Opportunistic screening of low bone mass using knowledge distillation-based deep learning in chest X-rays with external validations.

Opportunistic Osteoporosis Screening Using Low-Dose Computed Tomography (LDCT): Promising Strategy, but Challenges Remain.

The rates of bone mineral density testing for osteoporosis among healthy mid-life women are high, although their osteoporosis or fracture risk is low. To reduce unnecessary testing, we created and evaluated a tool to guide bone density testing based on the woman's age, weight, fracture history, and menopausal status. This study aims to improve case finding of mid-life women with low bone mass on bone mineral density (BMD) assessment. Among healthy women aged 40-60 years having their first BMD test, osteoporosis risk factors were assessed by questionnaire and BMD by dual-energy X-ray absorptiometry. The combination of risk factors that best discriminated women with/without low bone mass (T-score ≤ -2.0) was determined from the logistic regression model area under the curve (AUC) and internally validated using bootstrapping. Using the model odds ratios, a clinical prediction rule was created and its discriminative properties assessed and compared with that of the osteoporosis self-assessment tool (OST). Sensitivity analyses examined results for pre-/peri- and post-menopausal women, separately. Of 1,664 women referred for baseline BMD testing, 433 with conditions known to be associated with bone loss were excluded. Of 1,231 eligible women, 944 (77%) participated and 87 (9.2%) had low bone mass (35 pre-/peri- and 52 post-menopausal). Four risk factors for low bone mass were identified and incorporated into a clinical prediction rule. Selecting women for BMD testing with weight of ≤70 kg or any two of age >51, years' post-menopause of ≥1, and history of fragility fracture after age 40 was associated with 93% sensitivity to identify women with low bone mass, compared with 47% sensitivity for an OST score of ≤1 (AUC 0.75 versus OST AUC 0.69, p = 0.04). Results restricted to post-menopausal women were similar. Among healthy mid-life women receiving a baseline BMD test, few had low bone mass, supporting the need for guidance about testing. A prediction rule with four risk factors had improved sensitivity over the OST. Further validation is warranted.

Baptista, F, de Marco, RL, Zymbal, V, and Janz, KF. Reference standards for vertical jump power and handgrip strength for screening the risk of low bone and muscle mass for age in youth. J Strength Cond Res 39(8): e974-e981, 2025-This study examined the predictive validity of vertical jump power and handgrip strength to discriminate at-risk youth for low muscle mass and bone mass for age. The sample consisted of 529 subjects of ages 10-18 years. Handgrip strength and vertical jump power were assessed using a hand dynamometer and a countermovement jump performed on a force platform. Dual-energy X-ray absorptiometry was used to assess lean body mass normalized for body height (kg·m -2 ) and bone mineral density (g·cm -2 ) of the whole body less head. These variables were used to determine the risk of low bone and muscle mass, defined by a Z -score ≤ -1.0 for both variables. All variables were standardized by the lambda-mu-sigma method according to sex and age group, using the sample as a reference. By sex, the analysis included the area under the curve (AUC), sensitivity (Se), and specificity (Sp). The ability to discriminate the risk of low bone and muscle mass through the assessment of musculoskeletal fitness was good to exceptional for vertical jump power (AUCs ≥0.88, Se and Sp = 78-91%) and acceptable to good for handgrip strength (AUCs = 0.75-0.88, Se and Sp = 68-73%). Risk Z -scores for musculoskeletal fitness ranged from -0.5 to -0.8, depending on the test and sex. Handgrip strength and especially vertical jump power can be used to screen the risk of pediatric low bone and muscle mass. Slight decreases in musculoskeletal fitness can be an inexpensive and noninvasive indicator of muscle and bone health.

