Osteocalcin gene polymorphisms influence concentration of serum osteocalcin and enhance fracture identification

Osteoporosis is a major health problem affecting more than 75 million people throughout Europe, the United States, and Japan. Epidemiologic studies have determined that both genetic and environmental factors contribute to the pathogenesis of osteoporosis. We have investigated the association between polymorphisms at the osteocalcin locus and variables linked to bone health. Osteocalcin provides a link between bone and energy metabolism, hence its potential importance as an osteoporosis candidate gene. In this study, we included a total of 996 women (all aged 75 years) from the Osteoporosis Prospective Risk Assessment (OPRA) cohort. We sequenced the osteocalcin gene along with flanking regions to search for novel coding polymorphisms. We also analyzed four polymorphisms selected from within and flanking regions of the osteocalcin gene to study their association with serum total osteocalcin levels (S-TotalOC), total-body (TB) bone mineral density (BMD), fracture, TB fat mass, and body mass index (BMI). The promoter polymorphism rs1800247 was significantly associated with S-TotalOC (p = .012) after controlling for BMI and TB BMD. The polymorphism rs1543297 was significantly associated with prospectively occurring fractures (p = .008). In a model taking into account rs1543297 and rs1800247, along with TB BMD, BMI, smoking, and S-TotalOC, the polymorphisms together were able to identify an additional 6% of women who sustained a fracture (p = .02). We found no association between the polymorphisms and TB BMD, BMI, or TB fat mass. In conclusion, polymorphisms in and around the osteocalcin locus are significantly associated with S-TotalOC and fracture. Genotyping at the osteocalcin locus could add valuable information in the identification of women at risk of osteoporosis.

Variation in the PTH gene, hip fracture, and femoral neck geometry in elderly women

Parathyroid hormone (PTH) is a principal regulator of calcium homeostasis. Previously, we studied single-nucleotide polymorphisms present in the major genes in the PTH pathway (PTH, PTHrP, PTHR1, PTHR2) in relation to bone mineral density (BMD) and fracture incidence. We found that haplotypes of the PTH gene were associated with fracture risk independent of BMD. In the present study, we evaluated the relationship between PTH haplotypes and femoral neck bone size. Hip structure analysis and BMD of the femoral neck was assessed by DXA in elderly women from the Malmö Osteoporosis Prospective Risk Assessment study. Data on hip fracture, sustained as a result of low trauma, after the age of 45 years were also analyzed. Haplotypes derived from six polymorphisms in the PTH locus were analyzed in 750 women. Carriers of haplotype 9 had lower values for hip geometry parameters cross-sectional moment of inertia (P = 0.029), femoral neck width (P = 0.049), and section modulous (P = 0.06), suggestive of increased fracture risk at the hip. However, this did not translate into an increased incidence of hip fracture in the studied population. Women who suffered a hip fracture compared to those who had not had longer hip axis length (HAL) (P < 0.001). HAL was not significantly different among haplotypes. Polymorphisms in the PTH gene are associated with differences in aspects of femoral neck geometry in elderly women; however, the major predictor of hip fracture in our population was HAL, to which PTH gene variation does not contribute significantly.

Bone turnover markers are correlated with quantitative ultrasound of the calcaneus: 5-year longitudinal data

SUMMARY

Associations between bone turnover markers and calcaneal ultrasound (quantitative ultrasound, QUS) were studied in a population-based sample of 810 elderly women. Baseline bone turnover markers correlated with baseline QUS as well as with 5-year prospective changes in QUS.

INTRODUCTION

Bone turnover markers are associated with areal bone mineral density, but the knowledge on the association with QUS is limited.

METHODS

Eight hundred ten women, all 75 years old, were investigated at baseline. Five hundred six completed a 5-year follow-up. Bone turnover markers and calcaneal QUS [speed of sound (SoS), broadband ultrasound attenuation (BUA), stiffness] were investigated at baseline. QUS was investigated at follow-up.

RESULTS

All bone turnover markers were correlated with baseline QUS [standardized regression (Beta(std)) values from -0.07, p < 0.05 to -0.23, p < 0.001], with the exception of bone-specific alkaline phosphatase (S-Bone ALP) which was not correlated with BUA and stiffness index. When the correlations between baseline bone turnover markers and 5-year changes in QUS were analyzed, three serum osteocalcins were correlated with changes of SoS and stiffness index (Beta(std) = -0.11, p < 0.05 to -0.17, p < 0.001). Also S-CTX-I correlated with changes of SoS and stiffness index (Beta(std) = -0.10 and -0.09, respectively, p < 0.05). S-TRACP5b, urinary deoxypyridinoline/crea, and U-MidOC/crea correlated with changes of SoS (Beta(std) = -0.10 and p < 0.05 for all). S-Bone ALP did not correlate with change of QUS. None of the bone turnover markers correlated with changes of BUA.

CONCLUSIONS

Bone turnover markers correlate with concomitantly assessed QUS as well as with longitudinal change in QUS.

Serial assessment of serum bone metabolism markers identifies women with the highest rate of bone loss and osteoporosis risk

CONTEXT

One of the important challenges in the management of osteoporosis is to identify women who are at high risk of developing osteoporosis and fragility fractures.

OBJECTIVE

Our objective was to evaluate whether assessment of bone metabolism at multiple occasions can identify women with the highest risk for bone loss.

DESIGN

The Malmö Osteoporosis Prospective Risk Assessment study is an ongoing longitudinal study. Participants have been evaluated at baseline and after 1, 3, and 5 yr.

SETTING

We conducted a population-based study.

PARTICIPANTS

Participants included 1044 women, all 75 yr old at baseline.

MAIN OUTCOME MEASURES

Seven bone turnover markers were assessed at baseline and at 1, 3, and 5 yr (n = 573). The 5-yr change in areal bone mineral density (aBMD) was also determined.

RESULTS

Baseline markers correlated weakly to change in total body aBMD. The associations were more pronounced when the average of the baseline and 1-yr measurements was used (standardized regression coefficients -0.12 to -0.23, P < 0.01). Adding the 3-yr and 5-yr measurement further strengthened the correlation (regression coefficients up to -0.30, P < 0.001). Women with constantly high turnover lost significantly more bone at total body assessment (-2.6%) than women with intermediate (-1.6%) or low turnover (-0.2%, P for trend < 0.001). They also had a greater decrease in hip BMD (-8.3, -6.0, and -5.1%, respectively, P = 0.010). Results were similar also in the subgroup of women with osteopenia.

CONCLUSIONS

Our results suggest that serial assessment of bone turnover improves the identification of women with the highest rate of bone loss and osteoporosis risk.

Variation in the bone morphogenetic protein-2 gene: effects on fat and lean body mass in young and elderly women

OBJECTIVE

Bone morphogenetic protein-2 (BMP2) plays a critical role in osteoblastogenesis and adipogenesis from osteoprogenitor cells. The balance between osteogenic and adipogenic effects is influenced by BMP2 concentration, transcription factors and age. BMP2 single nucleotide polymorphisms (SNPs) may contribute to osteoporosis risk, but the relationship between adiposity and body composition has not been explored. We investigated the relationship between BMP2 polymorphisms and body composition in young and elderly women.

