatty acids) in liver (P < 0.001), plasma (P = 0.019) and adipose tissue (P = 0.045). However, piglets fed diets 1 and 3 had higher (P < 0.001) brain DHA than those fed diets with a higher (n-6):(n-3) ratio. Higher plasma DHA was associated with less bone resorption (r = -0.44, P = 0.01). Therefore, elevation of dietary (n-3) fatty acids supports growth and fatty acid status while not compromising bone mass. The results may be of relevance to the nutritional management of preterm infants whose DHA status is often too low and bone resorption too high.     

Maternal Vitamin D Status and Gestational Weight Gain as Correlates of Neonatal Bone Mass in Healthy Term Breastfed Young Infants from Montreal,Canada

The implications of maternal gestational weight gain (GWG) and vitamin D status to neonatal bone health are unclear. We tested whether maternal 25-hydroxyvitamin D (25(OH)D) and GWG relate to neonatal bone mineral content (BMC) and bone mineral density (BMD). Healthy term appropriate for gestational age breastfed neonates (n = 142) and their mothers were recruited 24–36 h after delivery and followed at 1.0 ± 0.5 month. At birth, obstetric data were collected and newborn serum 25(OH)D was measured. At 1 month, neonatal whole-body (WB) BMC, WB BMC relative to body weight (WB BMC/kg), lumbar spine BMC and BMD, maternal and neonatal 25(OH)D concentrations, and anthropometry were measured. Infant BMC and BMD between maternal 25(OH)D (<50, ≥50 nmol/L) and GWG (insufficient, adequate, and excessive) categories were compared. Maternal 25(OH)D was not related to infant whole-body BMC, BMC/kg, lumbar spine BMC, and BMD. Infants in the excessive maternal GWG category had greater (p = 0.0003) whole-body BMC and BMC/kg and lumbar spine BMC and BMD than inadequate GWG, and greater (p = 0.0063) whole-body BMC/kg and lumbar spine BMC and BMD than adequate GWG. These results suggest that maternal GWG, but not vitamin D status, modestly relates to bone mass in neonates.     

Birthweight, vitamin D receptor genotype and the programming of osteoporosis

Studies of the association between polymorphisms of the gene for the vitamin D receptor (VDR) and adult bone mass have been inconsistent, pointing to the possibility that gene--environment interactions may vary in different populations. We have demonstrated previously an association between weight in infancy (a marker of the intrauterine and early post-natal environment) and each of adult bone mass and VDR genotype. We therefore sought to extend these observations in an elderly UK cohort and to investigate the possibility of an interaction between these genetic and early environmental markers of later osteoporosis risk. One hundred and sixty-five men and 126 women aged 61--73 years for whom birth records were available underwent bone mass measurements at baseline and follow-up 4 years later. Whole-blood samples were obtained, DNA extracted using standard techniques and polymorphisms in the VDR and collagen type I alpha 1 (Col IA1) genes identified. In the cohort as a whole, there were no significant associations between either birthweight or VDR genotype and bone mineral density (BMD) or bone loss rate at either site. However, the relationship between lumbar spine BMD and VDR genotype varied according to birthweight. Among individuals in the lowest third of birthweight, spine BMD was higher (P = 0.01) in individuals of genotype 'BB' after adjustment for age, sex and weight at baseline. In contrast, spine BMD was reduced (P = 0.04) in individuals of the same genotype who were in the highest third of the birthweight distribution. A significant (P = 0.02) statistical interaction was also found between VDR genotype and birthweight as determinants of BMD. Similar but slightly weaker associations were seen between lumbar spine bone mineral content (BMC) and VDR genotype in the lowest birthweight tertile. When examining the relationship between Col1A1 genotype and bone mass, lumbar spine BMC was higher in individuals of genotype 'Ss' or 'ss' in the lowest birthweight tertile (P = 0.02) after adjustment for age, sex and weight at baseline. These results suggest that genetic influences on adult bone size and mineral density may be modified by undernutrition in utero.     

