No abstract

Self-reported frailty is associated with low calcaneal BMD and can be used to identify subjects with a greater risk of osteoporosis than expected from traditional risk factors.

Osteoporotic fractures are related not only to bone mineral density (BMD) but also to bone structure or microarchitecture, which is not assessed routinely with currently available methods. We have developed radiographic texture analysis (RTA) for calcaneal images from a peripheral densitometer as an easy, noninvasive method for assessing bone structure. We conducted a cross-sectional study of the relationship between RTA and prevalent vertebral fractures (n = 148) among 900 subjects (ages 19 to 99 years, 94 males) referred for bone densitometry as part of their routine medical care. RTA features were derived from Fourier-based image analysis of the radiographic texture pattern (including root mean square, first moment, and power spectral analyses). RTA features were associated with age, weight, gender, and race, as well as glucocorticoid use. When controlling for clinical risk factors and BMD (or a summary measure calculated using FRAX algorithms), RTA features were significantly different for subjects with and without prevalent vertebral fractures [adjusted odds ratio (OR) = 1.5 per 1 standard deviation (SD) decrease in RTA feature beta, 95% confidence interval (CI) 1.2–1.8, p = .001]. Gender and use of pharmacologic therapy for osteoporosis did not significantly affect this association, suggesting that RTA can be applied to a wide range of densitometry patients. We conclude that RTA obtained using a portable instrument has a potential as a noninvasive method to enhance identification of patients at increased risk of osteoporotic fractures. Copyright © 2010 American Society for Bone and Mineral Research

The 2013 Position Development Conference of the International Society for Clinical Densitometry (ISCD) has adopted simplified indications for vertebral fracture assessment (VFA) based on an analysis of the Study of Osteoporotic Fractures (SOF). This showed that a simpler regression model, which included only age, bone mineral density (BMD), and height loss, was able to differentiate women with vertebral fractures from those without vertebral fractures almost as well as more complex models. We aimed to verify these findings in 1228 women referred for BMD testing and determine if the 2013 ISCD indications for VFA would perform as well the 2007 indications. The simple and complex SOF-based models were similar in terms of sensitivity (88.4% vs 89.4%), specificity (44.4% vs 45.5%), positive (25.9% vs 26.5%) and negative (94.5% vs 95.1%) predictive values, and area under the receiver operating characteristics curve (AUROC) (0.664 vs 0.674). The 2013 and 2007 ISCD VFA indications did not differ significantly in terms of sensitivity (88.2% vs 91.3%), specificity (41.3% vs 37.5%), positive (25.3% vs 22.9%) and negative (93.9% vs 95.5%) predictive values, and AUROC (0.648 vs 0.644). Our study provides support for the use of the simplified 2013 ISCD VFA indications as a practical approach to VFA testing.

The human brain is generally anatomically symmetrical, boasting mirror-like brain regions in the left and right hemispheres. Despite this symmetry, fine-scale structural asymmetries are prevalent and are believed to be responsible for distinct functional divisions within the brain. Prior studies propose that these asymmetric structures are predominantly primate-specific or even unique to humans, suggesting that the genes contributing to the structural asymmetry of the human brain might have evolved recently. In our study, we identified approximately 1,500 traits associated with human brain asymmetry by collecting paired brain MRI features from the UK Biobank. Each trait is measured in a specific region of one hemisphere and mirrored in the corresponding region of the other hemisphere. Conducting genome-wide association studies on these traits, we identified over 1,000 quantitative trait loci (QTLs). Around these index single nucleotide polymorphisms (SNPs), we found approximately 200 genes that are enriched in brain-related Gene Ontology terms and are predominantly up-regulated in brain tissues. Interestingly, most of these genes are evolutionarily old, originating just prior to the emergence of Bilateria (bilaterally symmetrical animals) and Euteleostomi (bony vertebrates with a brain), at a significantly higher ratio than expected. Further analyses of these genes reveal a brain-specific up-regulation in humans relative to other mammalian species. This suggests that the structural asymmetry of the human brain has been shaped by evolutionarily ancient genes that have assumed new functions over time.