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D M Reid

Publications and source records attributed to D M Reid.

At least 37 records · Page 2Linked to original sources

Health-related quality of life and radiographic vertebral fracture.

BACKGROUND: Vertebral fractures are associated with back pain and disability; however, relatively little is known about the impact of radiographic vertebral fractures on quality of life in population samples. The aim of this study was to determine the impact of a recent radiographic vertebral fracture on health-related quality of life (HRQoL). METHODS: Men and women aged 50 years and over were recruited from population registers in 12 European centers. Subjects completed an interviewer-administered questionnaire and had lateral spine radiographs performed. Subjects in these centers were followed prospectively and had repeat spinal radiographs performed a mean of 3.8 years later. Prevalent deformities were defined using established morphometric criteria, and incident vertebral fractures by both morphometric criteria and qualitative assessment. For each incident fracture case, three controls matched for age, gender, and center were selected: one with a prevalent deformity (at baseline) and two without prevalent deformities. All subjects were interviewed or completed a postal questionnaire instrument which included Short Form 12 (SF-12), the EQ-5D (former EuroQol), and the quality of life questionnaire of the International Osteoporosis Foundation (QUALEFFO). The median time from the second spinal radiograph until the quality of life survey was 1.9 years. Comparison between cases and their matched controls was undertaken using the signed rank test. RESULTS: 73 subjects with incident vertebral fracture (cases), mean age 64.8 years (of whom 23 had a baseline deformity), and 196 controls, mean age 63.9 years (of whom 60 had a baseline deformity), were studied. There were strong correlations between the domain scores for each of the three instruments. There was no statistically significant difference in any of the domain scores between cases and those controls with a prevalent deformity. However, compared with the controls without a prevalent deformity the cases had significantly impaired quality of life as determined using the total QUALEFFO score (38.2 vs 33.7), the physical component score of the SF-12 (39.9 vs 43.7) and the health status score of the EQ-5D (62.3 vs 69.9). When the analysis was repeated after stratification of the cases by baseline deformity status (i.e., cases with and without a prevalent deformity at baseline), cases with a prevalent deformity had impaired quality of life compared with their matched controls, both with and without a prevalent deformity. In contrast there was no significant difference in quality of life among the cases without a prevalent deformity and either control group. CONCLUSIONS: In this population-based study a recent vertebral fracture was associated with impairment in quality of life, though this was mainly among those who had sustained a previous vertebral deformity.

Aged↗

A method for assessment of the shape of the proximal femur and its relationship to osteoporotic hip fracture.

The shape of the proximal femur has been demonstrated to be important in the occurrence of fractures of the femoral neck. Unfortunately, multiple geometric measurements frequently used to describe this shape are highly correlated. A new method, active shape modeling (ASM) has been developed to quantify the morphology of the femur. This describes the shape in terms of orthogonal modes of variation that, consequently, are all independent. To test this method, digitized standard pelvic radiographs were obtained from 26 women who had suffered a hip fracture and compared with images from 24 age-matched controls with no fracture. All subjects also had their bone mineral density (BMD) measured at five sites using dual-energy X-ray absorptiometry. An ASM was developed and principal components analysis used to identify the modes which best described the shape. Discriminant analysis was used to determine which variable, or combination of variables, was best able to discriminate between the groups. ASM alone correctly identified 74% of the individuals and placed them in the appropriate group. Only one of the BMD values (Ward's triangle) achieved a higher value (82%). A combination of Ward's triangle BMD and ASM improved the accuracy to 90%. Geometric variables used in this study were weaker, correctly classifying less than 60% of the study group. Logistic regression showed that after adjustment for age, body mass index, and BMD, the ASM data was still independently associated with hip fracture (odds ratio (OR)=1.83, 95% confidence interval 1.08 to 3.11). The odds ratio was calculated relative to a 10% increase in the probability of belonging to the fracture group. Though these initial results were obtained from a limited data set, this study shows that ASM may be a powerful method to help identify individuals at risk of a hip fracture in the future.

Aged↗

Association between a polymorphism affecting an AP1 binding site in the promoter of the TCIRG1 gene and bone mass in women.

