Assessment of fracture risk: value of random population-based samples--the Geelong Osteoporosis Study

Reference Intervals for Bone Impact Microindentation in Healthy Adults: A Multi-Centre International Study

Impact microindentation (IMI) is a novel technique for assessing bone material strength index (BMSi) in vivo, by measuring the depth of a micron-sized, spherical tip into cortical bone that is then indexed to the depth of the tip into a reference material. The aim of this study was to define the reference intervals for men and women by evaluating healthy adults from the United States of America, Europe and Australia. Participants included community-based volunteers and participants drawn from clinical and population-based studies. BMSi was measured on the tibial diaphysis using an OsteoProbe in 479 healthy adults (197 male and 282 female, ages 25 to 98 years) across seven research centres, between 2011 and 2018. Associations between BMSi, age, sex and areal bone mineral density (BMD) were examined following an a posteriori method. Unitless BMSi values ranged from 48 to 101. The mean (± standard deviation) BMSi for men was 84.4 ± 6.9 and for women, 79.0 ± 9.1. Healthy reference intervals for BMSi were identified as 71.0 to 97.9 for men and 59.8 to 95.2 for women. This study provides healthy reference data that can be used to calculate T- and Z-scores for BMSi and assist in determining the utility of BMSi in fracture prediction. These data will be useful for positioning individuals within the population and for identifying those with BMSi at the extremes of the population.

Normative Data for Impact Microindentation for Australian Men: Cross-Sectional Data From the Geelong Osteoporosis Study

Impact microindentation (IMI) is a novel technique for assessing the bone material strength index (BMSi) in vivo. However, no studies have presented normative data for BMSi. The aim of this study was to develop such normative data using a population-based sample of men, randomly selected from electoral rolls for the Barwon Statistical Division in southeastern Australia to participate in the Geelong Osteoporosis Study. BMSi was measured on the tibial plateau using an OsteoProbe in 405 men (ages 33 to 96 years) during the period 2016 to 2019. Associations between BMSi, age, and anthropometry were examined using linear regression models. BMSi values ranged from 49.0 to 100.5. BMSi was negatively correlated with age (r = -0.152, p = 0.002), weight (r = -0.103, p = 0.039), and BMI (r = -0.187, p < 0.001), and positively correlated with height (r = +0.107, p = 0.032). Mean ± SD BMSi was 82.6 ± 7.0 for the whole group, and ranged from 85.6 ± 6.0 for ages 30 to 39 years to 79.8 ± 6.6 for ages 80+ years. This study provides normative data that can be used to calculate T- and Z-scores for BMSi. These data will be useful for identifying men with low BMSi. Further research is warranted to derive optimal cut points for BMSi that discriminate fracture risk. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Normative Data for Lean Mass Using FNIH Criteria in an Australian Setting

Recommendations from the FNIH Sarcopenia Project are that appendicular lean mass (ALM, kg) adjusted for body mass index (BMI, kg/m²) be used for identifying low lean mass, with ALM/BMI cutpoints of < 0.789 m² for men and < 0.512 m² for women. We report normative ALM/BMI values for Australian adults, and compare the performance of cutpoints derived from reference values for this population with FNIH values for identifying low lean mass. Body composition was measured by DXA (Lunar) for 1411 men and 960 women, aged 20-93 years, from the Geelong Osteoporosis Study, a population-based study in Australia. Sex-stratified means and standard deviations for DXA-derived ALM/BMI were generated for each age-decade, and cutpoints equivalent to T-scores of - 2.0 were derived using reference data for 374 men and 308 women aged 20-39 years. Mean ALM/BMI values were greater for men than women, and decreased with age in both sexes. Cutpoints for ALM/BMI corresponding to T-scores of - 2.0 were 0.827 m² for men and 0.518 m² for women. For individuals aged 65+ years, cross-classification of low lean mass according to FNIH criteria (ALM/BMI < 0.789 m² men and < 0.512 m² women) in comparison with our cutpoints for ALM/BMI showed overall agreement of 94.6% for men and 99.0% for women (κ 0.73 and 0.89, respectively). We report good agreement for low ALM indexed to BMI, particularly for women, between classifications based on recommendations from the FNIH Sarcopenia Project for identifying clinically significant weakness, with low values identified within our population distribution of ALM/BMI.

