The Lichfield bone study: the skeletal response to exercise in healthy young men

The skeletal response to short-term exercise training remains poorly described. We thus studied the lower limb skeletal response of 723 Caucasian male army recruits to a 12-wk training regime. Femoral bone volume was assessed using magnetic resonance imaging, bone ultrastructure by quantitative ultrasound (QUS), and bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) of the hip. Left hip BMD increased with training (mean ± SD: 0.85 ± 3.24, 2.93 ± 4.85, and 1.89 ± 2.85% for femoral neck, Ward's area, and total hip, respectively; all P < 0.001). Left calcaneal broadband ultrasound attenuation rose 3.57 ± 0.5% (P < 0.001), and left and right femoral cortical volume by 1.09 ± 4.05 and 0.71 ± 4.05%, respectively (P = 0.0001 and 0.003), largely through the rise in periosteal volume (0.78 ± 3.14 and 0.59 ± 2.58% for right and left, respectively, P < 0.001) with endosteal volumes unchanged. Before training, DXA and QUS measures were independent of limb dominance. However, the dominant femur had higher periosteal (25,991.49 vs. 2,5572 mm(3), P < 0.001), endosteal (6,063.33 vs. 5,983.12 mm(3), P = 0.001), and cortical volumes (19,928 vs. 19,589.56 mm(3), P = 0.001). Changes in DXA, QUS, and magnetic resonance imaging measures were independent of limb dominance. We show, for the first time, that short-term exercise training in young men is associated not only with a rise in human femoral BMD, but also in femoral bone volume, the latter largely through a periosteal response.     

The effect of voluntary exercise on bone mineral density and skeletal muscles in the rat model at ovariectomized and sham stages

The changes of bone mineral density (BMD) and skeletal muscles were evaluated in the rat model at either sham or ovariectomized stages to attempt to make clear the effect of voluntary running exercise on bone metabolism. In comparison with the control groups within the ovariectomized (OVX) and the sham groups, in the running groups, (1) the urinary phosphorus (P) and creatinine (Cr) excretions showed an increase concurrently with the increase in the running distance; (2) the weight of the quadriceps femoris was significantly higher; and (3) the BMD of appendicular and axial bones was significantly greater. These results suggest that voluntary running exercise could effect the BMD, the weight of the skeletal muscles, and the acceleration of energy metabolism.     

Pregnancy-associated changes in bone density and bone turnover in the physiological state: prospective data on sixteen women.

Areal bone mineral density (BMD, g/cm 2) was measured for the total body, lumbar spine and hip with dual-energy x-ray absorptiometry (DXA) before pregnancy and after delivery in sixteen women aged 21 - 35 years. Additional measurements included quantitative ultrasound indices (broadband ultrasound attenuation, BUA, at the calcaneus at baseline and at 16, 26, and 36 weeks of pregnancy, and postpartum) as well as biochemical markers of bone formation and resorption (measured before pregnancy and during pregnancy at 16, 22, 26, 30, 34, and 36 weeks of pregnancy and postpartum). The results of measurements were as follows: 1. Postpartum BMD showed a significant reduction in the total body (- 13.4 %), in the spine (- 9.2 %) and in the hip (-7.8 % at the femoral neck and - 9.2 % at the Ward's triangle) compared to pre-pregnancy values. 2. Biochemical markers of bone resorption increased by 26 weeks. 3. Bone ultrasound measurements that provide information on bone density before delivery did not change throughout pregnancy. A significant reduction of BUA (- 14.5 % compared to baseline) was observed postpartum only. These data would suggest that pregnancy-induced bone loss develops rapidly after the 36 week of pregnancy, possibly via enhanced bone resorption.     

The effects of weight loss on relative bone mineral density in premenopausal women

Objective:

This study compared BMD relative to body weight following a ～6‐month weight loss program and a 1‐year weight maintenance phase in premenopausal women and determined whether African American (AA) and European‐American (EA) women's BMD respond similarly during weight loss.

Design and Methods:

Premenopausal women (n = 115, 34 ± 5 years) were evaluated in an overweight state (BMI between 27 and 30 kg/m²), following an 800 kcal/day diet/exercise program designed to reduce BMI<25 kg/m², and 1‐year following weight loss.

