The correlation between bone mineral density/trabecular bone score and body mass index, height, and weight

Genetics and pathogenesis of scoliosis

Background

Scoliosis is defined as a lateral spine curvature of at least 10° with vertebral rotation, as seen on a posterior-anterior radiograph, often accompanied by reduced thoracic kyphosis. Scoliosis affects all age groups: idiopathic scoliosis is the most common spinal disorder in children and adolescents, while adult degenerative scoliosis typically affects individuals over fifty. In the United States, approximately 3 million new cases of scoliosis are diagnosed annually, with a predicted increase in part due to global aging. Despite its prevalence, the etiopathogenesis of scoliosis remains unclear.

Methods

This comprehensive review analyzes the literature on the etiopathogenetic evidence for both idiopathic and adult degenerative scoliosis. PubMed and Google Scholar databases were searched for studies on the genetic factors and etiopathogenetic mechanisms of scoliosis development and progression, with the search limited to articles in English.

Results

For idiopathic scoliosis, genetic factors are categorized into three groups: genes associated with susceptibility, disease progression, and both. We identify gene groups related to different biological processes and explore multifaceted pathogenesis of idiopathic scoliosis, including evolutionary adaptations to bipedalism and developmental and homeostatic spinal aberrations. For adult degenerative scoliosis, we segregate genetic and pathogenic evidence into categories of angiogenesis and inflammation, extracellular matrix degradation, neural associations, and hormonal influences. Finally, we compare findings in idiopathic scoliosis and adult degenerative scoliosis, discuss current limitations in scoliosis research, propose a new model for scoliosis etiopathogenesis, and highlight promising areas for future studies.

Conclusions

Scoliosis is a complex, multifaceted disease with largely enigmatic origins and mechanisms of progression, keeping it under continuous scientific scrutiny.

Age estimation at death in individuals over 50 using CT images: An innovative anthropological approach

OBJECTIVES

The aim of the present work is to develop a novel method for predicting age in individuals over 50 years old, utilizing regression models.

METHODS

The conducted study is of an analytical cross-sectional nature, involving a sample of 44 young subjects and 107 elderly subjects. The necessary data for this research were extracted from "The New Mexico Decedent Image Database." Based on the phenomenon of height shrinkage with age, we created models for young subjects and applied them to elderly subjects, allowing us to extract the variables.

RESULTS

We obtained highly encouraging results with an R2 of 0.73, a mean absolute error of 3.94, and stable cross-validation. We used a Student's t-test, which demonstrated no significant difference between predicted and actual values (p-value >0.05). We also conducted a learning curve analysis and examined residuals against predicted values. This suggests that the forecasts are accurate, with no significant bias in predictions.

CONCLUSION

This work has allowed us to conclude that it is possible to reliably estimate the age of subjects over 50, taking into account age-related physiological and pathological changes.

Correlation between Forearm Bone Mineral Density Measured by Dual Energy X-ray Absorptiometry and Hounsfield Units Value Measured by CT in Lumbar Spine

BACKGROUND

Our aim was to determine if the dual-energy X-ray absorptiometry (DXA)-measured forearm bone mineral density (BMD) correlates with the Hounsfield unit (HU) values obtained from computed tomography (CT).

METHODS

A retrospective analysis of 164 patients with degenerative diseases of the lumbar spine was performed. DXA was used to measure the BMD and T-scores of each patient's forearm. Lumbar CT was used to measure the CT HU values in three axial images of the L1-L4 vertebral bodies, and the average was calculated. According to the preoperative DXA T-score, they were divided into a normal group, an osteopenia group, and an osteoporosis group. Pearson's correlation coefficient was used to analyze the correlations of CT HU values in L1-L4 with BMD and T-scores in the corresponding vertebral body. The receiver operating characteristic curve (ROC) was used to determine the CT HU thresholds between osteoporosis and non-osteoporosis groups.

RESULTS

Forearm BMD was moderately correlated with L1-L4 CT HU values (0.4 < R2 < 0.6), and the correlation coefficients (R2) were 0.552, 0.578, 0.582, and 0.577, respectively (all p < 0.001). Forearm T-scores were moderately correlated with L1-L4 CT HU values (0.4 < R2 < 0.6), and the correlation coefficients (R2) were 0.595, 0.609, 0.605, and 0.605, respectively (all p < 0.001). The thresholds of L1-L4 between the osteoporosis group (t ≤ -2.5) and the non-osteoporosis group (t > -2.5) were 110.0 HU (sensitivity 74% and specificity 76%), 112.5 HU (sensitivity 67% and 83% specificity), 92.4 HU (81% sensitivity and 70% specificity), and 98.7 HU (74% sensitivity and 78% specificity), respectively.

CONCLUSIONS

Based on the moderate positive correlation between forearm DXA-measured BMD and HU values, forearm DXA provides a theoretical basis for evaluating lumbar vertebral bone mass. Preoperative forearm DXA may be useful in the formulation of surgical plans and the prevention of postoperative complications in patients with lumbar degenerative diseases.

Heat-killed Limosilactobacillus reuteri ATCC PTA 6475 prevents bone loss in ovariectomized mice: A preliminary study

Osteoporosis is an important health problem that occurs due to an imbalance between bone formation and resorption. Hormonal deficiency post-menopause is a significant risk factor. The probiotic Limosilactobacillus reuteri has been reported to prevent ovariectomy (Ovx)-induced bone loss in mice and reduce bone loss in postmenopausal women. Despite the numerous health benefits of probiotics, as they are live bacteria, the administration is not risk-free for certain groups (e.g., neonates and immunosuppressed patients). We evaluated the effects of L. reuteri (ATCC PTA 6475) and its heat-killed (postbiotic) form on Ovx-induced bone loss. Adult female mice (BALB/c) were randomly divided into four groups: group C-control (sham); group OVX-C-Ovx; group OVX-POS-Ovx + heat-killed probiotic; group OVX-PRO-Ovx + probiotic. L. reuteri or the postbiotic was administered to the groups (1.3x109 CFU/day) by gavage. Bacterial morphology after heat treatment was accessed by scanning electron microscopy (SEM). The treatment started one week after Ovx and lasted 28 days (4 weeks). The animals were euthanized at the end of the treatment period. Bone microarchitecture and ileum Occludin and pro-inflammatory cytokines gene expression were evaluated by computed microtomography and qPCR techniques, respectively. The Ovx groups had lower percentage of bone volume (BV/TV) and number of bone trabeculae as well as greater total porosity compared to the control group. Treatment with live and heat-killed L. reuteri resulted in higher BV/TV and trabecular thickness than the Ovx group. The heat treatment caused some cell surface disruptions, but its structure resembled that of the live probiotic in SEM analysis. There were no statistical differences in Occludin, Il-6 and Tnf-α gene expression. Both viable and heat-killed L. reuteri prevented bone loss on ovariectomized mice, independently of gut Occludin and intestinal Il-6 and Tnf-α gene expression.