DESIGN

Population-based association study.

METHODS

Four BMP2 SNPs studied. Total body fat and lean mass measured by DEXA in two cohorts: 'PEAK-25' women aged 25 (+/-0.00) (n=993) and osteoporosis prospective risk assessment (OPRA) women aged 75 (+/-0.00) years (n=1001).

RESULTS

We found no association between BMP2 SNPs and fat or lean mass, however, we observed consistent although non-significant trends. Polymorphisms, rs235767 and Ser37Ala, exerted opposing effects on most parameters of soft tissue and bone mass in both cohorts. This relationship appeared to be age specific with large differences between alleles observed (fat mass; Ser37Ala: 14.3% (PEAK-25), -3.5% (OPRA)). These initial results appear to suggest that alleles exerting a beneficial effect in young women may subsequently contribute to phenotypes associated with osteoporosis risk in elderly women.

CONCLUSIONS

While further analyses in other comparative populations are necessary, in this study of almost 2000 women we observed interesting, although non-significant trends, regarding the effects of variation in the BMP2 gene on parameters of body mass. Although the exact nature of the relationship remains uncertain, we suggest that the mechanisms are influenced by age and environmental factors.

Genetic variation in the PTH pathway and bone phenotypes in elderly women: evaluation of PTH, PTHLH, PTHR1 and PTHR2 genes

INTRODUCTION

Parathyroid hormone (PTH) is a key regulator of calcium metabolism. Parathyroid hormone-like hormone (PTHrP) contributes to skeletal development through regulation of chondrocyte proliferation and differentiation during early bone growth. Both PTH and PTHrP act through the same receptor (PTHR1). A second receptor, PTHR2, has been identified although its function is comparatively unknown. PTH hyper-secretion induces bone resorption, whereas intermittent injection of PTH increases bone mass. To explore the effects of genetic variation in the PTH pathway, we have analysed variations in PTH, PTHLH, PTHR1 and PTHR2 in relation to bone mass and fracture incidence in elderly women.

MATERIALS AND METHODS

This study includes 1044 elderly women, all 75 years old, from the Malmö Osteoporosis Prospective Risk Assessment study (OPRA). Single nucleotide polymorphisms (SNPs) from 4 genes and derived haplotypes in the PTH signaling pathway were analysed in 745-1005 women; 6 SNPs in the PTH gene and 3 SNPs each in the PTHLH, PTHR1 and PTHR2 genes were investigated in relation to BMD (assessed at baseline), fracture (434 prevalent fractures of all types over lifetime, self-reported and 174 incident fractures up to 7 years, X-ray verified) and serum PTH.

RESULTS AND CONCLUSION

Individually, SNPs in the 4 loci did not show any significant association with BMD. Neither were PTHLH, PTHR1 and PTHR2 polymorphisms associated with fracture. Three of 5 common haplotypes, accounting for >98% of alleles at the PTH locus, were identified as independent predictors of fracture. Haplotype 9 (19%) was suggestive of an association with fractures of any type sustained during lifetime (p=0.018), with carriers of one or more copies of the haplotype having the lowest incidence (p=0.006). Haplotypes 1 (13%) and 5 (37%) and 9 were suggestive of an association with fractures sustained between 50 and 75 years (p=0.02, p=0.013 and p=0.034). Carriers of haplotypes 1 and 5 were more likely to suffer a fracture (haplotype 1, p=0.045; haplotype 5, p=0.008). We conclude, that while further genotyping across the gene is recommended, in this cohort of elderly Swedish women, polymorphisms in PTH may contribute to the risk of fracture through mechanisms that are independent of BMD.

Rates of fracture in participants and non-participants in the Osteoporosis Prospective Risk Assessment study

We invited 1604 randomly selected women, all 75 years of age, to participate in a study on the risk factors for fracture. The women were divided into three groups consisting of 1044 (65%) who attended the complete study, 308 (19%) respondents to the study questionnaire only and 252 (16%) who did not respond. The occurrence of the life-time fracture was ascertained from radiological records in all groups and by questionnaires from the attendees and respondents. According to the radiological records, fewer of the questionnaire respondents (88 of 308, 28.6%) and non-respondents (68 of 252, 27%) had sustained at least one fracture when compared with the attendees (435 of 1044, 41.7%; chi-squared test, p < 0.001). According to the questionnaire, fewer of the respondents (96 of 308, 31.1%) had sustained at least one previous fracture when compared with the attendees (457 of 1044, 43.7%; chi-squared test, p < 0.001). Any study concerning the risk of fracture may attract those with experience of a fracture which explains the higher previous life-time incidence among the attendees. This factor may cause bias in epidemiological studies.

Variation in the BMP2 gene: bone mineral density and ultrasound in young adult and elderly women

Bone morphogenetic protein-2 (BMP2) plays a key role in bone formation and maintenance. Studies of polymorphisms within the gene in relation to bone mineral density (BMD) and fracture have been inconsistent. Our aim was to investigate associations between polymorphisms in the BMP2 gene and bone mass, fracture, and quantitative ultrasound (QUS) measures at different stages of skeletal development. Study subjects were participants of two population-based cohorts of Swedish women: the PEAK-25 cohort of young adult women aged 25 years (n = 993) and the OPRA cohort of elderly women aged 75 years (n = 1,001). We analyzed four single-nucleotide polymorphisms (SNPs) across the BMP2 gene including the Ser37Ala SNP previously identified in relation to BMD, QUS of the calcaneus, and, in the elderly women, fracture. BMP2 gene variations were associated with QUS of bone, independent of BMD, but only in the young women. Even after adjusting for confounding factors, SNP rs235754 in the 3' region of the gene was significantly associated with the ultrasound parameters speed of sound (P = 0.003) and stiffness (P = 0.002). The 5' SNP rs235710 showed trends for QUS parameters (P = 0.02-0.07). No association with BMP2 SNPs was observed in either cohort for either BMD or fracture. While further, more extensive genotyping across the gene is recommended, as we may not have captured all information, our preliminary data suggest that variation in BMP2 may play a previously unidentified role in aspects of bone quality, which may be age- and site-dependent.

