Statistical shape modelling of hip and lumbar spine morphology and their relationship in the MRC National Survey of Health and Development.

The anatomical shape of bones and joints is important for their proper function but quantifying this, and detecting pathological variations, is difficult to do. Numerical descriptions would also enable correlations between joint shapes to be explored. Statistical shape modelling (SSM) is a method of image analysis employing pattern recognition statistics to describe and quantify such shapes from images; it uses principal components analysis to generate modes of variation describing each image in terms of a set of numerical scores after removing global size variation. We used SSM to quantify the shapes of the hip and the lumbar spine in dual-energy x-ray absorptiometry (DXA) images from 1511 individuals in the MRC National Survey of Health and Development at ages 60-64 years. We compared shapes of both joints in men and women and hypothesised that hip and spine shape would be strongly correlated. We also investigated associations with height, weight, body mass index (BMI) and local (hip or lumber spine) bone mineral density. In the hip, all except one of the first 10 modes differed between men and women. Men had a wider femoral neck, smaller neck-shaft angle, increased presence of osteophytes and a loss of the femoral head/neck curvature compared with women. Women presented with a flattening of the femoral head and greater acetabular coverage of the femoral head. Greater weight was associated with a shorter, wider femoral neck and larger greater and lesser trochanters. Taller height was accompanied by a flattening of the curve between superior head and neck and a larger lesser trochanter. Four of the first eight modes describing lumbar spine shape differed between men and women. Women tended to have a more lordotic spine than men with relatively smaller but caudally increasing anterior-posterior (a-p) vertebral diameters. Men were more likely to have a straighter spine with larger vertebral a-p diameters relative to vertebral height than women, increasing cranially. A weak correlation was found between body weight and a-p vertebral diameter. No correlations were found between shape modes and height in men, whereas in women there was a weak positive correlation between height and evenness of spinal curvature. Linear relationships between hip and spine shapes were weak and inconsistent in both sexes, thereby offering little support for our hypothesis. In conclusion, men and women entering their seventh decade have small but statistically significant differences in the shapes of their hips and their spines. Associations with height, weight, BMI and BMD are small and correspond to subtle variations whose anatomical significance is not yet clear. Correlations between hip and spine shapes are small.

Frailty and bone health in European men.

Background: frailty is associated with an increased risk of fragility fractures. Less is known, however, about the association between frailty and bone health. Methods: men aged 40-79 years were recruited from population registers in eight European centres for participation in the European Male Aging Study. Subjects completed a comprehensive assessment which included quantitative ultrasound (QUS) scan of the heel (Hologic-SAHARA) and in two centres, dual-energy bone densitometry (dual-energy x-ray absorptiometry, DXA). Frailty was defined based on an adaptation of Fried's phenotype criteria and a frailty index (FI) was constructed. The association between frailty and the QUS and DXA parameters was determined using linear regression, with adjustments for age, body mass index and centre. Results: in total, 3,231 subjects contributed data to the analysis. Using the Fried categorisation of frailty, pre-frail and frail men had significantly lower speed of sound (SOS), broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) compared to robust men (P< 0.05). Similar results were seen using the FI after categorisation into 'high', 'medium' and 'low' levels of frailty. Using the Fried categorisation, frail men had lower femoral neck bone mineral density (BMD) compared to robust men (P < 0.05), but not lower lumbar spine BMD. Using the FI categorisation, a 'high' level of frailty (FI > 0.35) was associated with lower lumbar spine BMD (P < 0.05) when compared to those with low (FI < 0.2), but not lower femoral neck BMD. When analysed as a continuous variable, higher FI was linked with lower SOS, BUA and QUI (P < 0.05). Conclusions: optimisation of bone health as well as prevention of falls should be considered as strategies to reduce fractures in frail older people.

Opportunistic Identification of Vertebral Fractures.