Age- and sex-related changes in vertebral trabecular bone architecture in Neolithic and Mediaeval populations from Poland

This paper investigates trabecular bone ontogenetic changes in two different Polish populations, one prehistoric and the other historical. The studied populations are from the Brześć Kujawski region in Kujawy (north-central Poland), one from the Neolithic Period (4500-4000 BC) and one from the Middle Ages (twelfth-sixteenth centuries AD), in total 62 vertebral specimens (32 males, 30 females). Eight morphometric parameters acquired from microCT scan images were analysed. Two-way ANOVA after Box-Cox transformation and multifactorial regression model were calculated. A significant decrease in percentage bone volume fraction (BV/TV; [%]) with age at death was observed in the studied sample; Tb.N (trabecular number) was also significantly decreased with age; trabecular separation (Tb.Sp) increased with advancing age; connectivity density (Conn.D) was negatively correlated with biological age and higher in the Neolithic population. These data are found to be compatible with data from the current biomedical literature, while no loss of horizontal trabeculae was recorded as would be expected based on modern osteoporosis.

A novel non-invasive method for predicting bone mineral density and fracture risk using demographic and anthropometric measures

Fractures are costly to treat and can significantly increase morbidity. Although dual-energy x-ray absorptiometry (DEXA) is used to screen at risk people with low bone mineral density (BMD), not all areas have access to one. We sought to create a readily accessible, inexpensive, high-throughput prediction tool for BMD that may identify people at risk of fracture for further evaluation. Anthropometric and demographic data were collected from 492 volunteers (♂275, ♀217; [44 ​± ​20] years; Body Mass Index (BMI) = [27.6 ​± ​6.0] kg/m2) in addition to total body bone mineral content (BMC, kg) and BMD measurements of the spine, pelvis, arms, legs and total body. Multiple-linear-regression with step-wise removal was used to develop a two-step prediction model for BMC followed by BMC. Model selection was determined by the highest adjusted R2, lowest error of estimate, and lowest level of variance inflation (α ​= ​0.05). Height (HTcm), age (years), sexm=1, f=0, %body fat (%fat), fat free mass (FFMkg), fat mass (FMkg), leg length (LLcm), shoulder width (SHWDTHcm), trunk length (TRNKLcm), and pelvis width (PWDTHcm) were observed to be significant predictors in the following two-step model (p ​< ​0.05). Step1: BMC (kg) = (0.006 3 × HT) ​+ ​(-0.002 4 × AGE) ​+ ​(0.171 2 × SEXm=1, f=0) ​+ ​(0.031 4 × FFM) ​+ ​(0.001 × FM) ​+ ​(0.008 9 × SHWDTH) ​+ ​(-0.014 5 × TRNKL) ​+ ​(-0.027 8 × PWDTH) - 0.507 3; R2 ​= ​0.819, SE ​± ​0.301. Step2: Total body BMD (g/cm2) = (-0.002 8 × HT) ​+ ​(-0.043 7 × SEXm=1, f=0) ​+ ​(0.000 8 × %FAT) ​+ ​(0.297 0 × BMC) ​+ ​(-0.002 3 × LL) ​+ ​(0.002 3 × SHWDTH) ​+ ​(-0.002 5 × TRNKL) ​+ ​(-0.011 3 × PWDTH) ​+ ​1.379; R2 ​= ​0.89, SE ​± ​0.054. Similar models were also developed to predict leg, arm, spine, and pelvis BMD (R2 ​= ​0.796-0.864, p ​< ​0.05). The equations developed here represent promising tools for identifying individuals with low BMD at risk of fracture who would benefit from further evaluation, especially in the resource or time restricted setting.

Role of Body Composition in the Prediction of Skeletal Fragility Induced by Hormone Deprivation Therapies in Cancer Patients

PURPOSE OF REVIEW

This review paper is intended to show that changes in body composition are key in the pathogenesis of bone fragility amongst patients with breast and prostate cancer receiving hormone deprivation therapies (HDTs) and that the mechanism is based on the development of alterations in bone quality rather than in bone quantity.

RECENT FINDINGS

Preclinical and clinical data suggest a tight connection amongst bone, adipose and muscular tissues by means of several soluble mediators, potentially leading to (1) bone resorption and bone quality deterioration in sarcopenic obese subjects, (2) bone mineral deposition in healthy trained subjects. Cancer patients treated with HDTs frequently fall into the first condition, named osteosarcopenic obesity. Current clinical guidelines for the prevention of treatment-induced osteoporosis focus on bone mineral density (BMD) as a main predictive factor for fracture risk; however, the pathophysiology underlying HDT-induced bone fragility differs from that of primary and postmenopausal osteoporosis, suggesting a prevalent role for bone quality alterations. Focusing on available data from clinical trials, in our review we suggest osteosarcopenic obesity as a common target for the prevention and treatment of HDTs-related metabolic and skeletal complications, beyond a BMD-centred approach.

Biological principles of adult degenerative scoliosis

The global aging population has led to an increase in geriatric diseases, including adult degenerative scoliosis (ADS). ADS is a spinal deformity affecting adults, particularly females. It is characterized by asymmetric intervertebral disc and facet joint degeneration, leading to spinal imbalance that can result in severe pain and neurological deficits, thus significantly reducing the quality of life. Despite improved management, molecular mechanisms driving ADS remain unclear. Current literature primarily comprises epidemiological and clinical studies. Here, we investigate the molecular mechanisms underlying ADS, with a focus on angiogenesis, inflammation, extracellular matrix remodeling, osteoporosis, sarcopenia, and biomechanical stress. We discuss current limitations and challenges in the field and highlight potential translational applications that may arise with a better understanding of these mechanisms.

The effect of body size and composition on lumbar spine trabecular bone score in morphologically diverse subjects

AIM

The trabecular bone score (TBS) is a tool for assessing bone quality and health. Current TBS algorithm corrects for body mass index (BMI), as a proxy of regional tissue thickness. However, this approach fails to consider BMI inaccuracies due to individual differences in body stature, composition and somatotype. This study investigated the relationship between TBS and body size and composition in subjects with a normal BMI, but with large morphological diversity in body fatness and height.