Accelerometer-measured daily physical activity among octogenerians: results and associations to other indices of physical performance and bone density

Information on objectively assessed physical activity in elderly people is scarce. The aim of this study was to investigate accelerometer measures in elderly women, and its relation to other indices of physical activity and bone density. A subset of 57 women, all 80 years old, (range 80.0-80.7) of the Malmö OPRA study was equipped with an MTI accelerometer for a period of 5-7 days. A 7-day activity log was used. At baseline a self-assessment questionnaire was used and isometric muscle strength (knee), gait speed, balance and bone density measurements [dual-energy X-ray absorptiometry (total body, hip, and spine), and quantitative ultrasound of the calcaneus] were measured. About 14% (8 out of 57) had a moderate to vigorous physical activity (MVPA) (>1,952 counts per min [CPM]) exceeding 30 min/day. The median CPM was 18. When compared to questionnaire data, the correlation between MVPA and physical activity was 0.50 (P < 0.001). The corresponding result for CPM was 0.48, P < 0.001. When compared to the activity log, the correlation between MVPA and physical activity away from home was 0.49 (P < 0.001). The corresponding result for CPM was 0.55, P < 0.001. The correlation between MVPA and gait speed was 0.41 (P = 0.002). The corresponding result for CPM was 0.40, P = 0.002. There were no correlations to the measurements of muscle strength, balance or bone density (all P > or = 0.07). Accelerometers can be used for measuring of physical activity also of the elderly. Questions on daily physical activity correlated modestly with accelerometer results in elderly women. Accelerometer results were not correlated to measures of balance, muscle strength and bone density.

Prediction of bone loss using biochemical markers of bone turnover

The association between baseline levels of eleven bone turnover markers and 5-year rate of bone density change was prospectively studied in a population-based sample of 601 75-year-old women. Several bone formation and resorption markers as well as urinary osteocalcin were modestly correlated to rate of bone density change.

INTRODUCTION

Prediction of bone loss by bone turnover markers (BTMs) has been investigated with conflicting results. There is limited information in the elderly.

METHODS

Eleven bone turnover markers were analyzed in 75-year old women in the OPRA study (n = 601) and compared to the 5-year change of areal bone mineral density (aBMD) in seven skeletal regions.

RESULTS

Annual aBMD change varied between +0.4% (spine) and -2.0% (femoral neck). Significant associations (p < 0.01) were found for four different serum osteocalcins (S-OCs) (standardized regression coefficient -0.20 to -0.22), urinary deoxypyridinoline (-0.19), serum TRACP5b (-0.19), serum CTX-I (-0.21), two of the three urinary osteocalcins (U-OCs) (-0.16) and aBMD change of the leg region (derived from the total body measurement). After adjustment for baseline aBMD, associations were found for all S-OCs (-0.11 to -0.16), two of the three U-OCs (-0.14 to -0.16) and aBMD change at the total hip, and for three of the four S-OCs (-0.14 to -0.15), S-TRACP5b (-0.11), two of the three U-OCs (-0.14 to -0.15) and aBMD change at the femoral neck. There were no significant results concerning aBMD change at the spine.

CONCLUSION

This study indicates that BTMs are correlated with aBMD loss in some skeletal regions in elderly women.

Effect of fracture on bone turnover markers: a longitudinal study comparing marker levels before and after injury in 113 elderly women

In this longitudinal, prospective, and population-based study (n = 1044), seven BTMs were assessed before and after trauma in 113 elderly women (85 with fractures). Markers were not altered in the immediate postfracture period but were clearly elevated during fracture repair. Recent fracture should thus be taken into account when markers are used in clinical practice.

INTRODUCTION

Fracture may influence the levels of bone turnover markers (BTM) and have implications for their use in clinical practice. In this longitudinal, prospective, and population-based study, we assessed prefracture levels of BTMs and compared them with postfracture levels of the same individuals immediately after fracture and during fracture repair. This is the first study in which the effect of fracture on bone markers has been evaluated with prefracture samples available.

MATERIALS AND METHODS

Serum and urine were collected at the emergency unit from 85 women (77.9 +/- 1.8 yr) who sustained a fracture after low-energy trauma and 28 controls (77.8 +/- 2.0 yr) with similar trauma but no fracture. All were participants of the Malmö OPRA study (n = 1044), and pretrauma samples were collected 1.05 +/- 0.85 yr before. Bone turnover was assessed by seven different BTMs reflecting different stages of bone metabolism {C-terminal cross-linked telopeptides of type I collagen [S-CTX], S-TRACP5b, N-terminal propeptides of type I collagen [S-PINP], serum osteocalcin (S-OC[1-49] and S-TotalOC), urinary deoxypyridinoline [U-DPD], and urinary osteocalcin [U-OC]}.

RESULTS

BTMs sampled within a few hours after fracture were not altered from preinjury levels. Both bone formation and bone resorption markers were, however, significantly increased 4 mo after fracture. The elevation was most pronounced after hip fracture. Bone turnover remained elevated up to 12 mo after fracture.

CONCLUSIONS

We believe this study extends our knowledge on the skeletal postfracture metabolic processes. In addition, it may provide a basis for future means to monitor pharmacological intervention promoting fracture healing.

The impact of estradiol on bone mineral density is modulated by the specific estrogen receptor-alpha cofactor retinoblastoma-interacting zinc finger protein-1 insertion/deletion polymorphism

CONTEXT

Estrogens regulate bone mass by binding to the estrogen receptor (ER)-alpha as well as ER-beta. The specific ERalpha cofactor retinoblastoma-interacting zinc finger protein (RIZ)-1 enhances ERalpha function in the presence of estrogen.

OBJECTIVE

The objective of the study was to determine whether a RIZ P704 insertion (+)/deletion (-) (indel) polymorphism modulates the impact of estradiol on bone mineral density (BMD) and study the association between the polymorphism and BMD in elderly subjects.

DESIGN

This was a population-based, prospective, and cross-sectional study, the Swedish MrOS Study, and the Malmö OPRA Study, respectively.

SETTING

The study was conducted at three academic medical centers: Sahlgrenska Academy in Gothenburg, Malmö University Hospital, and Uppsala University Hospital.

PARTICIPANTS

In total, 4058 men and women, aged 69-81 yr, were randomly selected from population registries.

MAIN OUTCOME MEASURES

BMD (grams per square centimeter) was measured at femoral neck, trochanter, lumbar spine, and total body.

RESULTS

The RIZ P704(+/+) genotype was associated with low BMD in both women (femoral neck, P < 0.001; trochanter, P < 0.01; lumbar spine, P < 0.05; total body, P < 0.01) and men (lumbar spine, P < 0.05). However, the association between the polymorphism and BMD was dependent on estradiol status. The positive correlation between serum estradiol and BMD was significantly modulated by the genotype with a stronger correlation in the P704(+/+) group than the P704(-/-) group (r = 0.19 vs. r = 0.08, P < 0.05).

CONCLUSIONS

These large-scale studies of elderly men and women indicate that the ERalpha cofactor RIZ gene has a prominent effect on BMD, and the P704 genotype modulates the impact of estradiol on BMD. Further studies are required to determine whether this polymorphism modulates the estrogenic response to estradiol treatment.

Associations between homocysteine, bone turnover, BMD, mortality, and fracture risk in elderly women

Homocysteine has been suggested to be a risk factor for fracture, but the causal relationship is not clear. In 996 women from the OPRA study, high homocysteine level was associated with high bone marker levels and low BMD at baseline. During a mean 7-year follow-up, high homocysteine level was associated with mortality, but no clear association to fracture risk existed.

INTRODUCTION

Recently, the association between high serum homocysteine (Hcy) levels and an increased risk of fracture has been described.