钙摄入量对青春前期女童骨量增长的影响—两年随机干预实验

目的研究不同钙摄入量对于青春前期女童骨量增长的影响,为该人群钙适宜摄入量的修订提供科学依据。方法以年龄10.0±0.7岁的241名青春前期健康女童为对象,设计普通膳食组、牛奶补充组和钙剂补充组三组,总钙摄入量分别为600、900和1200mg/d,进行2年干预,采用多次称量及3d膳食询问法获得2年间日均膳食钙摄入量,使用双能X线骨密度仪测量干预前后全身、腰椎及近端股骨骨矿物密度和骨矿物含量。结果2年间三组的平均钙摄入量分别为552±61、864±139和1166±207mg/d;日均钙摄入量与全身、多位点骨矿物含量和骨矿物密度显著正相关;当日均钙摄入量达到864mg/d时,全身骨矿物含量增加值显著高于钙摄入量为552mg/d膳食组;当日均钙摄入量达到1166mg/d时,股骨颈骨矿物含量及骨矿物密度和腰椎骨矿物密度的增加值显著高于未达到1166mg/d的干预组。结论9～11.5岁的青春前期女童钙摄入量达到1166mg/d,全身特别是负重部位能获得较高骨矿物含量和骨矿物密度增长,提示青春前期钙适宜摄入量可能为1200mg/d。     

Low bone mass in premenopausal chronic dieting obese women

BACKGROUND: Obese premenopausal women are thought to be at low risk for osteoporosis due to increased body weight and effects of estrogen on weight-bearing bone. OBJECTIVE: To examine the effect of restrained eating on obese women, we examined bone mineral density (BMD) and content (BMC) of the spine and femur in obese women who were restrained eaters, with emphasis on the relationship between BMC and determinants of bone mass, and current eating behaviors, dietary intake, physical activity, and indices of calcium regulation, bone metabolism, stress and inflammation. DESIGN: A total of 78 obese, Caucasian, female, restrained eaters, ages 30-45 y, were enrolled in a weight lose program. Height, weight, bone turnover markers, serum parathyroid hormone (PTH), cortisol, c-reactive protein (CRP), dietary intake, eating behaviors, physical activity, and BMD and BMC were measured. SETTING: This study was conducted at the University of California, in Davis, CA, USA. RESULTS: In all, 31% of women had osteopenia or osteoporosis (OSTEO). In the OSTEO group, 87.5% of women had osteoporosis or osteopenia of the lumbar spine and 12.5% of the women had osteoporosis or osteopenia in femur. A significant positive correlation between BMC and energy expenditure (r=0.256), and a significant negative correlation between BMC and number of times on a weight loss diet (r=-0.250) and cognitive restraint (r=-0.239) were observed. No significant differences were observed between OSTEO women and nonosteoporotic women for current eating behaviors, dietary intake, physical activity habits, bone turnover, calcium regulation, stress, or inflammation. CONCLUSIONS: Obese restrained eaters are at risk for low bone mass. Prior dieting may be responsible. Chronic dieters should be encouraged to decrease their dietary restraint, develop healthy eating habits and increase physical activity.     

绝经后女性血清脂联素与骨转换生化指标的关系

目的探讨绝经后女性血清脂联素(Adiponectin)与骨转换生化指标的关系。方法用酶联免疫吸附试验测定287名40～80岁健康绝经后女性血清脂联素以及血清骨特异性碱性磷酸酶(Bone alkaline phosphatase,BAP)和Ⅰ型胶原交联氨基末端肽(cross-linked N-telopeptide of type I collagen,NTx);用双能X线骨密度扫描仪(dual energy X-ray absorptiometry,DEXA)测定总体、腰椎正位、总髋部骨、左前臂骨密度(bone mineral density,BMD)以及体脂、瘦体质量;分析它们之间的关系。结果BAP与总体骨密度、腰椎BMD、髋部总体BMD、前臂BMD均呈负相关(r=-0.210、-0.236、-0.223、-0.226,P0.05),校正年龄和体质指数后,相关性都依然存在(r=-0.168、-0.187、-0.169、-0.175,P0.05)。NTx与总体BMD、腰椎BMD、髋部总体BMD、前臂BMD均呈负相关(r=-0.238、-0.232、-0.239、-0.221,P0.05),校正年龄和体质指数后,相关性都依然存在(r=-0.201、-0.189、-0.193、-0.185,P0.05)。脂联素与BAP、NTx均呈正相关(r=0.202、0.215,P0.05),校正年龄和体脂后,相关性都依然存在(r=0.169、0.183,P0.05)。脂联素与BAP以二次方程模型拟合程度最好,其最大决定系数(R2)为0.055;脂联素与NTx以二次方程模型拟合程度最好,其最大决定系数(R2)为0.089。绝经后骨质疏松(postmenopausal osteoporosis,PMO)女性血清脂联素水平较年龄相匹配的正常对照组增高(P0.05)。结论血清脂联素水平与骨转换生化指标呈正相关,提示脂联素可能为新型骨转换预测因子。     