METHODS

Young male subjects (n = 97; age 17.2±1.0 years), including ski jumpers (n = 25), volleyball players (n = 48) and non-athletes (controls n = 39), were recruited. The TBS was determined from L1-L4 dual-energy X-ray absorptiometry (DXA) scans using TBSiNsight software.

RESULTS

TBS correlated negatively with height and tissue thickness in the L1-L4 area in ski jumpers (r = -0.516 and r = -0.529), volleyball players (r = -0.525 and r = -0.436), and the total group (r = -0.559 and r = -0.463), respectively. Multiple regression analyses revealed that height, L1-L4 soft tissue thickness, fat mass and muscle mass were significant determinants of TBS (R2 = 0.587, p<0.001). L1-L4 soft tissue thickness explained 27% and height 14% of the TBS variance.

CONCLUSION

The negative association of TBS and both features suggests that a very low L1-L4 tissue thickness may lead to overestimation of the TBS, while tall stature may have the opposite effect. It seems that the utility of the TBS as a skeletal assessment tool in lean and/or tall young male subjects could be improved if tissues thickness in the lumbar spine area and stature instead of BMI were considered in the algorithm.

Predisposing factors for a second fragile hip fracture in a population of 1130 patients with hip fractures, treated at Oulu University Hospital in 2013-2016: a retrospective study

OBJECTIVE

The life-time risk of a second fragile hip fracture is 8.4%, but the risk factors that predispose to a second hip fracture remain unresolved. This study aimed to define risk factors that predisposed patients to a second hip fracture.

METHODS

For this retrospective study, we retrieved clinical data on 1130 patients with fragile hip fractures (67.2% female, mean age: 79.3 years) that underwent surgery at the Oulu University Hospital in 2013-2016. These data included the fracture risk assessment score (measured with the FRAX tool), the bone-mass T-score, laboratory values, ambulatory capacity, and the time of death.

RESULTS

In this population, 12.4% of patients sustained a second hip fracture. The predisposing factors for a second hip fracture were: female (p = 0.016), a high FRAX score (p = 0.020), and low physical capacity (p < 0.001). The vitamin D level recommended for treating osteoporosis (i.e., vitamin D > 75 nmol/l) was observed in only 24% of patients, and 42% of patients had ionized calcium levels below the reference range. According to the level of the cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), 37% of patients did not have high bone turnover. We found a positive correlation between age and ICTP (p = 0.001). The risk of death was higher after the second hip fracture (p = 0.005), but we found no difference in age between patients with first and second hip fractures (p = 0.11).

CONCLUSION

After a hip fracture, a second hip fracture is a well-known risk. Nevertheless, we found that only one-third of patients with a second hip fracture had used anti-osteoporosis medication at any time previously. These findings suggested that second hip fractures were most likely to occur in patients with osteopenic T-score values, in women more often than men, and in patients with high FRAX scores and low ambulatory capacity.

Bone Mineral Density, Trabecular Bone Score and Fractures in Patients Hospitalized for Heart Failure

BACKGROUND

This study aimed to evaluate the bone mineral density (BMD), trabecular bone score (TBS), and fracture history of middle-aged patients hospitalized for heart failure (HF), as well as analyze the association of these factors with cardiometabolic parameters and muscle strength.

METHODS

A cross-sectional study with patients aged 40 to 64 years hospitalized for HF was performed. Dual energy X-ray absorptiometry was performed to obtain BMD and TBS. Fracture history, handgrip strength (HGS), and clinical and laboratory cardiometabolic parameters of the patients were evaluated.

RESULTS

Altogether, 109 patients were evaluated (female 50.5%). Medians and interquartile ranges for age and length of hospital stay were 58.0 (53.0-61.0) years and 20.0 (11.0-32.0) days, respectively. Osteoporosis was observed in 15.6% of the patients, low TBS was observed in 22.8%, and 6 patients had a history of fragile fracture. No differences between the sexes regarding BMD (p=0.335) or TBS (p=0.736) classifications were observed. No association was observed between low BMD and HF classification (p>0.05) regarding the ejection fraction, ischemic etiology, or New York Heart Association Functional Classification. However, there was a significant association between high serum parathyroid hormone (PTH) and the presence of osteoporosis (62.5 [37.2-119.0] pg/mL vs. 34.2 [25.0-54.1] pg/mL; p=0.016). There was a negative correlation between serum PTH and TBS (r=-0.329, p=0.038) and a higher frequency of reduced HGS in patients with low TBS (92.3% vs. 50.0%; p=0.009).

CONCLUSIONS

We found relevant frequencies of osteoporosis and bone microarchitecture degradation in middle-aged patients with HF, which were related to high serum PTH concentrations.

Association of Short-Term Changes in Menstrual Frequency, Medication Use, Weight and Exercise on Bone Mineral Density in College-Aged Women

To evaluate if experiencing a short-term exposure (18-months) to factors such as menstrual irregularities, dieting, changes in exercise or body weight, and medication usage is associated with bone mineral density (BMD) in college-aged females. A retrospective survey assessing health behaviors during a recent 18-month time period and a DXA scan were completed in 641 females. A total of 45.5% of participants reported amenorrhea during the 18-month time period. Those who experienced amenorrhea had lower femoral neck BMD (p = 0.018), trochanter (p = 0.018) and spine BMD (p = 0.022) compared to eumenorrheic women. Lifetime oral contraceptive usage longer than six months was negatively associated with BMD at femoral neck (p = 0.018) and total hip (p = 0.021). Women who lost weight trended towards having the lowest BMD at all sites compared to women who gained weight. Following a very-low calorie diet during the time period was negatively correlated with spine BMD (p = 0.001). Time spent in vigorous and very vigorous activity was weakly correlated with some hip BMD sites but time spent in extremely vigorous activity was not. In conclusion, females who experienced weight loss, amenorrhea, or a very low-calorie diet within an 18-month period of time in young adulthood had lower BMD. Additionally, oral contraceptive usage for longer than six months during their lifetime was associated with lower BMD.

Reduced hip bone mineral density is associated with high levels of calciprotein particles in patients with Fabry disease

Calciprotein particles (CPP) are nanoscale mineralo-protein aggregates that help stabilize excess mineral in the circulation. We examined the relationship between CPP and bone mineral density in Fabry disease patients. We found an inverse correlation with total hip and femoral neck density, but none with lumbar spine.