MATERIALS AND METHODS

Hcy levels were measured at baseline in 996 women, all 75 years old. Vitamin B(12), folate, serum cross-linking telopeptide of type I collagen (CTX), serum TRACP5b, serum osteocalcin, urine deoxypyridinoline, PTH, areal BMD (aBMD), calcaneal quantitative ultrasound (QUS), and physical performance were assessed at baseline. Fractures and mortality were recorded during a mean follow-up of 7.0 years.

RESULTS

Bone marker levels were higher in women with Hcy in the highest quartile compared with all other women (p < 0.05). The most evident correlation between Hcy and a bone marker was seen with CTX (r = 0.19, p < 0.001). aBMD (hip) was 4% lower, QUS was up to 2% lower, and gait speed was 11% slower among women with Hcy in the highest quartile compared with the other women (p < 0.05). During the follow-up, 267 women sustained at least one low-energy fracture (including 69 hip fractures). When women in the highest Hcy quartile were compared with all other women, the hazard ratios (HRs) for sustaining any type of fracture was 1.18 (95% CI, 0.89-1.36) and for hip fracture was 1.50 (95% CI, 0.91-1.94). For the same group of women, the mortality risk was 2.16 (95% CI, 1.58-2.55). Adjustments for confounders did not substantially change these associations. Adjustment for PTH increased the HR for hip fracture to 1.67 (95% CI, 1.01-2.17). Low vitamin B(12) or folate was not associated with increased fracture risk or mortality.

CONCLUSIONS

High Hcy levels were associated with higher bone turnover, poor physical performance, and lower BMD. There was no clear association to fracture risk. The increased mortality among women with high Hcy levels indicates that a high Hcy level may be a marker of frailty.

The relation between previous fractures and physical performance in elderly women

OBJECTIVE

To examine the association between previous fracture and different aspects of physical performance.

DESIGN

Population-based retrospective study.

SETTING

Orthopaedic research department.

PARTICIPANTS

Randomly selected women (N = 1044), all 75 years old and participants of the Malmö Osteoporosis Prospective Risk Assessment study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Type of and time since any previous fracture event were compared with results of tests on physical performance function (Romberg test, computerized sway test, gait speed, questionnaire) at the age of 75.

RESULTS

Women with no previous fractures (n = 505) had a better median Romberg balance of 94 seconds (interquartile range [IQR], 75-118s) than women with 1, 2, or 3 or more fractures, who had a median balance of 88 seconds (IQR, 71-111s), 85 seconds (IQR, 68-107s), and 81 seconds (IQR, 65-109s), respectively (Kruskal-Wallis analysis of variance, P = .002). Balance was inferior in women who had sustained a previous fracture between the ages of 65 and 75 years compared with women with no previous fractures or fractures before the age of 65 years. Gait speed and questions on tendency to fall followed the same pattern. The computerized sway test could not differ between women with and without previous fractures.

CONCLUSIONS

Poor physical performance is associated with previous fractures. Inferior physical performance may exist up to 10 years after a fracture.

Increased bone density and decreased bone turnover, but no evident alteration of fracture susceptibility in elderly women with diabetes mellitus

Bone density, bone turnover and fracture susceptibility were evaluated in 1,132 randomly recruited women, all 75 years old. Seventy-four of the women had diabetes, while 1,058 women did not. Areal bone mineral density (aBMD) of the hip and lumbar spine was investigated by dual energy X-ray absorptiometry (DXA), and bone mass of the calcaneus was measured by ultrasound. Urinary deoxypyridinoline/creatinine (U-DPD/Crea) and serum C-terminal cross-linked telopeptide of type 1 collagen (S-CTX) were assessed as markers of bone resorption. Serum bone-specific alkaline phosphatase (S-bone ALP) and serum osteocalcin (S-OC) were assessed as markers of bone formation. Also, serum 25(OH) vitamin D and serum parathyroid hormone (S-PTH) were assessed. Fracture susceptibility was evaluated retrospectively and prospectively for up to 6.5 years. In diabetic women, the aBMD of the femoral neck was 11% higher (p<0.001), and BMD of the lumbar spine was 8% higher (p=0.002) than in non-diabetic women. There was no difference in bone mass by ultrasound of the calcaneus. Women with diabetes had higher BMD of the femoral neck (p<0.001) and lumbar spine (p=0.03) also after correction for differences in body weight. In diabetic women, U-DPD/Crea, S-CTX, and S-OC were decreased when compared with non-diabetic women (p=0.001 or less). After correction for covariance of body weight and plasma creatinine, S-CTX (p<0.001) and S-OC (p<0.001) were still lower in the diabetic women. Diabetic patients had hypovitaminosis D (p=0.008), a difference explained by differences in time spent outdoors and body weight. S-PTH did not differ between the groups. Women with diabetes had no more lifetime fractures (52%) than women without diabetic disease (57%), (p=0.31). This study shows that elderly women with diabetes and without severe renal insufficiency have high bone mass and low bone turnover. The high bone mass and low bone turnover is not likely to have a strong influence on fracture susceptibility.

Association between 25-hydroxy vitamin D levels, physical activity, muscle strength and fractures in the prospective population-based OPRA Study of Elderly Women

Vitamin D supplements have been used to prevent fractures. The effect may be mediated through increased bone mass, but also through reduced falling propensity. The aim of this study was to evaluate the association between 25-hydroxy vitamin D levels (25OHD), fall-associated variables (including tests of functional performance), and fracture in ambulatory women. At baseline 25OHD was measured in 986 women. Fall-associated variables were investigated at baseline. Fractures were recorded during a 3-year follow-up. Four percent of the women had 25OHD levels below 20 ng/ml (50 nmol/l), and 26% had 25OHD levels below 30 ng/ml (75 nmol/l). 25OHD correlated with gait speed (r =0.17, P <0.001), the Romberg balance test (r =0.14, P <0.001), self-estimated activity level (r =0.15, P <0.001), and thigh muscle strength (r =0.08, P =0.02). During the 3-year follow-up, 119 out of the 986 women sustained at least one fracture. The Cox proportional hazard ratio (HR) (95% confidence interval) for sustaining a fracture during the follow-up was 2.04 (1.04-4.04) for the group of women with 25OHD below 20 ng/ml, in which 9 out of 43 women sustained a fracture. Thirty-two of the 256 women with 25OHD levels below 30 ng/ml sustained a fracture during the follow-up, with a non-significant HR of 1.07 (1.07-1.61). This cohort of elderly, ambulatory women had a high mean 25OHD. A low 25OHD was associated with inferior physical activity level, gait speed and balance. A 25OHD level below 30 ng/ml was not associated with an increased risk of fractures in this study. However, a subgroup of women with 25OHD levels below 20 ng/ml had a tendency to an increased risk of fractures, which may be associated with an inferior physical activity and postural stability.

