The presence of a prevalent vertebral deformity increases the risk of a future vertebral fracture. The aim of this study was to determine whether certain characteristics of the prevalent deformity, ...including its shape and location in the spine, influenced this effect. The 3100 men and 3500 women who took part in this analysis were recruited from population registers for participation in the European Prospective Osteoporosis Study (EPOS). Subjects had lateral thoracic and lumbar spine x-rays at baseline, and again after a mean interval of 3.8 years. Prevalent morphometric vertebral deformities on the baseline film were identified by the McCloskey–Kanis method. Incident fractures were defined as vertebrae that also satisfied the McCloskey–Kanis criterion for prevalent deformities on the follow-up film, and in addition had at least one height (anterior, mid, or posterior) which had reduced by at least 20% between films. Poisson regression was used to assess the association between various characteristics of the prevalent deformity and the risk of an incident vertebral fracture, with generalised estimating equations used to allow for the fact that each subject contributed several vertebrae to the analysis. The risk of an incident fracture increased with the number of prevalent deformities: relative risk (RR) for one prevalent deformity 3.2 (95% confidence interval (CI); 2.1, 4.8); 9.8 (95% CI;6.1, 15.8) for 2; and 23.3 (95% CI;15.3, 35.4) for 3 or more. Relative risks differed significantly according to the shape of the prevalent deformity, ranging from 5.9 (95% CI; 4.1, 8.6) if the anterior and mid heights were reduced to 1.6 (95% CI;0.8, 3.2) if the posterior and mid heights were reduced. Risks varied also according to the severity of the deformity. There were fivefold differences in relative risk of incident fracture depending on the location of the prevalent deformity within the spine. Compared to vertebrae in subjects with no deformities at baseline, the relative risk of an incident fracture within three vertebrae of a prevalent deformity was greater (7.7 (95% CI;5.6, 10.5)) than the risk in more distant vertebrae (4.0 (95% CI;2.6, 6.0)). In summary, the risk of a subsequent vertebral fracture in individuals with preexisting deformities is importantly influenced by the characteristics of these deformities.
Several algorithms are currently in use for evaluating vertebral deformities from plain lateral radiographs of the lumbar and thoracic spine. However, the effects of measurement imprecision as well ...as uncertainties over image magnification on the correct identification of prevalent and incident vertebral deformities with these algorithms has been little studied. In a pilot study for the European Prospective Osteoporosis Study (EPOS), plain radiographs were submitted to a single central evaluating centre for measurement of vertebral height from T4 to L4. The thoracic and lumbar spines were imaged on separate films, and we have assessed the precision of measurement of vertebral heights and height ratios. The standard deviation of the differences between films of each of three height measurements ranged from 1.1 to 1.2 mm. A two-stage strategy for identifying incident deformities was devised. This required that the vertebra be a prevalent deformity at the time of the second radiograph and also that at least one of the vertebral ratios should have changed significantly since the first radiograph. The second stage removed all but two of the 18 vertebrae flagged positive in the first stage but not considered to be certain incident fractures by clinical reading of the radiographs.
The objective of this retrospective study was to investigate the relation between serum leptin level and fat deposition in patients with eating disorders. 40 female inpatients with anorexia (n=24) or ...bulimia nervosa (n=16) were assessed for leptin level, body mass index (BMI), and percentage body fat by dual-energy X-ray absorbometry (DXA). The results show that percentage body fat is a better predictor for leptin level and clinical findings in eating disordered patients than BMI. We discuss the necessity for DXA measurements in anorectic patients for prognostic and research purposes.