Vertebral fractures are powerful predictors of future fracture, so, their identification is important to ensure that patients are commenced on appropriate bone protective or bone-enhancing therapy. Risk factors (e.g., low bone mineral density and increasing age) and symptoms (back pain, loss of height) may herald the presence of vertebral fractures, which are usually confirmed by performing spinal radiographs or, increasingly, using vertebral fracture assessment with dual-energy X-ray absorptiometry scanners. However, a large number (30% or more) of vertebral fractures are asymptomatic and do not come to clinical attention. There is, therefore, scope for opportunistic (fortuitous) identification of vertebral fractures from various imaging modalities (radiographs, computed tomography, magnetic resonance imaging, and radionuclide scans) performed for other clinical indications and which include the spine in the field of view, with midline sagittal reformatted images from computed tomography having the greatest potential for such opportunistic detection. Numerous studies confirm this potential for identification but consistently find underreporting of vertebral fractures. So, a valuable opportunity to improve the management of patients at increased risk of future fracture is being squandered. Educational training programs for all clinicians and constant reiteration, stressing the importance of the accurate and clear reporting of vertebral fractures ("you only see what you look for"), can improve the situation, and automated computer-aided diagnostic tools also show promise to solve the problem of this underreporting of vertebral fractures.

Bone Densitometry in Children.

Maximizing peak bone mass in childhood is relevant to optimizing bone health in later life, so the study of the skeleton in children in health and disease is important. Dual-energy X-ray absorptiometry (DXA) is the most widely used clinical tool for the assessment of bone status in children. Technological developments in DXA enable vertebral fracture assessment at much lower ionizing radiation doses than spinal radiographs. Quantitative computed tomography remains predominantly a research tool but has some advantages over DXA in not being size dependent. High-resolution peripheral computed tomography measures trabecular and cortical bone microstructure but is technically challenging, particularly in children, and not widely available, so it is unlikely to be used in clinical practice. Other quantitative techniques (quantitative magnetic resonance imaging, digital X-ray absorptiometry, quantitative ultrasound) have been applied in children but remain research applications, and they are only covered briefly in this review.

Idiopathic Juvenile Osteoporosis: Clinical Experience from a Single Centre and Screening of LRP5 and LRP6 Genes.

We report clinical findings, bone mineral density (BMD) and bone biopsy data in ten children with features of classic idiopathic juvenile osteoporosis (IJO). We also screened the patients for mutations in LRP5 and LRP6. We found low BMD in the lumbar spine, the hip and distal radius. In the spine and distal radius, the reduction in BMD was more marked in the trabecular compartment. Biopsy confirmed that the trabecular compartment is more severely involved with reduction in bone formation and increase in bone resorption. No mutations in LRP5 and LRP6 could be identified. IJO is likely to be a heterogeneous bone disorder, and next-generation genomic sequencing studies may help reveal causative genes.

Imaging of Ancient Egyptian Animal Mummies.

Human mummies have long been studied by using imaging as a primary investigative method. Mummified animal remains from ancient Egypt are less well researched, yet much can be learned about species diversity and the methods of preservation. Noninvasive imaging methods enable mummy bundles to remain intact, with no detrimental physical effects, thus ensuring protection of a valuable archaeological resource. This article is based on the research experience gathered during 13 years (2000-2012) with 152 animal mummies held in the collections of 17 museums in the United Kingdom. Conventional radiography, computed radiography, digital radiography, and computed tomography (CT) available in the clinical setting were used to assess the value of each imaging modality in the study of animal mummies and related material. Radiography proved to be an excellent research method that provided initial insight into the contents of the mummy bundle, and CT contributed additional useful detail in some cases. Paleoradiologic analyses enabled information on mummy bundle contents to be proved, including the nature of the skeletal remains and the methods of mummification. An optimum method involving radiography and CT is described.

Low heel ultrasound parameters predict mortality in men: results from the European Male Ageing Study (EMAS).