Results:

BMD relative to body weight (Z‐scores) increased after weight loss, but decreased during the 1‐year weight maintenance phase. All 1‐year follow‐up BMD Z‐scores were increased (except L1) compared to baseline measurements (P < 0.05). These sites included the hip neck (+0.088, P = 0.014), total hip (+0.099, P = 0.001), L2 (+0.127, P = 0.013), L3 (+0.135, P = 0.014), and L4 (+0.199, P = 0.002). AAs had significantly higher absolute BMD at all sites (P < 0.05) compared to EAs, but no time by race interactions were evident during weight loss (except in L3).

Conclusion:

These results may indicate that weight loss is safe with regard to bone health for overweight premenopausal women.     

Resistance exercise as a countermeasure to disuse-induced bone loss.

During spaceflight, skeletal unloading results in loss of bone mineral density (BMD). This occurs primarily in the spine and lower body regions. This loss of skeletal mass could prove hazardous to astronauts on flights of long duration. In this study, intense resistance exercise was used to test whether a training regimen would prevent the loss of BMD that accompanies disuse. Nine subjects (5 men, 4 women) participated in a supine maximal resistance exercise training program during 17 wk of horizontal bed rest. These subjects were compared with 18 control subjects (13 men, 5 women) who followed the same bed rest protocol without exercise. Determination of treatment effect was based on measures of BMD, bone metabolism markers, and calcium balance obtained before, during, and after bed rest. Exercisers and controls had significantly (P < 0.05) different means, represented by the respective following percent changes: lumbar spine BMD, +3% vs. -1%; total hip BMD, +1% vs. -3%; calcaneus BMD, +1% vs. -9%; pelvis BMD, -0.5% vs. -3%; total body BMD, 0% vs. -1%; bone-specific alkaline phosphatase, +64% vs. 0%; alkaline phosphatase, +31% vs. +5%; osteocalcin, +43% vs. +10%; 1,25 dihydroxyvitamin D, +12% vs. -15%; parathyroid hormone intact molecule, +18% vs. -25%; and serum and ionized calcium, -1% vs. +1%. The difference in net calcium balance was also significant (+21 mg/day vs. -199 mg/day, exercise vs. control). The gastrocnemius and soleus muscle volumes decreased significantly in the exercise group, but the loss was significantly less than observed in the control group. The results indicate that resistance exercise had a positive treatment effect and thus might be useful as a countermeasure to prevent the deleterious skeletal changes associated with long-duration spaceflight.     

Accelerated vertebral bone loss in relation to the menopause: a cross-sectional study on lumbar bone density in 286 women of 46 to 55 years of age

Bone mineral density (BMD) of the lumbar spine was measured in 286 women (46–55 years of age) using dual photon absorptiometry. The women were classified in three categories: premenopausal, perimenopausal and postmenopausal. The postmenopausal group was subdivided according to the number of years since the last uterine bleeding. with multiple linear regression analysis of lumbar BMD on age and menopausal status, an acceleration of bone loss was observed during the perimenopausal period and the following first two postmenopausal years. No significant bone loss was detected in relation to age or during the later postmenopausal years. Applying both an additive and a multiplicative model of bone loss, the mean perimenopausal bone loss was 0.061 gramequivalents hydroxyapatite (geqHA)/cm² and 6.4%, respectively. In the first 2 postmenopausal years the mean bone loss was 0.044 geqHA/cm² and 5.1% per year. These results suggest a substantial menopause related acceleration of lumbar bone loss in a relatively short time span with its onset in the perimenopausal period.     

The pathophysiological implications of circulating androgens on bone mineral density in a normal female population

In this cross-sectional study performed on 147 healthy or osteoporotic, but otherwise normal premenopausal (n = 26 and n = 13, respectively) or postmenopausal (n = 40 and n = 68, respectively) women aged 40.1+/-9.9 and 61.9+/-8.9 years, respectively (range 20-82 years), serum ovarian and adrenal sex steroids and their relationship to bone mineral density (BMD) were evaluated. The levels of dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), androstenedione (AD), and estradiol correlated positively with BMD at the hip and spine as did serum testosterone with BMD at the spine. An inverse relationship was found between sex hormone binding globulin (SHBG) levels and BMD at the spine and hip. After adjustment for age, body mass, and sex steroid confounders, the bioavailable testosterone value (but not the DHEAS, DHEA, AD, or SHBG) values was demonstrated to be an independent determinant of BMD at the spine (beta 0.18, P<0.02) and hip (beta 0.24, P<0.02). Similarly, estradiol was found to be an independent determinant of BMD at the spine (beta 0.25, P<0.007). However, only SHBG levels (but not other steroid parameters) correlated positively with indices of bone remodeling, namely, serum osteocalcin and cross-linked telopeptide of type I collagen (ICTP). The present study suggests that a major decline in index of free testosterone (testosterone/SHBG) may influence the development of female osteoporosis. The clinical significance of circulating SHBG levels in the assessement of bone metabolic turnover remains to be established.     

