Method to derive the infrared complex refractive indices n(λ) and k(λ) for organic solids from KBr pellet absorption measurements

Obtaining the complex refractive index vectors n(ν~) and k(ν~) allows calculation of the (infrared) reflectance spectrum that is obtained from a solid in any of its many morphological forms. We report an adaptation to the KBr pellet technique using two gravimetric dilutions to derive quantitative n(ν~)/k(ν~) for dozens of powders with greater repeatability. The optical constants of bisphenol A and sucrose are compared to those derived by other methods, particularly for powdered materials. The variability of the k values for bisphenol A was examined by 10 individual measurements, showing an average coefficient of variation for k peak heights of 5.6%. Though no established standards exist, the pellet-derived k peak values of bisphenol A differ by 11% and 31% from their single-angle- and ellipsometry-derived values, respectively. These values provide an initial estimate of the precision and accuracy of complex refractive indices that can be derived using this method. Limitations and advantages of the method are discussed, the salient advantage being a more rapid method to derive n/k for those species that do not readily form crystals or specular pellets.

Chemical and Biological Engineering Strategies to Make and Modify Next-Generation Hydrogel Biomaterials

There is a growing interest in the development of technologies to probe and direct in vitro cellular function for fundamental organoid and stem cell biology, functional tissue and metabolic engineering, and biotherapeutic formulation. Recapitulating many critical aspects of the native cellular niche, hydrogel biomaterials have proven to be a defining platform technology in this space, catapulting biological investigation from traditional two-dimensional (2D) culture into the 3D world. Seeking to better emulate the dynamic heterogeneity characteristic of all living tissues, global efforts over the last several years have centered around upgrading hydrogel design from relatively simple and static architectures into stimuli-responsive and spatiotemporally evolvable niches. Towards this end, advances from traditionally disparate fields including bioorthogonal click chemistry, chemoenzymatic synthesis, and DNA nanotechnology have been co-opted and integrated to construct 4D-tunable systems that undergo preprogrammed functional changes in response to user-defined inputs. In this Review, we highlight how advances in synthetic, semisynthetic, and bio-based chemistries have played a critical role in the triggered creation and customization of next-generation hydrogel biomaterials. We also chart how these advances stand to energize the translational pipeline of hydrogels from bench to market and close with an outlook on outstanding opportunities and challenges that lay ahead.

Solid phase characterization and transformation of illite mineral with gas-phase ammonia treatment

In situ remediation applications of ammonia (NH₃) gas have potential for sequestration of subsurface contamination. Ammonia gas injections initially increase the pore water pH leading to mineral dissolution followed by formation of secondary precipitates as the pH is neutralized. However, there is a lack of understanding of fundamental alteration processes due to NH₃ treatment. In these batch studies, phyllosilicate minerals (illite and montmorillonite) were exposed to NH₃ gas with subsequent aeration to simulate in situ remediation. Following treatments, solids were characterized using a variety of techniques, including X-ray diffraction, N₂ adsorption-desorption analysis for surface area, Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), and microscopy methods to investigate physicochemical transformations. Results indicate that, at high pH, the clays are altered as observed by differences in morphology and particle size via microscopy. However, the two clays interact differently with NH₃. While montmorillonite interlayers collapsed due to intercalation, illite layers were unaffected as confirmed by FTIR analysis. Further, structural changes in silicate ([SiO₄]^n-) and aluminol (Al-OH) groups were identified by NMR and FTIR. This research showed that mineral alteration processes occur during and after NH₃ gas treatment which may be used to remove radionuclides from the aqueous phase through sorption, co-precipitation, and coating with secondary phyllosilicate alteration products.

No effect of monthly supplementation with 12000 IU, 24000 IU or 48000 IU vitamin D3 for one year on muscle function: The vitamin D in older people study

Vitamin D plays a role in muscle function through genomic and non-genomic processes. The objective of this RCT was to determine the effect of monthly supplemental vitamin D₃ onmuscle function in 70+ years old adults. Participants (n = 379) were randomized to receive, 12,000 IU, 24,000 IU or 48,000 IU of vitamin D₃ monthly for 12 months. Standardized Hand Grip Strength (GS) and Timed-Up and Go (TUG) were measured before and after vitamin D₃ supplementation. Fasting total plasma 25 hydroxyvitamin D (25OHD) and Parathyroid Hormone (PTH) concentrations were measured by Liquid Chromatography Tandem Mass Spectrometry (LC-MSMS) and immunoassay, respectively. Baseline plasma 25OHD concentrations were 41.3 (SD 19.9), 39.5 (SD 20.6), 38.9 (SD 19.7) nmol/L; GS values were 28.5 (SD 13.4), 28.8 (SD 13.0) and 28.1 (SD 12.1) kg and TUG test values were 10.8 (SD 2.5), 11.6 (SD 2.9) and 11.9 (SD 3.6) s for the 12,000 IU, 24,000 IU and 48,000 IU dose groups, respectively. Baseline plasma 25OHD concentration < 25 nmol/L was associated with lower GS (P = 0.003). Post-interventional plasma 25OHD concentrations increased to 55.9 (SD 15.6), 64.6 (SD15.3) and 79.0 (SD 15.1) nmol/L in the 12,000 IU, 24,000 IU and 48,000 IU dose groups, respectively and there was a significant dose-related response in post-interventional plasma 25OHD concentration (p<0.0001). Post-interventional GS values were 24.1 (SD 10.1), 26.2 (SD10.6) and 25.7 (SD 9.4) kg and TUG test values were 11.5 (SD 2.6), 12.0 (SD 3.7) and 11.9 (SD 3.2) s for 12,000 IU, 24,000 IU and 48,000 IU dose groups, respectively. The change (Δ) in GS and TUG from pre to post-intervention was not different between treatment groups before and after the adjustment for confounders, suggesting no effect of the intervention. Plasma 25OHD concentration was not associated with GS and TUG test after supplementation. In conclusion, plasma 25OHD concentration < 25 nmol/L was associated with lower GS at baseline. However, monthly vitamin D₃ supplementation with 12,000 IU, 24,000 IU and 48,000 IU, for 12 months had no effect on muscle function in older adults aged 70+ years. Trial Registration : EudraCT 2011-004890-10 and ISRCTN35648481.

Obesity, bone density relative to body weight and prevalent vertebral fracture at age 62 years: the Newcastle thousand families study

Obesity increases the likelihood of prevalent vertebral fracture (VF) in men and women at age 62 years. The higher absolute bone mineral density (BMD) observed in obese individuals is disproportionate to body weight, and this may partly explain the greater prevalence of VF in this group.