Reference Ranges for Trabecular Bone Score in Australian Men and Women: A Cross-Sectional Study

Trabecular bone score (TBS) is a novel method for indirectly assessing trabecular microarchitecture at the lumbar spine, providing information complementary to areal BMD. However, limited reference ranges exist for the normative distribution of TBS, particularly in men. The aim of this study was to develop such a reference range in Australian men and women. This study included 894 men and 682 women (aged 24 to 98 years) enrolled in the Geelong Osteoporosis Study. TBS was determined retrospectively by analysis of lumbar spine DXA scans (Lunar Prodigy) using TBS iNsight software (version 2.2). Multivariable regression techniques were used to determine best-fit models for TBS incorporating age, height, and weight. Age-related differences in TBS were best modelled with a linear relationship in men and a cubic relationship in women. Combined best-fit models for TBS included age and weight in men, and age and height in women. This study provides normative reference ranges for TBS in Australian men and women, and further indicates that TBS may identify individuals at risk for fracture despite normal BMD. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Body mass index and the risk of low bone mass-related fractures in women compared with men: A PRISMA-compliant meta-analysis of prospective cohort studies

BACKGROUND

Body mass index (BMI) is inconsistently associated with the progression of low bone mass-related fractures. We conducted a systematic review and meta-analysis to summarize the evidence regarding the relationship between BMI and the risk of fracture in men and women separately. Furthermore, we analyzed the association between BMI and fracture risk in women compared with men.

METHODS

PubMed, EmBase, and the Cochrane Library were searched up to November 2015 to identify prospective cohort studies of low bone mass-related fractures. Prospective cohort studies that reported effect estimates of fracture risk for different BMI categories compared to normal weight were included. Relative risk (RR) and the ratio of relative risk (RRR) were calculated using a random-effect model to measure the relationship between BMI and fracture risk.

RESULTS

We analyzed 37 cohorts (32 articles), which included a total of 506,004 women and 118,372 men; overall, 38,200 incident cases were reported. Overall, a lower BMI was not associated with fracture risk in men (RR: 1.50, 95% confidence interval [CI]: 1.00-2.26; P = 0.051) or women (RR: 1.25, 95% CI: 0.97-1.62; P = 0.083). Although a higher BMI might play a beneficial impact in men (RR: 0.80, 95% CI: 0.69-0.93; P = 0.003), it has little effect in women (RR: 0.91, 95% CI: 0.74-1.11; P = 0.343). In addition, an increase in BMI by 5 kg/m decreased the risk of fractures in men (RR: 0.90, 95% CI: 0.83-0.98; P = 0.017) and women (RR: 0.85, 95% CI: 0.81-0.89; P < 0.001). Finally, there was no evidence of a sex difference in the RR for fractures between participants with different BMI categories compared with those with normal BMI. Finally, gender did not affect the risk of fracture for any category of BMI values.

CONCLUSION

Higher BMI may affect the risk of fractures regardless of the sex. This association may be due to the interaction between the participants' BMI and their bone mass density.

Sulfuretin induces osteoblast differentiation through activation of TGF-β signaling