PURPOSE

Calciprotein particles (CPP) are colloidal mineral-protein complexes made up primarily of the circulating glycoprotein fetuin-A, calcium, and phosphate. They form in extracellular fluid and facilitate the stabilization, transport, and clearance of excess minerals from the circulation. While most are monomers, they also exist in larger primary (CPP-I) and secondary (CPP-II) form, both of which are reported to be raised in pathological states. This study sought to investigate CPP levels in the serum of patients with Fabry disease, an X-linked systemic lysosomal storage disorder that is associated with generalized inflammation and low bone mineral density (BMD).

METHODS

We compared serum CPP-I and CPP-II levels in 59 patients with Fabry disease (37 female) with levels in an age-matched healthy adult cohort (n=28) and evaluated their association with BMD and biochemical data obtained from routine clinical review.

RESULTS

CPP-I and CPP-II levels were higher in male Fabry disease patients than female sufferers as well as their corresponding sex- and age-matched controls. CPP-II levels were inversely correlated with BMD at the total hip and femoral neck, but not the lumbar spine. Regression analyses revealed that these associations were independent of common determinants of BMD, but at the femoral neck, a significant association was only found in female patients.

CONCLUSION

Low hip BMD was associated with high CPP-II in patients with Fabry disease, but further work is needed to investigate the relevance of sex-related differences and to establish whether CPP measurement may aid assessment of bone disease in this setting.

Sarcopenia: Body Composition and Gait Analysis

Background

Age-induced sarcopenia negatively affects walking stability and increases the risk of falls, which is the leading cause of accidental death in the elderly.

Objective

This study aimed to analyze and contrast body composition and gait characteristics in those with sarcopenia in relation to healthy controls to shed some light on the prevention of falls in elderly patients with sarcopenia.

Materials and Methods

In this study, 68 community dwellers were scanned by the Hologic QDR-4500A Dual-energy X-ray absorptiometry (DXA). The appendicular lean mass index (ALMI) results were used to distinguish the normal participants from those with sarcopenia: 24 in the sarcopenia group, and 44 into the normal group. The participants were asked to undergo gait analysis on a plantar pressure measurement system. Statistical analysis was conducted to contrast both groups' gait and butterfly parameters from their gait test, and then a gait forward dynamics method was performed to quantify the analysis for both groups.

Results

The ALMI of the female was not related to their age (r = 0.06) while that of the male was weakly related (r = 0.17). Body mass index (BMI) from both groups was normal, although with a statistically greater BMI from the normal group compared with sarcopenia (p &lt; 0.001). Greater values and significant differences were found in step length and stride length from the normal elderly group (p &lt; 0.01), and so was the length of the gait line and single support line (p &lt; 0.05). Gait forward dynamics analysis results showed no motor neural or musculoskeletal disorders in their gait performance from the sarcopenia group.

Conclusion

For the elderly, age did not largely affect the ALMI, BMI, or T-score, but BMI and ALMI were strongly correlated. In this study, significant differences were found in certain gait parameters between the elderly with sarcopenia and the normal elderly, which were related to absolute muscle strength, suggesting that sarcopenia was a disease mainly caused by decreased muscle mass. In addition, when abnormities were identified in step length, stride length, length of gait line, or length of single support line, it is proposed to take a DXA scan to confirm whether the elderly suffer from sarcopenia.

Moderating Effect of the Lean Tissue Index on the Relationship between the Trabecular Bone Score and Augmentation Index in Dialysis Naïve Patients with Stage 5 Chronic Kidney Disease

Osteopenia, sarcopenia, and increased vascular stiffness are common in patients with chronic kidney disease-mineral bone disorder (CKD-MBD) with protein energy wasting and can lead to worse clinical outcomes. We investigated the potential moderating role of the lean tissue index (LTI) in the relationship between bone microarchitecture and vascular stiffness in dialysis naïve patients with stage 5 CKD. Bioimpedance spectroscopy for evaluating LTI, lumbar spine dual energy X-ray absorptiometry for determining the trabecular bone score (TBS), and arterial applanation tonometry measurements for the central augmentation index, at a heart rate of 75 beats/minute (cAIx75), were simultaneously performed in 117 consecutive patients. A hierarchical regression analysis was conducted to assess the moderating effect of LTI on the relationship between TBS and cAIx75 after adjusting for age and sex. The effect of the interaction between LTI and TBS on cAIx75 was statistically significant (p = 0.030), demonstrating that the cAIx75 tends to decrease more, with the joint effect of LTI and TBS. In the separate analyses, the interaction effect was significant only in women (p = 0.048) and the group of diabetes (p = 0.042). Our study suggests that the evaluation of changes in body composition, bone health, and vascular stiffness needs to be performed simultaneously in patients with advanced-stage CKD. Further research in patients with different stages of CKD warranted to generalize and apply our results to patients in other stages.

Body Composition as a Modulator of Bone Health Changes in Patients with Inflammatory Bowel Disease

Background: Bone impairment of multifactorial etiology is a common feature in inflammatory bowel disease (IBD). Body composition parameters, which might be selectively modified in these patients, are important determinants of bone strength. Our aim was to investigate the relationship between components of body composition and bone parameters in IBD patients. Methods: This is a cross-sectional, retrospective study including 80 IBD patients (43 women, 37 men). Lumbar spine (LS), femoral neck (FN) and whole body DXA scans were performed to analyze regional bone mineral density (BMD), as well as body composition, including appendicular skeletal muscle mass index (ASMI), total and visceral fat mass (VAT). Trabecular bone score (TBS) was assessed using iNsight Software. Results: Twenty (25%) IBD patients had inadequate LS-BMD z scores (<=−2DS). Lean mass (LM) was a significant determinant of LS-BMD, after adjusting for age, gender, BMI and fat mass (p < 0.01), while fat mass% remained associated with FN-BMD (p < 0.01). TBS correlated positively with BMI (r = 0.24, p < 0.05), LS-BMD (r = 0.56, p < 0.001), ASMI (r = 0.34, p < 0.001) and negatively with VAT/total fat% (r = −0.27, p < 0.05). Multivariate analysis showed that ASMI, LS-BMD (positively) and VAT/total fat% (negatively) were independently associated with TBS. Conclusions: In IBD patients, skeletal muscle mass and fat percentage and distribution are important factors associated with bone health.

Influence of Screw-Hole Defect Size on the Biomechanical Properties of Feline Femora in an Ex Vivo Model

OBJECTIVE

 The study aims to evaluate the biomechanical properties of feline femora with craniocaudal screw-hole defects of increasing diameter, subjected to three-point bending and torsion to failure at two different loading rates.

