Loss of hip bone mineral density over time is associated with spine and hip fracture incidence in osteoporotic postmenopausal women

Modelling future bone mineral density: Simplicity or complexity?

BACKGROUND

Osteoporotic fractures are a major global public health issue, leading to patient suffering and death, and considerable healthcare costs. Bone mineral density (BMD) measurement is important to identify those with osteoporosis and assess their risk of fracture. Both the absolute BMD and the change in BMD over time contribute to fracture risk. Predicting future fracture in individual patients is challenging and impacts clinical decisions such as when to intervene or repeat BMD measurement. Although the importance of BMD change is recognised, an effective way to incorporate this marginal effect into clinical algorithms is lacking.

METHODS

We compared two methods using longitudinal DXA data generated from subjects with two or more hip DXA scans on the same machine between 2000 and 2018. A simpler statistical method (ZBM) was used to predict an individual's future BMD based on the mean BMD and the standard deviation of the reference group and their BMD measured in the latest scan. A more complex deep learning (DL)-based method was developed to cope with multidimensional longitudinal data, variables extracted from patients' historical DXA scan(s), as well as features drawn from the ZBM method. Sensitivity analyses of several subgroups was conducted to evaluate the performance of the derived models.

RESULTS

2948 white adults aged 40-90 years met our study inclusion: 2652 (90 %) females and 296 (10 %) males. Our DL-based models performed significantly better than the ZBM models in women, particularly our Hybrid-DL model. In contrast, the ZBM-based models performed as well or better than DL-based models in men.

CONCLUSIONS

Deep learning-based and statistical models have potential to forecast future BMD using longitudinal clinical data. These methods have the potential to augment clinical decisions regarding when to repeat BMD testing in the assessment of osteoporosis.

Femoral neck fracture in sickle cell anemia: A comprehensive case study

Key Clinical Message

The significance of taking femoral neck stress fractures into account as a possible consequence in sickle cell anemia patients is underscored by this case report. In this high-risk group, early identification, timely diagnosis, and suitable care are crucial for averting major problems and improving results. When sickle cell anemia patients complain with hip or groin discomfort, healthcare practitioners should keep a high index of suspicion for femoral neck stress fractures to assure prompt management and prevent long-term impairment.

Abstract

Sickle cell disease (SCD) is a prevalent genetic hemoglobinopathy with significant global implications, affecting a substantial portion of the population. Avascular necrosis of the femoral head is a common complication in SCD, leading to severe joint damage and immobility. This case report is of a 20-year-old male who presented with severe hip pain due to a femoral neck stress fracture, which progressed to a complete fracture. This patient had a past medical history of sickle cell anemia and a malunited subtrochanteric fracture that resulted in shortening, external rotation, and a limping gait. Surgical treatment via subtrochanteric osteotomy with fixation using a dynamic hip screw with or without iliac crest bone graft was planned, with a satisfactory reduction and closure of the fracture gap, postoperatively. In cases of sickle cell anemia patients, bone complications such as both osteonecrosis and stress fractures are common. As a healthcare provider, it is important to manage and address these not only through medical interventions, but also through counseling and patient education. Patients must be reminded about the importance of compliance with medical advice to avoid progression or recurrence of complications.

Follow-up Bone Mineral Density Testing: 2023 Official Positions of the International Society for Clinical Densitometry

Dual-energy X-ray absorptiometry (DXA) is the gold standard method for measuring bone mineral density (BMD) which is most strongly associated with fracture risk. BMD is therefore the basis for the World Health Organization's densitometric definition of osteoporosis. The International Society for Clinical Densitometry (ISCD) promotes best densitometry practices and its official positions reflect critical review of current evidence by domain experts. This document reports new official positions regarding follow-up DXA examinations based on a systematic review of literature published through December 2022. Adoption of official positions requires consensus agreement from an expert panel following a modified RAND protocol. Unless explicitly altered by the new position statements, prior ISCD official positions remain in force. This update reflects increased consideration of the clinical context prompting repeat examination. Follow-up DXA should be performed with pre-defined objectives when the results would have an impact on patient management. Testing intervals should be individualized according to the patient's age, sex, fracture risk and treatment history. Incident fractures and therapeutic approach are key considerations. Appropriately ordered and interpreted follow-up DXA examinations support diagnostic and therapeutic decision making, thereby contributing to excellent clinical care. Future research should address the complementary roles of clinical findings, imaging and laboratory testing to guide management.

