Vertebral Scheuermann's disease in Europe: prevalence, geographic variation and radiological correlates in men and women aged 50 and over.

UNLABELLED: In 27 centres across Europe, the prevalence of deforming spinal Scheuermann's disease in age-stratified population-based samples of over 10,000 men and women aged 50+ averaged 8% in each sex, but was highly variable between centres. Low DXA BMD was un-associated with Scheuermann's, helping the differential diagnosis from osteoporosis. INTRODUCTION: This study aims to assess the prevalence of Scheuermann's disease of the spine across Europe in men and women over 50 years of age, to quantitate its association with bone mineral density (BMD) and to assess its role as a confounder for the radiographic diagnosis of osteoporotic fracture. METHODS: In 27 centres participating in the population-based European Vertebral Osteoporosis Study (EVOS), standardised lateral radiographs of the lumbar and of the thoracic spine from T4 to L4 were assessed in all those of adequate quality. The presence of Scheuermann's disease, a confounder for prevalent fracture in later life, was defined by the presence of at least one Schmorl's node or irregular endplate together with kyphosis (sagittal Cobb angle >40° between T4 and T12) or a wedged-shaped vertebral body. Alternatively, the (rare) Edgren-Vaino sign was taken as diagnostic. The 6-point-per-vertebral-body (13 vertebrae) method was used to assess osteoporotic vertebral shape and fracture caseness. DXA BMD of the L2-L4 and femoral neck regions was measured in subsets. We also assessed the presence of Scheuermann's by alternative published algorithms when these used the radiographic signs we assessed. RESULTS: Vertebral radiographic images from 4486 men and 5655 women passed all quality checks. Prevalence of Scheuermann's varied considerably between centres, and based on random effect modelling, the overall European prevalence using our method was 8% with no significant difference between sexes. The highest prevalences were seen in Germany, Sweden, the UK and France and low prevalences were seen in Hungary, Poland and Slovakia. Centre-level prevalences in men and women were highly correlated. Scheuermann's was not associated with BMD of the spine or hip. CONCLUSIONS: Since most of the variation in population impact of Scheuermann's was unaccounted for by the radiological and anthropometric data, the search for new genetic and environmental determinants of this disease is encouraged.

Low BMD is less predictive than reported falls for future limb fractures in women across Europe: results from the European Prospective Osteoporosis Study.

We have previously shown that center- and sex-specific fall rates explained one-third of between-center variation in upper limb fractures across Europe. In this current analysis, our aim was to determine how much of the between-center variation in fractures could be attributed to repeated falling, bone mineral density (BMD), and other risk factors in individuals, and to compare the relative contributions of center-specific BMD vs. center-specific fall rates. A clinical history of fracture was assessed prospectively in 2451 men and 2919 women aged 50-80 from 20 centers participating in the European Prospective Osteoporosis Study (EPOS) using standardized questionnaires (mean follow-up = 3 years). Bone mineral density (BMD, femoral neck, trochanter, and/or spine) was measured in 2103 men and 2565 women at these centers. Cox regression was used to model the risk of incident fracture as a function of the person-specific covariates: age, BMD, personal fracture history (PFH), family hip fracture history (FAMHIP), time spent walking/cycling, number of 'all falls' and falls not causing fracture ('fracture-free') during follow-up, alcohol consumption, and body mass index. Center effects were modeled by inclusion of multiplicative gamma-distributed random effects, termed center-shared frailty (CSF), with mean 1 and finite variance theta (theta) acting on the hazard rate. The relative contributions of center-specific fall risk and center-specific BMD on the incidence of limb fractures were evaluated as components of CSF. In women, the risk of any incident nonspine fracture (n = 190) increased with age, PFH, FAMHIP, > or =1 h/day walking/cycling, and number of 'all falls' during follow-up (all P < 0.074). 'Fracture-free' falls (P = 0.726) and femoral neck BMD did not have a significant effect at the individual level, but there was a significant center-shared frailty effect (theta = 0.271, P = 0.001) that was reduced by 4% after adjusting for mean center BMD and reduced by 19% when adjusted for mean center fall rate. Femoral trochanter BMD was a significant determinant of lower limb fractures (n = 53, P = 0.014) and the center-shared frailty effect was significant for upper limb fractures (theta = 0.271, P = 0.011). This upper limb fracture center effect was unchanged after adjusting for mean center BMD but was reduced by 36% after adjusting for center mean fall rates. In men, risk of any nonspine fracture (n = 75) increased with PFH, fall during follow-up (P < 0.026), and with a decrease in trochanteric BMD [RR 1.38 (1.08, 1.79) per 1 SD decrease]. There was no center effect evident (theta = 0.081, P = 0.096). We conclude that BMD alone cannot be validly used to discriminate between the risk of upper limb fractures across populations without taking account of population-specific variations in fall risk and other factors. These variations might reflect shared environmental or possibly genetic factors that contribute quite substantially to the risk of upper limb fractures in women.

