| 11. |
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| 12. |
- Bornefalk, Eva, et al.
(författare)
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Age-dependent effect of oral glucocorticoids on markers of bone resorption in patients with acute asthma
- 1998
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 63:1, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- It is generally accepted that bone formation is depressed during corticosteroid treatment, but the effects of glucocorticoids on bone resorption are less well characterized. We have investigated the effects of short-term treatment with high-dose oral glucocorticoids on biochemical markers of bone turnover in 20 consecutive patients with asthma who sought help for acute respiratory obstruction in our emergency department. Serum concentrations of the carboxy-terminal cross-linked telopeptide of type 1 collagen (1CTP), reflecting bone resorption, and the carboxy-terminal propeptide of type 1 procollagen (P1CP), reflecting bone formation, were measured by radioimmunoassay. Changes of the circulating levels of the bone resorption marker 1CTP after treatment were age dependent with a significant negative correlation (r = -0.54, P = 0.01). The dependency on age remained when correcting, in a multiple linear regression analysis, for 1CTP levels at admission, weight, sex, and daily maintenance dose of inhaled glucocorticoids. Circulating levels of P1CP were suppressed in the whole group 1 week after initiation of glucocorticoid therapy, from 123.3 +/- 10.2 ng/ml at admission to 88.1 +/- 6.3 ng/ml after 1 week (P < 0.01). The changes in P1CP levels were not related to age. Our data indicate that bone formation is suppressed by glucocorticoids in all age groups, whereas the effect of glucocorticoids on markers of bone resorption is dependent on age.
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| 13. |
- Brage, M, et al.
(författare)
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Different cysteine proteinases involved in bone resorption and osteoclast formation.
- 2005
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Ingår i: Calcified tissue international. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 76:6, s. 439-47
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Tidskriftsartikel (refereegranskat)abstract
- Cysteine proteinases, especially cathepsin K, play an important role in osteoclastic degradation of bone matrix proteins and the process can, consequently, be significantly inhibited by cysteine proteinase inhibitors. We have recently reported that cystatin C and other cysteine proteinase inhibitors also reduce osteoclast formation. However, it is not known which cysteine proteinase(s) are involved in osteoclast differentiation. In the present study, we compared the relative potencies of cystatins C and D as inhibitors of bone resorption in cultured mouse calvariae, osteoclastogenesis in mouse bone marrow cultures, and cathepsin K activity. Inhibition of cathepsin K activity was assessed by determining equilibrium constants for inhibitor complexes in fluorogenic substrate assays. The data demonstrate that whereas human cystatins C and D are equipotent as inhibitors of bone resorption, cystatin D is 10-fold less potent as an inhibitor of osteoclastogenesis and 200-fold less potent as an inhibitor of cathepsin K activity. A recombinant human cystatin C variant with Gly substitutions for residues Arg8, Leu9, Val10, and Trp106 did not inhibit bone resorption, had 1,000-fold decreased inhibitory effect on cathepsin K activity compared to wildtype cystatin C, but was equipotent with wildtype cystatin C as an inhibitor of osteoclastogenesis. It is concluded that (i) different cysteine proteinases are likely to be involved in bone resorption and osteoclast formation, (ii) cathepsin K may not be an exclusive target enzyme in any of the two systems, and (iii) the enzyme(s) involved in osteoclastogenesis might not be a typical papain-like cysteine proteinase.
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| 14. |
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| 15. |
- Brahm, Helena, et al.