INTRODUCTION

Obesity is a global epidemic, and there remains uncertainty over the effect of obesity on skeletal health, particularly in the context of osteoporosis. The aim of this study was to investigate associations of body mass index (BMI) and obesity with BMD and prevalent VF in men and women aged 62 years.

METHODS

Three hundred and forty-two men and women aged 62.5 ± 0.5 years from the Newcastle Thousand Families Study birth cohort underwent DXA evaluations of femoral neck and lumbar spine BMD and of the lateral spine for vertebral fracture assessment.

RESULTS

The likelihood of prevalent VF was significantly increased in men when compared to women (OR = 2.7, p < 0.001, 95% Cl 1.7-4.4). As BMI increased in women, so did the likelihood of prevalent any-grade VF (OR = 1.09, p = 0.006, 95% CI 1.02-1.17). Compared to normal weight women, obese women were more likely to have at least one VF (OR = 2.65, p = 0.025, CI 1.13-6.20) and at least one grade 1 vertebral deformity (OR = 4.39, p = 0.005, CI 1.57-12.28). Obese men were more likely to have a grade 2 and/or grade 3 VF compared to men of normal weight (OR = 3.36, p = 0.032, CI 1.11-10.16). In men and women, BMI was negatively associated with femoral neck BMD/weight (R = - 0.65, R = - 0.66, p < 0.001) and lumbar spine BMD/weight (R = - 0.66, R - 0.60, p < 0.001).

CONCLUSIONS

Obesity appears to be a risk factor for prevalent VF, and although absolute BMD is higher in obese individuals, this does not appear commensurate to their increased body weight.

Does regional loss of bone density explain low trauma distal forearm fractures in men (the Mr F study)?

The pathogenesis of low trauma wrist fractures in men is not fully understood. This study found that these men have lower bone mineral density at the forearm itself, as well as the hip and spine, and has shown that forearm bone mineral density is the best predictor of wrist fracture.

INTRODUCTION

Men with distal forearm fractures have reduced bone density at the lumbar spine and hip sites, an increased risk of osteoporosis and a higher incidence of further fractures. The aim of this case-control study was to investigate whether or not there is a regional loss of bone mineral density (BMD) at the forearm between men with and without distal forearm fractures.

METHODS

Sixty-one men with low trauma distal forearm fracture and 59 age-matched bone healthy control subjects were recruited. All subjects underwent a DXA scan of forearm, hip and spine, biochemical investigations, health questionnaires, SF-36v2 and Fracture Risk Assessment Tool (FRAX). The non-fractured arm was investigated in subjects with fracture and both forearms in control subjects.

RESULTS

BMD was significantly lower at the ultradistal forearm in men with fracture compared to control subjects, in both the dominant (mean (SD) 0.386 g/cm² (0.049) versus 0.436 g/cm² (0.054), p < 0.001) and non-dominant arm (mean (SD) 0.387 g/cm² (0.060) versus 0.432 g/cm² (0.061), p = 0.001). Fracture subjects also had a significantly lower BMD at hip and spine sites compared with control subjects. Logistic regression analysis showed that the best predictor of forearm fracture was ultradistal forearm BMD (OR = 0.871 (0.805-0.943), p = 0.001), with the likelihood of fracture decreasing by 12.9% for every 0.01 g/cm² increase in ultradistal forearm BMD.

CONCLUSIONS

Men with low trauma distal forearm fracture have significantly lower regional BMD at the ultradistal forearm, which contributes to an increased forearm fracture risk. They also have generalised reduction in BMD, so that low trauma forearm fractures in men should be considered as indicator fractures for osteoporosis.

Serum 25-hydroxyvitamin D concentration and its determinants in the very old: the Newcastle 85+ Study

SUMMARY

Data on vitamin D status in very old adults are lacking. The aim of this study was to assess 25-hydroxyvitamin D [25(OH)D] concentrations and its predictors in 775 adults aged 85 years old living in North-East England. Low 25(OH)D was alarmingly high during winter/spring months, but its biological significance is unknown.

INTRODUCTION

Despite recent concerns about the high prevalence of vitamin D deficiency in much of the British adult and paediatric population, there is a dearth of data on vitamin D status and its predictors in very old adults. The objective of the present study was to describe vitamin D status and its associated factors in a broadly representative sample of very old men and women aged 85 years living in the North East of England (55° N).

METHODS

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were analysed in 775 participants in the baseline phase of the Newcastle 85+ cohort study. Season of blood sampling, dietary, health, lifestyle and anthropometric data were collected and included as potential predictors of vitamin D status in ordinal regression models.

RESULTS

Median serum 25(OH)D concentrations were 27, 45, 43 and 33 nmol/L during spring, summer, autumn and winter, respectively. The prevalence of vitamin D deficiency according to North American Institute of Medicine guidelines [serum 25(OH)D <30 nmol/L] varied significantly with season with the highest prevalence observed in spring (51%) and the lowest prevalence observed in autumn (23%; P < 0.001). Reported median (inter-quartile range) dietary intakes of vitamin D were very low at 2.9 (1.2-3.3) μg/day. In multivariate ordinal regression models, non-users of either prescribed or non-prescribed vitamin D preparations and winter and spring blood sampling were associated with lower 25(OH)D concentrations. Dietary vitamin D intake, disability score and disease count were not independently associated with vitamin D status in the cohort.

CONCLUSION

There is an alarming high prevalence of vitamin D deficiency (<30 nmol/L) in 85-year-olds living in North East England at all times of the year but particularly during winter and spring. Use of vitamin D containing preparations (both supplements and medications) appeared to be the strongest predictor of 25(OH)D concentrations in these very old adults.

pophelper: an R package and web app to analyse and visualize population structure

The pophelper r package and web app are software tools to aid in population structure analyses. They can be used for the analyses and visualization of output generated from population assignment programs such as admixture, structure and tess. Some of the functions include parsing output run files to tabulate data, estimating K using the Evanno method, generating files for clumpp and functionality to create barplots. These functions can be streamlined into standard r analysis workflows. The latest version of the package is available on github (https://github.com/royfrancis/pophelper). An interactive web version of the pophelper package is available which covers the same functionalities as the r package version with features such as interactive plots, cluster alignment during plotting, sorting individuals and ordering of population groups. The interactive version is available at http://pophelper.com/.

