[The prevalence of osteoporosis and associated health care use in women 45 years and older in Germany. Results of the first German Telephone Health Survey 2003]

The prevalence of osteoporosis and associated factors were assessed among women 45 years and older as part of the first nationwide German Telephone Health Survey (GSTel03). A total of 14.2% of women reported that a doctor had ever diagnosed them with osteoporosis. Among these about, 15% also reported a physician-diagnosed fragility fracture, the fracture question was restricted to the subgroup of women with osteoporosis. Point estimates of overall osteoporosis prevalence increased significantly across 10-year age bands from 4% in the lowest to 30% in the highest age group. There was no significant association of osteoporosis with socioeconomic status or residence in former East vs West Germany; however, osteoporosis was significantly overrepresented among women with a migration background in comparison to women born in Germany (age-adjusted odds ratio: 1.68; 95% CI: 1.07-2.63). In age-adjusted logistic regression models, osteoporosis was significantly related to physician-diagnosed arthritis or rheumatoid arthritis, significant stature loss (>5 cm) compared to height at age 25 years, postmenopausal hormone therapy, lower ratings of subjective health as well as increased utilization of health care services. No significant association was observed with body mass index computed from self-reported height and weight. In conclusion, despite methodological limitations, these population-based, representative data support the observation that osteoporosis is a prevalent and serious health problem among older women and reflect the considerable variability with regard to diagnosis and management of this condition. Studies evaluating quality of care as well as monitoring of disease endpoints and risk factors based on representative samples of the population are needed.

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.

Participation in a quality of care study and consequences for generalizability of general practice research

BACKGROUND

Non-participation of General Practitioners (GPs) hampers primary care research. Using existing network structures can improve participation, but may introduce sampling effects.

OBJECTIVES

To examine the role of network-based recruitment and other determinants of participation, and to estimate effects of sampling and non-participation on generalizability.

METHODS

For a study of quality of care assessment, we recruited GPs from a regionally defined population and a GP network. Effects of sampling and non-participation were analysed by comparing characteristics between participants, target samples, and reference data for all German GPs. Factors influencing study participation were assessed in multiple logistic regression.

RESULTS

Compared to the regional sample, network GPs were more likely to complete survey questionnaires (92% versus 69%) and to participate in the study (66% versus 23%). Compared to national reference data, study participants from both populations were younger, had a higher level of professional training, and included more men. These differences were already present in the network target sample, but were largely attributable to selective participation in the regional sample. Network membership remained the strongest determinant of participation in multiple logistic regression (odds ratio 5.01; 95% confidence interval 2.53-9.91). A younger age, higher professional training, and membership in the German Society of General Practice were also predictive of participation.

CONCLUSIONS

Although network-based recruitment of GPs increases participation rates, sample effects are similar in size and direction as effects of non-participation in the regionally defined population. Careful analysis of participants based on publicly available data is therefore crucial for the assessment of generalizability.

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.

[Documentation of electronic patient records (EPRS) in German general practices: a telephone survey]

In Germany, use and contents of EPRs are largely unknown and expected to be highly variable, due to missing standards. We conducted a telephone survey to describe and compare computer documentation habits in general practices. Specifically, we were interested in: (1) the type of medical data recorded; and (2) which factors influence the extent to which doctors used the EPR while seeing their patients. The sampling frame consisted of family physicians participating in a general practice research project: 32% (145/452) of family physicians in the district of Göttingen, Lower Saxony, and 63% (52/83) of physicians from a quality assurance network of family practices in the district of Freiburg, Baden-Württemberg. With the exception of two practices in Göttingen, all practices (n = 165 of 167) took part in this survey. Diagnoses, digital codes for service fees, and prescriptions were computerized in nearly all practices, although doctors were significantly more involved in Freiburg than in Göttingen. Clinical symptoms and findings were recorded in 80% of Freiburg and 52% of Göttingen practices (p = 0.008). Overall, in 74% of Freiburg and 51% of Göttingen practices, the physicians opened the EPR while seeing patients (p = 0.022). Nearly half of the Göttingen practices (49%) and 24% of the Freiburg practices (p < 0.05) entered digital codes for service fees and diagnoses on paper before entering them electronically. In multivariate models adjusting for sex, target group and training specialty, internet access in the office was independently predictive of 'EPR-activity' (OR: 2.23; 95%-confidence interval: 1.12-4.43). There seems to be room for improvement in terms of degree and intensity of recording of clinically-relevant data. Technical interest, i.e., internet access in the office, seems to enhance electronic documentation activities.