The identification and examination of potential determinants controlling the progression of cell fate toward osteoblasts can be intriguing subjects. In this study, the effects of sulfuretin, a major compound isolated from Rhus verniciflua Stokes, on osteoblast differentiation were investigated. Treatments of sulfuretin induced alkaline phosphatase (ALP) activity in mesenchymal C3H10T1/2 cells and mineralization in preosteoblast MC3T3-E1 cells. Pro-osteogenic effects of sulfuretin were consistently observed in freshly isolated primary bone marrow cells. In mechanical studies, sulfuretin specifically induced expression of TGF-β target genes, such as SMAD7 and PAI-1, but not other signaling pathway-related genes. Similar to the results of gene expression analysis, reporter assays further demonstrated TGF-β-specific induction by sulfuretin. Furthermore, disruption of TGF-β signaling using treatment with TGF-β-specific inhibitor, SB-431542, and introduction of SMAD2/3 small interfering RNA impaired the effects of sulfuretin in inducing ALP activity and expression of ALP mRNA. Together, these data indicate that the pro-osteogenic effects of sulfuretin are mediated through activation of TGF-β signaling, further supporting the potential of sulfuretin in the prevention of bone-related diseases such as bone fracture and osteoporosis.

Reciprocal regulation of adipocyte and osteoblast differentiation of mesenchymal stem cells by Eupatorium japonicum prevents bone loss and adiposity increase in osteoporotic rats

Pathological increases in adipogenic potential with decreases in osteogenic differentiation occur in osteoporotic bone marrow cells. Previous studies have shown that bioactive materials isolated from natural products can reciprocally regulate adipogenic and osteogenic fates of bone marrow cells. In this study, we showed that Eupatorium japonicum stem extracts (EJE) suppressed lipid accumulation and inhibited the expression of adipocyte markers in multipotent C3H10T1/2 and primary bone marrow cells. Conversely, EJE stimulated alkaline phosphatase activity and induced the expression of osteoblast markers in C3H10T1/2 and primary bone marrow cells. Daily oral administration of 50 mg/kg of EJE for 6 weeks to ovariectomized rats prevented body weight increase and bone mineral density decrease. Finally, activity-guided fractionation led to the identification of coumaric acid and coumaric acid methyl ester as bioactive anti-adipogenic and pro-osteogenic components in EJE. Taken together, our data indicate a promising possibility of E. japonicum as a functional food and as a therapeutic intervention for preventing osteoporosis and bone fractures.

Total and appendicular lean mass reference ranges for Australian men and women: the Geelong osteoporosis study

The aim of this study was to develop reference ranges for total and appendicular lean mass measured using dual-energy X-ray absorptiometry (DXA) from a randomly selected population-based sample of men and women residing in southeastern Australia. Men (n = 1,411) and women (n = 960) aged 20-93 years, enrolled in the Geelong Osteoporosis Study, were randomly selected from the Barwon Statistical Division using the electoral roll as a sampling frame in 2001-2006 (67 % participation) and 1993-1997 (77 % participation), respectively. Using DXA (Lunar DPX-L or Prodigy Pro) at baseline for men and at the 10-year follow-up for women (2004-2008), total and appendicular lean mass were measured. Means and standard deviations for each lean mass measure (absolute and relative to height squared) were generated for each age decade, and cutpoints equivalent to T scores of -2.0 and -1.0 were calculated using data from young adult men and women aged 20-39 years. Young adult reference data were derived from 374 men and 308 women. Cutpoints for relative appendicular lean mass equal to T scores of -2.0 and -1.0 were 6.94 and 7.87 kg/m(2) for men and 5.30 and 6.07 kg/m(2) for women. The proportions of men and women aged ≥80 years with a T score less than -2.0 were 16.0 and 6.2 %, respectively. These reference ranges may be useful for identifying lean mass deficits in the assessment of muscle wasting and sarcopenia.

2013 International Society for Clinical Densitometry Position Development Conference: Task Force on Normative Databases

Following the standard protocol for development of Official Positions for the International Society for Clinical Densitometry, the Expert Panel heard the report and recommendations from the Task Force on Normative Databases; using the RAND methodology, agreement was reached on the following statements: 1. Manufacturers should continue to use their own databases for the lumbar spine as the reference standard for T-scores. 2. Manufacturers should continue to use National Health and Nutrition Examination Survey III data as the reference standard for femoral neck and total hip T-scores. 3. If local reference data are available, they should be used to calculate only Z-scores but not T-scores. 4. A uniform Caucasian (non-race adjusted) female reference database should be used to calculate T-scores for men of all ethnic groups.