FRAX-based assessment and intervention thresholds--an exploration of thresholds in women aged 50 years and older in the UK

Under current guidelines, based on prior fracture probability thresholds, inequalities in access to therapy arise especially at older ages (≥70 years) depending on the presence or absence of a prior fracture. An alternative threshold (a fixed threshold from the age of 70 years) reduces this disparity, increases treatment access and decreases the need for bone densitometry.

INTRODUCTION

Several international guidelines set age-specific intervention thresholds at the 10-year probability of fracture equivalent to a woman of average BMI with a prior fracture. At older ages (≥70 years), women with prior fracture selected for treatment are at lower average absolute risk than those selected for treatment in the absence of prior fracture, prompting consideration of alternative thresholds in this age group.

METHODS

Using a simulated population of 50,633 women aged 50-90 years in the UK, with a distribution of risk factors similar to that in the European FRAX derivation cohorts and a UK-matched age distribution, the current NOGG intervention and assessment thresholds were compared to one where the thresholds remained constant from 70 years upwards.

RESULTS

Under current thresholds, 45.1% of women aged ≥70 years would be eligible for therapy, comprising 37.5% with prior fracture, 2.2% with high risk but no prior fracture and 5.4% selected for treatment after bone mineral density (BMD) measurement. Mean hip fracture probability was 11.3, 23.3 and 17.6%, respectively, in these groups. Under the alternative thresholds, the overall proportion of women treated increased from 45.1 to 52.9%, with 8.4% at high risk but no prior fracture and 7.0% selected for treatment after BMD measurement. In the latter group, the mean probability of hip fracture was identical to that observed in women with prior fracture (11.3%). The alternative threshold also reduced the need for BMD measurement, particularly at older ages (>80 years).

CONCLUSIONS

The alternative thresholds equilibrate fracture risk, particularly hip fracture risk, in those with or without prior fracture selected for treatment and reduce BMD usage at older ages.

Magnitude of fragility fracture risk in the very old--are we meeting their needs? The Newcastle 85+ Study

Fractures due to osteoporosis are common in older people. This study assessed the management of osteoporosis in a group of 85-year-olds and found both assessment and current treatment to be suboptimal.

INTRODUCTION

Fragility fractures are a major cause of excess mortality, substantial morbidity, and health and social service expenditure in older people. However, much less is known about fracture risk and its management in the very old, despite this being the fastest growing age group of our population.

METHODS

Cross-sectional analysis of people who reached the age of 85 during the year of 2006 was carried out. Data were gathered by general practice record review (GPRR) and a multidimensional health assessment (MDHA).

RESULTS

Seven hundred thirty-nine individuals were recruited. Mean age was 85.55 years (SD 0.44), and 60.2% were female; 33.7% (n = 249) had experienced one or more fragility fractures (F 45.2% vs M 16.3% p < 0.001); in total, 332 fractures occurred in these 249 individuals. A formal documented diagnosis of osteoporosis occurred in 12.4%, and 38% of individuals had experienced a fall in the last 12 months. When the fracture risk assessment tool (FRAX) and National Osteoporosis Guideline Group (NOGG) guidelines were applied, osteoporosis treatment would be recommended in 35.0%, with a further 26.1% identified as needing bone mineral density (BMD) measurement and 38.9% not requiring treatment or BMD assessment. Women were more likely than men to need treatment (47.4 vs 16.3%, p < 0.001, odds ratio (OR) 4.62 (3.22-5.63)) and measurement of BMD (40.0 vs 5.1%, p < 0.001, OR 12.4 (7.13-21.6)). Of the 259 individuals identified as requiring treatment, only 74 (28.6%) were on adequate osteoporosis treatment.

CONCLUSION

The prevalence of high fracture risk in the very old is much higher than the documented diagnosis of osteoporosis or the use of adequate treatments.

Age and aerobic training status effects on plasma and skeletal muscle tPA and PAI-1

INTRODUCTION

Reductions in fibrinolytic potential occur with both aging and physical inactivity and are associated with an increased cardiovascular disease risk. Plasmin, the enzyme responsible for the enzymatic degradation of fibrin clots, is activated by tissue plasminogen activator (tPA), while plasminogen activator inhibitor-1 (PAI-1) inhibits its activation. Currently, fibrinolysis research focuses almost exclusively on changes within the plasma. However, tPA and PAI-1 are expressed by human skeletal muscle (SM). Currently, no studies have focused on changes in SM fibrinolytic activity with regard to aging and aerobic fitness.

PURPOSE

The purpose of this study was to cross-sectionally evaluate effects of age and aerobic fitness on tPA and PAI-1 expressions and activity in SM.

METHODS

Twenty-six male subjects were categorized into the following groups: (1) young aerobically trained (n = 8); (2) older aerobically trained (n = 6); (3) young aerobically untrained (n = 7); and (4) older aerobically untrained (n = 5). Muscle biopsies were obtained from each subject. SM tPA activity was assessed using gel zymography and SM tPA and PAI-1 expressions were assessed using RT-PCR.

RESULTS

Trained subjects had higher SM tPA activity compared to untrained (25.3 ± 2.4 × 10(3) vs. 21.5 ± 5.6 × 10(3) pixels, respectively; p = 0.03) with no effect observed for age. VO2 max and SM tPA activity were also significantly correlated (r = 0.42; p < 0.04). SM tPA expression was higher in older participants, but no effect of fitness level was observed. No differences were observed for PAI-1 expression in SM.

CONCLUSIONS

Higher levels of aerobic fitness are associated with increased fibrinolytic activity in SM.

Efficacy and safety of strontium ranelate in the treatment of osteoporosis in men

CONTEXT

Strontium ranelate reduces vertebral and nonvertebral fracture risk in postmenopausal osteoporosis.

OBJECTIVE

The objective of this study was to determine the efficacy and safety of strontium ranelate in osteoporosis in men over 2 years (main analysis after 1 year).

DESIGN

This was an international, unbalanced (2:1), double-blind, randomized placebo-controlled trial (MALEO [MALE Osteoporosis]).

SETTING

This international study included 54 centers in 14 countries.

PARTICIPANTS

PARTICIPANTS were 261 white men with primary osteoporosis.

INTERVENTION

Strontium ranelate at 2 g/d (n = 174) or placebo (n = 87) was administered.

MAIN OUTCOME MEASURES

Lumbar spine (L2-L4), femoral neck, and total hip bone mineral density (BMD), biochemical bone markers, and safety were measured.