Back pain, disability, and radiographic vertebral fracture in European women: a prospective study

Vertebral fractures are associated with back pain and disability. There are, however, few prospective data looking at back pain and disability following identification of radiographic vertebral fracture. The aim of this analysis was to determine the impact of radiographically identified vertebral fracture on the subsequent occurrence of back pain and disability. Women aged 50 years and over were recruited from population registers in 18 European centers for participation in the European Prospective Osteoporosis Study. Participants completed an interviewer-administered questionnaire which included questions about back pain in the past year and various activities of daily living, and they had lateral spine radiographs performed. Participants in these centers were followed prospectively and had repeat spine radiographs performed a mean of 3.7 years later. In addition they completed a questionnaire with the same baseline questions concerning back pain and activities of daily living. The presence of prevalent and incident vertebral fracture was defined using established morphometric criteria. The data were analyzed using logistic regression with back pain or disability (present or absent) at follow-up as the outcome variable with adjustment made for the baseline value of the variable. The study included 2,260 women, mean age 62.2 years. The mean time between baseline and follow-up survey was 5.0 years. Two hundred and forty participants had prevalent fractures at the baseline survey, and 85 developed incident fractures during follow-up. After adjustment for age, center, and the baseline level of disability, compared with those without baseline prevalent fracture, those with a prevalent fracture (odds ratio [OR] = 1.4; 95% confidence interval [CI] 1.0 to 2.0) or an incident fracture (OR = 1.7; 95% CI, 0.9 to 3.2) were more likely to report disability at follow-up, though the confidence intervals embraced unity. Those with both a prevalent and incident fracture, however, were significantly more likely to report disability at follow-up (OR = 3.1; 95% CI, 1.4 to 7.0). After adjustment for age, center, and frequency of back pain at baseline, compared with those without baseline vertebral fracture, those with a prevalent fracture were no more likely to report back pain at follow-up (OR = 1.2; 95% CI, 0.8 to 1.7). There was a small increased risk among those with a preexisting fracture who had sustained an incident fracture during follow-up (OR = 1.6; 95% CI, 0.6 to 4.1) though the confidence intervals embraced unity. In conclusion, although there was no significant increase in the level of back pain an average of 5 years following identification of radiographic vertebral fracture, women who suffered a further fracture during follow-up experienced substantial levels of disability with impairment in key physical functions of independent living.

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)

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.

[Medical care research based on family doctor routine data--are interface-communicated treatment data feasible?]

AIMS OF THE STUDY

As part of an ongoing project on the utilisation of generic drugs in general practice we aimed at determining whether the transfer of prescriptions and patient characteristics from doctors' computerized medical records via the BDT (Behandlungsdatenträger) interface was feasible, and whether these data are suitable for research in pharmacoepidemiology.

METHODS

All 1,395 general practitioners from 6 regions in Germany were invited to participate in the 'generics project'; 232 (17 %) agreed. The 17 software companies whose systems were used by the participating practices were asked to grant access to the BDT interface. For a prescription survey, doctors were supposed to export BDT files from two 3-month periods each in 2000 and 2001. Data were anonymised and relevant information extracted with a special programme.

RESULTS

So far, BDT data are available from 79 practices. They are suitable for practice- and patient-related prescribing analyses. By filter modifications, additional information (such as diagnoses, referrals, clinical findings or accounting codes) can be obtained. The procedure was well accepted if doctors and practice staff were assisted by computer experts. Some difficulties, however, were encountered in obtaining access to the BDT-interface from the software companies. Lack of standardisation of the BDT interface required additional conditioning of the data.

CONCLUSION

The BDT interface offers an opportunity to export computerised patient records without the requirement of additional documentation. If routine data are more readily available for health services research, a standardised data structure and open access must be assured e. g. by centralised certification via the Federal statutory health organisation.