Repeating Measurement of Bone Mineral Density when Monitoring with Dual-energy X-ray Absorptiometry: 2019 ISCD Official Position

Bone mineral density (BMD) can be measured at multiple skeletal sites using various technologies to aid clinical decision-making in bone and mineral disorders. BMD by dual-energy X-ray absorptiometry (DXA) has a critical role in predicting risk of fracture, diagnosis of osteoporosis, and monitoring patients. In clinical practice, DXA remains the most available and best validated tool for monitoring patients. A quality baseline DXA scan is essential for comparison with all subsequent scans. Monitoring patients with serial measurements requires technical expertise and knowledge of the least significant change in order to determine when follow-up scans should be repeated. Prior ISCD Official Positions have clarified how and when repeat DXA is useful as well as the interpretation of results. The 2019 ISCD Official Positions considered new evidence and clarifies if and when BMD should be repeated. There is good evidence showing that repeat BMD measurement can identify people who experience bone loss, which is an independent predictor of fracture risk. There is good evidence showing that the reduction in spine and hip fractures with osteoporosis medication is proportional to the change in BMD with treatment. There is evidence that measuring BMD is useful following discontinuation of osteoporosis treatment. There is less documentation addressing the effectiveness of monitoring BMD to improve medication adherence, whether monitoring of BMD reduces the risk of fracture, or effectively discriminates patients who should and should not recommence treatment following an interruption of medication. Further research is needed in all of these areas.

Changes in Bone Mineral Density in the Year after Critical Illness

RATIONALE

Critical illness may be associated with increased bone turnover and loss of bone mineral density (BMD). Prospective evidence describing long-term changes in BMD after critical illness is needed to further define this relationship.

OBJECTIVES

To measure the change in BMD and bone turnover markers (BTMs) in subjects 1 year after critical illness compared with population-based control subjects.

METHODS

We studied adult patients admitted to a tertiary intensive care unit (ICU) who required mechanical ventilation for at least 24 hours. We measured clinical characteristics, BTMs, and BMD during admission and 1 year after ICU discharge. We compared change in BMD to age- and sex-matched control subjects from the Geelong Osteoporosis Study.

MEASUREMENTS AND MAIN RESULTS

Sixty-six patients completed BMD testing. BMD decreased significantly in the year after critical illness at both femoral neck and anterior-posterior spine sites. The annual decrease was significantly greater in the ICU cohort compared with matched control subjects (anterior-posterior spine, -1.59%; 95% confidence interval, -2.18 to -1.01; P < 0.001; femoral neck, -1.20%; 95% confidence interval, -1.69 to -0.70; P < 0.001). There was a significant increase in 10-year fracture risk for major fractures (4.85 ± 5.25 vs. 5.50 ± 5.52; P < 0.001) and hip fractures (1.57 ± 2.40 vs. 1.79 ± 2.69; P = 0.001). The pattern of bone resorption markers was consistent with accelerated bone turnover.

CONCLUSIONS

Critically ill individuals experience a significantly greater decrease in BMD in the year after admission compared with population-based control subjects. Their bone turnover biomarker pattern is consistent with an increased rate of bone loss.

