Hyponatremia, a risk factor for osteoporosis and fractures in women.

SUMMARY: Hyponatremia has been linked to an increased risk of osteoporosis and fractures. We found an increased hazard ratio of major osteoporotic fractures adjusted for potential confounders, including osteoporosis and medication. A reduced BMD was not sufficiently explaining the association. Our data indicate that hyponatremia should be considered a risk factor for osteoporosis and fractures. INTRODUCTION: Hyponatremia is the most common electrolyte disorder in clinical practice and could be a risk factor for both osteoporosis and fractures. Mild hyponatremia has traditionally been regarded as a benign and asymptomatic condition; however, data from large population and animal studies have led to a reappraisal of this view. The purpose of this study was to evaluate the association of hyponatremia with osteoporosis and major osteoporotic fractures (MOF) in women. METHODS: This is a historical cohort study with fracture follow-up. The study consisted of 5610 patients with available serum sodium and a bone density measurement. Information on potential risk factor was obtained through a questionnaire. Additional information on medication, comorbidities, and fractures was obtained through national registries. RESULTS: Hyponatremia was associated with significant lower T-scores at total hip and a borderline significant lower T-score at femoral neck in the multivariate analysis. No association was found between hyponatremia and the lumbar spine T-score. Hyponatremia was associated with an increased hazard ratio of sustaining a MOF in the period from 6 months prior to 12 months after serum sodium measurement. Finally, data showed a relationship with increasing serum sodium and an increasing T-score estimate and a decreasing hazard ratio of MOF. CONCLUSIONS: Our data suggest that hyponatremia in women increases the risk of osteoporosis and MOF. The increased risk of MOF was independent of osteoporosis.

Accuracy of densitometric vertebral fracture assessment when performed by DXA technicians--a cross-sectional, multiobserver study.

UNLABELLED: Six dual-energy X-ray absorptiometry (DXA) technicians reviewed lateral images of the spine for deformed vertebrae. The images were acquired with a DXA scanner in 235 patients referred for osteoporosis assessment. The outcome was compared to findings on spinal radiographs assessed by two radiologists. Three DXA technicians performed acceptable or better in identifying patients with fractured vertebrae. INTRODUCTION: This is the first study to evaluate the accuracy of vertebral fracture assessment (VFA) when used by DXA technicians as a triage test to select patients with deformed vertebrae for spinal radiographs. METHODS: Lateral single-energy scans and radiographs of the thoracolumbar spine (T4-L4) were acquired in 235 patients aged 65 years or more referred for osteoporosis assessment. Six DXA technicians evaluated lateral scans using dedicated software. The DXA technicians were trained to identify deformed vertebrae, but they did not assess the aetiology of deformity. Two radiologists evaluated the radiographs and their consensus evaluation served as the reference test for vertebral fracture. The main outcome was sensitivity and specificity of the DXA technicians' identification of patients with one or more grade II-III deformities according to Genant's classification. RESULTS: The proportion of patients with one or more grade II-III vertebral fractures was 0.35. Sensitivity ranged from 0.61 to 0.83 and specificity ranged from 0.78 to 0.95 across the DXA technicians. In patients with grade II-III deformities on VFA, the mean probability of one or more grade II-III fractures was 0.74 (range 0.66-0.86). Conversely, in patients without such deformities, the mean probability of grade II-III fractures was 0.14 (range 0.10-0.18). Accuracy was lower for grade I-III deformities for all the DXA technicians. CONCLUSION: Three of six DXA technicians achieved acceptable or better accuracy when using VFA to triage patients with grade II-III vertebral deformities for spinal radiographs. Heterogeneity between DXA technicians appears to be due to differences in subjective thresholds. VFA triage by DXA technicians to identify patients with grade II-III fractures is feasible.

Newborn regional body composition is influenced by maternal obesity, gestational weight gain and the birthweight standard score.