(författare)
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Relationships between bone mass measurements and lifetime physical activity in a Swedish population
- 1998
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 62:5, s. 400-412
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Tidskriftsartikel (refereegranskat)abstract
- Lifetime occupational and leisure time activities were assessed by a questionnaire in order to evaluate their relationship to bone mass measurements and biochemical markers of bone metabolism in a population of 61 women and 61 men, randomly selected from a Swedish population register, to represent ages between 22 and 85 years. We also considered possible confounders by using questions about smoking habits, milk consumption, hormone replacement therapy (HRT), and menopausal age. Bone mineral density (BMD) and bone mineral content (bone mass, BMC) of the total body, lumbar spine, and proximal femur (neck, trochanter, Ward's triangle) were measured by dual energy X-ray absorptiometry (DXA), and BMD of the forearm with single energy X-ray absorptiometry (SXA). In addition, both DXA and SXA provided information on bone area. Quantitative ultrasound measurements (QUS) at the heel were performed to assess the speed of sound (SOS) and broadband ultrasound attenuation (BUA). Fasting blood samples were analyzed for biochemical markers of bone metabolism as well as parathyroid hormone (PTH) and total serum calcium. After adjustment for confounding factors, neither BMD nor QUS measurements were consistently related to lifetime leisure time or occupational activities; nor were there any consistent patterns relating biochemical markers of bone metabolism to bone mass measurements. However, physical activity seemed to influence bone mass, area, and width more than density. In men, high levels of leisure time activity were associated with raised values for lumbar spine area (6.2%) and width (3.3%) as well as for femoral neck area (5.5%) compared with their low activity counterpart. Men exposed to high levels of occupational activity demonstrated lower lumbar spine BMD (10.9%) and area (5.3%) than men with low activity levels. Within an unselected Swedish population, estimation of lifetime occupational and sport activities as well as bedrest, using a questionnaire, demonstrated no major effects on bone density. However, the association between high levels of lifetime activity and raised values for bone mass, area, and width indicate that geometrical changes in bone may provide better estimations of mechanically induced bone strength than bone density, at least in men.
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| 16. |
- Brändström, Helena, et al.
(författare)
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Single nucleotide polymorphisms in the human gene for osteoprotegerin are not related to bone mineral density or fracture in elderly women
- 2004
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 0171-967X .- 1432-0827. ; 74:1, s. 18-24
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 17. |
- Buttazzoni, Christian, et al.
(författare)
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A Pediatric Bone Mass Scan Has Poor Ability to Predict Adult Bone Mass: A 28-Year Prospective Study in 214 Children.
- 2014
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 94:2, s. 232-239
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Tidskriftsartikel (refereegranskat)abstract
- As the correlation of bone mass from childhood to adulthood is unclear, we conducted a long-term prospective observational study to determine if a pediatric bone mass scan could predict adult bone mass. We measured cortical bone mineral content (BMC [g]), bone mineral density (BMD [g/cm(2)]), and bone width (cm) in the distal forearm by single photon absorptiometry in 120 boys and 94 girls with a mean age of 10 years (range 3-17) and mean 28 years (range 25-29) later. We calculated individual and age-specific bone mass Z scores, using the control cohort included at baseline as reference, and evaluated correlations between the two measurements with Pearson's correlation coefficient. Individual Z scores were also stratified in quartiles to register movements between quartiles from growth to adulthood. BMD Z scores in childhood and adulthood correlated in both boys (r = 0.35, p < 0.0001) and girls (r = 0.50, p < 0.0001) and in both children ≥10 years at baseline (boys r = 0.43 and girls r = 0.58, both p < 0.0001) and children <10 years at baseline (boys r = 0.26 and girls r = 0.40, both p < 0.05). Of the children in the lowest quartile of BMD, 58 % had left the lowest quartile in adulthood. A pediatric bone scan with a value in the lowest quartile had a sensitivity of 48 % (95 % confidence interval [CI] 27-69 %) and a specificity of 76 % (95 % CI 66-84 %) to identify individuals who would remain in the lowest quartile also in adulthood. Childhood forearm BMD explained 12 % of the variance in adult BMD in men and 25 % in women. A pediatric distal forearm BMD scan has poor ability to predict adult bone mass.
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| 18. |
- Buttazzoni, Christian, et al.
(författare)
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A Pediatric Bone Mass Scan has Poor Ability to Predict Peak Bone Mass: An 11-Year Prospective Study in 121 Children.
- 2015
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 96:5, s. 379-388
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Tidskriftsartikel (refereegranskat)abstract
- This 11-year prospective longitudinal study examined how a pre-pubertal pediatric bone mass scan predicts peak bone mass. We measured bone mineral content (BMC; g), bone mineral density (BMD; g/cm(2)), and bone area (cm(2)) in femoral neck, total body and lumbar spine by dual-energy X-ray absorptiometry in a population-based cohort including 65 boys and 56 girls. At baseline all participants were pre-pubertal with a mean age of 8 years (range 6-9), they were re-measured at a mean 11 years (range 10-12) later. The participants were then mean 19 years (range 18-19), an age range that corresponds to peak bone mass in femoral neck in our population. We calculated individual BMC, BMD, and bone size Z scores, using all participants at each measurement as reference and evaluated correlations between the two measurements. Individual Z scores were also stratified in quartiles to register movements between quartiles from pre-pubertal age to peak bone mass. The correlation coefficients (r) between pre-pubertal and young adulthood measurements for femoral neck BMC, BMD, and bone area varied between 0.37 and 0.65. The reached BMC value at age 8 years explained 42 % of the variance in the BMC peak value; the corresponding values for BMD were 31 % and bone area 14 %. Among the participants with femoral neck BMD in the lowest childhood quartile, 52 % had left this quartile at peak bone mass. A pediatric bone scan with a femoral neck BMD value in the lowest quartile had a sensitivity of 47 % [95 % confidence interval (CI) 28, 66] and a specificity of 82 % (95 % CI 72, 89) to identify individuals who would remain in the lowest quartile at peak bone mass. The pre-pubertal femoral neck BMD explained only 31 % of the variance in femoral neck peak bone mass. A pre-pubertal BMD scan in a population-based sample has poor ability to predict individuals who are at risk of low peak bone mass.