Vertebroplasty and kyphoplasty: New treatment strategies for fractures in the osteoporotic spine

During the last decade, two new treatment modalities for osteoporotic vertebral fractures have gained more interest: percutaneous vertebroplasty and kyphoplasty. The techniques and the short-term clinical results and complications have been presented but there is no scientific evidence-based information regarding the efficacy of the procedures, such as randomized controlled trials (RCT). Instead, we have to rely on prospective and retrospective uncontrolled short-term observational studies and case-control studies. These studies have shown consistently that the short-term results after the procedures are favorable as regards both pain relief and functional status. It is currently unknown, however, whether a vertebroplasty or a kyphoplasty gives a better outcome than nonoperative treatment, and whether the long-term results are as favorable as the short-term results.

[Treatment of osteoporotic vertebral compression. Explosive interest for vertebroplasty and kyphoplasty]

During the last 15 years, two new treatment strategies have gained worldwide attention in the treatment of osteoporotic vertebral fractures. The exponential increase in the use of percutaneous vertebro- or kyphoplasty has up to now not been supported by scientific sound evidence-based data. There exist no prospective randomised controlled trials (RCT) that support the efficacy of the treatments, not even adequate controlled studies. Instead we have to rely on prospective and retrospective uncontrolled short-term observational studies and case-control studies. These studies consistently indicate that the short-term results after the procedures in the treatment of osteoporotic vertebral fractures are favourable, regarding both pain relief and functional status. However, if a vertebro- or a kyphoplasty produces a better outcome than conservative treatment, and if the long-term results are as favourable as the short-term results in the treatment of osteoporotic vertebral fractures, is currently unknown.

Biochemical markers of bone turnover are influenced by recently sustained fracture

In striving to refine the clinical utility of different markers of bone metabolism, we should take into account numerous confounders, many of which are well known, such as sampling time, fasting status, and bone density. One further confounder may be ongoing fracture healing and/or post-fracture immobilization, which at least theoretically should impose an increased bone formation and resorption. Since both recent fracture and high bone turnover are independent predictors for new fracture, we thought it of importance to define the potential influence of such fracture on markers of bone turnover. From a population-based cohort of 1604 women, all 75 years old (the OPRA-study), 1024 women attended a clinical examination. The bone metabolism was assessed in serum, by three markers of bone formation [bone-specific alkaline phosphatase (S-Bone ALP), intact and N-Mid osteocalcin (S-Total OC), and total carboxylated osteocalcin (S-cOC)], two markers of bone resorption [C-terminal cross-linked telopeptides of type I collagen (S-CTX) and tartrate-resistant acid phosphatase type 5b (S-TRACP5b)], and in urine by one marker of bone resorption [deoxypyridinoline/creatinine (U-DPD/crea)] and two putative markers of bone resorption [urinary osteocalcins (U-OC/crea)]. Current physical activity and retrospective fracture data were recorded by questionnaires. The fracture data, for the entire cohort of 1604 women, were validated with radiographic referrals and reports, saved since the beginning of the last century. All data provided, except date of occurrence of retrospectively sustained fracture, were thus obtained cross-sectionally and in all women at the age of 75. Fracture had ever been sustained by 727 of the entire cohort (n = 1604), and by 523 of the attending women (n = 1024). All markers were marginally higher (significant only for U-DPD/crea, P = 0.027) in women who had ever sustained fracture, compared to women without fracture. In women with recent retrospective fracture (since 2 years) (n = 100), the levels of all markers, except the two S-OCs, were significantly higher (r = 0.20-0.33, P = 0.049-0.001) the more recently the fracture had been sustained. Women with low current physical activity had elevated levels of U-DPD/crea (P < 0.001) and one U-OC (P = 0.014), while the other markers were unaffected.

Clinical history and biologic age predicted falls better than objective functional tests

OBJECTIVE

Fall risk assessment is important because the consequences, such as a fracture, may be devastating. The objective of this study was to find the test or tests that best predicted falls in a population-based sample of elderly women.

STUDY DESIGN AND SETTING

The fall-predictive ability of a questionnaire, a subjective estimate of biologic age and objective functional tests (gait, balance [Romberg and sway test], thigh muscle strength, and visual acuity) were compared in 984 randomly selected women, all 75 years of age.

RESULTS

A recalled fall was the most important predictor for future falls. Only recalled falls and intake of psycho-active drugs independently predicted future falls. Women with at least five of the most important fall predictors (previous falls, conditions affecting the balance, tendency to fall, intake of psychoactive medication, inability to stand on one leg, high biologic age) had an odds ratio of 11.27 (95% confidence interval 4.61-27.60) for a fall (sensitivity 70%, specificity 79%).

CONCLUSION

The more time-consuming objective functional tests were of limited importance for fall prediction. A simple clinical history, the inability to stand on one leg, and a subjective estimate of biologic age were more important as part of the fall risk assessment.

Urinary osteocalcin as a marker of bone metabolism

BACKGROUND

Osteocalcin (OC) is produced by osteoblasts during bone formation, and circulating OC has been used in clinical investigations as a marker of bone metabolism. OC is excreted into urine by glomerular filtration and can be found in urine as midmolecule fragments.

METHODS

We developed and evaluated three immunoassays (U-MidOC, U-LongOC, and U-TotalOC) for the detection of various molecular forms of urine OC (U-OC). We evaluated the association of U-OC with other markers of bone turnover and with bone mass in 1044 elderly women and studied seasonal and circadian variation of U-OC.

RESULTS

U-OC correlated with other bone turnover markers [Spearman correlation (r), 0.30-0.57; P <0.0001], demonstrating the association between U-OC and skeletal metabolism. There was also a significant association between bone metabolism assessed by U-OC quartiles and bone mass assessed by total body bone mineral content (P <0.0001). The seasonal effects appeared to be rather small, but we observed a significant circadian rhythm similar to the one reported for serum OC with high values in the morning and low values in the afternoon.

CONCLUSIONS

The three immunoassays had unique specificities toward different naturally occurring U-OC fragments. U-OC concentrations measured with any of these assays correlated with bone turnover rates assessed by conventional serum markers of bone metabolism. The measurement of OC in urine samples could be used as an index of bone turnover in monitoring bone metabolism.