AIM: This study investigated whether newborn body composition is influenced by prepregnancy obesity and gestational weight gain (GWG) and explored any associations between body composition and birthweight standard score (z-score), categorised by size for gestational age. METHODS: We recruited 231 obese and 80 normal weight mothers and their newborn infants and assessed the babies' body composition using dual-energy X-ray absorptiometry. RESULTS: The total and abdominal fat masses of infants born to mother who were obese before pregnancy were 135 g (p < 0.001) and 18 g (p < 0.001) higher than the offspring of normal weight mothers. The infants' fat mass increased by 11 g (p < 0.001) for every kilogram of GWG. There were no associations between prepregnancy obesity and fat-free mass. The fat percentage was significantly higher in infants who were large for gestational age (15.3%) than small for gestational age (5.2%) and appropriate for gestational age (9.8%) (p < 0.001). Lower birthweight z-score was associated with a higher proportion of abdominal fat mass (p = 0.009). CONCLUSION: Infants born to obese mothers had higher fat mass at birth, with abdominal fat accumulation. Low birthweight was associated with a lower crude abdominal fat mass, but a higher proportion of total fat mass placed abdominally.

Periarticular and generalised bone loss in patients with early rheumatoid arthritis: influence of alendronate and intra-articular glucocorticoid treatment. Post hoc analyses from the CIMESTRA trial.

OBJECTIVES: The aims of this study were to investigate the influence of alendronate and intra-articular betamethasone treatment on bone mineral density (BMD) changes in hand, lumbar spine and femoral neck during 1 year of a treat-to-target study (Cyclosporine, Methotrexate, Steroid in RA (CIMESTRA)). PATIENTS AND METHODS: A hundred and sixty patients with early, active rheumatoid arthritis (RA) received methotrexate, intra-articular betamethasone and ciclosporin /placebo-ciclosporin. Patients with Z-score ≤0 also started alendronate 10 mg/day. BMD of the hand (digital x-ray radiogrammetry (DXR-BMDhand)), BMD of lumbar spine and femoral neck (dual x-ray absorptiometry (DXA-BMDlumbar spine and DXA-BMDfemoral neck)) and x-rays of hands, wrists and forefeet (modified Sharp-van der Heijde score) were measured at baseline and 1 year, with complete data available in 107 patients. RESULTS: The change in BMD in hand, lumbar spine and femoral neck was negatively associated with the dose of intra-articular betamethasone (p<0.01 for all), but the bone loss in hand was modest and in the axial skeleton comparable with that of healthy individuals. Alendronate did not influence changes in DXR-BMDhand, which averaged -2.8%, whereas significant changes were observed in DXA-BMDlumbar spine and DXA-BMDfemoral neck in alendronate-treated patients (1.8% and 0.8%) compared with untreated patients (-1.8% and -2.2%) (p<0.01 and 0.02). Alendronate did not affect the radiographic progression (alendronate-treated patients: 0 (range 0-19), non-alendronate: 0 (0-18)). CONCLUSIONS: In early active RA, intra-articular betamethasone injections added to disease-modifying antirheumatic drug (DMARD) treatment led to minimal loss of hip and lumbar BMD, and the loss could be prevented by treatment with alendronate. Alendronate treatment did not affect radiographic progression.

The impact of recombinant parathyroid hormone on malignancies and mortality: 7 years of experience based on nationwide Danish registers.

UNLABELLED: We used Danish registers to identify patients with osteoporosis, who had been treated with parathyroid hormone and evaluated the probability of developing cancer. We did not find an increased risk of cancer among the patients treated with parathyroid hormone. INTRODUCTION: We evaluated the incidences of malignancies and mortality in osteoporotic patients treated with rPTH. METHODS: Using Danish nationwide registers, we identified patients diagnosed with osteoporosis in the period 1995 through 2010. Each patient treated with rPTH ("case") was compared with 10 gender- and age-matched patients who did also have osteoporosis but did not receive rPTH ("control"). RESULTS: A total of 4,104 cases (80.3 % females) were identified. The mean age at the beginning of rPTH treatment was 70.9 (SD 9.7) years. During a follow-up time of 10,118 person-years for the cases and 88,005 person-years for the controls, a total of 255 cases (6.2 %) compared with 2,103 controls (5.1 %) experienced a cancer (Chi square, p = 0.003). We found an adjusted cancer related HR of 1.1 (95 %CI 0.9-1.4) among the cases. Lung cancer was the only cancer type with a significantly increased rate among patients receiving rPTH (HR 1.7; 95 % CI 1.3-2.3). No cases developed osteosarcomas and nine controls developed osteosarcoma. During follow-up, 627 (15.3 %) cases died and 4,175 (10.2 %) controls died, which yielded an excess mortality risk of 26 % (95 % CI 16-37 %). This could be due to differences in the prevalence of vertebral fractures between the rPTH-treated and non-treated patients. CONCLUSION: This study did not support the hypothesis describing a possible link between rPTH treatment and the development of cancer. We also conclude that osteosarcoma has not been diagnosed in any Danish patient receiving rPTH since the year 2003 when it was introduced on the market.

Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency.

UNLABELLED: Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength. INTRODUCTION: In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions. METHODS: Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months. RESULTS: After 24 months, cortical thickness was increased compared with the controls (6.43%, CI 3.34 to 9.61%; p = 0.0001) and metacarpal index (MCI) (6.14%, CI 3.95 to 8.38%; p < 0.0001), while the endosteal diameter decreased (-4.64%, CI -7.15 to -2.05; p < 0.001). Total bone width did not change significantly (0.68%, CI -1.17 to 2.57%; not significant (NS)). A gender effect was seen on bone width (p < 0.0001), endosteal diameter (p < 0.01) and cortical thickness (p < 0.01), but not with MCI (NS). CONCLUSIONS: Cortical bone reacts promptly to reinstitution of GH beyond the attainment of final height by increasing the cortical thickness through endosteal bone growth. This leads to a higher peak bone mass and may reduce the risk of cortical bone fragility later in life.

Zoledronic acid results in better health-related quality of life following hip fracture: the HORIZON-Recurrent Fracture Trial.

UNLABELLED: This study evaluated the benefits of ZOL versus placebo on health-related quality of life (HRQoL) among patients from HORIZON-RFT. At month 24 and end of the study visit, ZOL significantly improved patients' overall health state compared to placebo as assessed by the EQ-5D VAS. INTRODUCTION: To evaluate the benefits of zoledronic acid (ZOL) versus placebo on health-related quality of life (HRQoL) among patients from The Health Outcomes and Reduced Incidence With Zoledronic Acid Once Yearly Recurrent Fracture Trial (HORIZON-RFT). METHODS: In this randomized, double-blind, placebo-controlled trial, 2,127 patients were randomized to receive annual infusion of ZOL 5 mg (n = 1,065) or placebo (n = 1,062) within 90 days after surgical repair of low-trauma hip fracture. HRQoL was measured using EQ-5D Visual Analogue Scale (VAS) and utility scores (EuroQol instrument) at months 6, 12, 24, 36, and end of the study visit. Analysis of covariance model included baseline EQ-5D value, region, and treatment as explanatory variables. RESULTS: At baseline, patients (mean age 75 years; 24% men and 76% women) were well matched between treatment groups with mean EQ-5D VAS of 65.82 in ZOL and 65.70 in placebo group. At the end of the study, mean change from baseline in EQ-5D VAS was greater for ZOL vs. placebo in all patients (7.67 ± 0.56 vs. 5.42 ± 0.56), and in subgroups of patients experiencing clinical vertebral fractures (8.86 ± 4.91 vs. -1.69 ± 3.42), non-vertebral fractures (5.03 ± 2.48 vs. -1.07 ± 2.16), and clinical fractures (5.19 ± 2.25 vs. -0.72 ± 1.82) with treatment difference significantly in favor of ZOL. EQ-5D utility scores were comparable for ZOL and placebo groups, but more patients on placebo consistently had extreme difficulty in mobility (1.74% for ZOL vs. 2.13% for placebo; p = 0.6238), self-care (4.92% vs. 6.69%; p = 0.1013), and usual activities (10.28% vs. 12.91%; p = 0.0775). CONCLUSION: ZOL significantly improves HRQoL in patients with low-trauma hip fracture.

Association between timing of zoledronic acid infusion and hip fracture healing.