BACKGROUND: low bone mineral density measured by dual-energy x-ray absorptiometry is associated with increased mortality. The relationship between other skeletal phenotypes and mortality is unclear. The aim of this study was to determine the relationship between quantitative heel ultrasound parameters and mortality in a cohort of European men. METHODS: men aged 40-79 years were recruited for participation in a prospective study of male ageing: the European Male Ageing Study (EMAS). At baseline, subjects attended for quantitative ultrasound (QUS) of the heel (Hologic-SAHARA) and completed questionnaires on lifestyle factors and co-morbidities. Height and weight were measured. After a median of 4.3 years, subjects were invited to attend a follow-up assessment, and reasons for non-participation, including death, were recorded. The relationship between QUS parameters (broadband ultrasound attenuation [BUA] and speed of sound [SOS]) and mortality was assessed using Cox proportional hazards model. RESULTS: from a total of 3,244 men (mean age 59.8, standard deviation [SD] 10.8 years), 185 (5.7%) died during the follow-up period. After adjusting for age, centre, body mass index, physical activity, current smoking, number of co-morbidities and general health, each SD decrease in BUA was associated with a 20% higher risk of mortality (hazard ratio [HR] per SD = 1.2; 95% confidence interval [CI] = 1.0-1.4). Compared with those in higher quintiles (2nd-5th), those in the lowest quintile of BUA and SOS had a greater mortality risk (BUA: HR = 1.6; 95% CI = 1.1-2.3 and SOS: HR = 1.6; 95% CI = 1.2-2.2). CONCLUSION: lower heel ultrasound parameters are associated with increased mortality in European men.

Quantitative computer tomography in children and adolescents: the 2013 ISCD Pediatric Official Positions.

In 2007, International Society of Clinical Densitometry Pediatric Positions Task Forces reviewed the evidence for the clinical application of peripheral quantitative computed tomography (pQCT) in children and adolescents. At that time, numerous limitations regarding the clinical application of pQCT were identified, although its use as a research modality for investigation of bone strength was highlighted. The present report provides an updated review of evidence for the clinical application of pQCT, as well as additional reviews of whole body QCT scans of the central and peripheral skeletons, and high-resolution pQCT in children. Although these techniques remain in the domain of research, this report summarizes the recent literature and evidence of the clinical applicability and offers general recommendations regarding the use of these modalities in pediatric bone health assessment.

A validation of the first genome-wide association study of calcaneus ultrasound parameters in the European Male Ageing Study.

BACKGROUND: A number of single nucleotide polymorphisms (SNPs) have been associated with broadband ultrasound attenuation (BUA) and speed of sound (SOS) as measured by quantitative ultrasound (QUS) at the calcaneus in the Framingham 100K genome-wide association study (GWAS) but have not been validated in independent studies. The aim of this analysis was to determine if these SNPs are associated with QUS measurements assessed in a large independent population of European middle-aged and elderly men. The association between these SNPs and bone mineral density (BMD) measured using dual-energy X-ray absorptiometry (DXA) was also tested. METHODS: Men aged 40-79 years (N = 2960) were recruited from population registers in seven European centres for participation in an observational study of male ageing, the European Male Ageing Study (EMAS). QUS at the calcaneus was measured in all subjects and blood was taken for genetic analysis. Lumbar spine (LS), femoral neck (FN) and total hip (TH) BMD were measured by DXA in a subsample of 620 men in two centres. SNPs associated with BUA or SOS in the Framingham study with p < 10-4 were selected and genotyped using SEQUENOM technology. Linear regression was used to test for the association between SNPs and standardised (SD) bone outcomes under an additive genetic model adjusting for centre. The same direction of effect and p < 0.05 indicated replication. RESULTS: Thirty-four of 38 selected SNPs were successfully genotyped in 2377 men. Suggestive evidence of replication was observed for a single SNP, rs3754032, which was associated with a higher SOS (ß(SD) = 0.07, p = 0.032) but not BUA (ß(SD) = 0.02, p = 0.505) and is located in the 3'UTR of WDR77 (WD repeat domain 77) also known as androgen receptor cofactor p44. A single SNP, rs238358, was associated with BMD at the LS (ß(SD) = -0.22, p = 0.014), FN (ß(SD) = -0.31,p = 0.001) and TH (ß(SD) = -0.36, p = 0.002) in a locus previously associated with LS BMD in large-scale GWAS, incorporating AKAP11 and RANKL. CONCLUSIONS: We found suggestive evidence of association between a single SNP located in the 3'UTR of WDR77 with calcaneal ultrasound parameters. The majority of SNPs, associated with QUS parameters in the Framingham Study, were not replicated in an independent population sample of European men.

Influence of polymorphisms in the RANKL/RANK/OPG signaling pathway on volumetric bone mineral density and bone geometry at the forearm in men.