This qualitative case study explored the influence that service-learning involvement has on undergraduate college students’ cognitive, environmental, and behavioral factors related to nutrition. As ...higher education is looking for ways to improve student health behaviors, service-learning is an unexplored area that has tremendous potential. Utilizing the major constructs of the social cognitive theory (Bandura, 1997; Glanz et al., 2015), the research questions guided the investigation of how participants in a previously established nutrition service-learning course described their cognitive, environment, and behavioral influences related to nutrition throughout the course. Participants also described their nutrition self-efficacy after participating in a service-learning nutrition course. Participants described their experiences through a pre-post survey, reflections, and voluntary interviews. Based on these constructs, this service-learning course was found to improve knowledge, awareness, values, and behaviors related to nutrition for all study participants. Findings show positive changes in nutrition-related self-efficacy, especially related to the meaning-making experience of the service-learning. Results from this study suggest that intentional reflection questions related to health behavior factors in health-based service-learning courses may be utilized to influence behavioral outcomes. Service-learning has been well established as a high-impact educational pedagogy (Astin et al., 2000; Kuh, 2015; Jacoby, 2015). As service-learning courses increase in higher education, understanding their effectiveness beyond academic outcomes is crucial. Service-learning courses have been demonstrated to influence positive health behaviors in community populations (Gray et al., 2017; Himelein et al., 2010; Jarvis et al., 2004), yet service-learning course outcomes have not been explored for health promotion among the students that are delivering the service. There is limited research available for evidence-based, comprehensive approaches to promoting health and student health behavior change during the college years (ACHA, 2018). An additional method to support improved student health behaviors through self-efficacy development could be through service-learning courses. Much of the research on non-environmental methods to influence health behaviors in college students is associated with self-efficacy development (Dinger, 1999; Kelly et al., 1991; O'Leary, 1985; Von Ah et al., 2004). Understanding student self-efficacy related to nutrition choices could be an indicator for positive nutrition behavioral changes (Bandura, 2004; Von Ah et al., 2004). The reflective methods already embedded into service-learning platforms can serve as a meaningful way to gather additional data related to the student experience, reflecting on health behaviors. Research has eluded to improved self-efficacy, growth, and self-understanding as a result from service-learning experiences (Astin, 2000; Jacoby, 2015; Kuh, 2015). Understanding students’ personal factors such as values, beliefs, and attitudes towards nutrition-related behaviors before, during, and after a service-learning course related to nutrition, can provide an in-depth understanding of the student experience that might lead to behavior change. The purpose of this study is to deepen the understanding of how service-learning courses might impact nutrition-related behaviors among the students providing the service.
The introduction of new devices demands the assessment of their capabilities in established terms. The accuracy, reproducibility and spatial resolution of in vitro (phantom) osteodensitometric and ...morphometric measurements of QDR 2000 Plus and EXPERT are presented. Design details of these DXA/MXA-devices are listed and discussed in combination with the data acquired in the test measurements and calculations. The image quality will improve with further software developments. The long-term reproducibility and in vivo reliability remains to be evaluated.
The problem of quantifying the structure of cancellous bone has been addressed in the past by histomorphometry and more recently by imaging techniques using X-ray attenuation. The current approaches ...compute and describe parts of the construction of the trabecular net. We developed a new technique which quantifies cancellous bone of human lumbar vertebrae as a whole. The interactions, transactions, and interrelationships of all parts of the structural composition of the trabeculae are accounted for and quantified. The method is based on the concept of structural complexity within the framework of nonlinear dynamics. The methodology was developed by using axial high resolution computed tomography images. The technique was transferred to quantitative computed tomography images and is based on the non-invasive assessment of 50 human L3 specimens. The value of Houndsfield units per pixel representing trabecular bone of the vertebrae was transformed into color-encoded and alphabet-encoded symbols. The procedure of transformation of the X-ray attenuation pixels into symbols was necessary as a basis on which measures of complexity were introduced to assess the composition of symbols within the images. The development of a generalization of symbolic dynamics, a mathematical method, to work with two-dimensional images was a prerequisite. The results of this study demonstrate that the structural composition of cancellous bone declines more rapidly than bone mineral density during the loss of bone. This outcome strongly suggests an exponential relationship between bone mineral density and the architectural composition of cancellous bone. Normal trabecular bone has a complex ordered structure. The structural composition during the osteopenic phase of bone loss is characterized by lower structural complexity and a significantly higher level of architectural disorder. A high grade of osteoporosis leads again to an ordered structure, although its structural complexity is minimal.