RESULTS

Baseline characteristics were similar in both groups in the whole population (age, 72.9 ± 6.0 years; lumbar spine BMD T-score, -2.7 ± 1.0; femoral neck BMD T-score, -2.3 ± 0.7). Men who received strontium ranelate over 2 years had greater increases in lumbar spine BMD than those who received placebo (relative change from baseline to end, 9.7% ± 7.5% vs 2.0% ± 5.5%; between-group difference estimate (SE), 7.7% (0.9%); 95% confidence interval, 5.9%-9.5%; P < .001). There were also significant between-group differences in relative changes in femoral neck BMD (P < .001) and total hip BMD (P < .001). At the end of treatment, mean levels of serum cross-linked telopeptides of type I collagen, a marker of bone resorption, were increased in both the strontium ranelate group (10.7% ± 58.0%; P = .022) and the placebo group (34.9% ± 65.8%; P < .001). The corresponding mean changes of bone alkaline phosphatase, a marker of bone formation, were 6.4% ± 28.5% (P = .005) and 1.9% ± 25.4% (P = .505), respectively. After 2 years, the blood strontium level (129 ± 66 μmol/L) was similar to that in trials of postmenopausal osteoporosis. Strontium ranelate was generally well tolerated.

CONCLUSIONS

The effects of strontium ranelate on BMD in osteoporotic men were similar to those in postmenopausal osteoporotic women, supporting its use in the treatment of osteoporosis in men.

Suppression of bone turnover by B-cell depletion in patients with rheumatoid arthritis

The role of B cells in inflammatory bone formation and resorption is controversial. We investigated this in patients with rheumatoid arthritis (RA) treated with rituximab, a B-cell depleting antibody. We found a significant suppression in bone turnover, possibly a direct effect or as a consequence of a reduction in inflammation and disease activity.

INTRODUCTION

RA is the most prevalent inflammatory joint disease, in which B cells play an important role. However, the role of B cells in bone turnover is controversial and RA subjects treated with rituximab, a B-cell depleting monoclonal antibody, provide an ideal model for determining the role of B cells in inflammatory bone resorption.

METHODS

Serum from 46 RA patients, collected pre- and post-rituximab therapy, was analysed for biomarkers of bone turnover (procollagen type I amino-terminal propeptide [P1NP], osteocalcin, β-isomerised carboxy-terminal telopeptide of type 1 collagen [βCTX] and osteoprotegerin [OPG]).

RESULTS

A significant decrease in bone resorption was observed 6 months after rituximab (median change βCTX -50 ng/L, 95%CI -136, -8 p < 0.001, this equates to -37%; 95%CI -6, -49), mirrored by a reduction in disease activity. Similarly, there was a significant increase in P1NP, a marker of bone formation (median change P1NP 5.0 μg/L, 95%CI -1.0, 11.2, p = 0.02; 13%; 95%CI -3, 39), but no significant change in osteocalcin or OPG levels. The percentage change from baseline of βCTX in a subgroup of patients (not on prednisolone or bisphosphonate) was significantly correlated with the percentage reduction in DAS28 score (r (s) = 0.570, p = 0.014).

CONCLUSIONS

In conclusion, we have found that B-cell depletion increases bone formation and decreases bone resorption in RA patients; this may be a direct effect on osteoblasts and osteoclasts, respectively, and be at least partially explained by the decreased inflammation and disease activity.

National Osteoporosis Society's Position Statement on hormone replacement therapy in the prevention and treatment of osteoporosis

Hormone replacement therapy (HRT) has been shown to increase bone density, reduce the risk of fracture and can successfully relieve menopausal symptoms. From a time when HRT was the major therapeutic option for the management of osteoporosis, women and their clinicians now have a range of treatments available. Following the publication of the Women's Health Initiative (WHI) and the Million Women Study highlighting potential side-effects, such as breast cancer, heart disease and stroke, many doctors and women are now reluctant to use HRT. The National Osteoporosis Society felt that the role of HRT in the management of osteoporosis needed to be clarified. Using the Charity's expert clinical and scientific advisers, and through public consultation with members and key stakeholders, a Position Statement has been published. We conclude that HRT has a role to play in the management of osteoporosis in postmenopausal women below the age of 60 years. The key recommendations of the Position Statement are presented in this paper.

Proceedings of the Rank Forum on Vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of 'optimal' concentration of serum 25(OH)D needs to define 'optimal' with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

A lifecourse study of bone resorption in men ages 49-51years: the Newcastle Thousand Families cohort study

It has been suggested that bone health in adulthood is programmed by development in utero. Most previous investigations addressing this topic have focussed on bone mineral density or content, rather than other indicators of bone health, such as biochemical markers of bone turnover. This study investigated whether potential predictors, from different stages of life, influence bone resorption in men aged 49-51years in the Newcastle Thousand Families birth cohort. The cohort originally consisted of all 1142 births in the city of Newcastle upon Tyne, UK in May and June 1947. Detailed information was collected prospectively during childhood, including birth weight and socio-economic circumstances. At 49-51years of age, 574 study members completed a detailed 'Health and Lifestyle' questionnaire, including the European Prospective Investigation of Cancer (EPIC) food frequency questionnaire and 412 study members attended for clinical examination, including 172 men in whom bone resorption was assessed by measurement of serum beta C-telopeptide of type 1 collagen (CTX). A significant trend was seen between increasingly disadvantaged socio-economic status at birth and increased bone resorption (p=0.04, r-squared 2.6%). However, birth weight, standardised for sex and gestational age, was not associated with serum CTX (p=0.77, r-squared 0.05%). Significant trends were also seen between increasing total energy intake (p=0.03, r-squared 2.9%), dietary intake of saturated fat (p=0.02, r-squared 2.6%), protein (p=0.04, r-squared 2.5%) and carbohydrates (p=0.04, r-squared 2.6%) and higher serum CTX. However, on adjustment for total energy intake, none of the other dietary variables was significant at the univariate level maintained significance. Our findings suggest that early socio-economic disadvantage and later dietary factors may be associated with increased bone resorption in middle aged men. However, as little of the variance in serum CTX was explained by the variables included within this investigation, further longitudinal studies, with sufficient statistical power, are required to assess predictors of bone resorption in adulthood and their relative importance.

