Aging in the lumbar spine. II. L1 and L2

The bodies of the first and second lumbar vertebrae, like those of L3 and L4, show a significant trend toward lowering and broadening with age. Superior, inferior, and midbody transverse breadths increase, but there is little or no increase in endplate "flaring" with age. There is essentially no change in the relationship between anterior and posterior heights, but as reported for L3 and L4, there is a sexual difference in the amount and type of wedging of the bodies of L1 and L2. Posterior wedging (posterior height less than anterior height) of these vertebrae is about twice as common in females as in males. Whites of both sexes show a statistically significant relationship between age and increased biconcavity of the endplates. Black females, but not the males, show a similar trend, especially in L1.     

Influence of age,gender and weight on spinal osteoarthritis in the elderly: An analysis of morphometric changes using X-ray images

Various factors in addition to normal aging are reported to be associated with spinal osteoarthritis. The links between the risk factors and osteoarthritis are unclear. This study proposes an analysis of factors associated with spinal osteoarthritis using a collection of cervical and lumbar X-ray images, maintained by the US National Library of Medicine. Five hundred and forty-eight images of adults (60–74 years old, 242 males, 306 females) are analyzed. Six to nine anatomical points are selected by an experienced radiologist on each vertebra. Four dimensionless indexes are calculated: the anterior-to-posterior height ratio (APR), the disc space relative to posterior height of vertebra (DS) and the number of osteophytes. Correlations of these parameters are estimated with three anthropometric indexes: age, gender and body mass index. The univariate relationships are evaluated using one-way analysis of variance and Kruskal-Wallis test. Osteophytes are more frequent for men than for women. Men have lower APR from the levels L1 to L4 and lower DS at the levels C4 and C5. The lumbar levels L2 and L4 are more affected with age by changes in APR. Obese group has a higher DS at the level C3-C4 and a higher APR at the level L1. The analysis of images shows the predominant effect of osteoarthritis at the lower levels of the cervical and lumbar spine.     

Morphometric variations of the lumbar vertebrae between Chinese and Indian adults.

A morphometric study of the lumbar vertebrae of 126 adult skeletons, 90 Chinese and 36 Indian, of both sexes without marginal osteophytes were performed. In each lumbar vertebra, the cephalad and caudad midsagittal diameters, the interpedicular diameter of the spinal canal as well as the midsagittal and transverse diameters and the height of the vertebral body were measured. The results showed that the midsagittal and transverse diameters, the heights of the lumbar vertebral bodies and the interpedicular diameters of the lumbar spinal canals increased progressively from L1 to L5, while the midsagittal diameters of the lumbar spinal canals decreased progressively from L1 to L5 in both Chinese and Indian adult skeletons. The lowest mean values of the cephalad and caudad midsagittal and the interpedicular diameters of the spinal canals in Chinese were found to be 5.04 +/- 0.15 mm at L5, 4.67 +/- 0.09 mm at L5 and 25.92 +/- 0.20 mm at L2, respectively, while in Indians they were found to be 4.54 +/- 0.18 mm at L5, 4.25 +/- 0.10 mm at L5 and 25.42 +/- 0.22 mm at L1, respectively. In addition, the mean diameters of the spinal canal and the vertebral body (except the height of the vertebral body) were significantly greater in the Chinese than in the Indian skeletons. The above findings indicate that the mean diameters of both the lumbar spinal canal and the vertebral body vary greatly between Chinese and Indian adults, i.e. there are no mean values of the vertebral dimensions that are valid for all populations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influences of Endplate Removal and Bone Mineral Density on the Biomechanical Properties of Lumbar Spine

Purpose

To investigate (1) effects of endplate removal and bone mineral density (BMD) on biomechanical properties of lumbar vertebrae (2) whether the distributions of mechanical strength and stiffness of endplate are affected by BMD.

Methods

A total of thirty-one lumbar spines (L1-L5) collected from fresh cadavers were used in this study. Bone density was measured using lateral DEXA scans and parts of samples were performed with partial or entire endplate removal. All the specimens were divided into three BMD groups. According to endplate integrity of the lumbar vertebrae, each BMD group was then divided into three subgroups: subgroup A: intact endplate; subgroup B: central region of endplate removal; subgroup C: entire endplate removal. The axial compression test was conducted with material testing system at a speed of 2mm/min. The experimental results were statistically analyzed using SPSS 17.0.