Interleukin-6 promoter polymorphism is associated with bone quality assessed by calcaneus ultrasound and previous fractures in a cohort of 75-year-old women

Interleukin 6 (IL-6) is a multifunctional cytokine and a potent stimulator of bone resorption and has been implicated in the pathogenesis of osteoporosis in postmenopausal women. The aim of this study was to investigate if a functional IL-6 promoter polymorphism (-174) was related to bone mass and fractures in a cohort consisting of 964 postmenopausal Caucasian women aged 75 years. Bone mineral density (BMD; g/cm2) of the femoral neck, lumbar spine and total body was measured using dual energy X-ray absorptiometry (DXA). Quantitative ultrasound (QUS) was also measured in the calcaneus and quantified as speed of sound (SOS; m/s), broadband ultrasound attenuation (BUA; dB/MHz), and stiffness index (SI). IL-6 genotypes was determined by restriction fragment length polymorphism (RFLP) using the restriction enzyme NlaIII. The frequencies of the different IL-6 genotypes were 27.5% (GG), 47.9% (GC), 24.6% (CC). The IL-6 polymorphism (presence of G) was independently related to a lower stiffness (beta=-0.07; P=0.03) and BUA (beta=-0.08; P=0.02), but not to BMD at any site measured by DXA. In the cohort, 420 subjects (44%) reported at least one fracture during their lifetime, and 349 (36%) reported at least one fracture after the age of 50. Using binary logistic regression, the IL-6 polymorphism (presence of G) was significantly related to an increased risk of a previous fracture during life (odds ratio 1.46, 95% CI 1.08-1.97) and to an increased risk of a fracture occurring after 50 years of age (odds ratio 1.37, 95% CI 1.004-1.88). The risk was further increased for fractures grouped as osteoporotic fractures (odds ratio 1.67, 95% CI 1.14-2.45), including forearm fractures (odds ratio 1.59, 95% CI 1.05-2.40). In conclusion, presence of G allele in the IL-6 promoter polymorphism at position -174 is independently related to previous fractures in postmenopausal women. This association may be related primarily to an altered bone quality identified by QUS and not a lower bone mass. This is also the first demonstration of association of IL-6 gene polymorphism to calcaneal QUS.

Just One Look, and Fractures and Death Can Be Predicted in Elderly Ambulatory Women

BACKGROUND

The chronological age is clearly the strongest risk factor for fractures or death. Age as a concept can be described exactly as chronological age. Age in relative terms can be described as biological age.

OBJECTIVE

We postulated that, even without taking into account known or unknown comorbidity, an immediate and totally subjective evaluation of an individual's biological age is predictive of forthcoming fractures and death.

METHODS

At baseline the biological age was estimated in 1,004 randomly recruited ambulatory 75-year-old women. All women were of the same ethnic background. Two independent observers estimated the biological age within 15 s of first sight of each woman. Based on this estimation of the biological age, the women were divided into tertiles. The women were then followed prospectively for a mean of 4.6 (range 3.0-6.5) years. All retrospective fractures and prospective fractures and deaths were registered.

RESULTS

When the tertile of the biologically oldest women was compared with all other women, their odds ratio for sustaining any type of prospective fracture was 1.71 (95% confidence interval 1.22-2.39), for hip fractures 2.69 (1.42-5.11), for clinical vertebral fractures 2.83 (1.57-5.11), and for multiple fractures 3.17 (1.64-6.10). Also, when retrospectively sustained fractures were included, the predictive ability for biological age remained. The death rate amongst the tertile of biologically oldest women was increased when compared with the rest of the women (odds ratio 4.33, CI 3.62-5.17).

CONCLUSIONS

In ambulatory elderly women, without specific consideration of comorbidity, a subjective estimate of the biological age is predictive of future fractures and death. Subjective estimation of the biological age, in relation to the chronological age, is a valuable indicator of health, conveying additional information that merits its use in clinical practice.

Biochemical markers of bone metabolism and prediction of fracture in elderly women

We studied the ability of various markers of bone turnover to predict fracture in 1040 randomly recruited 75-year-old women. A total of 178 of the women sustained at least one fracture during follow-up (mean, 4.6 years). In elderly women, TRACP5b and urinary fragments of osteocalcin are promising new markers for prediction of fracture, in particular, vertebral fracture.

INTRODUCTION

Biochemical markers reflecting bone turnover may improve the prediction of fractures.

MATERIALS AND METHODS

The ability of 10 markers of bone turnover to predict fracture in 1040 elderly women in the Malmö OPRA study was studied. Serum bone-specific alkaline phosphatase and four different forms of serum osteocalcin (S-OC) were analyzed as markers of bone formation and serum C-terminal cross-linking telopeptides of type I collagen (S-CTX), serum TRACP isoform 5b (S-TRACP5b) and urinary free deoxypyridinoline (U-DPD) as markers of bone resorption. Two novel assays for osteocalcin fragments in urine (U-OC) were analyzed. Areal BMD (aBMD) was measured by DXA in the femoral neck and lumbar spine.

RESULTS

In total, 231 fractures were sustained by 178 of the women during a 3- to 6.5-year (mean, 4.6 years) follow-up period. When women with prospective fractures were compared with women without fractures, S-TRACP5b, S-CTX, one S-OC, and one U-OC were higher in women with a fracture of any type (all p < 0.05), and all bone markers were higher in women with clinical vertebral fracture (all p < 0.05). Markers were not significantly elevated in women with hip fracture. When women within the highest quartile of a bone marker were compared with all others, S-TRACP5b and one U-OC predicted the occurrence of a fracture of any type (odds ratio [OR]), 1.55 and 1.53; p < 0.05). S-TRACP5b, the two U-OCs, and S-CTX predicted vertebral fracture (OR, 2.28, 2.75, 2.71, and 1.94, respectively; all p < 0.05), and the predictive value remained significant for S-TRACP5b and the two U-OCs after adjusting for aBMD (OR, 2.02-2.25; p < 0.05). Bone markers were not able to predict hip fracture.

CONCLUSION

These results show that biochemical markers of bone turnover can predict fracture, and in particular, fractures that engage trabecular bone. S-TRACP5b and U-OC are promising new markers for prediction of fracture.

Association of the collagen type 1 (COL1A 1) Sp1 binding site polymorphism to femoral neck bone mineral density and wrist fracture in 1044 elderly Swedish women

Identification of risk factors for osteoporosis has been essential for understanding the development of osteoporosis and related fragility fractures. A polymorphism of the binding site for the transcription factor Sp1 of the collagen I alpha 1 gene (COLIA1) has shown an association to bone mass and fracture, but the findings have not been consistent, which may be related to population differences. The Sp1 polymorphism was determined in 1044 women, all 75 years old, participating in the population-based Osteoporosis Prospective Risk Assessment study in Malmö (OPRA). Bone mineral density, heel ultrasound and all previous fractures were registered. BMD was 2.7% lower in the femoral neck in women carrying at least one copy of the "s" allele ( P = 0.027). There was no difference in bone mass at any other site, weight, BMI or age at menopause. Women with a prevalent wrist fracture (n = 181) had an increased presence of the "s" allele. The odds ratio for prevalent wrist fracture was 2.73 (95% CI 1.1-6.8) for the ss homozygotes and 1.4 (95% CI 1.0-2.0) for the Ss heterozygotes when compared with the SS homozygotes. In conclusion, in this large and homogeneous cohort of 75-year-old Swedish women, there was an association among the Sp1 COLIA1 polymorphism, bone mass, and fracture. The presence of at least one copy of the "s" allele was associated with lower femoral neck BMD and previous wrist fracture and in addition, it was related to an increased risk for wrist fracture.