Comparison of oxidative capacity among leg muscles in humans using gated 31P 2-D chemical shift imaging

In many small animals there are distinct differences in fiber-type composition among limb muscles, and these differences typically correspond to marked disparities in the oxidative capacities. However, whether there are similar differences in the oxidative capacity among leg muscles in humans is less clear. The purpose of this study was to compare the rate of phosphocreatine (PCr) recovery, a functional in vivo marker of oxidative capacity, in the lateral and medial gastrocnemius, soleus, and the anterior compartment of the leg (primarily the tibialis anterior) of humans. Subjects performed plantar flexion and dorsiflexion gated exercise protocols consisting of 70 sets of three rapid dynamic contractions (<2.86 s) at 20 s intervals (total: 23.3 min). Starting after the sixth set of contractions, (31)P 2-D CSI (8 x 8 matrix, 14-16 cm FOV, 3 cm slice, TR 2.86 s) were acquired via a linear transmit/receive surface coil using a GE 3T Excite System. The CSI data were zero-filled (32 x 32) and a single FID was produced for each time point in the lateral and medial gastrocnemius, soleus, and anterior compartment. The time constant for PCr recovery was calculated from tau = -Deltat/ln[D/(D + Q)], where Q is the percentage change in PCr due to contraction during the steady-state portion of the protocol, D the additional drop in PCr from rest, and Deltat is the interval between contractions. The tau of PCr recovery was longer (p < 0.05) in the anterior compartment (32 +/- 3 s) than in the lateral (23 +/- 2 s) and medial gastrocnemius muscles (24 +/- 3 s) and the soleus (22 +/- 3 s) muscles. These findings suggest that the oxidative capacity is lower in the anterior compartment than in the triceps surae muscles and is consistent with the notion that fiber-type phenotypes vary among the leg muscles of humans.

Hormone replacement therapy (HRT) or etidronate for osteoporosis in postmenopausal asthmatics on glucocorticoids: a randomised factorial trial

INTRODUCTION

The study was designed to establish the effects of HRT on osteoporosis and fractures over five years in postmenopausal women with asthma receiving regular glucocorticoids and to compare with etidronate.

METHODS

Postmenopausal patients receiving inhaled and/or oral glucocorticoids were randomly assigned to HRT, cyclical etidronate, HRT plus cyclical etidronate or no treatment for five years. The trial was multi-centre and aimed to recruit 750 patients. Outcomes were fractures and changes in bone mineral density (BMD).

RESULTS

For reasons detailed in the discussion section of the text, only 50 patients were entered. Three did not fulfil the eligibility criteria and were excluded from the analysis. Among the remaining 47 patients, three (6%) experienced new, symptomatic fractures, one on etidronate and two in the no treatment group. New or worsening morphometric fractures of the thoracolumbar spine occurred in 50% of the 22 patients with spinal radiographs on entry and at five years (one HRT, three etidronate, two HRT plus etidronate and five on no treatment). BMD improved by approximately 1% per annum in those receiving HRT and/or etidronate; comparisons of HRT vs no HRT tended to favour HRT but were only statistically significant at proximal femur. The same trends emerged in the etidronate vs no etidronate comparison, but none reached the 5% level of statistical significance.

DISCUSSION

For postmenopausal patients receiving glucocorticoids for asthma, HRT appears as effective as etidronate in preventing loss of BMD over five years and may have a similar effect on fracture prevention.

Sex steroids and bone turnover markers in men with symptomatic vertebral fractures

Sex steroids play an important role in the maintenance of bone density in men and women, but the circulating, biologically active unbound fraction is influenced by the concentration of sex hormone binding globulin (SHBG). SHBG increases with advancing age in men and leads to a reduction in serum free testosterone and oestradiol, which may then affect bone turnover, bone mineral density (BMD) and the risk of fractures. We have therefore measured total and unbound sex steroids, SHBG, bone turnover markers and BMD in 57 men with symptomatic low trauma vertebral fractures and 57 age-matched male control subjects. Fasting blood and urine samples were collected from all subjects, who also underwent BMD measurement of the lumbar spine and hip. Serum testosterone, oestradiol, SHBG, bone specific alkaline phosphatase (bone ALP) and urine free deoxypyridinoline/creatinine ratio (fDPD/Cr) were measured. Free sex steroid concentrations were calculated using their ratio with SHBG and albumin and bioavailable testosterone was measured using radioimmunoassay. The two groups were then compared and regression models developed to determine the best predictors of BMD and fracture. Men with vertebral fractures had significantly lower weight and BMD at all sites than control subjects (p<0.0001). Serum total testosterone and oestradiol did not differ between the two groups, but calculated free androgen and free oestradiol indices were lower in the fracture group than the control subjects (p=0.04), due to higher SHBG (46.6 versus 36.1 nmol/L: p=0.005). The men with vertebral fractures had significantly higher mean bone ALP (15.8 versus 11.8 microg/L: p=0.002) and fDPD/Cr (5.5 versus 4.0 nmol/mmol: p=0.03). Stepwise multiple regression analysis in both fracture and control groups found body weight to be the best predictor of BMD. In the fracture group weight predicted between 19.7 and 30.7% of the variance in BMD and in control subjects this was between 12.3 and 13.2%. SHBG contributed to the model for hip BMD in the fracture group alone, so that weight and SHBG together accounted for 32 to 42.9% of the variance. A model combining BMD at the spine, total femur and femoral neck with height loss best predicted fracture. In conclusion, men with symptomatic vertebral fractures have higher SHBG and lower calculated free sex steroid indices, increased bone turnover and lower BMD. Whilst body weight was the best predictor of BMD, symptomatic vertebral fracture was best predicted by BMD and height loss.

Back pain in osteoporotic vertebral fractures

This review article examines the epidemiology and pathogenesis of back pain and vertebral fractures in osteoporosis, reviewing the management of pain in patients with vertebral fractures and the direct and indirect effect of osteoporosis treatments on back pain.

INTRODUCTION

The management of patients with vertebral fractures has largely concentrated on the prevention of further fractures by the treatment of underlying osteoporosis, with drug treatment for acute and chronic back pain and the non-pharmacological management of vertebral fractures receiving less attention.

DISCUSSION

Emerging evidence suggests that, in addition to reducing the incidence of vertebral fractures, calcitonin, intravenous bisphosphonates and teriparatide may also have a direct effect on bone pain. Targeted analgesia, tailored to individual need is often required in both the acute and chronic phases following vertebral fracture. Vertebroplasty and kyphoplasty have also been approved for use in the management of vertebral fractures and may prove useful in selected patients unresponsive to conventional pain relief. There is some evidence to support the use of individualised tailored exercise programmes aimed at strengthening back muscles to maintain bone density and reduce further fracture incidence. In addition the use of specific orthoses may help to reduce kyphosis, improve mobility and reduce pain.

CONCLUSION

Chronic back pain associated with vertebral fracture provides a great challenge to health care professionals and the patient. This demands a combination of options, including not only therapeutic interventions, but also physiotherapy, psychological support and patient education.