Associations between physical activity and bone mass in black and white South African children at age 9 yr.

We investigated differences in physical activity (PA) levels between black and white South African 9-yr-old children and their association with bone mineral content (BMC) and density (BMD) by using dual-energy X-ray absorptiometry. PA was analyzed in terms of a metabolic (METPA; weighted metabolic score of intensity, frequency, and duration) and a mechanical (MECHPA; sum of all ground reaction forces multiplied by duration) component. There were significant ethnic differences in patterns of activity. White children expended a significantly greater energy score (METPA of 21.7 +/- 2.9) than black children (METPA of 9.5 +/- 0.5) (P < 0.001). When children were divided into quartiles according to the amount and intensity of sport played, the most active white children (using METPA scores) had significantly higher whole body BMD and higher hip and spine BMC and BMD than less active children. White children in the highest MECHPA quartile also showed significantly higher whole body, hip, and spine BMC and BMD than those children in the lowest quartile. No association between exercise and bone mass of black children was found. In this population, PA has an osteogenic association with white children, but not black children, which may be explained by the lower levels of PA in the black children. Despite this, black children had significantly greater bone mass at the hip and spine (girls only) (P < 0.001) even after adjustment for body size. The role of exercise in increasing bone mass may become increasingly critical as a protective mechanism against osteoporosis in both ethnic groups, especially because the genetic benefit exhibited by black children to higher bone mass may be weakened with time, as environmental influences become stronger.     

Vitamin D is a major determinant of bone mineral density at school age

Background

Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption, bone mineralization and bone mass attainment.

Methodology/Principal Findings

This school-based study investigated vitamin D status and its association with vitamin D intake and bone health in 195 Finnish children and adolescents (age range 7–19 years). Clinical characteristics, physical activity and dietary vitamin D intake were evaluated. Blood and urine samples were collected for serum 25-hydroxyvitamin D (25-OHD) and other parameters of calcium homeostasis. Bone mineral density (BMD) and body composition were measured with dual-energy X-ray absorptiometry (DXA). Altogether 71% of the subjects were vitamin D insufficient (25-OHD <50 nmol/L). The median 25-OHD was 41 nmol/L for girls and 45 nmol/L for boys, and the respective median vitamin D intakes 9.1 µg/day and 10 µg/day. In regression analysis, after adjusting for relevant factors, 25-OHD concentration explained 5.6% of the variance in lumbar BMD; 25-OHD and exercise together explained 7.6% of the variance in total hip BMD and 17% of the variance in whole body BMD. S-25-OHD was an independent determinant of lumbar spine and whole body BMD and in magnitude surpassed the effects of physical activity.

Conclusions/Significance

Vitamin D insufficiency was common even when vitamin D intake exceeded the recommended daily intake. Vitamin D status was a key determinant of BMD. The findings suggest urgent need to increase vitamin D intake to optimize bone health in children.     

Acute and delayed biochemical and physiological effects of exhaustive weightlifting exercise

The goal of the work was a study of the effect of exhaustive weightlifting exercise on prolonged changes in the physiological and biochemical variables characterizing the functional state of skeletal muscles. An exercise accentuated at muscles of the hip surface gave rise to a significant increase of the blood lactate concentration, which indicated that aerobic metabolism was a predominant mechanism of energy supply for muscle contraction. A reduction of the m. rectus femoris EMG amplitude and frequency, a decrease in the tone of tension, and an increase in the tone of relaxation were found immediately after exercise. One day later, the amplitude and the frequency of the EMG signal increased. On day 3, the activity of creatine kinase (CK, a marker of muscle injury) considerably increased, while the amplitude and frequency of EMG decreased. By the ninth day of recovery, all measured variables with the exception of CK were normalized. A significant negative correlation was found between the blood serum’s lactate concentration and m. rectus femoris EMG activity at the same time points. Blood serum CK activity and m. rectus femoris EMG and tone parameters were significantly correlated on the third postexercise day. The data demonstrate that exhaustive exercise-induced muscle injury resulted in phasic alterations in the electrical activity and the tone of the muscle apparently related to a decrease in pH because of lactate accumulation in the sarcoplasm and the cascade of reactions leading to muscle tissue damage.     