STUDY DESIGN

 Eighty femoral pairs were harvested from adult cat cadavers. For each bending and torsional experiment, there were five groups (n = 8 pairs) of increasing craniocaudal screw-hole defects (intact, 1.5 mm, 2.0 mm, 2.4 mm, 2.7mm). Mid-diaphyseal bicortical defects were created with an appropriate pilot drill-hole and tapped accordingly. Left and right femora of each pair were randomly assigned to a destructive loading protocol at low (10 mm/min; 0.5 degrees/s) or high rates (3,000 mm/min; 90 degrees/s) respectively. Stiffness, load/torque-to-failure, energy-to-failure and fracture morphology were recorded.

RESULTS

 Defect size to bone diameter ratio was significantly different between defect groups within bending and torsional experiments respectively (intact [0%; 0%], 1.5 mm [17.8%; 17.1%], 2.0 mm [22.8%; 23.5%], 2.4 mm [27.8%; 27.6%], 2.7 mm [31.1%; 32.4%]) (p < 0.001). No significant differences in stiffness and load/torque-to-failure were noted with increasing deficit sizes in all loading conditions. Screw-hole (2.7 mm) defects up to 33% bone diameter had a maximum of 20% reduction in bending and torsional strength compared with intact bone at both loading rates. Stiffness and load/torque-to-failure in both bending and torsion were increased in bones subjected to higher loading rates (p < 0.001).

CONCLUSION

 Screw-hole defects up to 2.7 mm did not significantly reduce feline bone failure properties in this ex vivo femoral study. These findings support current screw-size selection guidelines of up to 33% bone diameter as appropriate for use in feline fracture osteosynthesis.

Factors associated with TBS worse than BMD in non-osteoporotic elderly population: Bushehr elderly health program

BACKGROUND

Bone mineral density (BMD) and trabecular bone score (TBS) are moderately correlated. TBS is sometimes used as an adjuvant to BMD in the fracture risk assessment. Some individuals with normal BMD or osteopenia, have more degraded TBS. We aimed to identify factors associated with TBS worse than BMD in the non-osteoporotic elderly population.

METHODS

The study subjects were selected from 2384 women and men aged ≥60 years participating in the second stage of the Bushehr Elderly Health program, a population-based prospective cohort study in Iran. The BMDs of different sites and the lumbar spine texture were measured using dual-energy X-ray absorptiometry and the TBS algorithm, respectively. Subjects were categorized based on their BMD and TBS status. Logistic regression was performed to identify the factors associated with "TBS worse than BMD" in non-osteoporotic individuals.

RESULTS

Of 1335 participants included in the study, 112 of 457 women, and 54 of 878 men had worse TBS than BMD. In multivariable analysis, TBS worse than BMD in women was statistically significantly associated with years since menopause (OR: 1.04 (1.00-1.07)) and waist circumference (OR: 1.09 (1.05-1.14)). However, in men, the condition was statistically significantly associated with waist circumference (OR: 1.10 (1.03-1.17)), current smoking (OR: 2.54 (1.10-5.84)), and HDL-C (OR: 1.03 (1.00-1.06)).

CONCLUSION

The results of the study show that higher waist circumference is associated with more degraded TBS than BMD in both men and women. Years passed since menopause and current smoking, respectively in women and men, were associated with more degraded TBS. Considering TBS values in older individuals with higher waist circumference, or a history of smoking despite normal BMDs might help more accurate assessment of bone health. However, further studies are required to confirm the benefit.

Characteristics of the DXA Measurements in Patients Undergoing Lumbar Fusion for Lumbar Degenerative Diseases: A Retrospective Analysis of Over 1000 Patients

Purpose

To explore the characteristics and reliability of dual-energy x-ray absorptiometry (DXA) measurements in patients undergoing lumbar fusion for lumbar degenerative diseases (LDD).

Patients and Methods

A total of 1041 patients aged ≥50 years undergoing lumbar fusion for LDD were reviewed. The BMDs and T-scores of DXA were retrospectively analysed. The diagnosis of osteoporosis was in accordance with World Health Organization (WHO) criteria. Based on the guidelines of International Society for Clinical Densitometry (ISCD), an abnormal lumbar segment is identified as having unreliable T-scores when there is more than a 1.0 T-score difference between two adjacent vertebrae.

Results

The prevalence of osteoporosis diagnosed on DXA was 42.3%, and it was higher in women than in men (50.2% vs 31.8%, P < 0.001). Increasing age resulted in higher prevalence of osteoporosis in females. The prevalence of osteoporosis significantly declined with increasing BMI. The lowest lumbar T-score was mostly found at L1. Unreliable T-scores were mostly seen in the lower lumbar segment (L3-L4) and were the least common in L1-L2. The average amount of abnormal lumbar segments increased with age (P = 0.003) and BMI (P = 0.021). Furthermore, those with degenerative lumbar scoliosis had more abnormal segments (P < 0.001). Of the 95 patients with at least one fractured vertebra, 39 (41.1%) were not diagnosed as having osteoporosis on lumbar DXA.

Conclusion

Female, older age and low BMI are the risk factors for osteoporosis in patients undergoing lumbar fusion for LDD. Lower lumbar segments, such as L3-L4, are more likely to have unreliable T-scores. Patients with older age, higher BMI or degenerative scoliosis have more abnormal segments with unreliable T-scores. Lumbar DXA measurements are not sensitive enough to identify patients with vertebral fracture.

Bone characteristics and metabolic phenotypes of obesity in an Iranian Elderly population: Bushehr Elderly Health Program (BEHP)

INTRODUCTION

Obesity and osteoporosis are health problems with high impact on the morbidity and mortality rate. While the association between BMI and bone density is known, the combined effects of obesity and metabolic components on bone health have not yet been revealed. The objectives of this study were to determine the association between bone health and different phenotypes of obesity in an elderly population.

METHODS

This cross-sectional study was conducted on the data collected in the Bushehr Elderly Health Program (BEHP). The participants were classified in four groups based on the metabolic phenotypes of obesity (metabolic healthy obese (MHO), metabolic non-healthy non-obese (MNHNO), metabolic non-healthy obese (MNHO), and metabolic healthy non-obese (MHNO)). The association between osteoporosis and TBS and the metabolic phenotypes of obesity were assessed using multiple variable logistic regression models.

RESULTS

Totally, 2378 people (1227 women) were considered for analyses. The prevalence of MHNO, MHO, MNHNO, and MNHO were 902 (39.9%), 138 (6.1%), 758 (33.5%), and 464 (20.5%), respectively. In the multivariate logistic regression models, those with MHO (OR 0.22; 95% CI 0.12-0.36), MNHNO (OR 0.52; 95% CI 0.4-0.66), and MNHO phenotypes (OR 0.22; 95% CI 0.16-0.3) had a significantly lower risk of osteoporosis. Likewise, those having MHO (OR 2.38; 95% CI 1.51-3.76), MNHNO (OR 1.49; 95% CI 1.11-2), and MNHO (OR 2.50; 95% CI 1.82-3.42) phenotypes were found to had higher risk of low bone quality as confirmed by TBS.