UNLABELLED: Patients in the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly (HORIZON) Recurrent Fracture Trial were assessed for evidence of delayed hip fracture healing. No association was observed between zoledronic acid (ZOL) and delayed healing. We conclude that ZOL has no clinically evident effect on fracture healing, even when the drug is infused in the immediate postoperative period. INTRODUCTION: Intravenous zoledronic acid 5 mg (ZOL) given after a hip fracture reduces secondary fracture rates and mortality. It has been postulated that bisphosphonates may affect healing if given soon after a fracture. We sought to determine whether the timing of ZOL infusion affected the risk of delayed hip fracture healing. METHODS: In the HORIZON Recurrent Fracture Trial, patients were randomized within 90 days of a low-trauma hip fracture to receive either once-yearly ZOL (n = 1,065) or placebo (n = 1,062). Clinical symptoms of delayed hip fracture healing were sought at randomization, 6 months and 12 months after fracture; if present, a central adjudication committee blinded to treatment assignment reviewed radiographs and clinical records. Median follow-up was 1.9 years. RESULTS: The overall incidence of delayed healing was 3.2% (ZOL) and 2.7% (placebo; odds ratio [OR], 1.17; 95% confidence interval [CI], 0.72-1.90; p = 0.61). Logistic regression models revealed no association between ZOL and delayed healing even after adjusting for other risk factors (OR, 1.21; 95% CI, 0.74-1.99; p = 0.44). There was no interaction by timing of infusion, and nonunion rates were similar even when ZOL was given within 2 weeks of hip fracture repair. NSAID use was significantly associated with delayed fracture healing (OR, 2.55; 95% CI, 1.49-4.39; p < 0.001). CONCLUSIONS: ZOL has no clinically evident effect on fracture healing, even when the drug is infused in the immediate postoperative period.

The Osteoporosis Self-Assessment Tool versus alternative tests for selecting postmenopausal women for bone mineral density assessment: a comparative systematic review of accuracy.

SUMMARY: We performed a systematic review of studies comparing the Osteoporosis Self-Assessment Tool (OST) and other tests used to select women for bone mineral density (BMD) assessment. In comparative meta-analyses, we found that the accuracy of OST was similar to other tests that are based on information from the medical history. By contrast, assessment by quantitative ultrasonography at the heel was more accurate than OST in discriminating between women with high and low BMD. The methodological quality of the included studies was generally low. INTRODUCTION: Numerous tests are suggested for triaging postmenopausal women for bone mineral density (BMD) assessment by dual-energy X-ray absorptiometry. Previous studies suggest that OST, based on age and weight only, may be as accurate as more complex triage tests. We systematically compare the accuracy of OST and alternative triage tests in postmenopausal women. METHODS: We searched PubMed, Embase, Web of Science, citation lists, and conference proceedings. Our main measure of accuracy was the diagnostic odds ratio (DOR). We compared summary estimates of DOR (sDOR) for OST and alternative tests in pairwise meta-analyses by using the Moses-Littenberg approach. RESULTS: Summary estimates of DOR for OST and the clinical decision rules Simple Calculated Osteoporosis Risk Estimation (SCORE) and Osteoporosis Risk Assessment Instrument (ORAI) did not differ significantly in white women (relative sDOR: 0.57-1.17, all p >or= 0.11). By contrast, sDOR was higher for Stiffness Index assessed by calcaneal quantitative ultrasonography than for OST (relative sDOR: 1.9, p = 0.005). Studies were few in Asian and black women. Methodological quality, assessed with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist, was generally low. CONCLUSIONS: In white women, the accuracy of OST and alternative clinical decision rules was similar, whereas Stiffness Index was more accurate than OST. Low study quality renders transferability to clinical settings uncertain.

Performance of the Osteoporosis Self-Assessment Tool in ruling out low bone mineral density in postmenopausal women: a systematic review.

UNLABELLED: The Osteoporosis Self-Assessment Tool (OST) is a simple test that may be of clinical value to rule-out low bone mineral density. We performed a systematic review to assess its performance in postmenopausal women. We included 36 studies. OST performed moderately in ruling-out femoral neck T-score or=0.28). Methodological study quality was generally low. CONCLUSIONS: The clinical usefulness of OST is uncertain. OST could be useful for ruling-out femoral neck T-score

Digital x-ray radiogrammetry identifies women at risk of osteoporotic fracture: results from a prospective study.