Femoral neck bone adaptation to weight-bearing physical activity by computational analysis

Individual differences in bone mass distribution at the proximal femur may be determined by daily weight-bearing physical activity (PA) since bone self-adapts according to the mechanical loads that is submitted. The aim of this study was to analyse computationally the effect of different weight-bearing PA types in the adaptation of the femoral neck (FN) by analysing regional differences in bone mineral density (BMD) at the integral FN and its superior, inferior, anterior and posterior subregions. To achieve this, it was adopted a 3-D femoral finite element (FE) model coupled with a suitable bone remodeling model. Different PA types were determined based both on ordinary lifestyle and mechanically more demanding PA as low magnitude impacts (L–I), moderate-magnitude impacts from odd directions (O–I) and high-magnitude vertical impacts (H–I). It was observed that as time spent in weight-bearing PA increases, BMD augment around the integral FN, but with different bone mass gain rates between subregions depending on the magnitude and directions of the hip contact forces; H–I was the type of weight-bearing PA which structurally most favor the gain of bone mass superiorly at the FN while both the H–I and the O–I types of PA promoted the largest bone mass gain rates at the anterior and posterior subregions of the FN. Because these types of weight-bearing PA were associated with a more uniform bone mass spatial distribution at the FN, they should provide a potential basis for targeted PA-based intervention programs for improving hip strength.     

Bone mineral density correlates with fracture load in experimental side impacts of the pelvis

Pelvic fractures resulting from automotive side impacts are associated with high mortality and morbidity, as well as substantial economic costs. Previous experimental studies have produced varying results regarding the tolerance of the pelvis to lateral force and compression. While bone mineral density (BMD) has been shown to correlate with fracture loads in the proximal femur, no such correlation has been established for the pelvis. Presently, we studied the relationships between total hip BMD and impact response parameters in lateral impacts of twelve isolated human pelves. The results indicated that total hip BMD significantly correlated with fracture force, Fmax, and maximum ring compression, Cmax, of the fractured pelves. These findings are evidence that BMD may be useful in assessing the risk of pelvic fracture in automotive side impacts. Poor correlation was observed between total hip BMD and maximum viscous response, (VC)max, energy at fracture, Epeak, and time to fracture, tpeak. Mean Fmax and calculated tolerances for Cmax and (VC)max were lower than those established in previous studies using full cadavers, likely a result of our removal of soft tissues from the pelves prior to impact.     

Association of the 163A/G and 1181G/C osteoprotegerin polymorphism with bone mineral density.

The aim of the study was to investigate the distribution of 163 A/G osteoprotegerin gene promoter and 1181 G/C osteoprotegerin exon 1 polymorphisms in a group of women with different hormonal status and to analyze their relationship with BMD. Osteoprotegerin polymorphisms and BMD were analyzed in 332 women (69 premenopausal and 263 postmenopausal). BMD was quantified at the lumbar spine (L 2-4), femoral neck, and total hip. Genotyping for the presence of different polymorphisms was performed using the Custom Taqman ((R)) SNP Genotyping assays. There were not significant differences in BMD according to 163 A/G genotype. However, significant differences in lumbar spine BMD were found according to 1181 G/C alleles. Thus, women with CC genotype had significant higher BMD at the lumbar spine than those with GC or GG genotype. No differences were found in femoral neck and total hip BMD. In age-adjusted models, the 1181 G/C OPG polymorphism explained 2.2% of BMD variance at the spine, 0.3% at the femoral neck, and 0.9% at the total hip in the whole group. In the subgroup of premenopausal women, the polymorphism was strongly related to spine BMD, and explained 11.5% of the variance, whereas body weight explained 7.9%. The 1181 G/C polymorphism was associated with lumbar spine BMD in Spanish women. Premenopausal women with the CC genotype had a higher BMD.     