Identifying premenopausal women at risk for osteoporosis and related fractures is a potentially important way to reduce the burden of illness from this disease as low peak bone mass is a risk factor for postmenopausal osteoporosis. We examined predictors of 'low' peak bone mass in 668 healthy, pre-menopausal, Caucasian women ages 18-35 years. Predictors of bone mass were assessed using a detailed, standardized interview. Bone mass was assessed using two measures: dual-energy X-ray absorptiometry (DXA) at the femoral neck and lumbar spine, and quantitative ultrasound (QUS) of the heel, which evaluates stiffness, speed of sound (SOS) and broadband ultrasound attenuation (BUA). Bone mass was considered 'low' if the corresponding Z-score was <-1.00 (DXA values, stiffness) or if values were in the lowest quintile (BUA, SOS). Using multivariate logistic regression modeling, predictors of low bone mass based on QUS, DXA or both were determined. The mean age of the cohort was 27.3 years. Independent predictors of low bone mass by both DXA and QUS were: low body weight, menarche at age 15 years or later and physical inactivity as an adolescent. Individuals with all three risk factors had a 92% chance of having low bone mass using both techniques. This suggests that a simple risk factor assessment can identify most young women with low peak bone mass. Early intervention in this group of women may reduce the risk for osteoporosis in later life.

BACKGROUND AND OBJECTIVES:The effects of vitamin D on bone mass remain to be understood. This study was conducted with the objective of evaluating the influence of 25-hydroxyvitamin D (25OHD) levels on bone mineral density (BMD) among Saudi nationals.DESIGN AND SETTING:Cross-sectional study carried out at university hospital from 1 February 2008 to 31 May 2008.SUBJECTS AND METHODS:Healthy Saudi men and women in the peak bone mass (PBM) age group and those aged ≥50 years were recruited from the outpatient department of King Fahd University Hospital, Al Khobar, Saudi Arabia, between February 1, 2008, and May 31, 2008. Patient age and sex were documented, and body mass index was calculated. Hematological, biochemical, and serum 25OHD tests were performed. BMD was determined by dual-energy x-ray absorptiometry of the upper femur and lumbar spine. Patients were divided into three groups, based on their 25OHD level.RESULTS:Data from 400 patients were analyzed. Among individuals with a normal 25OHD level, 50% of women and 7% of men in the PBM age group and 26.4% of women and 49.2% of men aged ≥50 years had low bone mass. In patients with 25OHD insufficiency, 84.2% of women and 88.9% of men in the PBM age group and 83.3% of women and 80% of men aged ≥50 years had low bone mass. Results for patients with 25OHD deficiency revealed that none of the men and women in the PBM age group or ≥50 years old had normal BMD. Significant positive correlations between 25OHD level and BMD and significant negative correlations with parathyroid hormone were shown in most of the groups.CONCLUSIONS:This study showed that the vitamin D level significantly influences BMD reading among Saudi individuals. Evaluation and treatment of hypovitaminosis D should be considered during management of low bone mass.

Objective: To explore bone mass changes in patients with SAPHO syndrome, utilizing bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) and vertebral bone quality (VBQ) scores measured by MRI. Methods: Thirty-six patients with SAPHO syndrome at Peking Union Medical College Hospital from February 2014 to February 2024 were retrospectively collected with 36 age- and gender-matched healthy controls. DXA assessed BMD, corresponding T-score and Z-score of the lumbar spine (LS), femoral neck (FN), total hip (TH), and trabecular bone score (TBS). LS MRI T1-weighted imaging (T1WI) measured the VBQ scores. Correlations between BMD, TBS, and VBQ scores were analyzed using Pearson correlation. The predictive efficacy of VBQ scores for low bone mass and impaired bone microarchitecture in patients with SAPHO syndrome was assessed using receiver operating characteristic (ROC) curves, with the area under the curve (AUC), optimal diagnostic cut-off values, sensitivity, and specificity documented. Results: The mean age of patients with SAPHO syndrome was (44.8±9.5) years, with 8 (22.2%) males. There were 36 subjects in the control group with a mean age of (44.8±9.5) years and 8(22.2%) males. Compared to the controls, the case group had lower FN BMD, TH BMD, corresponding T-score and Z-score, TBS, and higher VBQ scores (all P<0.05). Compared to the controls, female patients in the case group had lower LS BMD, FN BMD, TH BMD, corresponding T-score and Z-score, TBS, and higher VBQ scores (all P<0.05), whereas only male patients in the case group had higher VBQ scores (P=0.028). Ten cases (27.8%) in the case group had low bone mass and 19 cases (52.8%) had impaired bone microarchitecture, higher than the 3 cases (8.3%) and 9 cases (25.0%) in controls respectively (both P<0.05). VBQ scores in the case group were negatively correlated with FN BMD, FN T-score, TH BMD, TH T-score, and TBS (r=-0.375, -0.391, -0.368, -0.361, and -0.389, respectively, all P<0.05). The AUCs of VBQ scores for predicting ROC curves of low bone mass and impaired bone microarchitecture in patients with SAPHO syndrome were 0.796 (95%CI: 0.649-0.944) and 0.694 (95%CI: 0.521-0.866), with a sensitivity of 100.0% and 47.4%, and a specificity of 53.9% and 88.2%, respectively. Conclusions: Patients with SAPHO syndrome present with low bone mass and impaired bone microarchitecture. VBQ score has a high sensitivity for predicting low bone mass and a high specificity for predicting impaired bone microarchitectural in patients with SAPHO syndrome.