Determinants of the size of incident vertebral deformities in European men and women in the sixth to ninth decades of age: the European Prospective Osteoporosis Study (EPOS).

UNLABELLED: More severe vertebral fractures have more personal impact. In the European Prospective Osteoporosis Study, more severe vertebral collapse was predictable from prior fracture characteristics. Subjects with bi-concave or crush fractures at baseline had a 2-fold increase in incident fracture size and thus increased risk of a disabling future fracture. INTRODUCTION: According to Euler's buckling theory, loss of horizontal trabeculae in vertebrae increases the risk of fracture and suggests that the extent of vertebral collapse will be increased in proportion. We tested the hypothesis that the characteristics of a baseline deformity would influence the size of a subsequent deformity. METHODS: In 207 subjects participating in the European Prospective Osteoporosis Study who suffered an incident spine fracture in a previously normal vertebra, we estimated loss of volume (fracture size) from plane film images of all vertebral bodies that were classified as having a new fracture. The sum of the three vertebral heights (anterior, mid-body, and posterior) obtained at follow-up was subtracted from the sum of the same measures at baseline. Each of the summed height loss for vertebrae with a McCloskey-Kanis deformity on the second film was expressed as a percentage. RESULTS AND CONCLUSIONS: In univariate models, the numbers of baseline deformities and the clinical category of the most severe baseline deformity were each significantly associated with the size of the most severe incident fracture and with the cumulated sum of all vertebral height losses. In multivariate modeling, age and the clinical category of the baseline deformity (crush > bi-concave > uni-concave > wedge) were the strongest determinants of both more severe and cumulative height loss. Baseline biconcave and crush fractures were associated at follow-up with new fractures that were approximately twice as large as those seen with other types of deformity or who previously had undeformed spines. In conclusion, the characteristics of a baseline vertebral deformity determines statistically the magnitude of vertebral body volume lost when a subsequent fracture occurs. Because severity of fracture and number of fractures are determinants of impact, the results should improve prediction of the future personal impact of osteoporosis once a baseline prevalent deformity has been identified.

Incidence of vertebral fracture in europe: results from the European Prospective Osteoporosis Study (EPOS).

Vertebral fracture is one of the major adverse clinical consequences of osteoporosis; however, there are few data concerning the incidence of vertebral fracture in population samples of men and women. The aim of this study was to determine the incidence of vertebral fracture in European men and women. A total of 14,011 men and women aged 50 years and over were recruited from population-based registers in 29 European centers and had an interviewer-administered questionnaire and lateral spinal radiographs performed. The response rate for participation in the study was approximately 50%. Repeat spinal radiographs were performed a mean of 3.8 years following the baseline film. All films were evaluated morphometrically. The definition of a morphometric fracture was a vertebra in which there was evidence of a 20% (+4 mm) or more reduction in anterior, middle, or posterior vertebral height between films--plus the additional requirement that a vertebra satisfy criteria for a prevalent deformity (using the McCloskey-Kanis method) in the follow-up film. There were 3174 men, mean age 63.1 years, and 3,614 women, mean age 62.2 years, with paired duplicate spinal radiographs (48% of those originally recruited to the baseline survey). The age standardized incidence of morphometric fracture was 10.7/1,000 person years (pyr) in women and 5.7/1,000 pyr in men. The age-standardized incidence of vertebral fracture as assessed qualitatively by the radiologist was broadly similar-12.1/1,000 pyr and 6.8/1,000 pyr, respectively. The incidence increased markedly with age in both men and women. There was some evidence of geographic variation in fracture occurrence; rates were higher in Sweden than elsewhere in Europe. This is the first large population-based study to ascertain the incidence of vertebral fracture in men and women over 50 years of age across Europe. The data confirm the frequent occurrence of the disorder in men as well as in women and the rise in incidence with age.

Hip geometry, bone mineral distribution, and bone strength in European men and women: the EPOS study.