Results

(1) Significant differences of biomechanical properties occurred among normal BMD, osteoporotic and serious osteoporotic group (P<0.05). (2) Spearman analysis showed that BMD was positively correlated with the failure load and stiffness of lumbar vertebrae. (3) For each BMD group, significant differences of biomechanical properties were found between subgroup A and C, and between subgroup B and C (P<0.05). (4) For each BMD group, there was no statistical difference of biomechanical properties between subgroup A and B (P>0.05).

Conclusions

Entire endplate removal can significantly decrease the structural properties of lumbar vertebrae with little change in biomechanical properties by preservation of peripheral region of the endplate. BMD is positively correlated to the structural properties of the lumbar vertebrae.     

Instantaneous centers of rotation for lumbar segmental extension in vivo

The study aimed to map instantaneous centers of rotation (ICRs) of lumbar motion segments during a functional lifting task and examine differences across segments and variations caused by magnitude of weight lifted. Eleven healthy participants lifted loads of three different magnitudes (4.5, 9, and 13.5 kg) from a trunk-flexed (~75°) to an upright position, while being imaged by a dynamic stereo X-ray (DSX) system. Tracked lumbar vertebral (L2-S1) motion data were processed into highly accurate 6DOF intervertebral (L2L3, L3L4, L4L5, L5S1) kinematics. ICRs were computed using the finite helical axis method. Effects of segment level and load magnitude on the anterior-posterior (AP) and superior-inferior (SI) ICR migration ranges were assessed with a mixed-effects model. Further, ICRs were averaged to a single center of rotation (COR) to assess segment-specific differences in COR AP- and SI-coordinates. The AP range was found to be significantly larger for L2L3 compared to L3L4 (p=0.02), L4L5 and L5S1 (p<0.001). Average ICR SI location was relatively higher – near the superior endplate of the inferior vertebra – for L4L5 and L5SI compared to L2L3 and L3L4 (p≤0.001) – located between the mid-transverse plane and superior endplate of the inferior vertebra – but differences were not significant amongst themselves (p>0.9). Load magnitude had a significant effect only on the SI component of ICR migration range (13.5 kg>9 kg and 4.5 kg; p=0.049 and 0.017 respectively). The reported segment-specific ICR data exemplify improved input parameters for lumbar spine biomechanical models and design of disc replacements, and base-line references for potential diagnostic applications.     

Dimensions of human lumbar vertebrae in the sagittal plane

Geometrical dimensions of the lumbar segments were determined from a series of lateral radiographs. A two-dimensional model of the lumbar vertebra in the sagittal plane is used. The model is based on five landmarks, which enable the determination of twelve geometrical parameters. The sample includes 157 healthy young males, 20-38 years old. Two-dimensional analysis of vertebral body height, depth and intervertebral spacing was performed. In all subjects disc height increases from L1 to L5, while anterior height is always bigger than posterior height, which emphasizes the lordotic shape of the lumbar region. Anthropometrical values are presented and geometrical relations between the lumbar segments are discussed.     

Some aspects of aging in the lumbar spine

I measured the bodies of vertebrae L3 and L4 of 338 skeletons from the Terry collection in the Smithsonian Institution, including Blacks and Whites, males and females, aged from 20 to 90 years. Transverse breadths of the upper and lower endplates (excluding osteophytes) and minimum transverse breadths all increase with age. In general, the greater broadening occurs in the endplates, but the middle of the body also broadens to such a degree that there is no demonstrable increase in vertebral “flaring” with age. In males, posterior body height decreases relative to anterior height, so that the lumbar bodies become more wedge-shaped with age, but females show essentially no change. Anterior height decreases in proportion to minimum breadth, so that the lumbar bodies become relatively lower and broader, and this change is significantly correlated with age in all groups. Midbody height decreases relative to anterior height, so that Nordin's biconcavity index is reduced with age. The increase in biconcavity remains evident even when average anterior-posterior height is used to calculate the index. At all age levels a high percentage of individuals have biconcavity indices of 80% or less, indicating that Nordin's standard of normality for this index, established from measurement on radiographs of the living, should be revised downward for use in evaluating osteoporosis in skeletal populations.     