Background: Clavicle radiogrammetry test related to chest radiography has been found to be useful in evaluation of osteoporosis. The diagnosis of osteoporosis was based on the measurement of bone mineral density (BMD) with dual energy x-ray absorptiometry. Objectives: The aim of this study was to evaluate bone mass measurement using clavicle radiograms to differentiate the goal standards related to the dual energy x-ray absorptiometry methods. Materials and methods: The population sample consisted of a 100 healthy Thai adult volunteers, (50 women, 50 men) aged from 24 to 76 years. The study subjects were divided as normal bone mass group, T-score ≥ -1.0 and the low bone mass group, T-score ≤ -1.0. Subsequently, posteroanterior (PA) chest radiographs were taken. Measurements of the clavicle radiograms were evaluated, and the images at the midshaft of both clavicles were calculated. An independent t-test was used to examine the differences between the normal and the low bone mass of each gender and two separate BMD sites. The confidence interval was 95% at level of significance 0.05. Pearson’s correlation was used to measure the strength and direction of linear relationship between the bone mass measurement using the dual energy x-ray absorptiometry (DEXA) test and clavicle radiogrammetry test. Results: The results showed 18 women and 28 men maintained a normal BMD, while 32 women and 22 men had low bone mass density. The average clavicle thickness measurements of the normal bone mass of the women group were lower than the normal bone mass measurements of men. Conversely, the low bone groups of women measurements were higher than low bone mass in the men’s group. A greater diminishing of cortical thickness of clavicle was found in the low bone mass than normal group for both genders. The average cortical thickness of clavicle in the low bone mass of women decreased by 17.8% (5.31 mm/6.46 mm) compared to normal women, while in men, which were fewer, 16.13% (7.07 mm/8.43 mm) between groups, respectively. The average measurements of the clavicle periosteal width and combined cortical thickness of clavicle showed a positive correlation with BMD, whereas, the clavicle endosteal width showed a negative correlation with BMD. Conclusion: Using the radiogrammetric method to measure the clavicle cortex thickness on the chest x-ray images showed a gradual thinning of the cortex with aging. By comparison, the measurements of clavicle cortex thickness showed a moderate relationship with BMD performed by DEXA in the assessment of osteoporosis.

A decline in physical function is common among elderly people who have lost both bone and muscle mass. The aim of this study was to investigate the relationship between low bone and muscle mass and physical function in elderly women of different age groups who exercise regularly. The analysis included 299 elderly women. Low bone mass was determined by a T-score of −2.5 or less, and low muscle mass was determined by a skeletal muscle mass index of <5.7 kg/m2. Physical function was measured by grip strength, knee extension strength, standing ability, gait function, and balance function. The participants were divided into four groups based on bone and muscle mass (healthy, low bone mass, low muscle mass, and low bone and muscle mass groups), and their physical functions were compared. There were no statistically significant differences in physical function between the low bone and muscle mass and the healthy groups. There were also no statistically significant differences in physical function among the four groups in the late elderly stage (75 and older). Elderly women who exercise regularly are less likely to experience a decline in physical function, even if they have reduced bone and muscle mass.