Hip geometry and bone mineral density (BMD) have been shown previously to relate, independently of each other, to risk of hip fracture. We used Lunar DPX "beta" versions of hip strength analysis (HSA) and hip axis length (HAL) software to analyze scans from ten representative age-stratified population samples in the European Prospective Osteoporosis Study (EPOS). All 1617 subjects were >50 years of age, and 1033 were women. The data were modeled with gender and center as categorical variables. The bone mineral density of the upper half of the femoral neck declined at a faster rate with age than that in the lower half. Femoral neck cross-sectional moment of inertia (CSMI), a measure of resistance to bending, showed no significant age reduction in either gender. However, height and weight effects on CSMI were significantly more beneficial in men than in women (0.002 < p < 0.012) and the weight effect appeared to be mediated by bone mineral content (BMC). Compressive stress (Cstress), defined as the stress in the femoral neck at its weakest cross section arising from a standardized fall, was higher in women. Although Cstress increased with body weight when BMC was held constant, in practice it fell through the association and statistical interaction of rising body weight with rising BMC. HAL, as expected, was strongly positively associated with male gender and also height (p < 0.0001). Hip strength-related indices were markedly center-dependent. Significant differences (p < 0.0001) were noted between the centers for all the variables investigated that related to hip geometry. Adjustment for femoral neck bone mineral content (totBMC) showed these center differences to account for >50% of center variation in hip strength, which remained highly significant (p < 0.0001). We conclude that there are substantial geographical differences in femoral neck geometry as well as in BMD. These geometric variations may contribute to the large variations in hip fracture risk across Europe. The effects of aging on hip strength need to be explored in longitudinal studies.

Falls explain between-center differences in the incidence of limb fracture across Europe.

There is important geographic variation in the occurrence of the major osteoporotic fractures across Europe. The aim of this study was to determine whether between-center variation in limb fracture rates across Europe could be explained by variation in the incidence of falls. Men and women, aged 50-79 years, were recruited from population-based registers in 30 European centers. Subjects were followed by postal questionnaire to ascertain the occurrence of incident fractures, and were also asked about the occurrence and number of recent falls. Self-reported fractures were confirmed, where possible, by review of the radiographs, medical record, or subject interview. The age- and gender-adjusted incidence of falls was calculated by center using Poisson regression. Poisson regression was also used to assess the extent to which between-center differences in the incidence of limb fractures could be explained by differences in the age- and gender-adjusted incidence of falls at those centers. In all, 6302 men (mean age 63.9 years) and 6761 women (mean age 63.1 years) completed at least one questionnaire concerning fractures and falls. During a median follow-up time of 3 years, 3647 falls were reported by men and 4783 by women. After adjusting for age and gender, there was evidence of significant between-center differences in the occurrence of falls. There was also between-center variation in the occurrence of upper limb, lower limb, and distal forearm fractures. Variation in the age- and gender-adjusted center-specific fall rates explained 24%, 14%, and 6% of the between-center variation in incidence of distal forearm and upper and lower limb fractures, respectively. Given the constraints inherent in such an analysis, in men and women aged 50-79 years, variation in fall rates could explain a significant proportion of the between-center variation in the incidence of limb fracture across Europe.

Reproducibility of a questionnaire on risk factors for osteoporosis in a multicentre prevalence survey: the European Vertebral Osteoporosis Study.

BACKGROUND: The European Vertebral Osteoporosis Study Group (EVOS) developed a questionnaire, back translated into 14 different European languages, for use in a multinational epidemiological study of vertebral osteoporosis. We investigated the reproducibility of this questionnaire in four of the participating study centres. METHODS: In all 151 men and women, aged 50-85 years, from Lubeck (Germany), Malmo (Sweden), Warsaw (Poland) and Oviedo (Northern Spain), were retested with the questionnaire on two occasions using a different observer within a 28-day period. RESULTS: Questions relating to personal or medical history were more reproducible than questions concerning subjective symptoms or aspects of lifestyle. The level of agreement for the non-ordinal categorical variables, as estimated by kappa, varied from 0.38 to 1.00 across the four centres. Agreement for the multicategory ordinal, mainly lifestyle, questions was in general poorer though improved when a weighted analysis was performed. For continuous data the 95% limits of agreement were narrow, and there was no evidence of bias between interviewers. There were no important differences in reproducibility across the four centres for either categorical or continuous data. CONCLUSION: The study indicates that the questionnaire may produce useful and comparable information concerning risk factors for osteoporosis across different countries and in different languages. It also highlights that questionnaire instruments designed for use in multinational population-based studies may provide data of comparable quality across a range of settings.

Is the predictive power of previous fractures for new spine and non-spine fractures associated with biochemical evidence of altered bone remodelling? The EPOS study. European Prospective Osteoporosis Study.

