Supine vs decubitus lateral patient positioning in vertebral fracture assessment.

In vertebral fracture assessment (VFA), lateral scans are obtained with the patient positioned supine (C-arm densitometers) or lateral decubitus (fixed-arm densitometers). We aimed to determine the impact of positioning on image quality and fracture definition. We performed supine and decubitus lateral VFA in 50 postmenopausal women and used the algorithm-based qualitative method to identify vertebral fractures. We compared the 2 techniques for the identification of fractures (kappa analysis) and compared the numbers of unreadable vertebrae (indiscernible endplates) and vertebrae that were projected obliquely (Wilcoxon matched-pairs signed-rank test). The kappa score for agreement between the VFA techniques (to identify women with vertebral fractures) was 0.84 (95% confidence interval [CI]: 0.68-0.99), and for agreement with fracture assessments made from radiographs, kappa was 0.76 (95% CI: 0.57-0.94) for both supine and decubitus lateral VFA. There were more unreadable vertebrae with supine lateral (48 vertebrae in supine lateral compared with 14 in decubitus lateral; p=0.001), but oblique projection was less common (93 vertebrae compared with 145 in decubitus lateral; p=0.002). We conclude that there were significantly different projection effects with supine and decubitus lateral VFA, but these differences did not influence the identification of vertebral fractures in our study sample.

Performance of quantitative ultrasound measurements of bone for monitoring raloxifene therapy.

Raloxifene increases bone mineral density (BMD) and decreases vertebral fracture risk; the effects on quantitative ultrasound (QUS) variables, however, have been less well studied. We aimed to further evaluate the effectiveness of QUS for monitoring raloxifene treatment and withdrawal effects. Osteopenic, postmenopausal women (age=50-80 yr, n=125), who completed a 96-wk study (phase A) evaluating treatment compliance or monitoring, were invited to participate in a 96-wk raloxifene withdrawal study (phase B). Those originally receiving treatment were then randomized to continue on raloxifene (60 mg/d)+calcium (500 mg/d) (n=23) or to discontinue raloxifene and take placebo+calcium (500 mg/d) (n=23). Previously untreated women remained untreated (n=12). Yearly QUS and BMD measurements were performed. At the end of phase A, lumbar spine BMD (p=0.005), amplitude-dependent speed of sound (Ad-SoS) (p=0.006) and average SoS (p=0.040) decreased in untreated women but remained stable in treated women. Significant changes in Ad-SoS and ultrasonic bone profiler index had occurred in treated women by the end of phase B (p<0.01). All variables, except bone transmission time, were higher for those receiving any raloxifene treatment (p<0.05). Until further knowledge has been acquired, QUS measurement variables should only be used in conjunction with BMD when assessing changes in bone because of raloxifene therapy.

Risk factors for vertebral and nonvertebral fracture over 10 years: a population-based study in women.

UNLABELLED: Risk factors may vary for different types of fracture, in particular for vertebral fractures. We followed 367 women >50 yr of age from a population-based cohort for up to 10 yr. Factors that predicted vertebral rather than nonvertebral fractures related to physical weakness, poor health, and weight loss. Similar factors were also associated with greater bone loss at the hip. INTRODUCTION: Many risk factors predict fractures overall, but it is less clear whether certain factors relate to vertebral fractures in particular. The aim of this study was to compare the risk factors for vertebral and nonvertebral fractures. MATERIALS AND METHODS: We carried out a 10-yr prospective population-based study of 375 women who were 50-85 yr of age initially. At baseline, we measured BMD, blood and urine biochemistry, and anthropometric measurements. Medical and lifestyle data were obtained by questionnaire. Incident vertebral fractures were determined for 311 subjects from spinal radiographs at 0, 2, 5, 7, and 10 yr using an algorithm-based qualitative method, and nonvertebral fractures were confirmed radiographically. Relative risks were calculated by Cox regression analysis. RESULTS: During follow-up, 70 subjects sustained one or more nonvertebral fractures and 29 sustained one or more vertebral fractures. Risk factors that predicted both types of fracture included increasing age, decreasing BMD at all sites, prevalent vertebral fracture, and shorter estrogen exposure. For nonvertebral fractures only, the risk factors included low urinary creatinine and less frequent use of stairs. The factors for vertebral fractures included lighter weight, reduced body fat, heavy smoking, lower serum calcium, albumin, and thyroid T(3), weak grip strength, and poor physical capability. In a multivariate model, weight, fat mass, serum calcium and T(3), prevalent vertebral fracture, and physical capability remained significant. Furthermore, grip strength, serum albumin, weight loss, and physical capability were associated with rate of bone loss at the femoral neck, and a fast rate of bone loss was also associated with vertebral fractures. CONCLUSIONS: We conclude that overall frailty, which may consist of general poor health, small or thin body size, and lack of strength and physical capability, predicts vertebral fractures but is not a significant predictor of nonvertebral fractures. Bone loss rates are associated with similar risk factors and also with the incidence of vertebral fractures.

Establishing reference intervals for bone turnover markers in healthy postmenopausal women in a nonfasting state.

In order to interpret bone turnover markers (BTMs), we need to establish healthy reference intervals. It is difficult to establish reference intervals for older women because they commonly suffer from diseases or take medications that affect bone turnover. The aims of this study were: (1) to identify diseases and drugs that have a substantial effect on BTMs; (2) to establish reference intervals for premenopausal and postmenopausal women; and (3) to examine the effects of other factors on BTMs in healthy postmenopausal women. We studied women aged 30-39 years (n=258) and women aged 55-79 years (n=2419) from a five-European centre population-based study. We obtained a nonfasting serum and second morning void urine samples at a single baseline visit. BTMs were measured using automated immunoassay analysers. BTMs were higher in patients with vitamin D deficiency and chronic kidney disease. Three or more BTMs were higher in women who were osteoporotic and at least two BTMs were lower in women who were oestrogen replete, taking osteoporosis treatments or having diseases known to affect bone turnover. These were used as exclusion criteria for selecting the populations for the reference intervals. The reference intervals for BTMs were higher in postmenopausal than premenopausal women. Levels of BTMs were not dependent on geographical location and increased with age.