ObjectiveDecreased bone mineral density (BMD) impairs screw purchase in trabecular bone and can cause screw loosening following spinal instrumentation. Existing computed tomography (CT) scans could be used for opportunistic osteoporosis screening for decreased BMD. Purpose of this case-control study was to investigate the association of opportunistically assessed BMD with the outcome after spinal surgery with semi-rigid instrumentation for lumbar degenerative instability.MethodsWe reviewed consecutive patients that had primary surgery with semi-rigid instrumentation in our hospital. Patients that showed screw loosening in follow-up imaging qualified as cases. Patients that did not show screw loosening or—if no follow-up imaging was available (n = 8)—reported benefit from surgery ≥ 6 months after primary surgery qualified as controls. Matching criteria were sex, age, and surgical construct. Opportunistic BMD screening was performed at L1 to L4 in perioperative CT scans by automatic spine segmentation and using asynchronous calibration. Processing steps of this deep learning-driven approach can be reproduced using the freely available online-tool Anduin (https://anduin.bonescreen.de). Area under the curve (AUC) was calculated for BMD as a predictor of screw loosening.ResultsForty-six elderly patients (69.9 ± 9.1 years)—23 cases and 23 controls—were included. The majority of surgeries involved three spinal motion segments (n = 34). Twenty patients had low bone mass and 13 had osteoporotic BMD. Cases had significantly lower mean BMD (86.5 ± 29.5 mg/cm³) compared to controls (118.2 ± 32.9 mg/cm³, p = 0.001), i.e. patients with screw loosening showed reduced BMD. Screw loosening was best predicted by a BMD < 81.8 mg/cm³ (sensitivity = 91.3%, specificity = 56.5%, AUC = 0.769, p = 0.002).ConclusionPrevalence of osteoporosis or low bone mass (BMD ≤ 120 mg/cm³) was relatively high in this group of elderly patients undergoing spinal surgery. Screw loosening was associated with BMD close to the threshold for osteoporosis (< 80 mg/cm³). Opportunistic BMD screening is feasible using the presented approach and can guide the surgeon to take measures to prevent screw loosening and to increase favorable outcomes.

Predictors of bone mass in perimenopausal women. A prospective study of clinical data using photon absorptiometry

Osteoporosis remains under-diagnosed, particularly in African American men, despite the availability of reliable diagnostic tests. In women, several screening tools, including heel ultrasound and clinical assessment tools, reliably predict low bone mass, however the usefulness of these screening tools in African American men is unknown. The aim of this study was to determine the utility of screening tools, namely heel ultrasound, the osteoporosis self-assessment tool (OST), weight-based criterion (WBC) and body mass index (BMI), in screening for low bone mass in African American men. African American men 35 years of age and older were invited to participate. The OST risk index is a score based on age and weight [(weight in kilograms--age in years)x0.2]. Bone mineral density (BMD) of the heel was measured by heel ultrasound, and BMD of both the lumbar spine and hip were determined by dual energy X-ray absorptometry (DXA). One hundred and twenty-eight men fulfilled the inclusion criteria for our study. The population prevalence of osteopenia and osteoporosis were 39% and 7%, respectively. Using a heel ultrasound T-score cut-off value of -1 or less, we predicted low bone mass (T-score of -2 or less at the hip) with a sensitivity of 83%, a specificity of 71% and an area under the curve (AUC) of 0.80. Using an OST cut-off value of 4, we predicted low bone mass with a sensitivity of 83%, a specificity of 57% and an AUC of 0.83. The OST risk index ranged from 18.1 to -6.1, based on which we categorized risk as: low, 5 or greater; moderate, 0-4; high, -1 or less. Of the men with a high-risk OST score, 87% had either osteopenia or osteoporosis based on World Health Organization (WHO) criteria. Using the WBC alone with a cut-off value of 85 kg, we predicted low bone mass with a sensitivity of 74%, a specificity of 50% and an AUC of 0.70. A BMI cut-off value of 30 or greater yielded a sensitivity of 83%, a specificity of 43% and an AUC of 0.70 for the diagnosis of low bone mass. The prevalence of osteopenia and osteoporosis were unexpectedly high in outpatient African American male veterans, who are considered to be at low risk for low bone mass. Heel ultrasound was able to predict low bone mass with sufficiently high sensitivity and specificity for use as a screening tool. Surprisingly, WBC and BMI proved ineffective in predicting low bone mass with adequate sensitivity and specificity. The OST, a clinical formula based on weight and age, appeared to be an easy and reliable screening tool for identifying men at high risk for low bone mass.