甲状旁腺激素基因多态性与钙摄入量对青春期女童骨量增长的交互作用

目的:探讨甲状旁腺激素(PTH)基因多态性与钙摄入量对青春期女童骨量增长的交互作用。方法:选择228名9～11.5岁未月经初潮的健康女童进行2年追踪,用双能X线骨密度仪(DEXA)检测对象追踪前后全身、左侧近端股骨(包括股骨颈、大转子、粗隆间和华氏三角区)、L1～L4腰椎骨矿含量和骨密度,采用PCR-RFLP技术检测PTH基因BstBⅠ位点多态性。结果:BB基因型女童L1～L4腰椎骨矿含量增长率、左侧近端股骨、粗隆间和L1-L4腰椎骨密度增长率均高于含b等位基因女童(P=0.022～0.047)。BB基因型女童在高钙摄入(>950mg/d)时,粗隆间骨矿含量(ITBMC)增长率较中等和低钙摄入时分别高29.4%和35.0%,股骨颈骨密度(FNBMD)增长率分别高66.7%和46.2%。而含b等位基因女童的ITBMC和FNBMD增长率在不同钙摄入量之间没有显著性差异。结论:PTH基因BstBⅠ多态性与钙摄入量对青春期女童骨量增长存在交互作用,BB基因型女童高钙摄入可促进其骨量增长。     

绝经后女性血清脂肪因子瘦素、抵抗素、内脂素及Apelin与骨转换生化指标的关系

目的探讨绝经后女性血清脂肪因子瘦素(Leptin)、抵抗素(Resistin)、内脂素(Visfatin)及Apelin与骨转换生化指标的关系。方法酶联免疫吸附试验测定287名40～80岁健康绝经后女性血清Leptin、Resistin、Visfatin和Ape-lin,以及血清骨特异性碱性磷酸酶(Bonealk aline phosphatase,BAP)和Ⅰ型胶原交联氨基末端肽(cross-linked N-telopep-tide of type I collagen,NTx);用双能X线骨密度扫描仪(dual energy X-ray absorptiometry,DEXA)测定总体、腰椎正位、左前臂、总髋部骨密度(bone mineral density,BMD)以及体脂、瘦体质量;以方差分析、直线相关(Pearson)分析它们之间的关系。结果BAP与总体BMD、腰椎BMD、髋部总体BMD、前臂BMD均呈负相关(r=-0.210、-0.236、-0.223、-0.226,P0.05),校正年龄和BMI后,相关性都依然存在(r=-0.168、-0.187、-0.169、-0.175,P0.05)。NTx与总体BMD、腰椎BMD、髋部总体BMD、前臂BMD均呈负相关(r=-0.238、-0.232、-0.239、-0.221,P0.05),校正年龄和BMI后,相关性依然存在(r=-0.201、-0.189、-0.193、-0.185,P0.05)。Leptin、Resistin、Visfatin、Aplein与BAP、NTx相关差异均无统计学意义。绝经后骨质疏松女性与健康对照组间血清Leptin、Resistin、Visfatin、Apelin水平差异无统计学意义(P0.05)。结论Leptin、Resistin、Visfatin及Apelin不是骨代谢的关键调控因子。