CONCLUSIONS

The obese subjects have lower bone quality, regardless of their obesity phenotype.

Comparison of anterior and posterior trabecular bone microstructure of human mandible using cone-beam CT and micro CT

Background

The aim of this study was to compare the trabecular bone microstructures of anterior and posterior edentulous regions of human mandible using cone-beam computed tomography (CBCT) and micro computed tomography (µCT).

Methods

Twenty volumes of interests consisting of six anterior and fourteen posterior edentulous regions were obtained from human mandibular cadavers. A CBCT system with a resolution of 80 µm (3D Accuitomo 170, J. Morita, Kyoto, Japan) and a µCT system with a resolution of 35 µm (SkyScan 1173, Kontich, Belgium) were used to scan the mandibles. Three structural parameters namely, trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were analysed using CTAn software (v 1.11, SkyScan, Kontich, Belgium). For each system, the measurements obtained from anterior and posterior regions were tested using independent sample t-test. Subsequently, all measurements between systems were tested using paired t-test.

Results

In CBCT, all parameters of the anterior and posterior mandible showed no significant differences (p > 0.05). However, µCT showed a significant different of Tb.Th (p = 0.023) between anterior and posterior region. Regardless of regions, the measurements obtained using both imaging systems were significantly different (p ≤ 0.021) for Tb.Th and Tb.N.

Conclusions

The current study demonstrated that only the variation of Tb.Th between anterior and posterior edentulous region of mandible can be detected using µCT. In addition, CBCT is less feasible than µCT in assessing trabecular bone microstructures at both regions.

Bone Mineral Density Differences Across Female Olympic Lifters, Power Lifters, and Soccer Players

ABSTRACT

Jeon, W, Harrison, JM, Stanforth, PR, and Griffin, L. Bone mineral density differences across female Olympic lifters, power lifters, and soccer players. J Strength Cond Res 35(3): 638-643, 2021-Athletic training improves bone mineral density (BMD) through repeated mechanical loading. The location, intensity, and direction of applied mechanical pressure play an important role in determining BMD, making some sports more advantageous at improving BMD at specific regions. Thirty-seven (10 power lifters [PL], 8 Olympic lifters [OL], 8 soccer players [SP], and 11 recreationally active [RA]) women participated in a cross-sectional study. We measured lumbar spine (L1-L4), femoral neck, total-body BMD, and overall body composition (total fat mass, lean mass, percent body fat) with dual-energy x-ray absorptiometry. All athletic groups had greater total BMD than RA (p = 0.01 [PL]; p < 0.001 [OL]; p = 0.01 [SP]). Olympic lifters had the highest total BMD than all other athletic groups. Olympic lifters had the significantly greater total BMD than PL (p = 0.018), but there was no difference in total BMD between PL and SP. As compared with RA, OL showed greater BMD at both the total lumbar spine (p = 0.002) and the femoral neck (p = 0.007), whereas PL showed greater BMD only for the total lumbar spine (p = 0.019) and SP showed greater BMD only for the femoral neck (p = 0.002). Olympic-style lifting includes both high-impact and odd-impact loading modalities that are associated with the highest BMD at both the lumbar spine and femoral neck.

TBS in early postmenopausal women with severe vertebral osteoporosis

INTRODUCTION/BACKGROUND

Severe vertebral osteoporosis is a rare condition in early postmenopausal women. We seek to determine whether Trabecular Bone Score (TBS), which is a new bone texture measurement, could be of additional value in evaluating trabecular bone properties in this population.

METHODOLOGY

Lumbar spine (LS) and femoral neck (FN) bone mineral densities (BMDs) and TBS were measured in 105 early postmenopausal women (group 1: "cases", mean age: 53.1 ± 2.6 yrs.) with severe vertebral osteoporosis defined as a vertebral BMD T-score ≤ 3, as well as in 105 healthy postmenopausal women matched for age (group 2) and 105 older osteoporotic women matched for vertebral BMD (group 3, mean age: 63.9 ± 4 yrs.). None of the women had a secondary cause for osteoporosis. Correlations between TBS values and BMD were calculated after controlling for clinical characteristics.

RESULTS

The women in group 1 (cases) were significantly smaller and thinner and had a history of more fractures than the age-matched controls (p < 0.05). Mean LS and FN BMD values were significantly lower in the cases than in the age-matched controls (0.770 ± 0.05 vs 1.106 ± 0.11 g/cm² and 0.700 ± 0.07 vs 0.872 ± 0.12 g/cm², for LS and FN, respectively; p < 0.001). The mean TBS value was also significantly lower in the cases than in the age-matched controls (1.24 ± 0.08 vs 1.37 ± 0.07, p < 0.001) but significantly higher than in the older osteoporotic controls (1.20 ± 0.07, p < 0.05). After adjustment for vertebral BMD, the difference in TBS values between the cases and the age-matched controls was no longer significant although it remained significantly higher than in the older osteoporotic controls. This would suggest that in group 1, osteoporosis is rather the consequence of a low peak bone mass than of further bone degradation while the greater decrease in TBS value in elderly osteoporotic controls is more likely to reflect additional damage in bone microarchitecture associated with aging. In a multivariate analysis including age, vertebral and femoral neck BMD, height and weight (R² = 0.60, p < 0.0001), TBS was found to be negatively and independently associated with age (r = -0.31 p < 0.0001) and height (r = -0.20 p < 0.001). The FRAX score was significantly higher in group 1 and group 3 women than in the healthy control women (group 2). There were no changes in the results after adjustment for TBS.

CONCLUSIONS

Women presenting with severe vertebral osteoporosis at the beginning of menopause have TBS values that are, first and foremost, proportional to their BMD. Whether this indicates that osteoporosis in this population is the consequence of a low peak bone mass remains to be determined and further studies are required. Nevertheless, the value of measuring TBS in addition to BMD appears to be relatively negligible in early postmenopausal women with severe vertebral osteoporosis.

Bone Density and Body Fat Distribution in Postmenopausal Women

Background:

In postmenopause there are changes in metabolism of bone tissue and consequent decrease of bone density. With ageing redistribution of fat occurs and an increase in body weight. Because of hormone changes in postmenopause fat is redistributed from gluteofemoral area to the abdominal region.