The TCIRG1 gene encodes a component of the osteoclast vacuolar proton pump and previous work has shown that inactivating mutations of the TCIRG1 cause autosomal recessive osteopetrosis. In order to determine whether allelic variation in TCIRG1 contributes to the regulation of bone mineral density (BMD) in normal individuals, we studied the relationship between polymorphisms of TCIRG1 and BMD in a population-based cohort of 739 perimenopausal women. Five common polymorphisms were identified: two in the promoter, a conservative change within exon 4, one within intron 4 and one within intron 11. One of the promoter polymorphisms (G-1102A) lay within a consensus recognition site for the AP1 transcription factor. There was a significant association between the G-1102A genotype and BMD at the lumbar spine ( P = 0.01) and femoral neck ( P = 0.03). The association remained significant after correcting for age, weight, height, menopausal status/HRT use and smoking ( P = 0.008 for spine BMD and P = 0.03 for hip BMD), and homozygotes for the -1100 "G" allele had BMD values significantly higher than individuals who carried the -1100 "A" allele at both spine ( P = 0.007) and hip ( P = 0.047). Subgroup analysis showed that the association between G-1102A and BMD was restricted to premenopausal women who comprised 50.6% of the study group. None of the other polymorphisms or haplotypes were significantly associated with BMD in the study group as a whole or in any subgroup. Functional studies will need to be performed to determine the mechanisms that underlie this association, but we conclude that, in this relatively large population, allelic variation at the G-1102A site of TCIRG1 accounts for part of the heritable component of BMD in Scottish women, possibly by affecting peak bone mass.

Alleles↗

Bone density threshold and other predictors of vertebral fracture in patients receiving oral glucocorticoid therapy.

OBJECTIVE: To evaluate predictors of vertebral fractures, including a threshold for bone mineral density (BMD), in patients receiving oral glucocorticoids (GCs). METHODS: Data were obtained from 2 randomized clinical trials (prevention and treatment trials of risedronate) using similar methods, but different inclusion criteria were applied with regard to prior exposure to GCs. Predictors of vertebral fracture in the placebo group were identified using Cox regression with forward selection. The BMD threshold analysis involved a comparison of the 1-year fracture risk in postmenopausal women receiving placebo in the GC trials with that in postmenopausal women not taking GCs in 3 other trials. RESULTS: The study population comprised 306 patients with baseline and 1-year followup data on vertebral fractures (111 receiving placebo and 195 receiving risedronate). In the placebo group, the statistically significant predictors of incident fracture were the baseline lumbar spine BMD (for each 1-point decrease in T score, relative risk [RR] 1.85, 95% confidence interval [95% CI] 1.06-3.21) and the daily GC dose (for each 10-mg dose increase, RR 1.62, 95% CI 1.11-2.36). In the BMD threshold analysis, compared with nonusers of GCs, patients receiving GCs were younger, had a higher BMD at baseline, and had fewer prevalent fractures; nevertheless, the risk of fracture was higher in the GC users compared with nonusers (adjusted RR 5.67, 95% CI 2.57-12.54). The increased risk of fracture was observed in GC users regardless of whether osteoporosis was present. CONCLUSION: The daily, but not cumulative, GC dose was found to be a strong predictor of vertebral fracture in patients receiving GCs. At similar levels of BMD, postmenopausal women taking GCs, as compared with nonusers of GCs, had considerably higher risks of fracture.

Absorptiometry, Photon↗

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.

Age Distribution↗

Longitudinal changes in weight in perimenopausal and early postmenopausal women: effects of dietary energy intake, energy expenditure, dietary calcium intake and hormone replacement therapy.

OBJECTIVE: To investigate whether energy intake or energy expenditure affects 5-7 y weight gain in perimenopausal and early postmenopausal women, and whether hormone replacement therapy (HRT) use or dietary calcium (Ca) intake are contributory factors. DESIGN: Longitudinal, observational study of healthy women around the menopause. SUBJECTS: A total of 1064 initially premenopausal women, selected from a random population of 5119 women aged 45-54 y at baseline. In all, 907 women (85.2%) returned 6.3+/-0.6 y later for repeat measurements. Of these, 36% were postmenopausal (no HRT) and 45% had taken HRT, and 898 women completed the questionnaires. MEASUREMENTS: Weight, height, estimation of energy intake by food frequency questionnaire and physical activity level (PAL) by questionnaire. RESULTS: Change in PAL influenced weight change explaining 4.4% (P=0.001) of the variation. Alterations in dietary energy intake also had a small but significant effect (0.6% P=0.013). Dietary Ca intake had no effect on weight or weight change. CONCLUSION: Mean weight had increased and was influenced more by reduced energy expenditure rather than increased energy intake. HRT and dietary Ca intake did not influence weight gain.

Calcium, Dietary↗

Effect of pregnancy on bone mineral density and biochemical markers of bone turnover in a patient with juvenile idiopathic osteoporosis.