Biomarkers for osteoporosis management: utility in diagnosis, fracture risk prediction and therapy monitoring

Osteoporosis is a systemic disease characterized by low bone mass and microarchitectural deterioration of bone tissue, resulting in an increased risk of fracture. While the level of bone mass can be estimated by measuring bone mineral density (BMD) using dual X-ray absorptiometry (DXA), its measurement does not capture all the risk factors for fracture. Quantitative changes in skeletal turnover can be assessed easily and non-invasively by the measurement of serum and urinary biochemical markers; the most sensitive markers include serum osteocalcin, bone specific alkaline phosphatase, the N-terminal propeptide of type I collagen for bone formation, and the crosslinked C- (CTX) and N- (NTX) telopeptides of type I collagen for bone resorption. Advances in our knowledge of bone matrix biochemistry, most notably of post-translational modifications in type I collagen, are likely to lead to the development of new biochemical markers that reflect changes in the material property of bone, an important determinant of bone strength. Among those, the measurement of the urinary ratio of native (alpha) to isomerized (beta) CTX - an index of bone matrix maturation - has been shown to be predictive of fracture risk independently of BMD and bone turnover.In postmenopausal osteoporosis, levels of bone resorption markers above the upper limit of the premenopausal range are associated with an increased risk of hip, vertebral, and nonvertebral fracture, independent of BMD. Therefore, the combined use of BMD measurement and biochemical markers is helpful in risk assessment, especially in those women who are not identified as at risk by BMD measurement alone. Levels of bone markers decrease rapidly with antiresorptive therapies, and the levels reached after 3-6 months of therapy have been shown to be more strongly associated with fracture outcome than changes in BMD. Preliminary studies indicate that monitoring changes of bone formation markers could also be useful to monitor anabolic therapies, including intermittent parathyroid hormone administration and, possibly, to improve adherence to treatment. Thus, repeated measurements of bone markers during therapy may help improve the management of osteoporosis in patients.     

PHACTR3基因与中国汉族和美国高加索人群骨密度的关联研究

研究组前期的全基因组关联研究发现PHACTR3基因与骨折关联,为了检测该基因与骨密度的关联关系,采用精细定位关联研究来检测PHACTR3基因内及其附近的SNPs与骨密度的关系。首先在中国样本（1627个不相关的汉族样本）和美国样本（2286个不相关高加索样本）中对PHACTR3基因的140个SNPs进行基因分型,然后采用Plink软件检测PHACTR3基因与腰椎和髋部骨密度的关联关系。发现研究组以前报道的与骨折关联的SNPs rs1555364和rs6064822与腰椎和髋部骨密度关联（P=4．89×10^-2-1．26×10^-2）。另外还发现位于PHACTR3基因内含子中3个SNPs位点（rs6027138,rs1182531和rs1182532）与中国人群和白人腰椎骨密度均显著关联,将中国人与白人样本合并起来进行荟萃分析（Meta—analysis）,得到合并P值为1．40×10^-3到4．00×10^-4,另外发现rs6064820与髋部BMD相关联,合并P值为6．70×10^-3。本研究进一步证实了PHACTR3基因在骨密度变异中的作用,对骨质疏松发病机制的认识提供了新的理论依据。     

Effect of subclinical hypothyroidism and obesity on whole-body and regional bone mineral content

OBJECTIVE: The present investigation was aimed to evaluate the effect of subclinical hypothyroidism and obesity on bone mineral content (BMC) in different body segments. METHODS: Thirty-two premenopausal women (age: 37 +/- 9.9 years), with a wide range in body mass index (BMI), were studied. Subclinical hypothyroidism was defined by a basal TSH > or = 4 microU/l and/or a TRH-stimulated peak > or = 30 microU/l. For each subject, weight, height, BMI (weight/height(2)) and the waist/hip ratio were measured. Total BMC, total bone mineral density (BMD), leg BMC, leg BMD, trunk BMC, trunk BMD, arm BMC and arm BMD were determined using dual-energy X-ray absorptiometry. Thyroid function (basal and TRH-stimulated TSH, free T(3) and free T(4)) were determined from fasting blood samples for all subjects. RESULTS: Anova was conducted within all the groups to observe the effect of thyroid status and/or obesity on BMC and BMD. There was no statistical difference for age. Total BMC was affected by obesity (p < 0.05) but not by thyroid status, BMD of the legs was significantly influenced both by thyroid function and obesity (p < 0.01); total BMD was affected by hypothyroid status (p < 0.05). A direct relationship between leg BMD and TSH was demonstrated. CONCLUSION: Subclinical thyroid hypofunction and obesity seem to affect BMD differently in the body segments. An influence of gravitational force seems necessary in order to make evident the effect of subclinical hypothyroidism on bone. A condition of subclinical hypothyroidism should be considered when evaluating subjects for osteoporosis, since a BMD measured at the femoral neck may induce underestimation of initial osteoporosis.     