We sought to determine the influence of single-nucleotide polymorphisms (SNPs) in RANKL, RANK, and OPG on volumetric bone mineral density (vBMD) and bone geometry at the radius in men. Pairwise tag SNPs (r (2) ≥ 0.8) for RANKL (n = 8), RANK (n = 44), and OPG (n = 22) and five SNPs near RANKL and OPG strongly associated with areal BMD in genomewide association studies were previously genotyped in men aged 40-79 years in the European Male Ageing Study (EMAS). Here, these SNPs were analyzed in a subsample of men (n = 589) who had peripheral quantitative computed tomography (pQCT) performed at the distal (4%) and mid-shaft (50%) radius. Estimated parameters were total and trabecular vBMD (mg/mm(3)) and cross-sectional area (mm(2)) at the 4% site and cortical vBMD (mg/mm(3)); total, cortical, and medullary area (mm(2)); cortical thickness (mm); and stress strain index (SSI) (mm(3)) at the 50% site. We identified 12 OPG SNPs associated with vBMD and/or geometric parameters, including rs10505348 associated with total vBMD (ß [95% CI] = 9.35 [2.12-16.58], P = 0.011), cortical vBMD (ß [95% CI] = 5.62 [2.10-9.14], P = 0.002), cortical thickness (ß [95% CI] = 0.08 [0.03-0.13], P = 0.002), and medullary area (ß [95% CI] = -2.90 [-4.94 to -0.86], P = 0.005) and rs2073618 associated with cortical vBMD (ß [95% CI] = -4.30 [-7.78 to -0.82], P = 0.015) and cortical thickness (ß [95% CI] = -0.08 [-0.13 to -0.03], P = 0.001). Three RANK SNPs were associated with vBMD, including rs12956925 associated with trabecular vBMD (ß [95% CI] = -7.58 [-14.01 to -1.15], P = 0.021). There were five RANK SNPs associated with geometric parameters, including rs8083511 associated with distal radius cross-sectional area (ß [95% CI] = 8.90 [0.92-16.88], P = 0.029). No significant association was observed between RANKL SNPs and pQCT parameters. Our findings suggest that genetic variation in OPG and RANK influences radius vBMD and geometry in men.

Influence of insulin-like growth factor binding protein (IGFBP)-1 and IGFBP-3 on bone health: results from the European Male Ageing Study.

The aim of this study was to determine the influence of insulin-like growth factor binding protein (IGFBP)-1, IGFBP-3, and IGF-I on calcaneal ultrasound parameters in middle-aged and elderly European men. Men aged 40-79 years were recruited from population registers for participation in the European Male Ageing Study (EMAS). Subjects were invited by letter to complete a postal questionnaire and to attend for an interviewer-assisted questionnaire, quantitative ultrasound (QUS) of the calcaneus, and a fasting blood sample from which serum levels of IGFBP-1, IGFBP-3, IGF-I, estradiol (E(2)), and SHBG were assayed. The questionnaires included the Physical Activity Scale for the Elderly (PASE) and questions about smoking and alcohol consumption. Estimated bone mineral density (eBMD) was derived as a function of the QUS parameters speed of sound and broadband ultrasound attenuation. Height and weight were measured in all subjects. 3057 men, mean age 59.7 years (standard deviation 11.0) were included in the analysis. After adjusting for age, center, and BMI, higher levels of IGFBP-1 were associated with lower eBMD. Higher levels of both IGFBP-3 and IGF-I were associated with higher eBMD. After further adjustment for PASE score, current smoking, alcohol consumption, free E(2), and SHBG, IGFBP-3 and IGF-I, though not IGFBP-1, remained significantly associated with eBMD. IGFBP-1 was associated with bone health, though the effect could be explained by other factors. IGFBP-3 and IGF-I were independent determinants of bone health in middle-aged and elderly European men.

FRAX(®) Bone Mineral Density Task Force of the 2010 Joint International Society for Clinical Densitometry & International Osteoporosis Foundation Position Development Conference.