Calcaneal ultrasound reference ranges for Australian men and women: the Geelong Osteoporosis Study

Heel ultrasound is a more portable modality for assessing fracture risk than dual-energy X-ray absorptiometry and does not use ionising radiation. Fracture risk assessment requires appropriate reference data to enable comparisons. This study reports the first heel ultrasound reference ranges for the Australian population.

INTRODUCTION

This study aimed to develop calcaneal (heel) ultrasound reference ranges for the Australian adult population using a population-based random sample.

METHODS

Men and women aged≥20 years were randomly selected from the Barwon Statistical Division in 2001-2006 and 1993-1997, respectively, using the electoral roll. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were measured at the heel using a Lunar Achilles Ultrasonometer. Gender-specific means and standard deviations for BUA, SOS and SI were calculated for the entire sample (men 20-93 years, n=1,104; women 20-92 years, n=914) and for participants aged 20-29 years (men, n=157; women, n=151). Associations between ultrasound measures and age were examined using linear regression.

RESULTS

For men, mean±standard deviation BUA, SOS and SI were 118.7±15.8 dB/MHz, 1,577.0±43.7 m/s and 100.5±20.7, respectively; values for women were consistently lower (111.0±16.4 dB/MHz, P<0.001; 1,571.0±39.0 m/s, P=0.001; and 93.7±20.3, P<0.001, respectively). BUA was higher in young men compared with young women (124.5±14.4 vs 121.0±15.1 dB/MHz), but SOS (1,590.1±43.1 vs 1,592.5±35.0 m/s) and SI (108.0±19.9 vs 106.3±17.7) were not. The relationships between age and each ultrasound measure were linear and negative across the age range in men; associations were also negative in women but non-linear.

CONCLUSION

These data provide reference standards to facilitate the assessment of fracture risk in an Australian population using heel ultrasound.

Lumbar spine bone mineral density in US adults: demographic patterns and relationship with femur neck skeletal status

This analysis examines lumbar spine bone mineral density (BMD) of US adults from NHANES 2005-2008 by age, sex, and race/ethnicity. Prevalence of low spine BMD and agreement between the prevalence of low BMD at the spine and femur neck in older adults are also assessed.

INTRODUCTION

Lumbar spine BMD data from a representative sample of the US population have not been previously available.

METHODS

We used data from the National Health and Nutrition Examination Survey 2005-2008 to examine demographic patterns in lumbar spine BMD among US adults age ≥20 years and the prevalence of low lumbar spine BMD in adults age ≥50 years. Agreement between the prevalence of low BMD at the femur neck and spine in older adults was also assessed. Dual-energy X-ray absorptiometry was used to measure lumbar spine and femur neck BMD. World Health Organization definitions were used to categorize skeletal status as normal, osteopenia, or osteoporosis.

RESULTS

Compared to non-Hispanic whites, non-Hispanic blacks had higher and Mexican Americans had lower lumbar spine BMD. Lumbar spine BMD declined with age in women, but not in men. Approximately 4.7 million (10%) older US women and 1 million (3%) older men had lumbar spine osteoporosis in 2005-2008. Roughly one third of them differed in skeletal status at the spine and hip but most were normal at one site and osteopenic at the other. Only 3-10%, depending on sex, had osteoporosis at one skeletal site but not at the other skeletal site. Between 76% and 87% with discordant skeletal status had lumbar spine T-scores within 1 unit of the category threshold.

CONCLUSIONS

These findings suggest that measuring either the femur neck or the lumbar spine will correctly classify the majority of individuals who present for care as osteoporotic or not.

