| 1. |
- Alwis, Gayani, et al.
(författare)
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A 2-year school-based exercise programme in pre-pubertal boys induces skeletal benefits in lumbar spine.
- 2008
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Ingår i: Acta Pædiatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 97, s. 1564-1571
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to evaluate if a general school-based exercise intervention programme in pre-pubertal boys would render site-specific benefits in bone mineral accrual and gain in femoral neck structure. Methods: Eighty boys aged 7-9 years were included in a curriculum-based exercise intervention programme comprising 40 min of general physical activity per school day (200 min/week) for 2 years. Fifty-seven age-matched boys, assigned to the general Swedish school curriculum of 60 min/week, served as controls. Bone mineral content was measured with dual X-ray absorptiometry of the total body, the third lumbar vertebra and hip. Specific software, the hip structural analyses, evaluated the structural properties of the femoral neck. Annual changes were compared. The level of physical activity was estimated through questionnaires and accelerometers. Results: The mean annual bone mineral content gain in third lumbar vertebra was 3.0 percentage points (p < 0.01) and in width 1.3 percentage points (p < 0.01) greater in the intervention than in the control group. The weekly duration of exercise estimated through the questionnaire correlated with gain in bone mineral content in third lumbar vertebra (r = 0.25, p = 0.005) and vertebra width (r = 0.20, p = 0.02). Conclusion: A school-based exercise intervention programme in pre-pubertal boys enhances the skeletal benefits at lumbar spine.
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| 2. |
- Alwis, Gayani, et al.
(författare)
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A school-curriculum-based exercise intervention program for two years in pre-pubertal girls does not influence hip structure.
- 2008
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Ingår i: Dynamic Medicine. - : Springer Science and Business Media LLC. - 1476-5918. ; 7, s. 8-8
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: It is known that physical activity during growth has a positive influence on bone mineral accrual, and is thus possibly one strategy to prevent osteoporosis. However, as bone geometry, independent of areal bone mineral density (aBMD), influences fracture risk, this study aimed to evaluate whether hip structure in pre-pubertal girls is also affected by a two-year exercise intervention program. METHODS: Forty-two girls aged 7-9 years in a school-curriculum-based exercise intervention program comprising 40 minutes of general physical activity per school day (200 minutes per week) were compared with 43 age-matched girls who participated in the general Swedish physical education curriculum comprising a mean of 60 minutes per week. The hip was scanned by dual energy X-ray absorptiometry (DXA) and the hip structural analysis (HSA) software was applied to evaluate bone mineral content (BMC, g), areal bone mineral density (aBMD, g/cm2), periosteal diameter, cross-sectional area (CSA, cm2), section modulus (Z, cm3) and cross-sectional moment of inertia (CSMI, cm4) of the femoral neck (FN). Annual changes were compared. Subjective duration of physical activity was estimated by questionnaire and objective level of everyday physical activity at follow-up by means of accelerometers worn for four consecutive days. All children remained at Tanner stage 1 throughout the study. Group comparisons were made by independent student's t-test between means and analyses of covariance (ANCOVA). RESULTS: At baseline, the two groups did not differ with regard to age, anthropometrics or bone parameters. No between-group differences were observed for annual changes in the FN variables measured. CONCLUSION: A two-year school-based moderately intense general exercise program for 7-9-year-old pre-pubertal girls does not influence structural changes in the FN.
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| 3. |
- Karlsson, Magnus, et al.
(författare)
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Maternity and bone mineral density
- 2005
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 76:1, s. 41318-41318
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Forskningsöversikt (refereegranskat)abstract
- During pregnancy and lactation, changes occur in a variety of factors which have great potential to influence bone mineral density (BMD). Smoking habits, the level of alcohol consumption, the level of physical activity, body weight, soft tissue composition and hormone levels are all factors that change during the course of these conditions. Some of these factors are capable of increasing BMD, and some can reduce it. Due to these various changes, it is virtually impossible to predict the development in BMD that will occur during a pregnancy and lactation. However, longitudinal studies have suggested that both pregnancy and lactation are associated with a BMD loss of up to 5%, albeit that the BMD recovers after weaning. Cross-sectional studies have indicated that women with many children and a long total period of lactation have similar or higher BMD and similar or lower fracture risk than their peers who have not given birth. As the studies showing this trend have been observational and cross-sectional case-control studies, the conclusions can only be regarded as being suggestive, and no causality can be proven.