Cortical somatosensory potentials evoked by magnetic stimulation: effect of body height,age, and stimulus intensity

Cortical somatosensory evoked potentials elicited by non-invasive magnetic stimulation at Th10, Th12, and L5 vertebral levels and at mid-gluteus and ankle were studied in 45 normal controls varying in body height and age. Peak latencies of P2 evoked by ankle, mid-gluteus and L5 stimulation were correlated with body height. However, P2 latencies evoked by Th10 and Th12 stimulation were independent of body height. In contrast, all N2 latencies evoked by Th10, Th12, L5, mid-gluteus and ankle were correlated with body height. There were no correlations between latencies of P3 and N3 and body height. No peak latencies of cortical components were affected by age within the age group studied (15–67 years). In the intensity study, N2 showed double peaks when low to moderate stimulus intensities were applied to Th12 vertebra. Furthermore, in 2 patients with mild somatosensory dysfunction of lumbar roots or cord, N2 evoked by L5 stimulation revealed double peaks with prolonged interpeak latencies between the first peak of N2 and P3, which might be related to the temporal dispersion of the afferent fibers. These data suggest that the N2 component is induced by both fast and slow afferent fibers.     

Morphological variation of the thoracolumbar vertebrae in Macropodidae and its functional relevance

The present study was designed to investigate how the form of the marsupial thoracolumbar vertebrae varies to cope with the particular demands of diverse loading and locomotor behaviors. The vertebral columns of 10 species of Macropodidae, with various body masses and modes of locomotion, together with two other arboreal marsupials, koala and cuscus, were selected. Seventy-four three-dimensional landmark coordinates were acquired on each of the 10 last presacral vertebrae of the 70 vertebral columns. The interspecific variations of the third lumbar vertebra (L3, which approximates the mean) and the transitional patterns of the thoracolumbar segments were examined using the combined approach of generalized Procrustes analysis (GPA) and principal components analysis (PCA). The results of analyses of an individual vertebra (L3) and of the transitional patterns indicate significant interspecific differences. In the L3 study the first PC shows allometric shape variation, while the second PC seems to relate to adaptation for terrestrial versus arboreal locomotion. When the L3 vertebrae of the common spotted cuscus and koala are included for comparison, the vertebra of the tree kangaroo occupies an intermediate position between the hopping kangaroo and these arboreal marsupials. The L3 vertebrae in the arboreal marsupials possess a distinct dorsoventrally expanded vertebral body, and perpendicularly orientated spinous and transverse processes. The results of the present study suggest that vertebral shape in the kangaroo and wallaroos provides a structural adaptation to hopping through a relatively enlarged loading area and powerful lever system. In contrast, the small-sized bettongs (or rat kangaroos) have a relatively flexible column and elongated levers for the action of back muscles that extend and laterally flex the spine. The complex pattern of vertebral shape transition in the last 10 presacral vertebrae was examined using PCAs that compare between species information about vertebral shape variation along the thoracolumbar column. The results reinforce and emphasize important aspects of the patterns of variation seen in the detailed analysis of the third lumbar vertebra. The results also imply that size, spinal loading pattern, and locomotor behavior exert an influence on shaping the vertebra. Further, the morphological adaptations are consistent within these marsupials and this opens up the possibility that this kind of analysis may be useful in making functional inferences from fossil material.     