Vitamin D-binding protein gene microsatellite polymorphism influences BMD and risk of fractures in men

Here we report the results of a vitamin D-binding protein gene microsatellite polymorphism study in 170 men, comprising healthy male subjects and men with osteoporosis-related symptomatic vertebral fractures. We confirm the results of an earlier study in a different cohort, showing relationship between certain genotypes of (TAAAn)-Alu repeats and reduced BMD and vertebral fractures.

INTRODUCTION

Vitamin D-binding protein (DBP) plays a critical role in the transport and metabolism of metabolites of vitamin D, including the key calciotropic hormone 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3).

METHODS

We have investigated intra-intronic variable tandem (TAAA)n-Alu repeat expansion in the DBP gene in 170 men, comprising healthy male subjects and men with idiopathic osteoporosis and low trauma fractures.

RESULTS AND CONCLUSIONS

The predominant DBP-Alu genotype in the control subjects was 10/10 (frequency 0.421), whereas the frequency of this genotype in men with osteoporosis was 0.089. DBP-Alu alleles *10, *8 and *9, respectively, were the three commonest in both healthy subjects and men with osteoporosis. Allele *10 was associated with a lower risk of osteoporosis (OR 0.39, 95% CI 0.25-0.64; p < 0.0005), as was allele *11 (odds ratio 0.09, 95% CI 0.01-0.67; p < 0.007). Logistic regression gave similar results, showing that individuals with genotype 10/10 and 19-20 repeats (genotypes 9/10, 9/11, 10/10,) are protected from fracture or osteoporosis. Overall, there was a relationship between DBP Alu genotype and BMD, suggesting that DBP-Alu genotype may influence fracture risk. This effect may be mediated by changes in the circulating concentrations of DBP which influences free concentrations of vitamin D.

What do we currently know about nutrition and bone health in relation to United Kingdom public health policy with particular reference to calcium and vitamin D?

Public health policy in the UK related to nutrition and bone health has been shaped by reports from the Department of Health (DH), Food Standards Agency and WHO. Dietary reference values (DRV) for a number of nutrients were published in 1991 by the DH Committee on Medical Aspects of Food and Nutrition Policy. The subsequent DH report on nutrition and bone health in 1998 concentrated particularly on Ca and vitamin D, but also briefly addressed the effect of body weight, alcohol and other nutrients. Although this reviewed more recent evidence relating to the effect of higher intakes of Ca and vitamin D from longitudinal and interventional studies, no changes were made to the existing DRV. The Food Standards Agency published a report from their Expert Group on Vitamins and Minerals in 2003, which recommended safe upper limits for eight vitamins and minerals, with guidance provided on a further twenty-two nutrients, where there was less information on safety. The WHO report on diet, nutrition and the prevention of chronic diseases in 2003 addressed the prevention of osteoporosis, making recommendations on Ca, vitamin D, Na, fruit and vegetables, alcohol and body weight. The present paper examines current views on what constitutes an adequate dietary Ca intake and optimal vitamin D status, the DRV for vitamin D in subjects with little or no exposure to sunlight and the results of recent epidemiological studies on the relationship between fracture risk and body weight, alcohol intake and the consumption of other nutrients.

Calcaneal bone mineral density in older patients who have fallen

BACKGROUND

Annually, 35-40% of those aged >65 years fall; up to 5% of such falls result in fracture. Fracture is determined both by propensity to fall and by bone fragility.

AIM

To determine osteoporosis prevalence and predictors in patients who have fallen.

DESIGN

Observational cross-sectional study.

METHODS

We measured calcaneal BMD in 408 consecutive patients aged >50 years attending after falling. Fall number, fracture history, weight, height, and risk factors for falls and osteoporosis were recorded. T scores (SD above or below the mean for young adults) were derived in both sexes, and Z scores (SD above or below age-related normal score) in females.

RESULTS

In females (n = 300, 74%), mean (SD) T score was -1.1(1.6), and mean Z score was 0(1.4); 127 (42%) had osteoporosis (T score < - 1.6). ROC curves confirmed significant relationships between osteoporosis and age, weight and height (all p < 0.0001). Incorporating fracture history, our model (fracture aged >50 years, age >83 years, weight <57 kg, height <153 cm as dichotomous variables) predicted osteoporosis with 91% sensitivity, 34% specificity. Of 108 male fallers, 36 (33%) had osteoporosis. Age, height and weight all predicted osteoporosis (p < 0.02). The resulting model (fracture aged >50 years, age > or =80 years, weight < or =68 kg, height < or =167 cm as dichotomous variables) predicted osteoporosis with 92% sensitivity, 30% specificity.

DISCUSSION

Osteoporosis prevalence is not increased in female fallers compared to age-related norms; empirical use of osteoporosis treatment solely on the basis of falls thus appears inappropriate. In both sexes, the factors predicting osteoporosis were age, height and weight. Where BMD is not practical, possible or economical, our model may be a sensitive means of predicting fallers with osteoporosis.

Influence of IL-6, COL1A1, and VDR gene polymorphisms on bone mineral density in Crohn's disease

BACKGROUND

Osteoporosis is an important cause of morbidity in patients with Crohn's disease. The pathogenesis of reduced bone mineral density (BMD) is multifactorial. A range of genetic factors have been implicated in other populations of patients with osteoporosis.

AIM

To investigate the influence of interleukin 6 (IL-6), collagen type 1alpha1 (COL1A1), and vitamin D receptor gene (VDR) single nucleotide polymorphisms (SNP) on BMD in patients with Crohn's disease.

PATIENTS

A cohort of 245 well characterised patients with Crohn's disease were recruited from the inflammatory bowel disease register at the Freeman Hospital and Royal Victoria Infirmary, Newcastle upon Tyne, and the Queen Elizabeth Hospital, Gateshead, UK.

METHODS

Patients were genotyped for IL-6 C-174G SNP, COL1A1 Sp1 binding site G T SNP, VDR Taq1, and Fok1 SNPs, and CARD15 R702W, G908R, and L1007fs SNPs. BMD was measured at the lumbar spine (LSP) and hip using dual energy x ray absorptiometry.

RESULTS

A total of 158 female and 87 male patients, aged 24-70 years (mean 44), were recruited. There were no significant differences in the distribution of the tested SNPs when analysed for age, body mass index, pre/post-menopausal status, smoking, or steroid use. Two hundred and thirteen patients were genotyped for the IL-6 SNP. LSP and total hip BMD was significantly lower in patients with the GG genotype (48%) than the CC genotype (15%) (p = 0.041, p = 0.014). One hundred and eighty patients were genotyped for the COL1A1 SNP. There was no significant difference in BMD at LSP. Hip BMD was significantly lower in heterozygous patients compared with homozygous wild-types (p = 0.034). There were no significant differences in BMD between genotypes for the two VDR SNPs or the CARD15 genotypes examined.