Using digital X-ray radiogrammetry (DXR) on hand radiographs from a large population-based study, 1,370 postmenopausal women were evaluated in a prospective fashion; fracture occurrence was compared with DXR measurements of historic radiographs. Further, the aim of the study was to evaluate factors affecting DXR bone mineral density (BMD) in this cohort. The study is based on data from a subgroup of women participating in the third Copenhagen City Heart Study and additional data from a questionnaire obtained in 1999. The mean follow-up time was 6.1 years. During the observation period, 245 women suffered a fracture. Odds ratios (ORs) per 1 standard deviation decline in DXR-BMD were statistically significant for fracture in the groups of wrist fractures, proximal humerus fractures, vertebral fractures, and other fractures as well as in the total fracture group. In the hip fracture group, the P value almost reached significance (0.052). The highest ORs (2.4) were found in the group with proximal humerus fractures and in the vertebral fracture group (2.0). In the wrist fracture and hip fracture groups, ORs were 1.7 and 1.4, respectively. The group with other fractures had an OR of 1.7, and the OR in the entire fracture group was 1.6. Age, fracture, and smoking were negatively correlated with DXR-BMD, whereas BMI, age at menopause, hormone replacement therapy, and physical fitness and muscle strength were positively correlated with DXR-BMD. In conclusion, BMD estimated by DXR of the metacarpals predicts later osteoporotic fracture and seems to provide meaningful information on bone mass in epidemiological studies, where DXA measurements are not available.

Comparison of dual X-ray absorptiometry (DXA), digital X-ray radiogrammetry (DXR), and conventional radiographs in the evaluation of osteoporosis and bone erosions in patients with rheumatoid arthritis.

OBJECTIVE: To compare the relationship between bone mineral density (BMD) in the metacarpal bones and forearm measured by dual X-ray absorptiometry (DXA) and digital X-ray radiogrammetry (DXR) and radiological alterations in patients with early and established rheumatoid arthritis (RA). PATIENTS AND METHODS: In each of the three disease duration groups, 11 female RA patients were included. The patients were further divided into two groups according to bone erosions. BMD in the metacarpals was evaluated by DXA and DXR. RESULTS: A significant relationship between DXA-BMD and DXR-BMD was observed. DXR-BMD and the individually combined cortical thickness (CT) of the metacarpo-phalangeal (MCP) joints were related to disease duration and erosions. Patients with erosive disease had lower values of age- and sex-adjusted BMD measured with DXA, but most significantly with DXR. CONCLUSION: DXR appears to be a more sensitive method than DXA in detecting early bone loss in patients with RA. The relationship of DXR-BMD to disease duration and bone damage indicates that the DXR method may be useful in the evaluation of disease activity and progression.

Enlarged clitoris in wild polar bears (Ursus maritimus) can be misdiagnosed as pseudohermaphroditism.

A 23-year-old female polar bear (Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported 'pseudohermaphroditic' polar bears from Svalbard. It has been suggested that an enzyme defect (21-hydroxylase deficiency), androgen producing tumour or high exposure to organochlorines during the foetal stage or early development could be the reason for the supposed pseudohermaphroditism observed for Svalbard bears. Except for the enlarged clitoris, all dimensions of the external and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. A histological examination of the clitoral enlargement in the present East Greenland specimen allows a first-time histological evaluation of the earlier macroscopic field diagnosis from Svalbard. This examination revealed intense chronic ulcerative and perivascular clitoriditis similar to "acral lick dermatitis" frequently seen in domestic dogs (i.e., we did not find any signs of pseudohermaphroditic hyperplasia of clitoral tissue due to androgenic or antiestrogenic endocrine disruption). The levels of organohalogens and TEQ values were lower than concentration thresholds of toxicological risk. It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphroditism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East Greenland polar bear. Furthermore, caution should be exercised in suggesting linkages of such inflammatory abnormalities with correlations to anthropogenic pollutant exposures.

Bone loss in unclassified polyarthritis and early rheumatoid arthritis is better detected by digital x ray radiogrammetry than dual x ray absorptiometry: relationship with disease activity and radiographic outcome.