The aim of this study was to explore body composition parameters and hormone levels as risk factors for low bone mass (osteopenia/osteoporosis) in postmenopausal women. We analyzed biorepository samples from 139 postmenopausal women with no clinical evidence of cardiovascular disease. Inclusion criteria were menopause occurring after 40 years of age and no use of hormone therapy in the past 3 months. Bone mineral density and body composition were assessed by dual-energy x-ray absorptiometry. Sex hormone-binding globulin (SHBG) and follicle-stimulating hormone (FSH) levels were measured in all participants. Serum estradiol was measured by gas chromatography/tandem mass spectrometry in a subset of 57 participants. Free estrogen index was calculated by dividing estradiol by SHBG × 100. Body mass index (25.0 [22.5-26.5] vs 27.7 [26.6-31.9] kg/m 2 , P < 0.001), estradiol (3.0 [2.7-4.5] vs 6.0 [2.7-15.0] pg/mL, P = 0.006), waist circumference (84 ± 9 vs 93 ± 12 cm, P < 0.001), appendicular lean mass (ALM) (15.739 ± 2.129 vs 17.184 ± 2.104 kg, P = 0.001), and fat mass index (9.36 [7.29-11.43] vs 11.38 [9.95-15.33] kg/m 2 , P < 0.001) were lower in women with low bone mass by dual-energy x-ray absorptiometry. Univariate analysis showed that free estrogen index, time since menopause, SHBG, and fat mass were significant predictors of low bone mass, and ALM was a significant predictor against low bone mass. Appendicular lean mass persisted as an independent predictor against low bone mass in multivariate models with fat mass and SHBG. In turn, fat mass was no longer significant in this multivariate model after inclusion of SHBG. No association of FSH with low bone mass was observed. Appendicular lean mass was a significant independent predictor against low bone mass in postmenopausal women. Further prospective studies are needed to investigate whether lean mass, fat mass, and FSH have a direct effect on bone mass in postmenopausal women, adding to the consequences of hypoestrogenism in this group.

To find out which of the following parameters-serum levels of insulin-like growth factor 1 (IGF-1), osteoprotegerin (OPG), leptin, osteocalcin (OC), and urinary excretion of N-terminal telopeptide of type I collagen (NTx), can be used as an early marker for osteopenia/osteoporosis in women diagnosed by dual-energy X-ray absorptiometry (DXA), 282 premenopausal and 222 postmenopausal women aged 20-75 years were investigated by the measurement of bone mineral densities (BMDs) at lumbar spine (LS) and femoral neck (FN) by DXA, together with serum concentrations of IGF-1, OPG, leptin, OC, and urinary NTx. The characteristics of the earliest marker(s) were tested with the receiver operating characteristic (ROC) analysis. The area under the curve (AUC), sensitivity, and specificity parameters were determined. It was revealed that serum levels of IGF-1 and leptin changed the earliest, with both markers significantly decreasing (P < 0.0001) or increasing (P = 0.020), respectively, at age 30. However, in ROC analysis, IGF-1 was the only early parameter that had the capacity to differentiate the low bone mass/osteoporosis women from the normal ones (P < 0.0001). If the serum level of IGF-1 at 1.5 SD below its peak was adopted as a cutoff point, it could identify women with low bone mass/osteoporosis with a sensitivity of 73% and specificity of 67%. In the premenopausal women subgroup analysis, the low bone mass women (30/282, 10.6%) were older (38.2 +/- 1.7 vs. 34.5 +/- 0.5 years; P = 0.026), with lower serum levels of IGF-1 (215.1 +/- 22.4 vs. 278.8 +/- 9.4 ng/ml; P = 0.02) and less lean mass (33.1 +/- 0.6 vs. 34.8 +/- 0.2 kg; P = 0.010) than the normal ones. After controlling for age, the serum level of IGF-1 had a weak, but still significant, positive correlation with lean mass (r = 0.17, P < 0.001). In conclusion, measurement of serum IGF-1 in young women may help in the early identification of those at risk for developing low bone mass and osteoporosis.