CONCLUSION

IL-6 and COL1A1 gene polymorphisms influence BMD in patients with Crohn's disease but the particular VDR gene polymorphisms studied do not have a major effect.

Differences in bone mineral density and geometry in men and women: the Newcastle Thousand Families Study at 50 years old

In 1947 Sir James Spence initiated the Newcastle Thousand Families study, which recruited all 1142 children born in the city between May and June that year. At the age of 50 years, 832 survivors were traced and invited to attend for measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA). The aim was to compare BMD measurements of men and women in this cohort, before and after adjustment for skeletal size. The femoral neck shaft angles (NSA) were also measured manually from the DXA scan printouts. A total of 171 men and 218 women agreed to participate. As expected men had greater bone mineral content and bone area at all sites (p<0.0001) and were taller and heavier (p<0.0001) than women. Men also had significantly higher BMD than women at all regions (p<0.0002), except at the femoral neck or lumbar spine. After correction for skeletal size and body weight, men had statistically significantly lower volumetric BMD at all sites. The measurement of NSA had good intra/interobserver errors and precision (coefficient of variations 0.79%, 1.2% and 1.2%). Men had significantly larger NSAs (mean 130 degrees , range 121-138 degrees ) than women (mean 128 degrees , range 119-137 degrees ). We conclude that there are gender differences in BMD, skeletal size and geometry in middle aged men and women, which together with the subsequent rate of bone loss, may influence fracture risk in later life.

Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial

BACKGROUND

Elderly people who have a fracture are at high risk of another. Vitamin D and calcium supplements are often recommended for fracture prevention. We aimed to assess whether vitamin D3 and calcium, either alone or in combination, were effective in prevention of secondary fractures.

METHODS

In a factorial-design trial, 5292 people aged 70 years or older (4481 [85%] of whom were women) who were mobile before developing a low-trauma fracture were randomly assigned 800 IU daily oral vitamin D3, 1000 mg calcium, oral vitamin D3 (800 IU per day) combined with calcium (1000 mg per day), or placebo. Participants who were recruited in 21 UK hospitals were followed up for between 24 months and 62 months. Analysis was by intention-to-treat and the primary outcome was new low-energy fractures.

FINDINGS

698 (13%) of 5292 participants had a new low-trauma fracture, 183 (26%) of which were of the hip. The incidence of new, low-trauma fractures did not differ significantly between participants allocated calcium and those who were not (331 [12.6%] of 2617 vs 367 [13.7%] of 2675; hazard ratio (HR) 0.94 [95% CI 0.81-1.09]); between participants allocated vitamin D3 and those who were not (353 [13.3%] of 2649 vs 345 [13.1%] of 2643; 1.02 [0.88-1.19]); or between those allocated combination treatment and those assigned placebo (165 [12.6%] of 1306 vs 179 [13.4%] of 1332; HR for interaction term 1.01 [0.75-1.36]). The groups did not differ in the incidence of all-new fractures, fractures confirmed by radiography, hip fractures, death, number of falls, or quality of life. By 24 months, 2886 (54.5%) of 5292 were still taking tablets, 451 (8.5%) had died, 58 (1.1%) had withdrawn, and 1897 (35.8%) had stopped taking tablets but were still providing data for at least the main outcomes. Compliance with tablets containing calcium was significantly lower (difference: 9.4% [95% CI 6.6-12.2]), partly because of gastrointestinal symptoms. However, potentially serious adverse events were rare and did not differ between groups.

INTERPRETATION

The findings do not support routine oral supplementation with calcium and vitamin D3, either alone or in combination, for the prevention of further fractures in previously mobile elderly people.

Five year study of etidronate and/or calcium as prevention and treatment for osteoporosis and fractures in patients with asthma receiving long term oral and/or inhaled glucocorticoids

BACKGROUND

Glucocorticoids are associated with a reduction in bone density and an increased risk of fracture. Concurrent treatment with bisphosphonates reduces bone loss and may prevent fractures. A randomised study was performed to determine whether treatment with cyclical etidronate and/or calcium for 5 years prevents fractures or reverses/reduces bone loss in patients receiving glucocorticoid treatment for asthma.

METHODS

A multicentre, randomised, parallel group comparison of etidronate alone, calcium alone, etidronate + calcium, and no treatment, with stratification according to level of glucocorticoid exposure was carried out in 39 chest clinics in the UK. Three hundred and forty nine postmenopausal female and male outpatients with asthma aged 50-70 years were randomised. The main outcome measures were fractures and changes in bone mineral density (BMD).

RESULTS

Overall, 8% of the patients experienced symptomatic fractures and 17.5% developed either a symptomatic fracture and/or a semiquantitative vertebral fracture by the end of 5 years There were no significant differences between the four treatment groups. Comparing etidronate with no etidronate, the rates of new fractures were not significantly different for symptomatic fractures (OR 1.07 (95% CI 0.46 to 2.47)) or for any fractures (OR 0.82 (95% CI 0.45 to 1.47)). For the comparison of calcium with no calcium the corresponding ORs were 1.43 (95% CI 0.62 to 3.33) and 0.91 (95% CI 0.50 to 1.63). In post hoc analysis the effect of etidronate was greater in women than in men (interaction p value 0.02) with the fracture incidence roughly halved (OR 0.39, 95% CI 0.14 to 0.99). Etidronate increased BMD at the lumbar spine by 4.1% (p = 0.001) while calcium had no significant effect. At the proximal femur the effects of treatment were not significant (relative increases etidronate 1.6%; calcium 1.1%). The rate of new fractures in patients with fractures at entry (23.7%) was higher than in those without fractures at entry (14.3%): OR 1.87 (95% CI 1.06 to 3.07). No association was found between change in BMD and new fractures.

CONCLUSIONS

In patients receiving glucocorticoids for asthma etidronate significantly increased BMD over 5 years at the lumbar spine but not at the hip and had little if any protective effect against fractures, except possibly in postmenopausal women. The effects of calcium were not significant. Combination treatment had no advantage but increased unwanted effects.

