EXTENSIVE EXPERTISE IN ENDOCRINOLOGY: Osteoporosis management

Duration of fracture prevention after zoledronate treatment in women with osteopenia: observational follow-up of a 6-year randomised controlled trial to 10 years

BACKGROUND

We previously identified that zoledronate administered at 18-month intervals reduced fragility fractures by a third in a 6-year trial of women older than 65 years with osteopenia. This extension aims to identify the persistence of these effects.

METHODS

Of the 2000 ambulant, community dwelling, postmenopausal women older than 65 years recruited in Auckland, New Zealand, with T-scores at the total hip or femoral neck in the range -1·0 to -2·5, we invited participants who received four doses of intravenous zoledronate, completed follow-up to year 6 of the core trial, did not have metabolic bone disease (other than osteoporosis), and were not using bone-active drugs into this 4-year observational study extension, during which further treatment was at the discretion of their own doctors. Participants were asked to notify study staff of any new fractures and were telephoned at 7·5 years and 9·0 years to update their health status. Participants were then invited to an onsite visit at 10·0 years. Fractures and other health events were documented at each contact and analysed in all women who entered the extension, and bone mineral density (BMD; analysed in participants without notable use of bone-active medications who attended an onsite visit at 10 years) and turnover markers (measured from fasting morning blood in a random subset of 50 participants) were measured at year 10.

FINDINGS

Of the 1000 women randomly assigned to receive zoledronate in the core trial, 796 participants were eligible for the extension, of whom 762 (96%) entered the extension between Sept 24, 2015, and Dec 13, 2017. Mean follow-up duration was 4·24 years (SD 0·57, range 0·61-6·55; final follow-up on May 25, 2022). 727 (91%) of participants were assessed at 10 years. 25 women died during the extension, six withdrew for medical reasons, and four were lost to follow-up. 92 women suffered 114 non-vertebral fractures during the extension. Non-vertebral fracture rates increased from a nadir of 15 fractures per 1000 woman-years (95% CI 10-21) in the last 2 years of the core trial to 24 fractures (17-33) in years 6-8 and 42 fractures (32-53) in years 8-10, similar to that in the placebo group in the last 2 years of the core trial. Total hip BMD (relative risk per 0·1 g/cm2 0·73, 95% CI 0·57-0·93; p=0·011) and a previous history of non-vertebral fracture (1·74, 1·12-2·69; p=0·013) at year 6 predicted incident fractures but change in total hip BMD did not. Total hip BMD decreased from 4·2% above study baseline to 0·8% above baseline (p<0·0001) during the extension. Turnover markers were not useful for predicting BMD loss in individuals. Osteonecrosis of the jaw or atypical femoral fractures did not occur in any participants.

INTERPRETATION

The reduced fracture rates following zoledronate in the core trial were substantially maintained for 1·5-3·5 years after the last zoledronate infusion, but not thereafter.

FUNDING

Health Research Council of New Zealand.

Medication-related osteonecrosis of the jaw (MRONJ): a review of pathogenesis hypothesis and therapy strategies

Medication-related osteonecrosis of the jaw (MRONJ), a severe side effect caused by antiresorptive antiangiogenic medication, particularly bisphosphonates (BPs), has become a challenging disease with serious and profound effects on the physical and mental health of patients. Although it occurs with high frequency and is harmful, the exact mechanism of MRONJ remains unknown, and systematic and targeted approaches are still lacking. Maxillofacial surgeons focus on the etiology of osteonecrosis in the mandible and maxilla as well as the appropriate oral interventions for high-risk patients. Adequate nursing care and pharmacotherapy management are also crucial. This review provides a current overview of the clinicopathologic feature and research of MRONJ caused by BPs, with an emphasis on the potential mechanisms and current therapy and prevention strategies of the disease. We are of the opinion that an in-depth comprehension of the mechanisms underlying MRONJ will facilitate the development of more precise and efficacious therapeutic approaches, resulting in enhanced clinical outcomes for patients.