FRAX(®) is a fracture risk assessment algorithm developed by the World Health Organization in cooperation with other medical organizations and societies. Using easily available clinical information and femoral neck bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), when available, FRAX(®) is used to predict the 10-year probability of hip fracture and major osteoporotic fracture. These values may be included in country specific guidelines to aid clinicians in determining when fracture risk is sufficiently high that the patient is likely to benefit from pharmacological therapy to reduce that risk. Since the introduction of FRAX(®) into clinical practice, many practical clinical questions have arisen regarding its use. To address such questions, the International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundations (IOF) assigned task forces to review the best available medical evidence and make recommendations for optimal use of FRAX(®) in clinical practice. Questions were identified and divided into three general categories. A task force was assigned to investigating the medical evidence in each category and developing clinically useful recommendations. The BMD Task Force addressed issues that included the potential use of skeletal sites other than the femoral neck, the use of technologies other than DXA, and the deletion or addition of clinical data for FRAX(®) input. The evidence and recommendations were presented to a panel of experts at the ISCD-IOF FRAX(®) Position Development Conference, resulting in the development of ISCD-IOF Official Positions addressing FRAX(®)-related issues.

Official Positions for FRAX® Bone Mineral Density and FRAX® simplification from Joint Official Positions Development Conference of the International Society for Clinical Densitometry and International Osteoporosis Foundation on FRAX®.

Tools to predict fracture risk are useful for selecting patients for pharmacological therapy in order to reduce fracture risk and redirect limited healthcare resources to those who are most likely to benefit. FRAX® is a World Health Organization fracture risk assessment algorithm for estimating the 10-year probability of hip fracture and major osteoporotic fracture. Effective application of FRAX® in clinical practice requires a thorough understanding of its limitations as well as its utility. For some patients, FRAX® may underestimate or overestimate fracture risk. In order to address some of the common issues encountered with the use of FRAX® for individual patients, the International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundation (IOF) assigned task forces to review the medical evidence and make recommendations for optimal use of FRAX® in clinical practice. Among the issues addressed were the use of bone mineral density (BMD) measurements at skeletal sites other than the femoral neck, the use of technologies other than dual-energy X-ray absorptiometry, the use of FRAX® without BMD input, the use of FRAX® to monitor treatment, and the addition of the rate of bone loss as a clinical risk factor for FRAX®. The evidence and recommendations were presented to a panel of experts at the Joint ISCD-IOF FRAX® Position Development Conference, resulting in the development of Joint ISCD-IOF Official Positions addressing FRAX®-related issues.

Disease activity and severity in early inflammatory arthritis predict hand cortical bone loss.

OBJECTIVES: To determine the influence of disease-related variables on hand cortical bone loss in women with early inflammatory arthritis (IA), and whether hand cortical bone mass predicts subsequent joint damage. METHOD: Adults aged ≥ 16 years with recent onset of IA were recruited to the Norfolk Arthritis Register between 1990 and 1998, and followed prospectively. At baseline, patients had their joints examined for swelling and tenderness and had CRP and disease activity 28-joint assessment score (DAS-28) measured. Radiographs of the hands were performed in a subgroup of patients at Year 1 and at follow-up, which were assessed using digital X-ray radiogrammetry (DXR). They were also evaluated for the presence of erosions using Larsen's method. Linear mixed models were used to investigate whether disease-related factors predicted change in DXR-areal bone mineral density (BMD(a)). We also evaluated whether DXR-BMD(a) predicted the subsequent occurrence of erosive disease. RESULTS: Two hundred and four women, mean (s.d.) age 55.1 (14.0) years, were included. Median follow-up between radiographs was 4 years. The mean within-subject change in BMD(a) was 0.024 g/cm(2) equivalent to 1% decline per year. After adjustment for age, height and weight, compared with those within the lower tertile for CRP, those in the upper tertile had greater subsequent loss of bone. This was true also for DAS-28 and Larsen score. Among those without erosions on the initial radiograph (121), DXR-BMD(a) at baseline did not predict the new occurrence of erosions. CONCLUSION: Increased disease activity and severity are associated with accelerated bone loss. However, lower BMD(a) did not predict the new occurrence of erosive disease.

Partial growth hormone deficiency is associated with an adverse cardiovascular risk profile and increased carotid intima-medial thickness.