Determinants of incident vertebral fracture in men and women: results from the European Prospective Osteoporosis Study (EPOS)

The aim of this analysis was to determine the influence of lifestyle, anthropometric and reproductive factors on the subsequent risk of incident vertebral fracture in men and women aged 50-79 years. Subjects were recruited from population registers from 28 centers across Europe. At baseline, they completed an interviewer-administered questionnaire and had lateral thoraco-lumbar spine radiographs performed. Repeat spinal radiographs were performed a mean of 3.8 years later. Incident vertebral fractures were defined morphometrically and also qualitatively by an experienced radiologist. Poisson regression was used to determine the influence of the baseline risk factor variables on the occurrence of incident vertebral fracture. A total of 3173 men (mean age 63.1 years) and 3402 women (mean age 62.2 years) contributed data to the analysis. In total there were 193 incident morphometric and 224 qualitative fractures. In women, an age at menarche 16 years or older was associated with an increased risk of vertebral fracture (RR = 1.80; 95%CI 1.24, 2.63), whilst use of hormonal replacement was protective (RR = 0.58; 95%CI 0.34, 0.99). None of the lifestyle factors studied including smoking, alcohol intake, physical activity or milk consumption showed any consistent associations with incident vertebral fracture. In men and women, increasing body weight and body mass index were associated with a reduced risk of vertebral fracture though, apart from body mass index in men, the confidence intervals embraced unity. For most variables the strengths of the associations observed were similar using the qualitative and morphometric approaches to fracture definition. In conclusion our data suggest that modification of other lifestyle risk factors is unlikely to have a major impact on the population occurrence of vertebral fractures. The important biological mechanisms underlying vertebral fracture risk need to be explored using new investigational strategies.

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.

Incidence of limb fracture across Europe: results from the European Prospective Osteoporosis Study (EPOS)

The aim of this population-based prospective study was to determine the incidence of limb fracture by site and gender in different regions of Europe. Men and women aged 50-79 years were recruited from population registers in 31 European centers. Subjects were invited to attend for an interviewer-administered questionnaire and lateral spinal radiographs. Subjects were subsequently followed up using an annual postal questionnaire which included questions concerning the occurrence of new fractures. Self-reported fractures were confirmed where possible by radiograph, attending physician or subject interview. There were 6451 men and 6936 women followed for a median of 3.0 years. During this time there were 140 incident limb fractures in men and 391 in women. The age-adjusted incidence of any limb fracture was 7.3/1000 person-years [pyrs] in men and 19 per 1000 pyrs in women, equivalent to a 2.5 times excess in women. Among women, the incidence of hip, humerus and distal forearm fracture, though not 'other' limb fracture, increased with age, while in men only the incidence of hip and humerus fracture increased with age. Among women, there was evidence of significant variation in the occurrence of hip, distal forearm and humerus fractures across Europe, with incidence rates higher in Scandinavia than in other European regions, though for distal forearm fracture the incidence in east Europe was similar to that observed in Scandinavia. Among men, there was no evidence of significant geographic variation in the occurrence of these fractures. This is the first large population-based study to characterize the incidence of limb fracture in men and women over 50 years of age across Europe. There are substantial differences in the descriptive epidemiology of limb fracture by region and gender.

Association of transforming growth factor-beta1 (TGFbeta1) T29 --> C gene polymorphism with bone mineral density (BMD), changes in BMD, and serum concentrations of TGF-beta1 in a population-based sample of postmenopausal german women

TGF-beta1 is thought to play an important role in bone turnover. Thus, the gene encoding TGF-beta1 is a prime candidate for the genetic regulation of bone density. Recent studies have suggested that a T29 --> C polymorphism in the signal sequence region of the TGF-beta1 gene may be related to bone mineral density (BMD) and bone loss in postmenopausal Japanese women. In the present study, we examined the relationship between this polymorphism and BMD in a population-based sample of 102 estrogen-deficient postmenopausal women from the Heidelberg cohort of the European Vertebral Osteoporosis Study (EVOS). Average BMD in women with the TT genotype was approximately 10% higher at both the lumbar spine and the femoral neck compared with women with the CC genotype (spine: 980 vs. 887 mg/cm2, P = 0.05; femoral neck: 755 vs. 674 mg/cm2; P = 0.02). Women with the TT genotype also experienced less overall bone loss at the total hip, compared with women with the CC genotype. Serum levels of TGF-beta1 were higher in women with the TT genotype than in those with the CC genotype (46.5 ng/ml vs. 32.3 ng/ml, P = 0.001). These data are clearly in contrast to findings in postmenopausal Japanese women where the CC genotype was associated with higher BMD and decreased bone loss. Further studies are therefore necessary to clarify the relationship between this polymorphism and BMD.