Vertebrae numbers of the early hominid lumbar spine

General doctrine holds that early hominids possessed a long lumbar spine with six segments. This is mainly based on Robinson's (1972) interpretation of a single partial Australopithecus africanus skeleton, Sts 14, from Sterkfontein, South Africa. As its sixth last presacral vertebra exhibits both thoracic and lumbar characteristics, current definitions of lumbar vertebrae and lumbar ribs are discussed in the present study. A re-analysis of its entire preserved vertebral column and comparison with Stw 431, another partial A. africanus skeleton from Sterkfontein, and the Homo erectus skeleton KNM-WT 15000 from Nariokotome, Kenya, did not provide strong evidence for the presence of six lumbar vertebrae in either of these early hominids. Thus, in Sts 14 the sixth last presacral vertebra has on one side a movable rib. In Stw 431, the corresponding vertebra shows indications for a rib facet. In KNM-WT, 15000 the same element is very fragmentary, but the neighbouring vertebrae do not support the view that it is L1. Although in all three fossils the transitional vertebra at which the articular facets change orientation seems to be at Th11, this is equal to a large percentage of modern humans. Indeed, a modal number of five lumbar vertebrae, as in modern humans, is more compatible with evolutionary principles. For example, six lumbar vertebrae would require repetitive shortening and lengthening not only of the lumbar, but also of the entire precaudal spine. Furthermore, six lumbar vertebrae are claimed to be biomechanically advantageous for early hominid bipedalism, yet an explanation is lacking as to why the lumbar region should have shortened in later humans. All this raises doubts about previous conclusions for the presence of six lumbar vertebrae in early hominids. The most parsimonious explanation is that they did not differ from modern humans in the segmentation of the vertebral column.     

Evaluation of "unique" aspects of human vertebral bodies and pedicles with a consideration of Australopithecus africanus

Recent functional studies of human vertebrae have revealed that loads borne by the axial skeleton during bipedal postures and locomotion pass through the pedicles and posterior elements as well as through the bodies and discs. Accordingly, particular morphological attributes of these vertebral elements have been linked exclusively with bipedalism. In order to test the validity of current form-function associations in human vertebral anatomy, this study considers the morphology of human thoracolumbar vertebral bodies and pedicles in the context of a wide comparative primate sample. The last lumbar vertebra of STS 14 (Australopithecus africanus) is also included in the analysis. Results indicate that certain features of human vertebrae previously thought to reflect bipedalism are characteristic of several nonhuman primates, including those whose posture is habitually pronograde. These features include the decrease in vertebral body surface area and the increase in cross-sectional area of the pedicle between the penultimate and last lumbar vertebra. In addition, although humans have relatively large and wide last lumbar pedicles, the enlargement and widening of the pedicle between the penultimate and last lumbar vertebra is not unique to humans. On the other hand, human vertebrae do exhibit several unique adaptations to bipedal posture and locomotion: (1) the vertebral body surface areas of the lower lumbar vertebrae and the cross-sectional areas of the last lumbar pedicles are large relative to body size, and (2) the last lumbar pedicles are wider relative to length and to body size than are those of nonhuman primates. The last lumbar vertebra of STS 14 does not exhibit any of these human-like vertebral features—its pedicles and body surface areas are relatively small, and its pedicles are not relatively wide, but relatively short.     

Biomechanical comparison of the effects of anterior,posterior and transforaminal lumbar interbody fusion on vibration characteristics of the human lumbar spine

Previous studies have compared the effects of different interbody fusion approaches on biomechanical responses of the lumbar spine to static loadings. However, very few have dealt with the whole body vibration (WBV) condition that is typically present in vehicles. This study was designed to determine the biomechanical differences among anterior, posterior and transforaminal lumbar interbody fusion (ALIF, PLIF and TLIF) under vertical WBV. A previously developed and validated finite element (FE) model of the intact L1–sacrum human lumbar spine was modified to simulate ALIF, PLIF and TLIF with bilateral pedicle screw fixation at L4–L5. Comparative studies on dynamic responses to the axial cyclic loading in these developed models were conducted. The results showed that at the fused L4–L5 level, dynamic responses of the von-Mises stress in L4 inferior and L5 superior endplates for the ALIF, PLIF and TLIF models were increased compared with the intact model. The endplate stresses in the TLIF model were lower than in the ALIF and PLIF models, but the TLIF generated greater stresses in the screws and rods compared with the ALIF and PLIF. At other levels, a decrease in dynamic responses of the disc bulge, annulus stress and intradiscal pressure was observed in all the fusion models compared with the intact one, but there was no obvious difference in these dynamic responses among the ALIF, PLIF and TLIF models. These findings might be useful in understanding vibration characteristics of the whole lumbar spine after different types of fusion surgery.     

