| 1. |
- Gerdhem, Paul, et al.
(författare)
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Associations between homocysteine, bone turnover, BMD, mortality, and fracture risk in elderly women
- 2007
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 22:1, s. 127-134
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Grundberg, Elin, et al.
(författare)
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Vitamin D receptor 3 ' haplotypes are unequally expressed in primary human bone cells and associated with increased fracture risk: The MrOS study in Sweden and Hong kong
- 2007
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 22:6, s. 832-840
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Tidskriftsartikel (refereegranskat)abstract
- The VDR is a prime candidate gene for osteoporosis. Here, we studied three common VDR haplotypes in relation to bone phenotypes in 5014 participants of the global MrOS Study. We also studied the relative expression of the haplotypes in human bone cells. One haplotype was associated with increased fracture risk and differently expressed in primary human bone cells. Introduction: Vitamin D plays an essential role in skeletal metabolism by binding to its nuclear steroid receptor, the vitamin D receptor (VDR). The heritability of BMD is well established, and the VDR gene is considered a prime candidate suggested to partially account for genetically controlled BMD variance in the population. Materials and Methods: Here, we reconstructed common haplotypes in the VDR 3 ' untranslated region (UTR) and studied the association to BMD and risk of vertebral fractures in elderly men from Sweden (n = 3014) and Hong Kong (n = 2000), all participants of the global MrOS Study. To assess any functional implications of the VDR polymorphisms, we studied allele-specific expressions of the different VDR 3 ' UTR haplotypes in the normal chromosomal context of 70 unrelated human trabecular bone samples. This was performed by quantitative genotyping of coding polymorphisms in RNA samples and in corresponding DNA samples isolated from the bone samples. Results: Three major haplotypes were reconstructed and in agreement with the previously well-defined baT, BAt, and bAT haplotypes, herein denoted Hap1, Hap2, and Hap3. The Hap1 haplotype was independently associated with increased risk of vertebral fractures in Swedish men (OR, 1.655; 95% Cl, 1.146-2.391;p < 0.01) and with lower lumbar spine BMD in elderly men from Sweden (p < 0.01) and Hong Kong (P < 0.05). The VDR gene was also shown to exhibit a 3 ' UTR haplotype dependent allelic imbalance, indicating that the VDR Hap1 allele was overexpressed in human trabecular bone samples. Conclusions: The results indicate that the relatively overexpressed VDR Hap1 haplotype could be considered a risk allele for osteoporosis regardless of ethnicity.
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| 3. |
- Hans, Didier, et al.
(författare)
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Assessment of the 10-year probability of osteoporotic hip fracture combining clinical risk factors and heel bone ultrasound: the EPISEM prospective cohort of 12,958 elderly women.
- 2008
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Ingår i: Journal of bone and mineral research. - : Wiley. - 1523-4681 .- 0884-0431. ; 23:7, s. 1045-51
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to develop a hip screening tool that combines relevant clinical risk factors (CRFs) and quantitative ultrasound (QUS) at the heel to determine the 10-yr probability of hip fractures in elderly women. The EPISEM database, comprised of approximately 13,000 women 70 yr of age, was derived from two population-based white European cohorts in France and Switzerland. All women had baseline data on CRFs and a baseline measurement of the stiffness index (SI) derived from QUS at the heel. Women were followed prospectively to identify incident fractures. Multivariate analysis was performed to determine the CRFs that contributed significantly to hip fracture risk, and these were used to generate a CRF score. Gradients of risk (GR; RR/SD change) and areas under receiver operating characteristic curves (AUC) were calculated for the CRF score, SI, and a score combining both. The 10-yr probability of hip fracture was computed for the combined model. Three hundred seven hip fractures were observed over a mean follow-up of 3.2 yr. In addition to SI, significant CRFs for hip fracture were body mass index (BMI), history of fracture, an impaired chair test, history of a recent fall, current cigarette smoking, and diabetes mellitus. The average GR for hip fracture was 2.10 per SD with the combined SI + CRF score compared with a GR of 1.77 with SI alone and of 1.52 with the CRF score alone. Thus, the use of CRFs enhanced the predictive value of SI alone. For example, in a woman 80 yr of age, the presence of two to four CRFs increased the probability of hip fracture from 16.9% to 26.6% and from 52.6% to 70.5% for SI Z-scores of +2 and -3, respectively. The combined use of CRFs and QUS SI is a promising tool to assess hip fracture probability in elderly women, especially when access to DXA is limited.