Juvenile idiopathic osteoporosis (JIO) is rare, presenting with vertebral fractures in the immediate prepubertal years; however, recovery is normally observed. We report the case of a 19-year-old pregnant woman previously diagnosed with JIO. She experienced three vertebral fractures in the third trimester of pregnancy. She delivered by caesarean section at 38 weeks gestation. Spinal bone mineral density decreased by 25%, hip bone mineral density by 10%, and forearm bone mineral density by 3% during pregnancy. Bone resorption markers, free pyridinoline and deoxypyridinoline (fPYD and fDPD), were elevated at baseline and markedly increased during pregnancy (fPYD/fDPD at 0, 10, 15, 20, and 28 weeks and immediately postpartum: 36.2/11.5, 52.9/15.8, 54.3/13.3, 51.1/13.3, 90/21.8, and 95.6/22.7 nmol/mmol creatinine, respectively) The bone formation marker, bone-specific alkaline phosphatase (BSAP), was within the reference range at baseline and increased in the third trimester. (BSAP at 0, 10, 15, 20, and 28 weeks and immediately postpartum: 20.5, 18.3, 17.7, 19.8, 26.9, and 30.0 U/liter, respectively). Parathyroid hormone (PTH) was measured by two methods to assess the possible effect of PTH fragments. PTH(1-84) (Roche) showed little change during the pregnancy, whereas the Nichols assay [(1-84) and(7-84) PTH fragment], revealed increases paralleling the changes in bone resorption. This young woman's bone turnover showed an exaggerated response to pregnancy, with bone resorption predominating over formation. PTH fragments may have partially mediated this effect.

Adult↗

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.

Aged↗

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.

Age Distribution↗

Cost-effectiveness of hormone replacement therapy for fracture prevention in young postmenopausal women: an economic analysis based on a prospective cohort study.

A recent systematic review of randomized controlled trials has shown that hormone replacement therapy (HRT) prevents fractures when taken soon after the menopause. HRT for treatment of menopausal symptoms is relatively cost-effective, but whether its use for prevention of perimenopausal fractures is economically efficient is unknown. We undertook a 6-year follow-up of 3645 perimenopausal women who had a bone mineral density (BMD) measurement with recommendation to use HRT if low BMD was present. Data were collected on incident fractures and costs. After an average of 6.2 years of follow-up HRT use significantly reduced incident fractures by 52% (95% CI: 67% to 18%). However, costs were increased by an average of pounds sterling 275 (95% CI: pounds sterling 228 to pounds sterling 330) for the group as a whole; for hysterectomized women costs were increased less (pounds sterling 138), but this was still significantly greater than for non-HRT users (95% CI: pounds sterling 6 to pounds sterling 275). The cost per averted fracture was about pounds sterling 11 000 (95% CI: pounds sterling 8625 to pounds sterling 13 872) for the whole group and for hysterectomized women the corresponding figure was substantially less (pounds sterling 1784; 95% CI: pounds sterling 59 to pounds sterling 3532). HRT given to women at or shortly after the menopause is therefore associated with a halving of fracture incidence. Such a policy for hysterectomized women without menopausal symptoms may be cost-effective as such women are at elevated risk of fracture and need cheaper, unopposed, estrogens.

Bone Density↗

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.

Aged↗

Correcting calf girth discriminates the incidence of falling but not bone mass by broadband ultrasound attenuation in elderly female subjects.

Calf circumference has been cited as an independent risk factor for hip fracture. Correcting this measured girth for subcutaneous adipose tissue or fluid accumulation provides a more valid estimate of lean tissue, but has not been reported in elderly populations. Two hundred eighty-eight randomly selected female volunteers, aged >or=70 years, were assessed by quantitative ultrasound (QUS) and clinical risk factors as part of a larger screening study for hip fracture risk. This involved measuring broadband ultrasound attenuation (BUA) and administering a structured risk factor questionnaire that included estimated daily skeletal loading (time standing or walking). Body mass index (BMI) was estimated using current body mass and height at age 25 years. Calf girth was measured using a standard anthropometric tape, the medial calf skinfold (a vertical fold at the point of maximum calf girth) was measured, and corrected calf girth (CCG) was calculated by subtracting the skinfold (in centimeters) multiplied by pi from calf girth. Subjects were aged 76.9 +/- 5.0 years, had BMIs of 24.3 +/- 3.9 kg/m(2), and spent an average of 5.5 +/- 2.0 h on their feet each day. Age, current body mass, BMI calf girth, and CCG all correlated with BUA (p < 0.01). CCG correlated with hours on the feet (p < 0.05), whereas calf girth did not (p > 0.05). Dividing the sample into tertiles by these correlates of BUA and predicting BUA using stepwise regression revealed different predictors for each tertile. Of the total sample, 93 had fallen in the last 12 months, whereas 195 had not. Independent t-tests showed these groups to be similar in age, BMI, and calf girth (p > 0.05), but fallers spent less time on their feet each day, and had smaller CCG (p < 0.05). This suggests that larger calf muscles may be protective against falling-possibly as a result of enhanced stability or greater neuromuscular control.

Accidental Falls↗

Lack of association between the SOST gene and bone mineral density in perimenopausal women: analysis of five polymorphisms.