Few related factors of low bone mass in Cushing's disease (CD) have been identified so far, and relevant sufficient powered studies in CD patients are rare. On account of the scarcity of data, we performed a well-powered study to identify related factors associated with low bone mass in young CD patients. This retrospective study included 153 CD patients (33 males and 120 females, under the age of 50 for men and premenopausal women). Bone mineral density (BMD) of the left hip and lumbar spine was measured by dual energy X-ray absorptiometry (DEXA). In this study, low bone mass was defined when the Z score was -2.0 or lower. Among those CD patients, low bone mass occurred in 74 patients (48.37%). Compared to patients with normal BMD, those patients with low bone mass had a higher level of serum cortisol at midnight (22.31 (17.95-29.62) vs. 17.80 (13.75-22.77), p=0.0006), testosterone in women (2.10 (1.33-2.89) vs. 1.54 (0.97-2.05), p=0.0012), higher portion of male (32.43% vs. 11.54%, p=0.0016) as well as hypertension (76.12% vs. 51.67%, p=0.0075), and lower IGF-1 index (0.59 (0.43-0.76) vs. 0.79 (0.60-1.02), p=0.0001). The Z score was positively associated with the IGF-1 index in both the lumbar spine (r = 0.35153, p < 0.0001) and the femoral neck (r = 0.24418, p=0.0057). The Z score in the femoral neck was negatively associated with osteocalcin (r = -0.22744, p=0.0229). Compared to the lowest tertile of the IGF-1 index (<0.5563), the patients with the highest tertile of the IGF-1 index (≥0.7993) had a lower prevalence of low bone mass (95% CI 0.02 (0.001-0.50), p=0.0002), even after adjusting for confounders such as age, gender, duration, BMI, hypertension, serum cortisol at midnight, PTH, and osteocalcin. The higher IGF-1 index was independently associated with lower prevalence of low bone mass in young CD patients, and IGF-1 might play an important role in the pathogenesis of CD-caused low bone mass.

Children with β-thalassemia major and β-thalassemia intermedia frequently have low bone mass. However, studies of bone mineral density (BMD) in children with transfusion-dependent (TD) or non-transfusion-dependent (NTD) hemoglobin (Hb) E/β-thalassemia are scarce. To determine the prevalence of low bone mass among mostly preadolescent children with NTD and TD Hb E/β thalassemia and the related factors. We investigated the BMD of the lumbar spine (LSBMD) and total body (TBBMD), measured by dual-energy X-ray absorptiometry, of 59 children with NTD Hb E/β-thalassemia and 50 with TD Hb E/β-thalassemia. The median age of the patients was 10.4 (6.2-13.5) years in the NTD group and 10.3 (5.9-14.1) years in the TD group. These children had a relatively low prevalence of low bone mass (NTD: 1.7%-10.2%; TD: 4%-14%). The values varied with the bone site measured and the BMD size-adjustment method used (height age vs. bone age). The NTD group had significantly lower TBBMD Z-scores (adjusted for height age) than the TD group. The proportion of patients with low lumbar spine bone mass (adjusted for bone age) was significantly higher for the TD group than for the NTD group. Our study demonstrates that most children with either disease had normal BMD. Patients with the NTD form had a lower TBBMD than those with the TD form. Low bone mass affected the lumbar spine of patients with TD Hb E/β-thalassemia more than those with the NTD form.