Seasonal variation in bone density in postmenopausal women

We investigated seasonal variation in bone density by cross-sectional designs in two large cohorts of women (N = 2337) in Sweden. One cohort was strictly population-based (all 75 yr old, N = 1044), and one cohort was patient-based (age > or = 55 yr, mean age 68, N = 1293). Each woman was assessed once and the inclusion was continuous throughout almost all days of the year. Bone mineral density (BMD) of the total body, hip, and lumbar spine was determined by means of dual X-ray absorptiometry (DXA). For both cohorts, the BMD was similar in those assessed during the period April-September compared to those assessed during the period October-March. On the other hand, when women who had been assessed during July-December were compared with women assessed during January-June, we found the BMD to be up to 5% lower during July-December in all skeletal regions in the population-based sample, and 4% lower at the Ward's triangle and trochanter in the patient-based sample. After correction for small differences in age and weight, women of both cohorts who had been assessed during July-December still had lower BMD at the hip compared with women assessed during January-June. In conclusion, we found no variation in bone density during the period April-September compared to the period October-March in these two cohorts of postmenopausal women. In elderly women living at a northern latitude, BMD may be a few percent lower during the period July-December compared to the period January-June.

Single nucleotide polymorphisms in the human gene for osteoprotegerin are not related to bone mineral density or fracture in elderly women

Osteoprotegerin (OPG), a secreted member of the tumor necrosis factor receptor family, is a potent inhibitor of osteoclast activation and differentiation. In animal models OPG prevents bone loss, and in humans bone resorption can be reduced by injections of OPG. OPG may also play a role in cardiovascular disease since mice lacking the OPG gene display arterial calcification. In a screening effort of the OPG gene, we recently discovered a single nucleotide polymorphism in the promoter region of OPG (T950C), and reported an association with vascular morphology and function in 59 healthy individuals. Due to the pronounced effect of OPG on bone turnover, the present study was conducted to investigate whether OPG polymorphisms are also associated with bone mineral density or with fracture. The relationship between single nucleotide polymorphisms in the promoter region of OPG (T950C) and the first intron (C1217T), and bone mineral density, measured by DXA in the hip or spine or ultrasound of the heel, was investigated in the Malmö OPRA-study of 1044 women, all 75 years old. The possible relation to fracture incidence was also analyzed. Among the 858 and 864 individuals respectively, genotyped, no significant associations between the investigated single nucleotide polymorphisms and bone mineral density measurements (T950C P = 0.50-0.64, C1217T P = 0.51-1.00), quantitative ultrasound measurements of the calcaneus, or fractures (T950C P = 0.61-0.66, C1217T P = 0.14-0.33) were found. Thus, our results show that polymorphisms in the OPG gene, one of which has previously been found to be associated with cardiovascular morphology and function, are not associated with bone mineral density in elderly Swedish women.

Bone mineral density in old age: the influence of age at menarche and menopause

Being aware that age at menarche, age at menopause, and length of fertile period influence bone mineral density (BMD) in the early postmenopausal period, we have failed to find any earlier studies where such an influence on the axial skeleton has been studied in old age when the incidence of hip fracture starts to increase. A large cohort of women, all 75 years old (n = 1044) participated in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) Study. The BMD of the lumbar spine and femoral neck was assessed by a dual-energy X-ray absorptiometry (DXA) technique. Age at menarche and at menopause was recalled with a questionnaire. Also, data on estrogen medication was collected. We found that, after excluding ever-users of potent estrogens (n = 49), there was a small but significant correlation of early menarcheal age with high BMD of the lumbar spine (r = -0.08; P = 0.017) and femoral neck (r = -0.10; P = 0.002) at age 75. Excluding the extremes (5% of the women) with very early or very late menarche, age at menarche no longer influenced the BMD in old age (r = -0.06; P = 0.113). Age at menopause had no influence on the BMD of the lumbar spine (r = 0.04; P = 0.246) or femoral neck (r = 0.00; P = 0.985), at age 75. The length of the fertile period did not influence BMD in old age. The influence of menarcheal or menopausal age on BMD at age 75 was not substantially altered after including body mass index (BMI) in a multiple regression model. Age at menarche or menopause seems to be of limited or no importance as a risk factor for osteoporosis when subjects are age 75 or older.

Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women

High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

Identification of novel proteolytic forms of osteocalcin in human urine

In this study, we report the isolation and characterization of osteocalcin in human urine using mass spectrometry and N-terminal sequencing. Multiple proteolytic forms of osteocalcin were found, which consisted of 16-27 residues from the middle region of the molecule. Several fragments had residue Gly7 at the N-terminus and the most predominant was fragment 7-31. Additional fragments starting from residue Asp14 were detected in the samples of children and young adults. Immunochemical detection of urine osteocalcin fragments had a statistically significant negative correlation to bone mineral density in evaluation of urine samples from 75-year-old women. Thus, the measurement of osteocalcin fragments in urine may have potential applications in diagnostics related to disorders of bone metabolism.

Bone mass cannot be predicted by estimations of frailty in elderly ambulatory women

BACKGROUND/METHODS

High biological age, or frailty, a possible risk factor for fragility fracture, and its relation to known risk factors for fracture (low bone mineral density (BMD), low muscle strength, poor gait performance and poor balance, previous falls, previous fractures and future risk of falls) were investigated in 993 randomly selected 75-year-old women. Frailty, which has no accepted definition, was here defined as a subjective immediate impression of an individual's general health appearance and was transferred into an arbitrary scale. 993 individuals were scored by at least one of four observers.

RESULTS

The frailty score and BMD were not correlated. A high frailty score was significantly correlated to poor gait (r = 0.53-0.59, p < 0.0001), poor balance (r = -0.49, p < 0.0001), low muscle strength (r = -0.25 to -0.41, p < 0.0001), low activity level (r = -0.43, p < 0.0001) and a high risk of falling (r = 0.24, p < 0.0001). The group of women who had experienced at least one fall the previous year had a higher frailty score (p < 0.0001) compared to those who had not. Women who had sustained a hip or femoral fracture after the age of 70 had a higher frailty score than women with no earlier fracture at all.

CONCLUSIONS

Bone mass cannot be predicted by our subjective frailty score in elderly, ambulant women. Since a high frailty score correlates with factors that affect or are likely to affect fall propensity, this could indicate that a high frailty score is a risk factor for fracture, independent of bone mass. Frailty may be regarded as a complex risk factor, including several assessments that can be objectively measured. Whether estimation of frailty is a method to improve the assessment of the patient at risk for a fragility fracture is yet to be proven and can only be shown in a prospective study of fracture occurrence.