Low serum concentrations of insulin-like growth factor I are associated with femoral bone loss in a population-based sample of postmenopausal women

OBJECTIVE

Cross-sectional studies suggest that the decline in insulin-like growth factor-I (IGF-1) levels with age may contribute to age-associated bone loss. However, prospective data on the relation between circulating IGF-I and bone loss in old age have not yet been reported.

DESIGN

A longitudinal study (follow-up time 3.3 years) of the change of bone mineral density (BMD) at the lumbar spine and femoral neck in relation to serum IGF-I.

PATIENTS

A population-based sample of 173 elderly men and 107 postmenopausal women without medical conditions or medication known to significantly affect BMD or serum IGF-I levels.

MEASUREMENTS

BMD at the lumbar spine and femoral neck at baseline and after a mean follow-up-time of 3.3 years, serum-IGF-I, insulin-like growth factor binding protein 3 (IGFBP-3), sex hormone-binding globulin (SHBG) and biologically available testosterone (BAT).

RESULTS

In women, there was a graded negative relationship between quartiles of serum IGF-I and bone loss at the proximal femur (P = 0.04), which persisted after adjustment for potential covariables of bone loss and serum IGF-I. In subgroup analysis the association between serum IGF-I and change in BMD was only apparent in women more than 10 years past menopause (r = + 0,38, P = 0.01). No association between serum IGF-I levels and changes in BMD was observed in men. IGF-I levels were not associated with changes in spinal BMD.

CONCLUSIONS

Our data suggest that low circulating levels of IGF-I in elderly women are associated with greater femoral bone loss, and support previous findings of gender differences in the relation between serum IGF-I and BMD in older age.

Serum interleukin 6 is a major predictor of bone loss in women specific to the first decade past menopause

The role of serum interleukin 6 (IL-6) as a predictor of bone loss was examined in a population-based, longitudinal study of 137 postmenopausal German women, 52-80 yr old at baseline. Serum IL-6 and other biochemical parameters were measured in baseline blood or urine specimens. Repeat standardized measures of bone mineral density (BMD) at the femur (total hip) and the lumbar spine (L2-L4) were taken by dual x-ray absorptiometry an average of 3.3 yr apart. Medical history and anthropometric measures were obtained from standardized interview and examination. Crude and age-adjusted mean serum IL-6 levels were significantly lower in postmenopausal women with than without hormone replacement therapy at baseline. Among nonusers of hormone replacement therapy, serum IL-6 concentrations were highly predictive of femoral bone loss, independently of potential confounders and plasma sex hormones. Statistical interaction between serum IL-6 and menopausal age or menopausal age group (>10 vs. < or =10 yr) indicated that the effect of IL-6 on bone loss weakened with increasing distance from menopause and was no longer significant in women more than 10 yr after menopause. Among women up to 10 yr past menopause (n = 39), serum IL-6 was the single most important predictor of femoral bone loss, accounting for up to 34% of the total variability of change in BMD. The unadjusted linear model predicted an annual 1.34% (95% confidence interval, 0.67-2.01) decrease in total hip BMD per log unit increase in serum IL-6. A similar, although nonsignificant, effect of serum IL-6 on vertebral bone loss was restricted to women within the first 6 yr after menopause (n = 18). These epidemiological data show that serum IL-6 is a predictor of postmenopausal bone loss, and that the effect appears to be most relevant through the first postmenopausal decade. Whether these findings reflect pathogenetic differences between early and postmenopausal bone loss, and whether serum IL-6 also predicts fracture risk need further elucidation.