BACKGROUND: In the European Prospective Osteoporosis Study (EPOS), a past spine fracture increased risk of an incident fracture 3.6 - 12-fold even after adjusting for BMD. We examined the possibility that biochemical marker levels were associated with this unexplained BMD-independent element of fracture risk. METHODS: Each of 182 cases in EPOS of spine or non-spine fracture that occurred in 3.8 years of follow-up was matched by age, sex and study centre with two randomly assigned never-fractured controls and one case of past fracture. Analytes measured blind were: osteocalcin, bone-specific alkaline phosphatase, total alkaline phosphatase, serum creatinine, calcium, phosphate and albumin, together with the collagen cross-links degradation products serum CTS and urine CTX. Most subjects also had bone density measured by DXA. RESULTS: Cases who had recent fractures did not differ in marker levels from cases who had their last fracture more than 3 years previously. No statistically significant effect of recent fracture was found for any marker except osteocalcin, which was 17.6% lower in recent peripheral cases compared to unfractured controls (p<0.05) and this was independent of BMD. CONCLUSION: Past fracture as a risk indicator for future fracture is not strongly mediated through increased bone turnover.

Bone turnover rate in postmenopausal women: bimodal distribution?

There is considerable evidence that elevated bone turnover is an independent form of low bone mineral density (BMD) risk factor of osteoporotic fractures. The aim of our study was to test whether a group of postmenopausal women could be divided into subgroups of high and low bone turnover rate using different pairs of bone turnover markers (one resorption, one formation). Cluster analysis was used to obtain high and low bone turnover subgroups within the study group. A magnitude of difference in lumbar spine BMD (expressed as Z-score) between high- and low-turnover groups was used as a criterion of division success. According to this criterion, the division obtained with a urinary type I collagen crosslinked N-telopeptide/bone alkaline phosphatase pair of markers appeared to be the most significant. This method of separation of two subgroups was highly concordant with the division based on the upper thresholds of the normal values for those markers found for the premenopausal women. It seems that the observed existence of high-and low-turnover subject clusters is not an incidental phenomenon, because the effects obtained for the whole study group were further confirmed by the consistent results of cluster analysis, performed separately for two randomly selected subgroups (A and B) from the study group. The results obtained appear to support the view that bone turnover rate in postmenopausal women is distributed in the bimodal fashion. This finding seems to justify further investigations of more elaborated models, enabling clinicians to individually classify their patients as low- or high-turnover cases with higher efficiency, as in the case of cutoff values for single markers.

[Genetic factors in osteoporosis]. / Czynniki genetyczne w osteoporozie.

Osteoporosis is a widespread disease affecting more than 1/4th of the female and 1/10th of the male population. It is characterised by a low bone mass, which in turn leads to osteoporotic fractures. Bone mass can be described as bone mineral density (BMD). BMD in human population is subject to quite significant interpersonal variability, for 75 to 80% of which, the genetic factors are responsible. To investigate the dependence of BMD on genetic factors, a possible links between the BMD and the natural polymorphism of so called "candidate genes" are checked. The first candidate gene to be investigated was the gene coding for the receptor of the active form of vitamin D. A statistical linkage between the naturally occurring polymorphism of that gene and the BMD was found by many research centres. It was found that certain polymorphic variants of that gene are linked to higher BMD's than the other ones. This trend existed in different human races and various age groups in many countries including Poland. A batch of negative results which appeared in some papers can be explained either by high calcium consumption in the given population, or the existence of another gene affecting bone metabolism and closely coupled to the vitamin D receptor gene. Other investigated and promising genes are the genes coding for other receptors (e.g. oestrogen), regulatory proteins (e.g. IL-6) and structural proteins (e.g. type I collagen).

[Clinical diagnosis of osteoporosis]. / Diagnostyka kliniczna osteoporozy.

Osteoporosis (OP) is a systemic heterogenic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fractures. The fractures are the clinical consequences of the disease. Before fractures occur there is a long period without clinical significance characterised only by osteopenia. Both sexes lose bone mass during lifetime but after menopause women lose bone much faster and are more prone to fragility fractures. Wrist fractures (Colles fractures) occur in the earliest postmenopausal period in the fifth decade of a woman's life, and these fractures are 7 times more frequent in women than in men. Vertebral fractures occur 10-15 years after the menopause. Only 10-20% of these cases are hospitalized because of pain, and up to 80% of the cases are clinically symptomless. Kyphosis and loss of height come in later years. The most serious fractures are those of the hip. They usually occur over the age of 70 and bring 8-10% hospital mortality, about 20% mortality in the following year, and 50% disability over the age of 80. The diagnosis of primary OP requires the exclusion of all possible secondary causes of OP. In the diagnosis of OP a medical history with risk factor of OP is very important, as well as physical examination, and some laboratory tests. X-ray bone evaluation and the bone densitometric measurements are very important in confirming of osteopenia and osteoporosis.

