Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study

Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual‐energy X‐ray (DXA)‐based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case‐cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT‐based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA‐based BMD leads to a small but significant (p < 0.005) improvement in model prediction for any fracture, with AUC increasing from 0.78 to 0.79, assessed using leave‐one‐out cross‐validation. For specific fracture types, the improvement is more significant (p < 0.0001), with AUC increasing from 0.71 to 0.77 for trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA‐based BMD to a CBM‐based predictive model does not result in any significant improvement. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.     

Overview of recruitment for the osteoporotic fractures in men study (MrOS)

Large, long term research studies present recruitment challenges that can be met with collaborative approaches to identify and enroll participants. The Osteoporotic Fractures in Men Study (MrOS), a multi-center observational study designed to determine risk factors for osteoporosis, fractures and prostate cancer in older men, recruited 5995 participants over a 25-month period. Enrolling a cohort that represented the race and age distribution of each community, and developing interest in an older male cohort about a condition commonly thought of as a "women's disease," were major recruitment challenges. During the start-up phase, recruitment challenges and strategies were analyzed and collective approaches were developed to address ways to motivate the target population. Key methods included mailings using community and provider contact lists; regional and senior newspaper advertisements; and presentations targeted to seniors. Sites used a centrally developed recruitment brochure. Response to mass mailings at some sites surpassed 10-15% and appointment show rates averaged above 85%. The final number enrolled in MrOS was 5% more than the original recruitment goal of 5700. Minority recruitment was enhanced through the use of the Health Care Financing Administration and other databases that allowed for targeted recruitment. Overall, minority enrollment was approximately 10.56% of the cohort (244 African American, 191 Asian). Men age>80 were enthusiastic and represent about 18% of enrollees. Through a coordinated approach of developing and refining recruitment strategies and materials, sites were able to adapt their original strategies and complete recruitment ahead of schedule.     

Cancer‐like metabolism of the mammalian retina

The retina, like many cancers, produces energy from glycolysis even in the presence of oxygen. This phenomenon is known as aerobic glycolysis and eponymously as the Warburg effect. In recent years, the Warburg effect has become an explosive area of study within the cancer research community. The expanding knowledge about the molecular mechanisms underpinning the Warburg effect in cancer promises to provide a greater understanding of mammalian retinal metabolism and has motivated cancer researchers to target the Warburg effect as a novel treatment strategy for cancer. However, if the molecular mechanisms underlying the Warburg effect are shared by the retina and cancer, treatments targeting the Warburg effect may have serious adverse effects on retinal metabolism. Herein, we provide an updated understanding of the Warburg effect in mammalian retina.     

The Role of Self-Beliefs in Predicting Postschool Outcomes for Deaf Young Adults

The aim of this study was to explore the role of self-beliefs in predicting postschool outcomes for deaf young adults in transition from secondary settings. Three self-level constructs were explored: self-concept, self-determination, and expectations about the future. This study utilized data from the National Longitudinal Transition Study-2 (NLTS2) that collected longitudinal data from youths with disabilities across the nation, 550 of which were deaf or hard of hearing and met the selection criteria in this study. This study examined the relationships between these deaf adolescents’ self-beliefs and actual future achievements that were reached as they transitioned to adult life, in three domains: life, employment, and education. Despite the generally positive self-beliefs of deaf individuals, which were, in some cases, related to postschool outcomes, the self-beliefs assessed in this study did not emerge as comprehensive predictors of postschool attainments. Findings suggest that for deaf individuals, successfully navigating transitions to adult life involves dimensions beyond individual agency. Positive self-beliefs are clearly a part of successfully attaining postschool outcomes, but deaf individuals may not have full access to equitable opportunities to capitalize on these beliefs.