OBJECTIVE: To compare changes in regional bone mineral density (BMD) of the metacarpal joints measured by dual x ray absorptiometry (DXA) and digital x ray radiogrammetry (DXR) in relation to disease activity and radiographic outcome in a two year follow up study of patients with early RA and unclassified polyarthritis. PATIENTS AND METHODS: 72 patients with symmetrically swollen and tender second and third metacarpophalangeal or proximal interphalangeal joints for at least four weeks and less than two years were included. 51 patients fulfilled the ACR criteria for RA. 21 patients had unclassified polyarthritis. The patients with RA were divided into groups according to mean disease activity, average glucocorticoid dose, and MRI and x ray detected bone erosions in the hands. Clinical and biochemical measurements were made every month and an x ray examination of the hands and BMD of the metacarpal joints every six months. RESULTS: DXR BMD decreased significantly only in patients with RA from month 6 and was associated with the mean disease activity. Patients with RA and erosive as well as non-erosive disease showed a significant decrease in the rate of bone loss, greatest in those with erosive disease. No changes in BMD measured by DXA were seen in any patient group. CONCLUSION: DXR is a useful measure of the destructive disease activity in patients with RA and unclassified polyarthritis, providing valuable information about bone changes associated with disease activity and erosive disease in early RA. DXR is better than DXA for detecting and monitoring periarticular osteoporosis of the metacarpal bone.

Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland.

The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined. Experience from cadmium-poisoned humans and laboratory mammals indicates that concentrations above 50-200 microg/g wet wt. may induce histopathological changes. Overall, 31 of the ringed seals had cadmium concentrations in the kidney cortex above 50 microg/g wet wt., 11 had concentrations above 100 and one had a concentration above 200 microg/g wet wt. Obvious histopathological changes (categorised mainly as glomerulonephritis) were found in 10 of the seals; however, none of these changes could be attributed to cadmium-induced renal damage (mainly tubulopathy) as described for other species. Damage to the proximal kidney tubules is known to induce demineralisation of the skeletal system (Fanconi's syndrome). Therefore, the three lowest lumbar vertebrae were scanned in 91 seals to measure the content of calcium. The 10 cases of nephropathy could neither be linked to the degree of mineralisation of the skeleton nor to the cadmium concentrations. Furthermore, the degree of mineralisation of the skeleton was not correlated with the cadmium concentration, age or sex. It can therefore be concluded that despite high levels of cadmium, none of the ringed seals showed any signs of cadmium-induced nephropathy or osteodystrophy. This might be explained by the composition of the ringed seals diet, which contains high levels of vitamin D, calcium, phosphorus, zinc, selenium and protein. These elements are all likely to counteract cadmium-induced damage. It is speculated that ringed seal are not particularly vulnerable to osteodystrophy, due to their continuous growth (bone mineralisation) throughout life and the oestrogen hormonal activity of females throughout life.

Metacarpal index by digital X-ray radiogrammetry: normative reference values and comparison with dual X-ray absorptiometry.

Metacarpal index (MCI), the combined cortical midmetacarpal thickness divided by the outer mid-metacarpal diameter, fell into oblivion when dual photon absorptiometry was introduced a quarter of a century ago. Modern PC-based digital X-ray diameter measurements offers a unique opportunity for precise and accurate measurements of MCI (DXR-MCI). We hypothesized that DXR-MCI in contrast to projected areal bone mineral density (BMD) (DXA-BMD) is independent of bone size and studied 384 normal women by measuring DXR-MCI and DXA-BMD of the lumbar spine, hip, and distal radius. A normative MCI database for women is presented. It has its maximum in the third decade, and a moderate biologic variation that seems to decline with age. It was found that DXR-MCI was independent of body weight and body surface area, whereas all DXA-BMD values were significantly dependent on them. Body height was significantly correlated with DXA-BMD at all sites, but less so with DXR-MCI. The latter was correlated with metacarpal bone length. It is suggested that the moderate correlation between MCI and body height would be abolished if the region of interest used for calculation of MCI be adjusted according to individual metacarpal bone length. DXR-MCI correlated significantly with DXA-BMD at the sites measured, and particularly well with that of the distal radius (r = 0.67; p < 0.0001).