Osteoporosis is a common disease characterized by a decrease in bone mass, architectural deterioration of the bone tissue, and an increased risk of fracture. The condition is under strong genetic control, involving a large variety of gene products, but to date the genes responsible remain poorly defined. Although population-based studies have identified polymorphisms in several candidate genes that are associated with bone mineral density (BMD), these account for only a small proportion of the population variance in bone mass. In this study, we looked for evidence of an allelic association between polymorphisms in the SOST gene and BMD. This gene was analyzed because loss-of-function mutations in SOST cause sclerosteosis, a sclerosing bone dysplasia associated with increased bone mass due to increased bone formation. We identified 26 different polymorphisms in the SOST gene and selected 5 of these for association analysis in a case-control study of 619 women with either high or low BMD, drawn from a random population-based survey of 5119 perimenopausal white women. The high BMD group comprised 326 women in whom lumbar spine BMD values adjusted for age, height, and weight were in the highest 16% of the population distribution, and the low BMD group comprised 293 women in whom BMD values were in the lowest 16% of the population distribution. The distribution of genotypes and alleles for each Single Nucleotide Polymorphism (SNP) examined did not differ in the low and high BMD groups. We conclude that, in this population, common allelic variations in the SOST gene do not contribute significantly to the regulation of high or low BMD.

Adaptor Proteins, Signal Transducing↗

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.

Accidental Falls↗

Prevalence of osteoporotic bone mineral density at the hip in Britain differs substantially from the US over 50 years of age: implications for clinical densitometry.

The purpose of this study was to compare hip bone mineral density (BMD) recorded in seven population based cohorts in Britain with the third National Health and Nutrition Examination Survey (NHANES III) US population-based reference data, in order to assess geographic variation in the prevalence of osteoporosis. Men and women aged 50-80+ years were randomly recruited from population and health registers. Dual X-ray absorptiometry (DXA) equipment was used to measure BMD at the hip, with the femoral neck and the trochanter regions studied. Prevalences of osteopenia and osteoporosis were estimated in accordance with World Health Organisation diagnostic criteria for women. Young normal data, used to establish cut-off criteria, was from NHANES III. Both male and female British subjects over 50-years-old were found to have significantly higher mean BMD at the femoral neck and trochanter than their US counterparts. Decline in BMD with age in British men appeared slower than in US men. Between British centres there were also statistically significant differences in BMD values in both sexes. British age-adjusted prevalences of osteopenia in women averaged 20% less than those of NHANES III, whereas the prevalence of osteoporosis was substantially lower in British subjects of both sexes (55% in women, 68% in men). Thus, applying the US NHANES III data as the referent, osteoporosis of the proximal femur in Britain appears to be less common than in the US, due primarily to differences in the lower tails of the BMD distributions. Providing that the relationship between fracture rates and BMD is the same in Britain and the US, it would still be appropriate to apply the reference data in fracture risk assessment in the UK.

Absorptiometry, Photon↗

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.

Age Distribution↗

Activation of the inducible nitric oxide synthase pathway contributes to inflammation-induced osteoporosis by suppressing bone formation and causing osteoblast apoptosis.

OBJECTIVE: Osteoporosis is a major clinical problem in chronic inflammatory diseases such as rheumatoid arthritis. The mechanism of bone loss in this condition remains unclear, but previous studies have indicated that depressed bone formation plays a causal role. Since cytokine-induced nitric oxide (NO) production has been shown to inhibit osteoblast growth and differentiation in vitro, this study was undertaken to investigate the role of the inducible NO synthase (iNOS) pathway in the pathogenesis of inflammation-mediated osteoporosis (IMO) by studying mice with targeted inactivation of the iNOS gene (iNOS knockout [iNOS KO] mice). METHODS: IMO was induced in wild-type (WT) and iNOS KO mice by subcutaneous injections of magnesium silicate. The skeletal response was assessed at the tibial metaphysis by measurements of bone mineral density (BMD), using peripheral quantitative computed tomography, by bone histomorphometry, and by measurements of bone cell apoptosis. RESULTS: NO production increased 2.5-fold (P < 0.005) in WT mice with IMO, but did not change significantly in iNOS KO mice. Total BMD values decreased by a mean +/- SEM of 14.4+/-2.0% in WT mice with IMO, compared with a decrease of 8.6+/-1.2% in iNOS KO mice with IMO (P < 0.01). Histomorphometric analysis confirmed that trabecular bone volume was lower in WT mice with IMO compared with iNOS KO mice with IMO (16.2+/-1.5% versus 23.4+/-2.6%; P < 0.05) and showed that IMO was associated with reduced bone formation and a 320% increase in osteoblast apoptosis (P < 0.005) in WT mice. In contrast, iNOS KO mice with IMO showed less inhibition of bone formation than WT mice and showed no significant increase in osteoblast apoptosis. CONCLUSION: Inducible NOS-mediated osteoblast apoptosis and depressed bone formation play important roles in the pathogenesis of IMO.

Animals↗

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.

Absorptiometry, Photon↗