Effect of previous and present physical activity on bone mass in elderly women

The importance of a physically active lifestyle as a preventive measure for maintaining bone mass is often stressed. The aim of this study was to evaluate the effect of everyday physical activity on bone mass from young adulthood to old age in 75-year-old women. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry technique in total body, hip (femoral neck and trochanter), and spine (LII-LIV) in a population-based cohort of 995 women, all 75 years old. Each woman responded to a questionnaire giving an estimate of the previous and present physical activity level at work and leisure time from youth and up to the present age of 75 years. No correlations were found between the different estimates of physical activity level and BMD. In a multiple regression analysis the different estimates of physical activity level did not have any combined effect on BMD in any of the skeletal regions measured; neither did the physical activity, previous or present, differ when the subgroup of women with a BMD in the highest quintile at all sites was compared with women with a BMD in the lowest quintile. The activity level in the various areas of life did not correlate to each other indicating that few women had chosen a generally active vs non-active lifestyle. A hypothetical positive effect on bone by one activity could therefore be diminished by another. The answer alternatives were mostly not normally distributed, which could also affect the results, making it difficult to identify women with extremely high or low physical activity level. In conclusion, the results from this study of randomly selected elderly women cannot confirm an effect of previous and present everyday physical activity on bone mass. Neither was it possible to find an effect of physical activity in those women with the highest BMD at all sites, suggesting that other factors are of greater importance for maintaining bone mass in elderly women.

Effects of cigarette-smoking on bone mass as assessed by dual-energy X-ray absorptiometry and ultrasound

In order to elucidate the influence of nicotine smoking on bone mass in elderly women, bone mass was cross-sectionally assessed by dual energy X-ray absorptiometry (DXA) in total body, hip and lumbar spine, as well as with ultrasound of calcaneus and phalanges of the hand. Subjects were 1,042, 75-year old women, recruited on a population basis (Osteoporosis Prospective Risk Assessment (OPRA) study). We found bone mineral density (BMD) to be lower in hip (0.71 vs. 0.76 g/cm2, p<0.0001 for femoral neck) and total body (0.96 vs. 1.02 g/cm2, p<0.0001) in current smokers compared to never-smokers. There was no difference in BMD of the lumbar spine between current smokers and never-smokers. Bone mass as assessed by ultrasound of the calcaneus was lower for speed of sound ( p<0.01), broadband ultrasound attenuation ( p<0.0001) and stiffness ( p<0.0001) in current smokers than in never-smokers. No differences were found for ultrasound measurements of the phalanges between smokers and never-smokers. Also, weight and current physical activity as assessed by a questionnaire differed significantly between current smokers and never-smokers. There was no evident difference between former smokers and never-smokers in any of the skeletal regions assessed by DXA or ultrasound. After correcting for differences in weight and physical activity, current smokers had lower BMD in all hip sites ( p<0.05) and total body ( p<0.01) compared to never-smokers. Ultrasound and BMD spine did not differ between these two groups after correction for weight and physical activity. We conclude that nicotine smoking has a negative influence on bone mass independent of differences in weight and physical activity. This difference is detected by DXA but not by ultrasound measurements of the calcaneus or the phalanges. The present data are encouraging since no bone mass differences were found between former and never-smokers.

Hemicallotasis for medial gonarthrosis: a short-term follow-up of 21 patients

We have prospectively evaluated 21 patients (22 knees; 15 men and 6 women) who underwent hemicallotasis osteotomy (HO), using an external fixator, of the proximal tibia due to medial gonarthrosis. Their median age at the time of operation was 52 (range 39-62) years. The follow- up period was 12-28 months. The Hospital for Special Surgery score (HSS) increased from median 71 preoperatively to 83 points at the follow-up ( p < 0.001). The median hip-knee-ankle angle (HKA) was 187 degrees preoperatively, 177 degrees after distraction, and 180 degrees at the time of follow-up ( p < 0.001). In 5 knees, valgus angulation was not achieved during the distraction phase, and in two-thirds of the knees, there was no valgus at follow-up. The total time in external fixation was median 13 (range 8-16) weeks. Pin tract problems occurred in 12 cases. There was one deep vein thrombosis, and 2 patients had to undergo re-operations due to technical errors. One patient acquired a bacterial arthritis 6 months after the operation. The clinical short-term results with HO seem to be comparable to those reported earlier for closing-wedge osteotomy. However, HO is a trying procedure for the patient as well as for the surgeon, due to frequent minor complications requiring frequent follow-ups.

Ultrasound of the phalanges is not related to a previous fracture. A comparison between ultrasound of the phalanges, calcaneus, and DXA of the spine and hip in 75-year-old women

Recently, an ultrasound (US) device for measurement of amplitude-dependent speed of sound in four proximal phalanges of the hand (DBM Sonic 1200, IGEA, Carpi, Mo, Italy) has been introduced but has not been thoroughly investigated in populations at most risk for fragility fractures (i.e., elderly women). As part of the Malmö Osteoporosis Prospective Risk Assessment study (OPRA), we investigated 1044 randomly selected women, all 75 yr of age, with US of the phalanges and, for comparison, also with two more established methods for bone mass measurement: US of the calcaneus and dual-energy X-ray absorptiometry (DXA) of the hip and spine, both methods having an ability to predict fracture. A self-assessment questionnaire was used to obtain information on previous fracture and age at fracture event. We found a low correlation between US of the phalanges and US of the calcaneus speed of sound (SoS) (r = 0.11, p < 0.01), US of the calcaneus (stiffness) (r = 0.09, p < 0.05), DXA of the femoral neck (r = 0.09, p < 0.05), and DXA of the spine (r = 0.10, p < 0.01) and no significant correlation between US of the phalanges and US of the calcaneus broadband ultrasound attenuation (BUA) and DXA trochanter. Also, no differences in US of the phalanges were found when comparing women without any fracture with women with at least one fracture, whereas US of the calcaneus (SoS, BUA, and stiffness) and DXA of the femoral neck, trochanter, and spine were all lower in the women with a fracture history (p < 0.0001). In addition, the precision of the US of the phalanges method was evaluated and found to be lower in these elderly women, compared to the precision reported by others and the manufacturer. In summary, the present data indicate that US of the phalanges is not a usable tool for estimating fracture risk in an elderly female population.

Is there a relationship between balance, gait performance and muscular strength in 75-year-old women?

OBJECTIVE

To see if there is a relationship between clinical and laboratory tests of balance, muscular strength and gait in elderly women.

DESIGN

A randomized population-based study.

SETTINGS

Malmö, Sweden.

METHODS

We investigated balance with a simple test of standing on one leg, as well as a computerized balance platform. Muscular strength was tested by computerized dynamometer. Extension and flexion of the knee and dorsiflexion of the ankle were tested. We measured the time and number of steps taken to walk a certain distance and the subjects' height and weight.

PARTICIPANTS

418 randomly selected 75-year-old women, of whom 230 took part.

RESULTS

There was no relation between the computerized balance tests and any of the other tests. The non-computerized balance test was correlated with gait time and number of steps (r = -0.50, P<0.001 and r = -0.40, P<0.001, respectively). Tests of extension and flexion, strength of the knee and ankle dorsiflexion were related to gait, speed and number of steps. Heavy women had poorer balance when assessed by the non-computerized test (r = -0.32, P<0.001) and with the computerized, stable platform, eyes-open test (r = 0.27, P<0.001) and eyes-closed test (r = 0.44, P<0.001). The heavier an individual was, the slower her gait and the shorter her steps, despite having stronger knee muscles.

CONCLUSION

There is no relationship between the simple balance tests and computerized platform tests. Muscle strength of the leg is not necessarily linked to balance, but rather to gait performance.