中等强度跑台运动预防去卵巢大鼠骨质疏松

目的观察中等强度跑台运动对去卵巢大鼠骨质疏松的预防作用。方法将30只3月龄未经产雌性SD大鼠随机分为假手术、去卵巢静止和去卵巢运动三个组。去卵巢运动组每周进行4次时间45min、速度18m/min、坡度5°的跑台训练。实验结束时,检测血清雌二醇（E2）、碱性磷酸酶（ALP）、抗酒石酸酸性磷酸酶（TRAP）和骨钙素（BGP）水平以及右侧游离股骨和胫骨的骨密度（BMD）和骨矿物含量（BMC）;同时观察左侧股骨远端和胫骨近端组织形态学变化。结果与假手术组比较,去卵巢静止组大鼠血清ALP活性和BGP含量显著升高,血清TRAP活性和E2含量显著下降,股骨近段和远端以及胫骨近端BMD和BMC显著下降,股骨远端和胫骨近端骨小梁断裂增加、数目减少;与去卵巢静止组比较,去卵巢运动组大鼠血清E2和BGP含量显著上升,股骨三个部位以及胫骨近端BMD和BMC显著增加,股骨远端和胫骨近端骨小梁断裂减少、数目增加。结论中等强度跑台运动能增加去卵巢大鼠血清E2和BGP含量,改善去卵巢大鼠骨组织学结构。     

Effect of low-repetition jump training on bone mineral density in young women.

The hypothesis of the present study was that low-repetition and high-impact training of 10 maximum vertical jumps/day, 3 times/wk would be effective for improving bone mineral density (BMD) in ordinary young women. Thirty-six female college students, with mean age, height, and weight of 20.7+/-0.7 yr, 158.9+/-4.6 cm, and 50.4+/-5.5 kg, respectively, were randomly divided into two groups: jump training and a control group. After the 6 mo of maximum vertical jumping exercise intervention, BMD in the femoral neck region significantly increased in the jump group from the baseline (0.984+/-0.081 vs. 1.010+/-0.080 mg/cm2; P<0.01), although there was no significant change in the control group (0.985+/-0.0143 vs. 0.974+/-0.134 mg/cm2). And also lumbar spine (L2-4) BMD significantly increased in the jump training group from the baseline (0.991+/-0.115 vs. 1.015+/-0.113 mg/cm2; P<0.01), whereas no significant change was observed in the control group (1.007+/-0.113 vs. 1.013+/-0.110 mg/cm2). No significant interactions were observed at other measurement sites, Ward's triangle, greater trochanter, and total hip BMD. Calcium intakes and accelometry-determined physical daily activity showed no significant difference between the two groups. From the results of the present study, low-repetition and high-impact jumps enhanced BMD at the specific bone sites in young women who had almost reached the age of peak bone mass.     

1型糖尿病患者骨密度的变化及相关因素分析(英文)

目的:观察1型糖尿病患者骨密度(bone mineral density,BMD)的变化及其影响因素。方法:采用双能X线骨密度仪测定108例1型糖尿病患者及106例非糖尿病人群腰椎1至4(L1、L2、L3、L4、、L1-4总体)及左侧髋部(股骨颈、大转子、ward's三角、股骨干及左髋总体)骨密度,同时测定受试者年龄、身高、体重、腰围、臀围,1型糖尿病患者病程、糖化血红蛋白(HbA1c)等指标,利用多元回归分析1型糖尿病患者骨密度的相关因素。结果:L1-4总体BMD和左髋总体BMD与年龄、HbA1c呈负相关,与BMI呈正相关(P0.05);左髋总体BMD与性别有关(P0.05)。结论:1型糖尿病患者BMD低于对照人群,1型糖尿病患者的性别、年龄、BMI、HbA1c水平与BMD关系密切。