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| 4. |
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| 5. |
- Rosengren, Björn E., et al.
(författare)
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Downturn in Childhood Bone Mass : A Cross-Sectional Study Over Four Decades
- 2022
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Ingår i: JBMR Plus. - : Wiley. - 2473-4039. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Screen time and physical inactivity have increased among children. As physical activity is a determinant of bone mass, there is a concern that children today have lower bone mass than earlier. If this is true, fractures may become more common in the future. In 2017–2018, we used single-photon absorptiometry (SPA) to measure distal forearm bone mineral density (BMD; mg/cm2) in a normative cohort of 238 boys and 204 girls aged 7 to 15 years. We compared these results to BMD in a normative cohort collected in 1979–1981 (55 boys and 61 girls aged 7 to 15 years) measured by the same scanner. To investigate difference between the two cohorts, we used multiple linear regression with age, sex, and cohort as predictors. Predicted bone density at age 16 years was estimated through the slope values. The bone density-age slope was flatter in the cohort measured in 2017–2018 than in the cohort measured 1979–1981 (−5.6 mg/cm2/yr [95% confidence interval −9.6 to −1.5]). Predicted bone density was at age 16 years in 2017–2018 in boys was 10% lower (−0.9 SD) and in girls 11% lower (−1.1 SD) than in their counterparts measured in 1979–1981. We found indications that children nowadays develop lower bone mass than four decades ago, giving concern that they may have a higher risk of osteoporosis and fragility fractures as they grow old.
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| 6. |
- Rosengren, Björn E., et al.
(författare)
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Time Trends in Trajectories of Forearm Mineral Content and Bone Size during Childhood—Results from Cross-Sectional Measurements with the Same Apparatus Four Decades Apart
- 2023
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Ingår i: JBMR Plus. - : Wiley. - 2473-4039. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Evidence suggests that single photon absorptiometry (SPA)-measured forearm bone mineral density (BMD) is lower in contemporary children in Malmö than it was four decades ago, but the fracture incidence in the at-risk population (all Malmö children) has been stable during the same period. The aim of this study was to evaluate if improvements in skeletal structure over time may explain this observation. In 2017–2018 we measured distal forearm bone mineral content (BMC; mg/cm) and periosteal diameter (mm) in 238 boys and 204 girls aged 7–15 using SPA. Based on the SPA measurements, we calculated forearm BMD (mg/cm2), bone mineral apparent density (BMAD, mg/cm3), section modulus, and strength index (BMAD × section modulus). The results were compared with those derived from measurements of 55 boys and 61 girls of the same ages using the same scanner in 1979–1981. We used log-linear regression with age, sex, and cohort as predictors to investigate differences in trait trajectories (trait versus age slopes [mean percent difference in beta values (95% confidence interval)]). SPA-measured forearm BMC was lower at each age in 2017–2018 compared to 1979–1981 (a mean age and sex adjusted relative difference of 9.1%), the forearm BMC trajectory was similar in 2017–2018 to that in 1979–1981 (reference) [0.0%/year (−1.0%, 1.0%)], while the 2017–2018 forearm periosteal diameter trajectory was steeper [1.1%/year (0.3%, 2.0%)]. Since bone size influences both BMD (BMC divided by scanned area) and mechanical characteristics, the forearm BMD trajectory was flatter in 2017–2018 [−1.1%/year (−2.0%, −0.2%)] and the forearm section modulus trajectory steeper [3.9%/year (1.4%, 6.4%)]. Forearm strength index trajectory was similar [1.8%/year (−0.5%, 4.1%)]. The lower SPA-measured forearm BMD trajectory in contemporary children compared to four decades ago may be offset by changes in forearm bone structure, resulting in similar overall bone strength.