Response of cortical bone to antiresorptive treatment.

A total of 113 postmenopausal women (69 controls, 33 using hormone replacement therapy (HRT), and 11 using bisphosphonate) were evaluated twice over 2 years with a new noninvasive, radiogrammetry-based technique called digital X-ray radiogrammetry (DXR) and conventional bone densitometry of the spine, hip, and forearm. Longitudinal changes in bone densitometry were compared with changes captured by DXR: BMD evaluated by DXR (BMDDXR), cortical thickness of the second metacarpal (CTMC2), and porosity of cortical bone. The expected annual postmenopausal reduction in BMD in the control group was detected by BMDspine (-0.8%, P < 0.01), BMDhip (-1.6%, P < 0.001), BMDforearm (-1.5%, P < 0.001), DXR-BMD (-0.8%, P < 0.001), and CTMC2 (-1.1%, P < 0.001). In the HRT group, smaller reductions were seen in BMDDXA, but only significant at the hip (-1.0%, P < 0.01) and distal forearm (-1.0%, P < 0.02). In the bisphosphonate group, cortical porosity was significantly reduced (P < 0.025). Comparing longitudinal changes in age-matched subsamples of controls and bisphosphonate treated, BMDDXR, CTMC2, and porosity of cortical bone all differed significantly (P < 0.01, P < 0.05, P < 0.05, respectively), whereas the BMDDXA measurements did not. In conclusion, DXR provides a densitometry equivalent measurement of the distal forearm and hand and seems to offer new information on the porosity of cortical bone. This may prove useful in the evaluation of bone loss and offer new insight into the effects of different antiresorptive treatment regimens used in the prevention of osteoporosis.

Estimation of bone mineral density by digital X-ray radiogrammetry: theoretical background and clinical testing.

A new automated radiogrammetric method to estimate bone mineral density (BMD) from a single radiograph of the hand and forearm is described. Five regions of interest in radius, ulna and the three middle metacarpal bones are identified and approximately 1800 geometrical measurements from these bones are used to obtain a BMD estimate of the distal forearm, referred to as BMDDXR (from digital X-ray radiogrammetry, DXR). The measured dimensions for each bone are the cortical thickness and the outer width, in combination with an stimate of the cortical porosity. The short-term in vivo precision of BMDDXR was observed to be 0.60% in a clinical study of 24 women and the in vitro variation over 12 different radiological clinics was found to be 1% of the young normal BMDDXR level. In a cohort of 416 women BMDDXR was found to be closely correlated with BMD at the distal forearm measured by dual-energy X-ray absoptiometry (r = 0.86, p < 0.0001) and also with BMD at the spine, total hip and femoral neck (r = 0.62, 0.69 and 0.73, respectively, p<0.0001 for all). The annual decline was estimated from the cohort to be 1.05% in the age group 55-65 years. Relative to this age-related loss, the reported short-term precision allows for monitoring intervals of 1.0 years and 1.6 years in order to detect expected age-related changes with a confidence of 80% and 95%, respectively. It is concluded that the DXR method offers a BMD estimate with a good correlation with distal forearm BMD, a low variation between geographical sites and a precision that potentially allows for relatively short observation intervals.

[Proper advice on nutrition. Recommendations concerning the conduct of the nutritional news]. / Redelig ernaeringsoplysning. Anbefalinger om hvordan ny viden om ernaering kan formidles.

The Committee on Proper Conduct in Public Advice on Nutrition, set up by the Danish Nutrition Council, has produced recommendations to persons involved in communicating results of nutrition research. The guidelines are targeted on scientists, industry, journalists and publishers as well as consumers to facilitate proper conduct in communication of own or other scientists' research results, which might influence consumers' choice and intake of food. The results are presented as recommendations and checklists providing the necessary requirements to bring people in a position to make the best possible evaluation of the new scientific results and to put the results into their proper perspective. The aim of this report is to improve the process so that the communicator focuses on the background information necessary for the reader/listener/viewer in the current situation to achieve a balanced view and benefit from the new scientific result.