Prevalent vertebral deformity predicts incident hip though not distal forearm fracture: results from the European Prospective Osteoporosis Study

The presence of a vertebral deformity increases the risk of subsequent spinal deformities. The aim of this analysis was to determine whether the presence of vertebral deformity predicts incident hip and other limb fractures. Six thousand three hundred and forty-four men and 6788 women aged 50 years and over were recruited from population registers in 31 European centers and followed prospectively for a median of 3 years. All subjects had radiographs performed at baseline and the presence of vertebral deformity was assessed using established morphometric methods. Incident limb fractures which occurred during the follow- up period were ascertained by annual postal questionnaire and confirmed by radiographs, review of medical records and personal interview. During a total of 40348 person-years of follow-up, 138 men and 391 women sustained a limb fracture. Amongst the women, after adjustment for age, prevalent vertebral deformity was a strong predictor of incident hip fracture, (rate ratio (RR) = 4.5; 95% CI 2.1-9.4) and a weak predictor of 'other' limb fractures (RR = 1.6; 95% CI 1.1-2.4), though not distal forearm fracture (RR = 1.0; 95% CI 0.6-1.6). The predictive risk increased with increasing number of prevalent deformities, particularly for subsequent hip fracture: for two or more deformities, RR = 7.2 (95% CI 3.0-17.3). Amongst men, vertebral deformity was not associated with an increased risk of incident limb fracture though there was a nonsignificant trend toward an increased risk of hip fracture with increasing number of deformities. In summary, prevalent radiographic vertebral deformities in women are a strong predictor of hip fracture, and to a lesser extent humerus and 'other' limb fractures; however, they do not predict distal forearm fractures.

The effects of lifestyle, dietary dairy intake and diabetes on bone density and vertebral deformity prevalence: the EVOS study

The risk of low and moderate energy fracture is related to bone mineral density (BMD). Yet it is uncertain whether the epidemiologic determinants of fracture risk are the same as for low bone density. The European Vertebral Osteoporosis Study was a population-based prevalence study of vertebral deformity in 36 age-stratified population samples aged 50-80 years. In nearly 4000 subjects (13 centers), BMD measurements were also made at the spine, femoral neck and femoral trochanter. To investigate whether effects of reported physical activity on spine deformity risk were mediated through BMD, we modeled these and other risk factor data with BMD as the dependent variate after adjusting for age, center, sex and body mass index (BMI). The significant determinants of vertebral deformity risk were also entered into logistic models of deformity risk that included BMD measurements as covariates. Both current and lifetime physical activity were positively associated with BMD. This effect was stronger with hip BMD than with spine BMD. Lifetime smoking exposure was associated with reduced BMD. Type 2 diabetes mellitus was associated with increased BMD. Weak positive associations were found between consumption of dairy products and BMD at the three measured sites and these were strengthened by an interaction with measures of physical activity in men. Physical activity in women had the largest beneficial effect in lean women and in women exposed to hormone replacement therapy. When fracture risk was modeled with BMD as a covariate, the lifestyle and dietary determinants became less strongly related to vertebral deformity risk, suggesting that BMD may have acted as an intermediary variable. However, heavy physical activity in men still increased spine deformity risk after adjusting for BMD. It is concluded that physical activity in both genders and milk consumption in young women might protect against vertebral deformities in later life through their effects on bone density. The adverse effect of smoking on BMD was confirmed. Heavy physical activity in men might increase spine deformity risk even when BMD is normal.

Sex difference in the validity of vertebral deformities as an index of prevalent vertebral osteoporotic fractures: a population survey of older men and women