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| 7. |
- Tveit, Magnus, et al.
(författare)
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Bone mass following physical activity in young years: a mean 39-year prospective controlled study in men.
- 2013
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 24:4, s. 1389-1397
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Tidskriftsartikel (refereegranskat)abstract
- This is a study on exercise-associated bone mineral density (BMD) which in men is maintained three decades after cessation of sports. In this prospective controlled cohort study active athletes had a BMD Z-score of 1.0 and after 39 years 0.5 to 1.2 depending on the measured region), using the same single-photon absorptiometry device, dual X-ray absorptiometry (DXA), and peripheral computed tomography (pQCT). INTRODUCTION: The aims of this study were to prospectively evaluate BMD changes in male athletes from activity into long-term retirement and to simultaneously evaluate other bone traits. METHODS: Bone mineral density (grams per square centimeter) was measured in 46 male athletes with a mean age of 22 years (range, 15-40) by using the same single-photon absorptiometry device, both at active career and a mean of 39 years (range, 38-40) later when they had long-term retired. At follow-up, BMD was also evaluated by DXA and pQCT. Twenty-four non-athletic males of similar age served as controls. Between-group differences are presented as means with 95 % confidence intervals. RESULTS: The active athletes (baseline) had a BMD Z-score of 1.0 (0.7, 1.4) in the femoral condyles. The retired athletes (follow-up) had a BMD Z-score of 0.5 to 1.2 depending on the measuring technique and the measured region. The tibial cortical area Z-score at follow-up was 0.8 (0.5, 1.2) and the tibial strength index Z-score 0.7 (0.4, 1.0). There were no changes in BMD Z-scores from activity to retirement, neither when estimated by the same device in different regions [∆ Z-score -0.3 (-0.8, 0.2)] nor in the same region with different devices [∆ Z-score 0.0 (-0.4, 0.4)]. The benefits remained after adjustments for anthropometrics and lifestyle. No correlation was seen with years since retirement. CONCLUSIONS: Exercise-associated high BMD in young years seems, in men, to be maintained three decades after cessation of high-level physical activity.
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| 8. |
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| 9. |
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| 10. |
- Ahlborg, Henrik, et al.
(författare)
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Prevalence of osteoporosis and incidence of hip fracture in women--secular trends over 30 years.
- 2010
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The number of hip fractures during recent decades has been reported to be increasing, partly because of an increasing proportion of elderly women in the society. However, whether changes in hip fracture annual incidence in women are attributable to secular changes in the prevalence of osteoporosis is unclear. METHODS: Bone mineral density was evaluated by single-photon absorptiometry at the distal radius in 456 women aged 50 years or above and living in the same city. The measurements were obtained by the same densitometer during three separate time periods: 1970-74 (n = 106), 1987-93 (n = 175) and 1998-1999 (n = 178), and the age-adjusted prevalence of osteoporosis in these three cohorts was calculated. Additionally, all hip fractures sustained in the target population of women aged 50 years or above between 1967 and 2001 were registered, whereupon the crude and the age-adjusted annual incidence of hip fractures were calculated. RESULTS: There was no significant difference in the age-adjusted prevalence of osteoporosis when the three cohorts were compared (P = 1.00). The crude annual incidence (per 10,000 women) of hip fracture in the target population increased by 110% from 40 in 1967 to 84 in 2001. The overall trend in the crude incidence between 1967 and 2001 was increasing (1.58 per 10,000 women per year; 95 percent confidence interval, 1.17 to 1.99), whereas the age-adjusted incidence was stable over the same period (0.22 per 10,000 women per year; 95 percent confidence interval, -0.16 to 0.60). CONCLUSIONS: The increased number of hip fracture in elderly women is more likely to be attributable to demographic changes in the population than to secular increase in the prevalence of osteoporosis.
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