OBJECTIVE: To quantify the relative prevalence of surrogate markers of vascular risk in adults with partial GH deficiency (GH insufficiency, GHI). CONTEXT: Hypopituitary adults with untreated GH deficiency (GHD) have an excess vascular mortality and demonstrate clustering of adverse vascular risk factors. The vascular risk profile of GHI adults has yet to be comprehensively studied. DESIGN: A cross-sectional case controlled study. PATIENTS: Thirty GHD adults, 24 GHI, and 30 age- and sex-matched controls. GHI adults were defined biochemically using two GH stimulation tests (peak GH 3-7 µg/l). MEASUREMENTS: Serum lipids and apolipoproteins, plasminogen activator inhibitor type-I (PAI-I), C-reactive protein (CRP), lipoprotein (a) [Lp(a)], fibrinogen, blood pressure and carotid intima-medial thickness (IMT). RESULTS: IGF-I levels of GHI adults were lower than controls (373 ± 123 vs 295 ± 104 µg/l; P < 0.001). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) values were consistently between those of, but not significantly different from, GHD and control subjects. GHI adults showed significantly elevated PAI-I levels [80 (13-98) vs 50.5 (3-98) ng/ml; P = 0.01], although no there were differences in CRP, Lp(a), and fibrinogen levels compared with control subjects. No differences in systolic or diastolic blood pressure were shown between study groups. In parallel with the increased vascular risk profile of GH-insufficient adults, carotid IMT was significantly increased (0.503 ± 0.08 vs 0.578 ± 0.130 mm; P = 0.02). TC, LDL-C, Waist-Hip Ratio (WHR), truncal fat mass, and IMT correlated with IGF-I levels and GH status. TG, K(ITT), and PAI-I additionally correlated with GH status, but not with IGF-I levels. CONCLUSION: GHI adults are at elevated vascular risk, reflected by adverse surrogate markers and increased carotid IMT. The surrogate risk marker profile parallels GHD adults, but is less divergent from that observed in healthy individuals. No data are yet available as to whether these anomalies will be reflected in an increased vascular mortality in GHI adults.

Influence of lifestyle factors on quantitative heel ultrasound measurements in middle-aged and elderly men.

We examined the distribution of quantitative heel ultrasound (QUS) parameters in population samples of European men and looked at the influence of lifestyle factors on the occurrence of these parameters. Men aged between 40 and 79 years were recruited from eight European centers and invited to attend for an interviewer-assisted questionnaire, assessment of physical performance, and quantitative ultrasound (QUS) of the calcaneus (Hologic; Sahara). The relationships between QUS parameters and lifestyle variables were assessed using linear regression with adjustments for age, center, and weight. Three thousand two hundred fifty-eight men, mean age 60.0 years, were included in the analysis. A higher PASE score (upper vs. lower tertile) was associated with a higher BUA (beta coefficient = 2.44 dB/ Mhz), SOS (beta = 6.83 m/s), and QUI (beta = 3.87). Compared to those who were inactive, those who walked or cycled more than an hour per day had a higher BUA (beta = 3.71 dB/Mhz), SOS (beta = 6.97 m/s), and QUI (beta = 4.50). A longer time to walk 50 ft was linked with a lower BUA (beta = -0.62 dB/ Mhz), SOS (beta = -1.06 m/s), and QUI (beta = -0.69). Smoking was associated with a reduction in BUA, SOS, and QUI. There was a U-shaped association with frequency of alcohol consumption. Modification of lifestyle, including increasing physical activity and stopping smoking, may help optimize bone strength and reduce the risk of fracture in middle-aged and elderly European men.

Influence of Lifestyle Factors on Quantitative Heel Ultrasound Measurements in Middle-Aged and Elderly Men.