Preparation of Intact Bovine Tail Intervertebral Discs for Organ Culture

The intervertebral disc (IVD) is the joint of the spine connecting vertebra to vertebra. It functions to transmit loading of the spine and give flexibility to the spine. It composes of three compartments: the innermost nucleus pulposus (NP) encompassing by the annulus fibrosus (AF), and two cartilaginous endplates connecting the NP and AF to the vertebral body on both sides. Discogenic pain possibly caused by degenerative intervertebral disc disease (DDD) and disc herniations has been identified as a major problem in our modern society. To study possible mechanisms of IVD degeneration, in vitro organ culture systems with live disc cells are highly appealing. The in vitro culture of intact bovine coccygeal IVDs has advanced to a relevant model system, which allows the study of mechano-biological aspects in a well-controlled physiological and mechanical environment. Bovine tail IVDs can be obtained relatively easy in higher numbers and are very similar to the human lumbar IVDs with respect to cell density, cell population and dimensions. However, previous bovine caudal IVD harvesting techniques retaining cartilaginous endplates and bony endplates failed after 1-2 days of culture since the nutrition pathways were obviously blocked by clotted blood. IVDs are the biggest avascular organs, thus, the nutrients to the cells in the NP are solely dependent on diffusion via the capillary buds from the adjacent vertebral body. Presence of bone debris and clotted blood on the endplate surfaces can hinder nutrient diffusion into the center of the disc and compromise cell viability. Our group established a relatively quick protocol to "crack"-out the IVDs from the tail with a low risk for contamination. We are able to permeabilize the freshly-cut bony endplate surfaces by using a surgical jet lavage system, which removes the blood clots and cutting debris and very efficiently reopens the nutrition diffusion pathway to the center of the IVD. The presence of growth plates on both sides of the vertebral bone has to be avoided and to be removed prior to culture. In this video, we outline the crucial steps during preparation and demonstrate the key to a successful organ culture maintaining high cell viability for 14 days under free swelling culture. The culture time could be extended when appropriate mechanical environment can be maintained by using mechanical loading bioreactor. The technique demonstrated here can be extended to other animal species such as porcine, ovine and leporine caudal and lumbar IVD isolation.     

Effect of loading rate on endplate and vertebral body strength in human lumbar vertebrae

Previous studies have implied that increases in loading rate resulted in changes in vertebral mechanical properties and these changes were causative factors in the different fracture types seen with high-speed events. Thus many researchers have explored the vertebral body response under various loading rate conditions. No other study has investigated the role of the endplate in high-speed vertebral injuries. The current study determined changes in the endplate and vertebral body strength with increases in displacement rate. The endplate and vertebral body failure loads in individual lumbar vertebrae were documented for two displacement rates: 10 and 2500 mm/s. Using cross-sectional areas from the endplate and vertebral body, failure stresses for both components were calculated and compared. Both the endplate and vertebral body failure loads increased significantly with increased loading rate (p<0.005). Although the vertebral body failure stress increased significantly with loading rate as well (p<0.01), the endplate stresses did not (p>0.35). In addition, the endplate and vertebral strengths were not significantly different under high-speed loading (p>0.60), which inhibits possible predictions as to which bony component would fail initially during a high-speed injury event. It is possible that load distribution may contribute more to the fracture patterns seen at high speeds over vertebral component strength.     

Parametric finite element analysis of vertebral bodies affected by tumors

The vertebral column is the most frequent site of metastatic involvement of the skeleton. Due to the proximity to the spinal cord, from 5% to 10% of all cancer patients develop neurologic manifestations. As a consequence, fracture risk prediction has significant clinical importance. In this study, we model the metastatically involved vertebra so as to parametrically investigate the effects of tumor size, material properties and compressive loading rate on vertebral strength. A two-dimensional axisymmetric finite element model of a spinal motion segment consisting of the first lumbar vertebral body (no posterior elements) and adjacent intervertebral disc was developed to allow the inclusion of a centrally located tumor in the vertebral body. After evaluating elastic, mixed, and poroelastic formulations, we concluded that the poroelastic representation was most suitable for modeling the metastatically involved vertebra's response to compressive load. Maximum principal strains were used to localize regions of potential vertebral trabecular bone failure. Radial and axial vertebral body displacements were used as relative indicators of spinal canal encroachment and endplate failure. Increased tumor size and loading rate, and reduced trabecular bone density all elevated axial and radial displacements and maximum tensile strains. The results of this parametric study suggest that vertebral tumor size and bone density contribute significantly to a patients risk for vertebral fracture and should be incorporated in clinical assessment paradigms.     