Application of neural network and nomogram for the prediction of risk factors for bone mineral density abnormalities: A cross-sectional NHANES-based survey

Background

The risk of bone mineral density abnormalities is inconsistent between eastern and western regions owing to differences in ethnicity and dietary habits. A diet comprising carbohydrates and dietary fiber is not the common daily diet of the American population. Thus far, no studies have assessed the risk of bone mineral density abnormalities in the American population, and no predictive model has considered the intake of carbohydrates, dietary fiber, and coffee, as well as levels of various electrolytes for assessing bone mineral density abnormalities, especially in the elderly. This study conducted a neural network analysis and established a predictive nomogram considering an unusual diet to determine risk factors for bone mineral density abnormalities in the American population, mainly to provide a reference for the prevention and treatment of related bone mineral density abnormalities.

Methods

Overall, 9871 patients who had complete data were selected from the National Health and Nutrition Examination Survey database during 2017-2020 as the research object, and patients' general clinical characteristics were compared. Neural networks and nomograms were analyzed to screen for and quantify risk factors for bone mineral density abnormalities. Finally, the receiver operating characteristic (ROC) curve, calibration curve, decision curve analysis (DCA), and community indifference curve (CIC) were constructed to comprehensively verify the accuracy, differential ability, and clinical practicability of the neural network and nomogram.

Results

The important risk factors for bone mineral density abnormalities were caffeine intake, carbohydrate consumption, body mass index (BMI), height, blood sodium, blood calcium, blood phosphorus, blood potassium, dietary fiber, vitamin D, participant age, weight, race, family history, and sex. The nomogram revealed that caffeine intake, carbohydrate consumption, blood potassium, and age were positively correlated with bone mineral density abnormalities, whereas BMI, height, blood phosphate, dietary fiber, and blood sodium were negatively correlated with bone mineral density abnormalities. Women were more prone to these abnormalities than men. The area under the ROC curve values of the neural network and nomogram were 85.8 % and 77.7 %, respectively. The Youden index was 58.04 % and 41.87 %, respectively. The detection sensitivity was 75.73 % and 65.06 %, respectively, and the specificity was 82.31 % and 76.81 %, respectively. Calibration curves of the neural network and nomogram showed better discrimination ability from the standard curve (P > 0.05). DCA and CIC analyses showed that the application of the neural network and nomogram to explore risk factors for bone mineral density abnormalities had certain clinical practicability, and the overall predictive effect of the model was good.

Conclusion

The outcomes of the neural network and nomogram analyses suggested that diet structure and electrolyte changes are important significant risk factors for bone mineral density abnormalities, especially with increasing carbohydrate and caffeine intake and decreasing dietary fiber intake. The established model can also provide a reference for future risk prediction.

Identification of hub genes and therapeutic drugs in osteonecrosis of the femoral head through integrated bioinformatics analysis and literature mining

Osteonecrosis of the femoral head (ONFH) is a multifactorial disease leading to severely limited function. By far, the etiology and pathogenesis of ONFH are not fully understood, and surgery is the only effective way to treat ONFH. This study aims to identify hub genes and therapeutic drugs in ONFH. Two gene expression profiles were downloaded from the gene expression omnibus database, and the hub genes and candidate drugs for ONFH were identified through integrated bioinformatics analysis and cross-validated by literature mining. A total of 159 DEGs were identified. PTGS2, LRRK2, ANXA5, IGF1R, MCL1, TIMP2, LYN, CD68, CBL, and RUNX2 were validated as 10 hub genes, which has considerable implications for future genetic research and related research fields of ONFH. Our findings indicate that 85 drugs interact with ONFH, with most drugs exhibiting a positive impact on ONFH by promoting osteogenesis and angiogenesis or inhibiting microcirculation embolism, rather than being anti-inflammatory. Our study provides novel insights into the pathogenesis, prevention, and treatment of ONFH.