Changes in trabecular bone composition during development of osteoporosis are used as a model for bone loss in microgravity conditions during a space flight. Symbolic dynamics and measures of ...complexity are proposed and applied to assess quantitatively the structural composition of bone tissue from 3D data sets of human tibia bone biopsies acquired by a micro-CT scanner. In order to justify the newly proposed approach, the measures of complexity of the bone architecture were compared with the results of traditional 2D bone histomorphometry. The proposed technique is able to quantify the structural loss of the bone tissue and may help to diagnose and to monitor changes in bone structure of patients on Earth as well as of the space-flying personnel.
To evaluate age- and gender-related mechanical properties and bone mineral density (BMD) of the proximal humerus at different levels and regions.
Mechanical indentation testing, DXA, QCT, pQCT and ...the radiogrammetry (Cortical Index, CI) were carried out in 70 freshly harvested humeri from 46 human cadavers (23 females, 23-males; median age 70.5 years).
In the female group, a high correlation between age and BMD was found (rho = 0.62 to -0.70, p < 0.01) with statistically significant differences between specimens of patients 69 years or younger, and 70 years or older (p < 0.05). In the group of female specimens of age 70 years or older, BMD values were found to be significantly lower compared to their male counterparts (p < 0.05). Regardless of the specimen's age, the highest BMD and bone strength were found in the proximal aspect and in the medial and dorsal regions of the proximal humerus.
These findings provide an insight into the fracture mechanism of the proximal humerus and should be the basis for designing structure-oriented implants with improved implant-bone stability in osteoporotic patients.
Physical exercise and sports increase muscular mass and the remodelling process of bones. The increment of bone depends on the type and the quality of sport. Short-term high-performance activities ...such as sprint, tennis, fencing lead to increased bone mineral density as well as weight lifting or heavy athletics. Swimming, bicycling, walking are associated with good musculature conditioning without an increase of bone mass. The effects on the bone by performing endurance activities are controversially discussed. Excessive sport leads to an increase of fatigue fractures. Low bone mass may result from hormonal disregulation in female athletes.
Various morphometric criteria have been used to define incident vertebral deformity. The aim of this analysis was to compare the relative validity of two established criteria and a novel method in ...which these criteria were combined. Men and women aged 50 years and over were recruited from population registers across Europe and had lateral spinal radiographs performed using a standard protocol. A subsample of individuals had bone mineral density (BMD) at the spine or femoral neck. Subjects were followed prospectively and a subsample had repeat spinal radiographs a median of 3.8 years after the baseline survey. All radiographs were evaluated morphometrically in the radiology coordinating center in Berlin. Anterior, middle and posterior height were recorded in all vertebrae from T4 to L4. On the basis of these morphometric measurements incident vertebral deformity was defined using one of three methods: (i) the change method - a change in any vertebral height of 20% or more between films, plus the additional requirement that a vertebral body have changed in absolute vertebral height by 4 mm or more; (ii) the point prevalence method, where a vertebra satisfies criteria for a prevalent deformity (McCloskey-Kanis) on the follow-up, though not the baseline film; (iii) a combination of the height reduction and the point prevalence criteria. Paired films were also evaluated qualitatively by an experienced radiologist for the presence of incident vertebral deformity. Logistic regression was used to compare the three morphometric methods using known risk factors for vertebral deformity including age, baseline vertebral deformity and BMD, and the qualitative evaluation. Computer simulation was used to determine the potential degree of bias and loss of statistical efficiency due to misclassification for each of the three methods, using the radiologist's assessment of incident deformity as the reference. Six thousand eight hundred subjects were included in this analysis. Of these 450 had sustained an incident vertebral deformity according to at least one of the three morphometric methods. The distribution of risk factors was similar in the subjects who satisfied only one morphometric criterion and those who satisfied neither. However, the subjects who satisfied both criteria had a very different distribution of risk factors: they were older, more likely to be female, more likely to have had a previous vertebral deformity and more likely to have an incident fracture in the opinion of an experienced radiologist. Using computer simulation, at low incidence levels, combining the criteria led to greater statistical efficiency and less bias in estimating associations with risk factors. Thus in this analysis the combination of the point prevalence and 20% change in height criterion for defining incident vertebral deformity showed a stronger relationship with clinical risk factors than either single criterion. Its application in population-based studies would increase the likelihood of detecting risk factors for incident vertebral deformity for a given sample size.
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