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| 19. |
- Buttazzoni, Christian, et al.
(författare)
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Preterm Children Born Small for Gestational Age are at Risk for Low Adult Bone Mass.
- 2016
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 98:2, s. 105-113
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Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional studies suggest that premature birth and low birth weight may both be associated with low peak bone mass. We followed bone traits in preterm individuals and controls for 27 years and examined the effects of birth weight relative to gestational age [stratified as small for gestational age (SGA) or appropriate for gestational (AGA)] on adult bone mineral density (BMD). We measured distal forearm BMC (g/cm) and BMD (g/cm(2)) with single-photon absorptiometry (SPA) in 46 preterm children (31 AGA and 15 SGA) at mean age 10.1 years (range 4-16) and in 84 healthy age-matched children. The measurements were repeated 27 years later with the same SPA apparatus but then also with dual energy absorptiometry and peripheral computed tomography (pQCT). Preterm individuals were shorter (p = 0.03) in adulthood than controls. Preterm AGA individuals had similar BMC and BMD height-adjusted Z-scores in adulthood compared to controls. Preterm SGA individuals had lower distal forearm BMC and BMD height-adjusted Z-scores in adulthood than both controls and preterm AGA individuals. Preterm SGA individuals had lower gain from childhood to adulthood in distal forearm BMC height-adjusted Z-scores than controls (p = 0.03). The deficits in preterm SGA individuals in adulthood were also captured by DEXA in height-adjusted femoral neck (FN) BMC Z-score and height-adjusted FN BMD Z-score and by pQCT in tibial cross-sectional area (CSA) Z-score and stress strain index (SSI) Z-score, where all measurements were lower than controls (all p values <0.05). Preterm SGA individuals are at increased risk of reaching low adult bone mass, at least partly due to a deficit in the accrual of bone mineral during growth. In our cohort, we were unable to find a similar risk in preterm AGA individuals.
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| 20. |
- Callréus, Mattias, et al.
(författare)
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Adverse Effects of Smoking on Peak Bone Mass May Be Attenuated by Higher Body Mass Index in Young Female Smokers.
- 2013
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 93:6, s. 517-525
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Tidskriftsartikel (refereegranskat)abstract
- Smoking is associated with postmenopausal bone loss and fracture, but the effect of smoking on bone in younger women is unclear. Peak bone mass is an important determinant for fracture risk; therefore, our aim was to evaluate the association between smoking and bone mass in 25-year-old women, specifically the influence of daily cigarette consumption and total exposure, duration, age at starting smoking, and time since smoking cessation on bone density and fracture risk. Smoking and bone mineral density (BMD) data were available for 1,054 women from the PEAK-25 cohort. Analyses comparing current smokers with women who never smoked were performed using number of cigarettes per day, pack-years, smoking duration, age smoking started, and, for former smokers, age at quitting. BMD did not differ between never, former, and current smokers; and the relative fracture risk in smokers was not significant (relative risk [RR] = 1.2, 95 % confidence interval 0.8-1.9). Among current smokers, BMD decreased with a dose response as cigarette consumption increased (femoral neck p = 0.037). BMD was not significantly lower in young women who had smoked for long duration or started smoking early (p = 0.07-0.64); long duration and early start were associated with higher body mass index (BMI; p = 0.038). Lower BMD persisted up to 24 months after smoking cessation (p = 0.027-0.050), becoming comparable to never-smokers after 24 months. Hip BMD was negatively associated with smoking and dose-dependent on cigarette consumption. Smoking duration was not associated with BMD, although young women with a long smoking history had higher BMI, which might attenuate the adverse effects from smoking.
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