Objective:

The objective of this study was to examine the relationship between bone density and a body mass index (BMI), and distribution of the fat tissue in women in postmenopause (WHR).

Methods:

This research was prospective, and it included total of 83 women, 53 women were in the natural postmenopause and 30 women with the regular menstruation.

Results:

BMI in women in postmenopause was statistically significantly higher than BMI in women with the regular menstruations (p= 0,005). There was no statistically significant difference between waist hip ratio in women in the postmenopause in relation to the women with the regular menstruations. In women in the postmenopause significant positive correlation between BMI and density of the neck of femur was found (Z and T-score) (p=0,019; p=0,005). There was also significant negative correlation between the WHR and density of the lumbal spine (backbone) in women in the postmenopause (Z-score) (p=0,043). The identical analysis in women with regular menstruations, negative correlation between the density of the lumbal spine was found again (Z-score) and WHR , but the same was highly expressed (p=0,041). The observed correlation between BMI and bone density in this group of women was not statistically significant.

Conclusion:

Based on the presented results we conclude that the higher the BMI (p=0,019; p=0,005) the higher density of the femoral neck postmenopausal women have, and lower bone density of the lumbar spine the higher ratio waist / hip (p = 0.043). In the women with regular menstruation bone density of the lumbar spine is the lower the higher the ratio of waist and hip (p=0,041), while there was no correlation between BMI and bone density in this group of women.

miRNA Mechanisms Underlying the Association of Beta Blocker Use and Bone Mineral Density

Osteoporosis is a debilitating and costly disease that causes fractures in 33% of women and 20% of men over the age of 50 years. Recent studies have shown that beta blocker (BB) users have higher bone mineral density (BMD) and decreased risk of fracture compared with non-users. The mechanism underlying this association is thought to be due to suppression of adrenergic signaling in osteoblasts, which leads to increased BMD in rodent models; however, the mechanism in humans is unknown. Also, several miRNAs are associated with adrenergic signaling and BMD in separate studies. To investigate potential miRNA mechanisms, we performed a cross-sectional analysis using clinical data, dual-energy X-ray absorptiometry (DXA) scans, and miRNA and mRNA profiling of whole blood from the Framingham Study's Offspring Cohort. We found nine miRNAs associated with BB use and increased BMD. In parallel network analyses, we discovered a subnetwork associated with BMD and BB use containing two of these nine miRNAs, miR-19a-3p and miR-186-5p. To strengthen this finding, we showed that these two miRNAs had significantly higher expression in individuals without incident fracture compared with those with fracture in an external data set. We also noted a similar trend in association between these miRNA and Z-score as calculated from heel ultrasound measures in two external cohorts (SOS-Hip and SHIP-TREND). Because miR-19a directly targets the ADRB1 mRNA transcript, we propose BB use may downregulate ADRB1 expression in osteoblasts through increased miR-19a-3p expression. We used enrichment analysis of miRNA targets to find potential indirect effects through insulin and parathyroid hormone signaling. This analysis provides a starting point for delineating the role of miRNA on the association between BB use and BMD. © 2020 American Society for Bone and Mineral Research (ASBMR).

Physical and lifestyle factors associated with trabecular bone score values

TBS is associated with age, weight, childhood physical activity, and BMD in men and age, height, BMD, and mobility in women.

INTRODUCTION

Trabecular bone score (TBS) indirectly assesses trabecular microarchitecture at the lumbar spine, providing complementary information to areal BMD. Many studies have investigated the relationships between BMD and lifestyle factors known to affect bone, but such research is limited for TBS. The aim of this study was to assess the relationship between TBS and lifestyle factors in Australian men and women.

METHODS

This cross-sectional study involved 894 men and 682 women (ages 24-98 years) enrolled in the Geelong Osteoporosis Study. TBS was assessed by analysis of lumbar spine DXA scans (Lunar Prodigy) using TBS iNsight software (Version 2.2). Bivariate and multivariable linear regression models were used to explore the associations between TBS and physical and lifestyle factors, including anthropometry, alcohol consumption, childhood physical activity, mobility, smoking status, prior low trauma fracture, medication use, and intakes of calcium and vitamin D.

RESULTS

In bivariate regression modelling, low mobility and the use of antiresorptive medication were associated with lower TBS in both men and women. Low childhood physical activity was also associated with lower TBS in men. Prior fracture, use of glucocorticosteroids, and total calcium intake were also associated with lower TBS in women. The final adjusted model for men included age, weight, childhood physical activity, and BMD, and for women, age, height, BMD, and mobility. No interaction terms were identified in the models.

CONCLUSIONS

Lower TBS is associated with older age, increased weight, low childhood physical activity, and lower BMD in men and older age, shorter stature, lower BMD, and low mobility in women.

Associations between bone mineral density, trabecular bone score, and body mass index in postmenopausal females

Objectives

Bone mineral density (BMD), as a gold standard determinant of osteoporosis, assesses only one of many characteristics contributing to the bone. Trabecular bone score (TBS) is applied to evaluate the microarchitecture of trabecular bone. A high body mass index (BMI) has been reported to have a positive correlation with BMD. However, the relation between BMI and TBS has remained unclear. Therefore, the aim of this study is to shed light on the associations between BMI, T-score, and TBS in postmenopausal women without a diagnosed underlying disease.

Methods

In this cross-sectional study, 1054 postmenopausal women were randomly recruited from the Department of Radiology, Isfahan University of Medical Sciences. Demographic characteristics and medical history of all subjects were collected from documents. TBS measurements for L1-L4 vertebrae were retrospectively performed by the TBS iNsight software using the dual X-ray absorptiometry (DXA) from the same region of spine of the subjects. The analysis was done to detect the correlation between TBS and BMI.

Results

A statistically significant negative correlation was found between TBS and BMI in patients with osteoporosis and low bone mass. In patients with normal T-scores, BMI was not significantly correlated to TBS (P > 0.05). Furthermore, there was a significant positive association between T-score and BMI.

Conclusions

Although a higher BMI had a protective effect against osteoporosis, higher BMI was associated with a lower TBS in patients with an abnormal T-score. However, BMI did not have a significant effect on TBS in patients with normal T-scores.

A Morphomic Index Is an Independent Predictor of Survival After Lung Cancer Resection

BACKGROUND

Sarcopenia, visceral fat volume, and bone density have been associated with lung cancer survival. We developed a morphomic index based on computed tomographic measurements of these components, and assessed its relationship to survival after lung cancer resection.