Genome-wide association study using extreme truncate selection identifies novel genes affecting bone mineral density and fracture risk

Osteoporotic fracture is a major cause of morbidity and mortality worldwide. Low bone mineral density (BMD) is a major predisposing factor to fracture and is known to be highly heritable. Site-, gender-, and age-specific genetic effects on BMD are thought to be significant, but have largely not been considered in the design of genome-wide association studies (GWAS) of BMD to date. We report here a GWAS using a novel study design focusing on women of a specific age (postmenopausal women, age 55-85 years), with either extreme high or low hip BMD (age- and gender-adjusted BMD z-scores of +1.5 to +4.0, n = 1055, or -4.0 to -1.5, n = 900), with replication in cohorts of women drawn from the general population (n = 20,898). The study replicates 21 of 26 known BMD-associated genes. Additionally, we report suggestive association of a further six new genetic associations in or around the genes CLCN7, GALNT3, IBSP, LTBP3, RSPO3, and SOX4, with replication in two independent datasets. A novel mouse model with a loss-of-function mutation in GALNT3 is also reported, which has high bone mass, supporting the involvement of this gene in BMD determination. In addition to identifying further genes associated with BMD, this study confirms the efficiency of extreme-truncate selection designs for quantitative trait association studies.

Bone mineral density reference ranges for Australian men: Geelong Osteoporosis Study

SUMMARY

A large population-based random sample of Australian white men was used to provide normative bone mineral density (BMD) data at multiple anatomical sites. The femoral neck BMD data are very similar to those obtained in USA non-Hispanic white males participating in the National Health and Nutrition Examination Survey III (NHANES III). The reference ranges will be suitable for similar populations.

INTRODUCTION

To provide normative BMD data for Australian men derived from a large population-based random sample.

METHODS

An age-stratified random sample of men was recruited from the Australian electoral rolls (n = 1,467 aged 20-97 years). BMD was quantified at multiple sites using Lunar densitometers.

RESULTS

Age-related differences in BMD were best predicted by linear relationships at the spine and hip and by quadratic functions at the whole body and forearm. At the spine, a small age-related increase in mean BMD was observed. Although in the subset with no spinal abnormalities, there was a decrease of 0.003 g/cm(2) per year from age 20. At the hip sites, mean BMD decreased at 0.001-0.006 g/cm(2) per year from age 20. At the forearm and whole body, BMD peaked at 41-47 years. Apart from a small difference in men greater than or equal to 80 years, the Australian femoral neck BMD data are not different to those obtained in USA non-Hispanic white males participating in NHANES III and were generally similar to those of large studies from Canada (CaMos) and Spain.

CONCLUSIONS

These data supply BMD reference ranges at multiple anatomical sites that will be applicable to white Australian men and similar populations such as USA non-Hispanic white men.

Epidemiology of fracture risk in the Women's Health Initiative

Osteoporosis is one of the most disabling consequences of aging in women. Strategies that permit earlier identification of women at risk for fracture are needed. The Women's Health Initiative has extended our knowledge of clinical risk factors and biomarkers of fracture risk in postmenopausal women. Based upon 11 clinically available risk factors (age, race/ethnicity, self-reported health, weight, height, physical activity, parental hip fracture, fracture history after age 54, current smoking, corticosteroid use, and history of treated diabetes), an algorithm has been developed to predict 5-year hip fracture risk. Biomarkers including low vitamin D or bioavailable testosterone and/or high cystatin C or sex hormone-binding globulin also predict risk for hip fracture independent of clinical risk factors. To address the growing incidence of fractures in minority women, clinical risk factors for fracture have been identified. These data demonstrate that we can better identify women, irrespective of race or ethnicity, at risk for fracture.

The population burden of fractures originates in women with osteopenia, not osteoporosis

INTRODUCTION

Osteoporosis is associated with increased risk for fracture. However, most postmenopausal women have bone mineral density (BMD) within the normal or osteopenic range. The aim of this study was to determine the proportion of the population burden of fragility fractures arising from women at modest risk for fracture.

METHODS

We measured baseline BMD in a population-based random sample of 616 postmenopausal women aged 60-94 years and followed these individuals for a median of 5.6 years (IQR 3.9-6.5) to determine the incidence of fractures according to age, BMD and the presence of a prior fracture.