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| 4. |
- Holmer, Helene, et al.
(författare)
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Fracture incidence in GH-deficient patients on complete hormone replacement including GH
- 2007
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 22:12, s. 1842-1850
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Tidskriftsartikel (refereegranskat)abstract
- Fracture risk in GHD patients is not definitely established. Studying fracture incidence in 832 patients on GH therapy and 2581 matched population controls, we recorded a doubled fracture risk in CO GHD women, but a significantly lower fracture risk in AO GHD men. Introduction: The objective of this study was to evaluate fracture incidence in patients wilh confirmed growth hormone deficiency (GHD) on replacement therapy (including growth hormone [GH]) compared with population controls, while also taking potential confounders and effect modifiers into account. Materials and Methods: Eight hundred thirty-two patients with GHD and 2581 matched population controls answered a questionnaire about fractures and other background information. Incidence rate ratio (IRR) and 95% CI for first fracture were estimated. The median time on GH therapy for childhood onset (CO) GHD men and women was 15 and 12 yr, respectively, and 6 and 5 yr for adult onset (AO) GHD men and women, respectively. Results: A more than doubled risk (IRR, 2.29; 95% CI, 1.23-4.28) for nonosteoporotic fractures was recorded in women with CO GHD, whereas no risk increase was observed among CO GHD men (IRR. 0.61) and AO GHD women (IRR, 1.08). A significantly decreased incidence of fractures (IRR, 0.54; 95% CI 0.34-0.86) was recorded in AO GHD men. Conclusions: Increased fracture risk in CO GHD women can most likely be explained by interaction between oral estrogen and the GH-IGF-I axis. The adequate substitution rate of testosterone (90%) and GH (94%) may have resulted in significantly lower fracture risk in AO GHD men.
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| 5. |
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| 6. |
- Johnell, Olof, et al.
(författare)
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Predictive value of BMD for hip and other fractures.
- 2005
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Ingår i: Journal of bone and mineral research. - 0884-0431 .- 1523-4681. ; 20:7, s. 1185-94
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between BMD and fracture risk was estimated in a meta-analysis of data from 12 cohort studies of approximately 39,000 men and women. Low hip BMD was an important predictor of fracture risk. The prediction of hip fracture with hip BMD also depended on age and z score. INTRODUCTION: The aim of this study was to quantify the relationship between BMD and fracture risk and examine the effect of age, sex, time since measurement, and initial BMD value. MATERIALS AND METHODS: We studied 9891 men and 29,082 women from 12 cohorts comprising EVOS/EPOS, EPIDOS, OFELY, CaMos, Rochester, Sheffield, Rotterdam, Kuopio, DOES, Hiroshima, and 2 cohorts from Gothenburg. Cohorts were followed for up to 16.3 years and a total of 168,366 person-years. The effect of BMD on fracture risk was examined using a Poisson model in each cohort and each sex separately. Results of the different studies were then merged using weighted coefficients. RESULTS: BMD measurement at the femoral neck with DXA was a strong predictor of hip fractures both in men and women with a similar predictive ability. At the age of 65 years, risk ratio increased by 2.94 (95% CI = 2.02-4.27) in men and by 2.88 (95% CI = 2.31-3.59) in women for each SD decrease in BMD. However, the effect was dependent on age, with a significantly higher gradient of risk at age 50 years than at age 80 years. Although the gradient of hip fracture risk decreased with age, the absolute risk still rose markedly with age. For any fracture and for any osteoporotic fracture, the gradient of risk was lower than for hip fractures. At the age of 65 years, the risk of osteoporotic fractures increased in men by 1.41 per SD decrease in BMD (95% CI = 1.33-1.51) and in women by 1.38 per SD (95% CI = 1.28-1.48). In contrast with hip fracture risk, the gradient of risk increased with age. For the prediction of any osteoporotic fracture (and any fracture), there was a higher gradient of risk the lower the BMD. At a z score of -4 SD, the risk gradient was 2.10 per SD (95% CI = 1.63-2.71) and at a z score of -1 SD, the risk was 1.73 per SD (95% CI = 1.59-1.89) in men and women combined. A similar but less pronounced and nonsignificant effect was observed for hip fractures. Data for ultrasound and peripheral measurements were available from three cohorts. The predictive ability of these devices was somewhat less than that of DXA measurements at the femoral neck by age, sex, and BMD value. CONCLUSIONS: We conclude that BMD is a risk factor for fracture of substantial importance and is similar in both sexes. Its validation on an international basis permits its use in case finding strategies. Its use should, however, take account of the variations in predictive value with age and BMD.