Relationships between changes in bone mineral density or bone turnover markers and vertebral fracture incidence in patients treated with bazedoxifene

We analyzed the relationships between bone mineral density (BMD) or bone turnover marker (BTM) changes and vertebral fracture incidence in women treated with bazedoxifene using a post hoc analysis from a 3-year randomized, placebo-controlled study evaluating the effect of bazedoxifene (20 or 40 mg) on fracture risk reduction. BMD was assessed at baseline and every 6 months for 3 years. Osteocalcin and C-telopeptide of type I collagen were assessed at baseline and at 3, 12, and 36 months. Vertebral fractures were assessed with a semiquantitative visual assessment. Data were available for 5,244 women, of whom 3,476 were treated with bazedoxifene. Using a logistic regression analysis and the classical Li approach, the proportion of fracture incidence explained by BMD change after 3 years of bazedoxifene treatment was 29 % for the total hip and 44 % for the femoral neck. The proportion of treatment explained by lumbar BMD change could not be quantified accurately because of the significant interaction between treatment and change in BMD. With the same model, the 12-month BTM changes explained up to 29 % of the fracture risk reduction observed with the two forms of bazedoxifene. In women treated with bazedoxifene, changes in femoral neck BMD, hip BMD, or BTMs explained a moderate proportion of the fracture risk reduction observed during the 3 years of follow-up. However, BMD or BTM changes cannot be recommended for individual monitoring of women treated with bazedoxifene.

Change in hip bone mineral density and risk of subsequent fractures in older men

Low bone mineral density (BMD) increases fracture risk; how changes in BMD influence fracture risk in older men is uncertain. BMD was assessed at two to three time points over 4.6 years using dual-energy X-ray absorptiometry (DXA) for 4470 men aged ≥65 years in the Osteoporotic Fractures in Men (MrOS) Study. Change in femoral neck BMD was estimated using mixed effects linear regression models. BMD change was categorized as "accelerated" (≤-0.034 g/cm(2) ), "expected" (between 0 and -0.034 g/cm(2) ), or "maintained" (≥0 g/cm(2) ). Fractures were adjudicated by central medical record review. Multivariate proportional hazards models estimated the risk of hip, nonspine/nonhip, and nonspine fracture over 4.5 years after the final BMD measure, during which time 371 (8.3%) men experienced at least one nonspine fracture, including 78 (1.7%) hip fractures. Men with accelerated femoral neck BMD loss had an increased risk of nonspine (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.4-2.8); nonspine/nonhip (HR = 1.6; 95% CI 1.1-2.3); and hip fracture (HR = 6.3; 95% CI 2.7-14.8) compared with men who maintained BMD over time. No difference in risk was seen for men with expected loss. Adjustment for the initial BMD measure did not alter the results. Adjustment for the final BMD measure attenuated the change in BMD-nonspine fracture and the change in BMD-nonspine/nonhip relationships such that they were no longer significant, whereas the change in the BMD-hip fracture relationship was attenuated (HR = 2.6; 95% CI 1.1-6.4). Total hip BMD change produced similar results. Accelerated decrease in BMD is a strong, independent risk factor for hip and other nonspine fractures in men.

Can Hip Fracture Prediction in Women be Estimated beyond Bone Mineral Density Measurement Alone?

The etiology of hip fractures is multifactorial and includes bone and fall-related factors. Low bone mineral density (BMD) and BMD-related and BMD-independent geometric components of bone strength, evaluated by hip strength analysis (HSA) and finite element analysis analyses on dual-energy X-ray absorptiometry (DXA) images, and ultrasound parameters are related to the presence and incidence of hip fracture. In addition, clinical risk factors contribute to the risk of hip fractures, independent of BMD. They are included in the fracture risk assessment tool (FRAX) case finding algorithm to estimate in the individual patient the 10-year risk of hip fracture, with and without BMD. Fall risks are not included in FRAX, but are included in other case finding tools, such as the Garvan algorithm, to predict the 5- and 10-year hip fracture risk. Hormones, cytokines, growth factors, markers of bone resorption and genetic background have been related to hip fracture risk. Vitamin D deficiency is endemic worldwide and low serum levels of 25-hydroxyvitamin D [25(OH)D] predict hip fracture risk. In the context of hip fracture prevention calculation of absolute fracture risk using clinical risks, BMD, bone geometry and fall-related risks is feasible, but needs further refinement by integrating bone and fall-related risk factors into a single case finding algorithm for clinical use.