RESULTS

Based on WHO criteria, 37.6% of the women had normal total hip BMD, 48.0% had osteopenia and 14.5% had osteoporosis. The incidence of fracture during follow-up was highest in women with osteoporosis, but only 26.9% of all fractures arose from this group; 73.1% occurred in women without osteoporosis (56.5% in women with osteopenia, 16.6% in women with normal BMD). Decreasing BMD, increasing age and prior fracture contributed independently to increased fracture risk; in a multivariate model, the relative risk for fracture increased 65% for each SD decrease in BMD (RR=1.65, 95%CI 1.32-2.05), increased 3% for every year of age (RR=1.03, 95%CI 1.01-1.06) and doubled with prevalent fracture (RR=2.01, 95% CI 1.40-2.88). A prevalent fracture increased the risk for fractures such that women with osteopenia and prevalent fracture had the same, if not greater, risk as women with osteoporosis alone.

CONCLUSIONS

Reducing the population burden of fractures requires attention to women with osteopenia, as well as osteoporosis, because over half of the fragility fractures in the population arise in these individuals, and women with osteopenia plus a prevalent fracture have the same fracture risk as women with osteoporosis.

Cross-calibration and minimum precision standards for dual-energy X-ray absorptiometry: the 2005 ISCD Official Positions

The International Society for Clinical Densitometry (ISCD) Committee on Standards of Bone Measurement (CSBM) consists of experts in technical aspects of bone densitometry. The CSBM recently reviewed the scientific literature on cross-calibration and precision assessment. A report with recommendations was presented at the 2005 ISCD Position Development Conference (PDC). Based on a thorough review of the data by the ISCD Expert Panel during the conference, the ISCD adopted Official Positions with respect to (1) cross-calibration when changing or replacing hardware; (2) the approach to cross-calibration when an entire system is changed to one made by either the same or a different manufacturer; (3) when no cross-calibration study or bone mineral density (BMD) comparison is done between facilities; and (4) the minimum acceptable precision for an individual technologist. We present here the ISCD Official Positions on these topics that were established as a result of the 2005 PDC, together with the associated rationales and supportive evidence.

Reference ranges for bone densitometers adopted Australia-wide: Geelong osteoporosis study

Bone densitometry reports a measure of fracture risk in comparison with young adults (T-scores) and age-matched peers (Z-scores). To date, each manufacturer has provided its own reference range resulting in lack of uniformity. The Australia and New Zealand Bone and Mineral Society and Osteoporosis Australia have recognized the need to standardize the reference range and have recommended that data generated by the Geelong Osteoporosis Study (GOS) be used Australia-wide. The GOS recruited a random, population-based sample of adult women and measured bone mineral density (BMD) at the proximal femur and spine using a Lunar DPX-L. These data were used to establish reference ranges for Lunar machines and, using conversion equations, for Norland and Hologic machines. The new standardized Australian reference ranges for BMD will enable consistent diagnosis of osteoporosis and categorization of fracture risk across different types of densitometers.

Quantitative ultrasound of the calcaneus as a screening tool to detect osteoporosis: different reference ranges for caucasian women, african american women, and caucasian men

The interpretation of results measured by quantitative ultrasound (QUS) of the heel depends on the population studied. We measured estimated bone mineral density (BMD) of the heel using the Hologic Sahara sonometer. People were studied at county fairs, health fairs, and churches. Subjects were not on treatments that would affect bone density, other than calcium supplementation. This included 823 Caucasian women, 131 African American women, and 301 Caucasian men. In contrast to women, for Caucasian men the squared term for age was not significant, and a straight line of decline was the best fit for estimated BMD. African American women had a standard deviation larger than that reported by Hologic for Caucasian women. We compared a history of self-reported fractures with a subject's estimated BMD. An estimated BMD of 0.57 gm/cm2 included 75% of all fractures. This cutoff point was associated with increased fracture prevalence in subjects over age 50, relative risk of 1.4. This result corresponds to the Hologic data T-score of -0.2. When used as a screening tool for osteoporosis fracture risk, an estimated BMD of 0.57 gm/cm2 seems reasonable in those subjects over age 50.