The use of digital X-ray radiogrammetry and peripheral dual energy X-ray absorptiometry in patients attending fracture clinic after distal forearm fracture

Despite the fact that 50% of postmenopausal women with Colles' fracture have evidence of osteoporosis, the vast majority of women with forearm fractures are neither investigated nor treated for osteoporosis. Digital X-ray radiogrammetry (DXR) provides an attractive option in patients with distal forearm fracture, as it requires no additional X-rays over and above those performed as part of clinical management. We have compared DXR analysis of nonstandardised plain films taken routinely in accident and emergency with peripheral dual energy X-ray absorptiometry (pDXA) in a group presenting with distal forearm fracture. Women presenting with a fracture of the distal forearm underwent pDXA measurements of the calcaneus. Plain X-rays performed at the time of presentation were taken to allow adequate fracture treatment. No additional radiographer training or standardisation of films was performed. The DXR technique relies upon visualisation of the metacarpal shafts and this was not visualised on 123 of 201 (61%) films. The AP plain film was thus assessed using DXR for BMD in the remaining 78 patients with a mean age of 70.6 years (SE = 1.3). Mean BMD for DXR was 0.46 g/cm2 (SE = 0.01) and for pDXA was 0.40 g/cm2 (SE = 0.01). The correlation between BMD measured using the two techniques was 0.55 (P < 0.001). Although DXR measurements could not be performed in all patients, this proportion could easily be increased by routinely including the metacarpal shaft region in X-rays obtained after suspected distal forearm fracture. The correlation between the pDXA and DXR results is comparable with those reported between DXA measurements at the forearm, spine and hip. Our study suggests that DXR may provide a feasible method for the assessment of future fracture risk. The potential advantage of DXR over calcaneal pDXA measurements is that standard forearm X-ray obtained as part of fracture management could be used.

Acute and long-term management of patients with vertebral fractures

Symptomatic vertebral fractures are associated with significant morbidity, excess mortality and health and social service expenditure. Up to 20% of patients with an incident vertebral fracture experience a further vertebral fracture within one year. It is therefore important that vertebral fractures are detected early, and treatment considered as soon as possible. Only a third of vertebral fractures come to medical attention, where they typically present with acute back pain, but other presentations include loss of height and increasing kyphosis. Spine X-rays should then be performed to confirm the diagnosis and exclude other pathology. Bone density measurements are not essential before starting treatment for osteoporosis in patients with low-trauma vertebral fractures, but may be useful to confirm osteoporosis when there is uncertainty about previous trauma. They may also aid in selecting the most appropriate therapy and monitoring response to treatment. Up to 30% of women and 55% of men with symptomatic vertebral crush fractures have underlying secondary osteoporosis, where treatment may lead to large increases in bone density. These conditions should therefore be sought by medical history, physical examination and appropriate investigations. The management of patients with acute vertebral fractures should include measures to reduce pain and improve mobility, as well as starting treatment for osteoporosis. Treatments have now been shown in randomized controlled trials to improve bone density and reduce the incidence of vertebral and non-vertebral fractures in patients with osteoporosis. Choice of treatment will depend on the underlying causes of bone loss, efficacy in any particular situation, cost, patient preference and the potential non-skeletal advantages and disadvantages.

A randomized controlled trial of calcium with vitamin D, alone or in combination with intravenous pamidronate, for the treatment of low bone mineral density associated with Crohn's disease

BACKGROUND

Osteoporosis is a common complication of Crohn's disease.

AIM

To study the effect on the bone mineral density of a bisphosphonate (pamidronate) given intravenously, in combination with oral calcium and vitamin D supplements, compared with oral calcium and vitamin D supplements alone.

METHODS

Seventy-four patients with Crohn's disease and low bone mineral density at the lumbar spine and/or hip were randomized to receive either a daily dose of 500 mg of calcium with 400 IU of vitamin D alone or in combination with four three-monthly infusions of 30 mg of intravenous pamidronate over the course of 12 months. The main outcome measure was the change in bone mineral density at the lumbar spine and hip, measured by dual X-ray absorptiometry, at baseline and 12 months.

RESULTS

Both groups gained bone mineral density at the lumbar spine and hip after 12 months. There were significant (P < 0.05) changes in the pamidronate group, with gains of + 2.6%[95% confidence interval (CI), 1.4-3.0] at the spine and + 1.6% (95% CI, 0.6-2.5) at the hip, compared with gains of + 1.6% (95% CI, - 0.1-3.2) and + 0.9% (95% CI, - 0.4-2.1) at the spine and hip, respectively, in the group taking vitamin D and calcium supplements alone.

CONCLUSIONS

In patients with Crohn's disease and low bone mineral density, intravenous pamidronate significantly increases the bone mineral density at the lumbar spine and hip.

Mutational and polymorphic analysis of the estradiol receptor-alpha gene in men with symptomatic vertebral fractures

In view of the importance of estrogens in the maintenance of the skeleton in men, we have carried out mutational analysis of all the exons of the estrogen-receptor-alpha (ER-alpha) gene in 64 men (36 patients with symptomatic vertebral crush fractures and 28 control subjects). Initial screening of the ER-alpha gene, carried out by single-strand conformation polymorphism analysis followed by sequencing, showed conservative mutations in exon 4 which resulted in a single base substitutions producing GGG-->GGC transition in codon 274. We also carried out polymorphic analysis of the ER-alpha gene at the PvuII restriction site in 82 men with a range of bone density measurements (53 with symptomatic vertebral fractures and 29 controls). The frequencies of PP, Pp, and pp genotypes were 20.7%, 48.8%, and 30.5%, respectively. The distribution of the alleles was similar in the patients with symptomatic vertebral crush fractures and male control subjects. There was no association between ER-alpha genotypes and bone mineral density or arthropometric parameters. This relatively small study suggests that mutations in the ER-alpha gene are unlikely to be a common cause of osteoporosis in men with vertebral fractures. Furthermore, polymorphic variation of the ER-alpha gene appears to have little effect on the pathogenesis of osteoporosis in men.

Osteoporosis

Osteoporosis is characterised by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk. It is a common condition affecting one in three women and one in 12 men, resulting in substantial morbidity, excess mortality, and health and social services expenditure. It is therefore important to develop strategies to prevent and treat osteoporosis in both men and women. This paper reviews the pathogenesis of primary and secondary osteoporosis, as well as diagnosis, investigation, and management. This should include lifestyle changes to reduce bone loss and decrease the risk of falls, the identification and treatment of secondary causes of bone loss, and specific treatment for osteoporosis. Hormone replacement therapy, raloxifene, bisphosphonates, calcium and vitamin D, calcitonin, and parathyroid hormone have all been shown to improve bone density and decrease the risk of fracture in specific situations. It is important that treatment is tailored to the individual patient, to ensure compliance and optimise the potential benefits.