New insights into the role of long non-coding RNAs in osteoporosis

Osteoporosis is a common disease in elderly individuals, and osteoporosis can easily lead to bone and hip fractures that seriously endanger the health of elderly individuals. At present, the treatment of osteoporosis is mainly anti-osteoporosis drugs, but there are side effects associated with anti-osteoporosis drugs. Therefore, it is very important to develop early diagnostic indicators and new therapeutic drugs for the prevention and treatment of osteoporosis. Long noncoding RNAs (lncRNAs), noncoding RNAs longer than 200 nucleotides, can be used as diagnostic markers for osteoporosis, and lncRNAs play an important role in the progression of osteoporosis. Many studies have shown that lncRNAs can be the target of osteoporosis. Therefore, herein, the role of lncRNAs in osteoporosis is summarized, aiming to provide some information for the prevention and treatment of osteoporosis.

Toosendanin inhibits osteoclast formation and alleviate postmenopausal osteoporosis by regulating the p38 signaling pathway

Disruption of the balance between osteoclasts and osteoblasts could lead to bone diseases including osteoporosis. It's well known that RANKL-RANK signaling plays a vital role in activating osteoclasts. Herein, we explored the therapeutic effects of toosendanin (TSN) in osteoporosis, showing that TSN attenuated RANKL-stimulated osteoclastogenesis and osteoclast-specific gene expression in vitro. Bioinformatics predicted that TSN could interfere p38 subunits and regulate the MAPK cascade, and we further verified and demonstrated that TSN significantly inhibited RANKL-induced p38 signaling through western blot. In ovariectomized mouse model, TSN effectively inhibited the formation of TRAP-positive osteoclasts and exhibited protective effect against bone loss. Altogether, these data indicate that TSN targeted p38 activation to inhibit osteoclastogenesis, suggesting the possible therapeutic use of TSN in osteoporosis in the future.

Role of metabolic equivalent between calcium intake and vertebral fractures: a cross-sectional study of NHANES 2013-2014

BACKGROUND

This study was to analyze the association of calcium intake and metabolic equivalent (MET) with vertebral fractures, and to explore the role of MET between calcium intake and vertebral fractures.

METHOD

This cross-sectional study used data from the National Health and Nutrition Examination Surveys (NHANES) 2013-2014. The study involved individuals aged ≥ 50 years old with complete information on vertebral fracture, calcium intake, and physical activity. Vertebral fracture assessment is obtained using dual-energy x-ray absorptiometry to perform a lateral scan of the thoracolumbar spine. Calcium intake included total nutrient intake and total dietary supplements. The total MET is the sum of the METs for each activity (Vigorous/ moderate work-related activities, walking or bicycling for transportation and vigorous/ moderate recreational activities). Univariate and multivariate logistic regression analyses were utilized to investigate the effect of calcium intake, MET, and their combined effect on vertebral fracture.

RESULTS

A total of 766 participants were included in the analysis, and 54 participants had vertebral fractures. The median calcium intake and MET were 8.43 mcg and 280.00, respectively. Multivariate results showed that neither calcium intake nor MET as continuous or categorical variables was significantly associated with vertebral fractures. MET < 160 and calcium intake ≥ 670 mg group was associated with the decreased risks of vertebral fracture [odds ratio (OR) = 0.47, 95% confidence interval (CI): 0.26-0.83, P = 0.032] after adjusting for age, race, energy, total femur bone mineral density (BMD), and femoral neck BMD. In the group of MET < 160, increased calcium intake was associated with a reduced risk of vertebral fracture, with a decreased OR value. In the group of MET ≥ 160, increased calcium intake was associated with an increased risk of vertebral fracture, with an increased OR value.

CONCLUSION

The combination of MET < 160 and calcium intake ≥ 670 mg was associated with decreased risks of vertebral fractures. There may be an interaction between calcium intake and MET on vertebral fracture risk.