We examined the distribution of quantitative heel ultrasound (QUS) parameters in population samples of European men and looked at the influence of lifestyle factors on the occurrence of these parameters. Men aged between 40 and 79 years were recruited from eight European centers and invited to attend for an interviewer-assisted questionnaire, assessment of physical performance, and quantitative ultrasound (QUS) of the calcaneus (Hologic; Sahara). The relationships between QUS parameters and lifestyle variables were assessed using linear regression with adjustments for age, center, and weight. Three thousand two hundred fifty-eight men, mean age 60.0 years, were included in the analysis. A higher PASE score (upper vs. lower tertile) was associated with a higher BUA (ß coefficient = 2.44 dB/Mhz), SOS (ß = 6.83 m/s), and QUI (ß = 3.87). Compared to those who were inactive, those who walked or cycled more than an hour per day had a higher BUA (ß = 3.71 dB/Mhz), SOS (ß = 6.97 m/s), and QUI (ß = 4.50). A longer time to walk 50 ft was linked with a lower BUA (ß = -0.62 dB/Mhz), SOS (ß = -1.06 m/s), and QUI (ß = -0.69). Smoking was associated with a reduction in BUA, SOS, and QUI. There was a U-shaped association with frequency of alcohol consumption. Modification of lifestyle, including increasing physical activity and stopping smoking, may help optimize bone strength and reduce the risk of fracture in middle-aged and elderly European men.

Radiation exposure in X-ray-based imaging techniques used in osteoporosis.

Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks.

Motor development in infancy and spine shape in early old age: Findings from a British birth cohort study.

Spine shape changes dramatically in early life, influenced by attainment of developmental milestones such as independent walking. Whether these associations persist across life is unknown. Therefore, we investigated associations between developmental milestones and spine shape, as determined using statistical shape models (SSMs) of lumbar spine from dual-energy X-ray absorptiometry scans in 1327 individuals (688 female) at 60 to 64 years in the MRC National Survey of Health and Development. Lumbar lordosis angle (L4 inferior endplate to T12 superior endplate) was measured using the two-line Cobb method. In analyses adjusted for sex, height, lean and fat mass, socioeconomic position, and birthweight, later walking age was associated with greater lordosis described by SSM1 (regression coefficient, 0.023; 95% CI, 0.000-0.047; P = .05) and direct angle measurement. Modest associations between walking age and less variation in anterior-posterior vertebral size caudally (SSM6) were also observed (0.021; 95% CI, -0.002 to 0.044; P = .07). Sex interactions showed that later walking was associated with larger relative vertebral anterior-posterior dimensions in men (SSM3; -0.043; 95% CI, -0.075 to 0.01; P = .01) but not women (0.018; 95% CI, -0.0007 to 0.043; P = .17). Similar associations were observed between age at independent standing and SSMs but there was little evidence of association between sitting age and spine shape. Unadjusted associations between walking age and SSMs 1 and 6 remained similar after adjustment for potential confounders and mediators. This suggests that these associations may be explained by altered mechanical loading of the spine during childhood growth, although other factors could contribute. Early life motor development, particularly walking, may have a lasting effect on the features of spine morphology with clinical significance.

Vitamin D status and muscle function in post-menarchal adolescent girls.

CONTEXT: There has been a resurgence of vitamin D deficiency among infants, toddlers, and adolescents in the United Kingdom. Myopathy is an important clinical symptom of vitamin D deficiency, yet it has not been widely studied. OBJECTIVE: Our objective was to investigate the relationship of baseline serum 25 hydroxyvitamin D [25(OH)D] concentration and PTH with muscle power and force. DESIGN: This was a cross-sectional study. SETTING: The study was community based in a secondary school. PARTICIPANTS: A total of 99 post-menarchal 12- to 14-yr-old females was included in the study. MAIN OUTCOME MEASURES: Jumping mechanography to measure muscle power, velocity, jump height, and Esslinger Fitness Index from a two-legged counter movement jump and force from multiple one-legged hops was performed. Body height, weight, and serum concentrations of 25(OH)D, PTH, and calcium were measured. RESULTS: Median serum 25(OH)D concentration was 21.3 nmol/liter (range 2.5-88.5) and PTH 3.7 pmol/liter (range 0.47-26.2). After correction for weight using a quadratic function, there was a positive relationship between 25(OH)D and jump velocity (P = 0.002), jump height (P = 0.005), power (P = 0.003), Esslinger Fitness Index (P = 0.003), and force (P = 0.05). There was a negative effect of PTH upon jump velocity (P = 0.04). CONCLUSION: From these data we conclude that vitamin D was significantly associated with muscle power and force in adolescent girls.