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| 7. |
- Karimian, Elham, et al.
(författare)
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Tamoxifen impairs both longitudinal and cortical bone growth in young male rats.
- 2008
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - : Wiley. - 1523-4681. ; 23:8, s. 1267-77
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Tidskriftsartikel (refereegranskat)abstract
- Tamoxifen (Tam) has been used experimentally to treat boys with gynecomastia and girls with McCune-Albright syndrome. This drug was recently shown to inhibit the growth of cultured fetal rat metatarsal bones and thus might also affect bone growth in vivo. Four-week-old Sprague-Dawley rats were gavaged daily with vehicle alone (peanut oil), Tam (40 mg/kg/d; 1 or 4 wk), or estradiol (40 microg/kg/d; 4 wk). Five of the 10 rats in each group were killed after 4 wk and the other five after 14 wk of recovery. Bone growth was followed by repeat DXA scans, whereas other bone parameters and spine length were evaluated by pQCT and X-ray at the time of death. Four-week Tam treatment significantly decreased body weight, nose-anus distance, spinal and tibial bone lengths, trabecular BMD, cortical periosteal circumference, and bone strength and also reduced serum IGF-I levels (424 +/- 54 versus 606 +/- 53 ng/ml in control; p < 0.05). Analysis of the tibial growth plate of treated rats showed elevated chondrocyte proliferation (BrdU) and apoptosis (TUNEL), as well as decreases in the number of hypertrophic chondrocytes and in the size of terminal hypertrophic chondrocytes. Despite a complete catch-up of body weight after 14 wk of recovery, the tibia was still shorter (p < 0.001) and its cortical region was smaller. We conclude that, when administered at a clinically relevant dose, Tam causes persistent retardation of longitudinal and cortical radial bone growth in young male rats. Our findings suggest that this inhibition results from local effects on the growth plate cartilage and systemic suppression of IGF-I production. Based on these rat data, we believe that Tam, if given to growing individuals, might compromise cortical bone growth, bone strength, and adult height.
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| 8. |
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| 9. |
- Kindblom, Jenny, 1971, et al.
(författare)
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Plasma osteocalcin is inversely related to fat mass and plasma glucose in elderly Swedish men
- 2009
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Ingår i: Journal of bone and mineral research. - : Wiley. - 1523-4681 .- 0884-0431. ; 24:5, s. 785-91
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Tidskriftsartikel (refereegranskat)abstract
- The osteoblast-derived protein osteocalcin has recently been shown to affect adiposity and glucose homeostasis in mice, suggesting that the skeleton influences energy metabolism through an endocrine mechanism. The aim of this study was to investigate the relationship between plasma osteocalcin and parameters reflecting fat mass and glucose homeostasis in humans. Fasting levels of plasma osteocalcin, plasma glucose, serum insulin, and lipids were analyzed in elderly men (75.3 +/- 3.2 yr of age) in the Gothenburg part (all subjects, n = 1010; nondiabetic, n = 857; diabetic, n = 153) of the MrOS Sweden study. Fat mass and lean mass were analyzed using DXA. Diabetic subjects had lower plasma osteocalcin (-21.7%, p < 0.001) than nondiabetic subjects. For both all subjects and nondiabetic subjects, plasma osteocalcin was clearly inversely related to body mass index (BMI), fat mass, and plasma glucose (p < 0.001), whereas it was not associated with height or lean mass. Plasma osteocalcin explained a substantial part (6.3%) of the variance in plasma glucose, whereas it associated moderately with serum insulin. Multiple linear regression models adjusting for serum insulin and fat mass showed that plasma osteocalcin was an independent negative predictor of plasma glucose (p < 0.001). We herein, for the first time in humans, show that plasma osteocalcin is inversely related to fat mass and plasma glucose. Although one should be cautious with mechanistic interpretations of cross-sectional association studies, our human data support recently published experimental studies, showing endocrine functions of osteoblast-derived osteocalcin on glucose and fat homeostasis.
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| 10. |
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