[Difficulties in the interpretation of bone densitometric measurements]. / Trudnosci w interpretacji badania densytometrycznego.

In evaluation of the densitometric measurements the most popular presentation of results is a form of t-score or z-score values. T-score is a result of bone mineral density (BMD) in SD below a peak bone mass and z-score is a figure in SD below the values of BMD of healthy individuals of the same age and sex. Osteoporosis is diagnosed if t-score is more than -2.5 ranges from -1.0 to -2.5. Z-score has less value in diagnosis of osteoporosis. The value of different densitometric techniques depends on age of the subject and a past history of fractures. In subjects below 65 yrs the best technique is DEXA (dual energy X ray absorptiometry) and the spine is the site of measurement. In subjects above 65 yrs the best site to measure BMD is the hip. Previous fractures at the site of measurement (vertebral crush fractures), osteoarthritis, kyphosis, could change the values of BMD (overestimate them), and there is a need for a very careful and critical interpretation of BMD results.

Whom to treat? The contribution of vertebral X-rays to risk-based algorithms for fracture prediction. Results from the European Prospective Osteoporosis Study.

INTRODUCTION: Vertebral fracture is a strong risk factor for future spine and hip fractures; yet recent data suggest that only 5-20% of subjects with a spine fracture are identified in primary care. We aimed to develop easily applicable algorithms predicting a high risk of future spine fracture in men and women over 50 years of age. METHODS: Data was analysed from 5,561 men and women aged 50+ years participating in the European Prospective Osteoporosis Study (EPOS). Lateral thoracic and lumbar spine radiographs were taken at baseline and at an average of 3.8 years later. These were evaluated by an experienced radiologist. The risk of a new (incident) vertebral fracture was modelled as a function of age, number of prevalent vertebral fractures, height loss, sex and other fracture history reported by the subject, including limb fractures occurring between X-rays. Receiver Operating Characteristic (ROC) curves were used to compare the predictive ability of models. RESULTS: In a negative binomial regression model without baseline X-ray data, the risk of incident vertebral fracture significantly increased with age [RR 1.74, 95% CI (1.44, 2.10) per decade], height loss [1.08 (1.04, 1.12) per cm decrease], female sex [1.48 (1.05, 2.09)], and recalled fracture history; [1.65 (1.15, 2.38) to 3.03 (1.66, 5.54)] according to fracture site. Baseline radiological assessment of prevalent vertebral fracture significantly improved the areas subtended by ROC curves from 0.71 (0.67, 0.74) to 0.74 (0.70, 0.77) P=0.013 for predicting 1+ incident fracture; and from 0.74 (0.67, 0.81) to 0.83 (0.76, 0.90) P=0.001 for 2+ incident fractures. Age, sex and height loss remained independently predictive. The relative risk of a new vertebral fracture increased with the number of prevalent vertebral fractures present from 3.08 (2.10, 4.52) for 1 fracture to 9.36 (5.72, 15.32) for 3+. At a specificity of 90%, the model including X-ray data improved the sensitivity for predicting 2+ and 1+ incident fractures by 6 and 4 fold respectively compared with random guessing. At 75% specificity the improvements were 3.2 and 2.4 fold respectively. With the modelling restricted to the subjects who had BMD measurements (n=2,409), the AUC for predicting 1+ vs. 0 incident vertebral fractures improved from 0.72 (0.66, 0.79) to 0.76 (0.71, 0.82) upon adding femoral neck BMD (P=0.010). CONCLUSION: We conclude that for those with existing vertebral fractures, an accurately read spine X-ray will form a central component in future algorithms for targeting treatment, especially to the most vulnerable. The sensitivity of this approach to identifying vertebral fracture cases requiring anti-osteoporosis treatment, even when X-rays are ordered highly selectively, exceeds by a large margin the current standard of practice as recorded anywhere in the world.

[Agonists-antagonists of estrogens, their potential use in prophylaxis and treatment of osteoporosis]. / Agonisci-antagonisci estrogenów, ich potencjalne zastosowanie w profilaktyce i leczeniu osteoporozy.

A new group of drugs-oestrogen agonists-antagonists (tamoxifen and raloxifen) is discussed. In view of their potentially favourable effects on the bone and lipids and lacking unfavourable action on the uterus and mammary gland, after successful completion of clinical studies, these preparations may be possibly important for the prophylaxis and treatment of osteoporosis.