The mechanical behaviour of bony endplate and annulus in prolapsed disc configuration

The mechanical response of intervertebral joints is deeply influenced by disc degeneration. The phenomenon is expressed in terms of variations in the biomechanical properties of the material, whose compressibility characteristics change because of the liquid content loss in the tissue and, what is even more important, to prolapse. In this work, the problem is investigated by means of a computational mechanics approach; a coupled material and geometric non-linear model is developed, representing vertebra, annulus and nucleus submitted to an axial load. A transversely isotropic law is assumed for cortical bone in the vertebral body and an isotropic law for the cancellous portion; a hyperelastic formulation is assumed for the disc, allowing effective interpretation of the mechanical characteristics of degeneration. The results obtained are reported with regard to bony endplate and annulus behaviour; interaction phenomena between bony endplate and nucleus are emphasized.     

“Lucy” (A.L. 288‐1) had five sacral vertebrae

A “long‐backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12‐13:6:4), a configuration acquired from a hominin‐panin last common ancestor (PLCA) having a vertebral formula of 7:13:6‐7:4. One founding line of evidence for this hypothesis is the recent assertion that the “Lucy” sacrum (A.L. 288‐1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially‐fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288‐1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288‐1an exhibits inferiorly‐projecting (right side) cornua and a kidney‐shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly‐projecting cornua, and have more circularly‐shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five‐element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288‐1 possessed five sacral vertebrae as in modern humans; thus, sacral number in “Lucy” does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. Am J Phys Anthropol 156:295–303, 2015. © 2014 Wiley Periodicals, Inc.     

Vertebral and rib anatomy in Caperea marginata: Implications for evolutionary patterning of the mammalian vertebral column

The pygmy right whale, Caperea marginata, is a rare mysticete cetacean with an unusual suite of axial skeletal characters. Distally expanded first ribs, a long thorax with broadly overlapping vertebral transverse processes, plate‐like posterior ribs, and a short tail contrast with other cetaceans and suggest unique developmental patterning. Twenty‐four individuals of diverse ontogenetic age were available for analysis. Multiple, variable examples of incomplete rib fusion in dependent calves indicate that the first rib of adults is an ontogenetic fusion product of ribs 1 and 2. The composite rib articulates by way of its anterior (Rib1) component to the sternum and by way of its posterior (Rib2) component with thoracic vertebra 2. Thoracic vertebra 1 lacks rib articulations. When rib fusion is taken into account, the most frequent column formulas are C7T18L1Cd16–17 = 42–43 and C7T17L1Cd16–18 = 41–43. Thoracic and lumbar series are not reciprocal in count, arguing against their developmental linkage. Instead, parallel reduction in both lumbar and caudal counts supports the existence of neocete patterning in Caperea, as in all other living cetaceans. Ontogenetic vertebral column elongation is most marked in the posterior thorax, lumbos, and anterior tail. Vertebrae in these column regions are excellent predictors of total body length.     

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。     

达斡尔族中小学生体质发育现状及20多年来的变化

本文报道了6~18岁1993名达斡尔族学生8项体质指标(身高、坐高、体重、肩宽、骨盆宽、胸围、腰围和臀围)的测量结果,并计算了10项体质指数。结果发现,达斡尔族在我国属体质发育较高的民族,并表现为一定的城乡差异;20多年来达斡尔族学生身高、体重、胸围全面增长,男女生身高最大增长年龄均提前约1岁左右,男生高年龄组身高和身体充实度增幅较大,但女生变化不大且肩宽和骨盆宽呈下降趋势。提示达斡尔族青少年体质发育表现为以生长突增提前为主的生长长期趋势,但女生高年龄组身高增长不明显、身体充实度有待提高,应采取营养和锻炼等措施促进其生长发育水平全面提高。