Non-pharmacological management of osteoporosis: a consensus of the Belgian Bone Club

This consensus article reviews the various aspects of the non-pharmacological management of osteoporosis, including the effects of nutriments, physical exercise, lifestyle, fall prevention, and hip protectors. Vertebroplasty is also briefly reviewed. Non-pharmacological management of osteoporosis is a broad concept. It must be viewed as an essential part of the prevention of fractures from childhood through adulthood and the old age. The topic also includes surgical procedures for the treatment of peripheral and vertebral fractures and the post-fracture rehabilitation. The present document is the result of a consensus, based on a systematic review and a critical appraisal of the literature. Diets deficient in calcium, proteins or vitamin D impair skeletal integrity. The effect of other nutriments is less clear, although an excessive consumption of sodium, caffeine, or fibres exerts negative effects on calcium balance. The deleterious effects of tobacco, excessive alcohol consumption and a low BMI are well accepted. Physical activity is of primary importance to reach optimal peak bone mass but, if numerous studies have shown the beneficial effects of various types of exercise on bone mass, fracture data as an endpoint are scanty. Fall prevention strategies are especially efficient in the community setting, but less evidence is available about their effectiveness in preventing fall-related injuries and fractures. The efficacy of hip protectors remains controversial. This is also true for vertebroplasty and kyphoplasty. Several randomized controlled studies had reported a short-term advantage of vertebroplasty over medical treatment for pain relief, but these findings have been questioned by recent sham-controlled randomized clinical studies.

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Osteoblast specific Y1 receptor deletion enhances bone mass

Neuropeptide Y, Y1 receptors are found in neuronal as well as bone tissue and Y1 signalling has been implicated in the regulation of bone mass. However, the contribution of Y1 receptors located in these different tissues, particularly that of the bone-specific Y1 receptors, to the regulation of bone homeostasis is unclear. Here we demonstrate that osteoblast-specific Y1 receptor deletion resulted in a marked increase in femoral cancellous bone volume, trabecular thickness and trabecular number. This is the result of elevated osteoblast activity as shown by increased mineral apposition rate and bone formation rate, and is associated with an upregulation in the mRNA expression levels of alkaline phosphatase, osteocalcin and dentin matrix protein-1. Furthermore, osteoblastic Y1 receptor deletion also led to increased mineral apposition rate on both the endocortical and the periosteal surfaces resulting in increased femoral diameter. Together these data demonstrate a direct role for the Y1 receptor on osteoblasts in the regulation of osteoblast activity and bone formation in vivo and suggest that targeting Y1 receptor signalling directly in the bone may have potential therapeutic implications for stimulating bone accrual in diseases such as osteoporosis.

The Shanghai Changfeng Study: a community-based prospective cohort study of chronic diseases among middle-aged and elderly: objectives and design

The Shanghai Changfeng Study is a community-based prospective cohort study of chronic diseases ongoing since February 2009 in Shanghai, China. The study focuses on multiple chronic diseases, including obesity and metabolic syndrome, diabetes, osteoporosis, liver diseases, cardiovascular diseases and neurologic diseases. 15,000 subjects of 40 years or over are planned to be recruited. The rationale, objectives and design of this study are described in this paper.

The Generation R Study: design and cohort update 2010

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health during fetal life, childhood and adulthood. The study focuses on four primary areas of research: (1) growth and physical development; (2) behavioural and cognitive development; (3) diseases in childhood; and (4) health and healthcare for pregnant women and children. In total, 9,778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. General follow-up rates until the age of 4 years exceed 75%. Data collection in mothers, fathers and preschool children included questionnaires, detailed physical and ultrasound examinations, behavioural observations, and biological samples. A genome wide association screen is available in the participating children. Regular detailed hands on assessment are performed from the age of 5 years onwards. Eventually, results forthcoming from the Generation R Study have to contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.