METHODS

Patients who underwent lung cancer resection from 1995 to 2014 were evaluated. A morphomic index (range of 0 to 3) was developed as the sum of the scores for three body components-dorsal muscle area, vertebral trabecular bone density, and visceral fat area-measured at vertebral levels T10 to T12, with a point assigned to each component when in the lowest tercile. The relationship of the morphomic index to overall survival was assessed by the log rank test. Overall survival was assessed using Cox proportional hazards models adjusted for relevant covariates.

RESULTS

We included 944 patients (451 women; 48%). The mean age was 66.4 ± 10.3 years. Median follow-up was 4.5 years. Median survival was associated with the morphomic index scores on univariate analysis (P < .001). Morphomic index scores of 2 (P = .026) and 3 (P = .004) referenced to score 0 or 1 were independent predictors of survival on Cox regression analysis.

CONCLUSIONS

A morphomic index is an independent predictor of survival after lung cancer resection. The index may help in calibrating patient expectations and in shared decision making regarding lung cancer surgery.

Effect of Weight Change Following Intentional Weight Loss on Bone Health in Older Adults with Obesity

OBJECTIVE

This study aimed to examine change in bone mineral density (BMD) and trabecular bone score among older adult weight regainers (WR) and weight maintainers (WM).

METHODS

Observational data come from 77 older adults (mean age: 67 [SD 5] years; 69% women; 70% white) with obesity (mean BMI: 33.6 [SD  3.7] kg/m² ) who lost weight during an 18-month weight loss intervention. Total body mass and body composition, along with regional (total hip, femoral neck, lumbar spine) BMD and trabecular bone score, were measured at baseline, 18 months, and 30 months. WR (n = 36) and WM (n = 41) categories were defined as a ≥ 5% or < 5% weight gain from 18 to 30 months, respectively.

RESULTS

Among skeletal indices, only total hip BMD was significantly reduced during the 18-month intervention period in both WRs (-3.9%; 95% CI: -5.8% to -2.0%) and WMs (-2.4%; 95% CI: -4.3% to -0.5%; P = 0.07). After adjustment for relevant baseline covariates and weight change from 0 to 18 months, 30-month change in total hip BMD was -2.6% (95% CI: -4.3% to -0.9%) and -3.9% (95% CI: -5.7% to -2.1%) among WRs and WMs, respectively (P = 0.07).

CONCLUSIONS

Loss of hip BMD persists in the year after a weight loss intervention among older adults with obesity, regardless of weight regain status.

Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Osteoporosis is a common bone disease characterized by reduced bone mass resulting from continuous bone resorption.

METHODS

PubMed, Scopus, and Embase were searched to find published trials on the effect of soy isoflavones on bone mineral density (BMD) and bone turnover markers (bone-specific alkaline phosphatase, osteocalcin, osteoprotegerin, pyridinoline, deoxypyridinoline, C-telopeptide, and N-telopeptide). Random-effects inverse-variance model was used to calculate the pooled effects.

RESULTS

A total of 5313 articles were found, screened, and assessed for eligibility, and finally 52 trials were included in the meta-analysis. Consumption of soy isoflavones caused significant improvement in BMD of lumbar spine (mean difference (MD) = 0.76%; 95% CI: 0.09, 1.42%; p = 0.03), hip (MD = 0.22%; 95% CI: 0.02, 0.42%; p = 0.04), and femoral neck (MD = 2.27%; 95% CI: 1.22, 3.31%; p < 0.001). Subgroup analysis showed that in all 3 sites, the improvement was significant in normal weight subjects and interventions longer than a year, although trial location and dosage were also factors influencing isoflavones' impact on BMD. Among markers of bone turnover, osteoprotegerin (MD = 5.79; 95% CI: 3.08, 8.51 pg/ml; p < 0.001), pyridinoline (MD = -5.13; 95% CI: -7.76, -2.50 nmol/mmol; p < 0.001), and C-telopeptides (MD = -0.08; 95% CI: -0.16, -0.00 ng/ml; p = 0.04) were favorably affected by isoflavones while osteocalcin and bone alkaline phosphatase did not change. Subgroup analysis of bone markers showed that in overweight/obese individuals and dosages <90 mg/day, isoflavones are more effective.

CONCLUSIONS

Soy isoflavones prevent osteoporosis-related bone loss in any weight status or treatment duration. They increase BMD in normal weight subjects and diminish bone resorption in overweight/obese individuals. Although bone resorption may be decelerated over short-term isoflavone consumption, periods longer than a year are probably needed to affect BMD. Isoflavones also appear benefits on bone in any dose or subjects' ethnicity.

The effect of metformin versus placebo in combination with insulin analogues on bone mineral density and trabecular bone score in patients with type 2 diabetes mellitus: a randomized placebo-controlled trial

Some antihyperglycemic medications have been found to affect bone metabolism. We assessed the long-term effects of metformin compared with placebo on bone mineral density (BMD) and trabecular bone score (TBS) in patients with type 2 diabetes. Metformin had no significant effect on BMD in the spine and hip or TBS compared with a placebo.

INTRODUCTION

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fractures despite a high bone mass. Some antihyperglycemic medications have been found to affect bone metabolism. We assessed the long-term effects of metformin compared with placebo on bone mineral density (BMD) and trabecular bone score (TBS).

METHODS

This was a sub-study of a multicenter, randomized, 18-month placebo-controlled, double-blinded trial with metformin vs. placebo in combination with different insulin regimens (the Copenhagen Insulin and Metformin Therapy trial) in patients with T2DM. BMD in the spine and hip and TBS in the spine were assessed by dual-energy X-ray absorptiometry at baseline and after 18 months follow-up.

RESULTS

Four hundred seven patients were included in this sub-study. There were no between-group differences in BMD or TBS. From baseline to 18 months, TBS decreased significantly in both groups (metformin group, - 0.041 [- 0.055, - 0.027]; placebo group - 0.046 [- 0.058, - 0.034]; both p < 0.001). BMD in the spine and total hip did not change significantly from baseline to 18 months. After adjustments for gender, age, vitamin D, smoking, BMI, duration of T2DM, HbA1c, and insulin dose, the TBS between-group differences increased but remained non-significant. HbA_1c was negatively associated with TBS (p = 0.009) as was longer duration of diabetes, with the femoral neck BMD (p = 0.003). Body mass index had a positive effect on the hip and femoral neck BMD (p < 0.001, p = 0.045, respectively).

CONCLUSIONS

Eighteen months of treatment with metformin had no significant effect on BMD in the spine and hip or TBS in patients with T2DM compared with a placebo. TBS decreased significantly in both groups.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT00657943).