Morphometric methods have been developed for standardized assessment of vertebral deformities in clinical and epidemiologic studies of spinal osteoporosis. However, vertebral deformity may be caused by a variety of other conditions. To examine the validity of morphometrically assessed vertebral deformities as an index of osteoporotic vertebral fractures, we developed an algorithm for radiological differential classification (RDC) based on a combination of quantitative and qualitative assessment of lateral spinal radiographs. Radiographs were obtained in a population of 50- to 80-year-old German women (n = 283) and men (n = 297) surveyed in the context of the European Vertebral Osteoporosis Study (EVOS). Morphometric methods (Eastell 3 SD and 4 SD criteria, McCloskey) were validated against RDC and against bone mineral density (BMD) at the femur and the lumbar spine. According to RDC 36 persons (6.2%) had at least one osteoporotic vertebral fracture; among 516 (88.9%) nonosteoporotics 154 had severe spondylosis, 132 had other spinal disease and 219 had normal findings; 14 persons (2.4%) could not be unequivocally classified. The prevalence of morphometrically assessed vertebral deformities ranged from 7.3% to 19.2% in women and from 3.5% to 16.6% in men, depending on the stringency of the morphometric criteria. The agreement between RDC and morphometric methods was poor. In men, 62-86% of cases with vertebral deformities were classified as nonosteoporotic (severe spondylosis or other spinal disease) by RDC, compared with 31-68% in women. Among these, most had wedge deformities of the thoracic spine. On the other hand, up to 80% of osteoporotic vertebral fractures in men and up to 48% in women were missed by morphometry, in particular endplate fractures at the lumbar spine. In the group with osteoporotic vertebral fractures by RDC the proportion of persons with osteoporosis according to the WHO criteria (T-score < -2.5 SD) was 90.0% in women and 86.6% in men, compared with 67.9-85.0% in women and 20.8-50.0% in men with vertebral deformities by various methods. Although vertebral deformities by most definitions were significantly and inversely related to BMD as a continuous variable in both sexes [OR; 95% CI ranged between (1.70; 1.07-2.70) and (3.69; 1.33-10.25)], a much stronger association existed between BMD and osteoporotic fractures defined by RDC [OR; 95% CI between (4.85; 2.30-10.24) and (15.40; 4.65-51.02)]. In the nonosteoporotic group individuals with severe spondylosis had significantly higher BMD values at the femoral neck (p < 0.01) and lumbar spine (p < 0.0004) compared with the normal group. On the basis of internal (RDC) and external (BMD) validation, we conclude that assessment of vertebral osteoporotic fracture by quantitative methods alone will result in considerable misclassification, especially in men. Criteria for differential diagnosis as used within RDC can be helpful for a standardized subclassification of vertebral deformities in studies of spinal osteoporosis.

Effects of menstrual history and use of medications on bone mineral density: the EVOS Study

We have previously shown considerable between-center variation in bone mineral density (BMD) in the 13 EVOS centers that performed bone densitometry on their sex- and age-stratified population samples, after adjusting for weight and age. We have now investigated whether part of the between-center variability may be attributed to between-center variations in the use of medications. Information was collected from 2088 women and 1908 men at baseline on whether the subjects had ever been prescribed calcium, calcitonin, anabolic steroids, fluoride, vitamin D, or glucocorticoids and, for the women, whether they had ever used the oral contraceptive pill (OCP) or hormone replacement therapy (HRT). Each of these variables was fitted into a regression model adjusted for age, height, weight, and center. Only OCP and HRT significantly affected BMD. Those who had ever used OCPs had spinal BMD 0.029 g/cm2 greater than those who had never used them. Users of HRT had higher BMD than nonusers: 0. 037 g/cm2 at the spine, 0.018 g/cm2 at the trochanter, and 0.018 g/cm2 at the femoral neck. As expected, there was a great variation between centers in the use of OCP and HRT, but there were no significant correlations between mean BMD at any site in a given center and the prevalence of OCP or HRT use in that center. The between-center variance in BMD at all three sites remained highly significant after adjusting for treatment (P < 0.001). We conclude that HRT and OCP use are associated with moderate increases in BMD. The geographical variability of BMD in Europe was not explained by treatment with pharmaceuticals.

[Epidemiology of osteoporosis]

Epidemiological studies have identified osteoporosis as a disease of significant public health impact and have delineated numerous potential risk factors. Nevertheless, it has proven difficult to establish preventive strategies for several reasons. First, there has been no final agreement on the definition of osteoporosis, which has hampered efforts to characterize the magnitude of the problem as a whole. Secondly, as osteoporosis is a multifactorial chronic disorder, effective programs for risk assessment and intervention depend on the development of complex disease models. In summarizing the contributions of epidemiological studies to the current understanding of osteoporosis this review intends to outline the scientific background for the European Vertebral Osteoporosis Study (EVOS) and its successors.