| 1. |
- Alwis, Gayani, et al.
(författare)
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A one-year exercise intervention program in pre-pubertal girls does not influence hip structure
- 2008
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 9:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously reported that a one-year school-based exercise intervention program influences the accrual of bone mineral in pre-pubertal girls. This report aims to evaluate if also hip structure is affected, as geometry independent of bone mineral influences fracture risk. Methods: Fifty-three girls aged 7-9 years were included in a curriculum-based exercise intervention program comprising 40 minutes of general physical activity per school day (200 minutes/week). Fifty healthy age-matched girls who participated in the general Swedish physical education curriculum (60 minutes/week) served as controls. The hip was scanned by dual X-ray absorptiometry (DXA) and the hip structural analysis (HSA) software was applied to evaluate bone mineral content (BMC), areal bone mineral density (aBMD), periosteal and endosteal diameter, cortical thickness, cross-sectional moment of inertia (CSMI), section modulus (Z) and cross-sectional area (CSA) of the femoral neck (FN). Annual changes were compared. Group comparisons were done by independent student's t-test between means and analyses of covariance (ANCOVA). Pearson's correlation test was used to evaluate associations between activity level and annual changes in FN. All children remained at Tanner stage 1 throughout the study. Results: No between-group differences were found during the 12 months study period for changes in the FN variables. The total duration of exercise during the year was not correlated with the changes in the FN traits. Conclusion: Evaluated by the DXA technique and the HSA software, a general one-year school-based exercise program for 7-9-year-old pre-pubertal girls seems not to influence the structure of the hip.
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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. |
- Alwis, Gayani, et al.
(författare)
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Bone mineral accrual and gain in skeletal width in pre-pubertal school children is independent of the mode of school transportation - one-year data from the prospective observational pediatric osteoporosis prevention (POP) study.
- 2007
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 8:1, s. 66-66
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Tidskriftsartikel (refereegranskat)abstract
- Background: Walking and cycling to school could be an important regular source of physical activity in growing children. The aim of this 12 months prospective observational study was thus to evaluate the effect of self-transportation to school on bone mineral accrual and gain in bone width in pre-pubertal children, both traits independently contributing to bone strength. Methods: Ninety-seven girls and 133 boys aged 7-9 years were recruited as a part of the Malmo Pediatric Osteoporosis Prevention (POP) Study in order to evaluate the influence of self-selected school transportation for the accrual of bone mineral and bone width. Children who walked or cycled to school were compared with children who went by bus or car. Bone mineral content (BMC) was measured by dual energy X-ray absorptiometry (DXA) in the lumbar spine (L2-L4), third lumbar vertebra (L3) and hip, and bone width was calculated at L3 and femoral neck (FN). Changes during the first 12 months were compared between the groups. Subjective duration of physical activity was estimated by a questionnaire and objective level of everyday physical activity at follow-up by accelerometers worn for four consecutive days. All children remained in Tanner stage 1 throughout the study. Comparisons were made by independent student's t-tests between means, ANCOVA and Fisher's exact tests. Results: There were no differences in baseline or annual changes in BMC or bone width when the transportation groups were compared. No differences were detected in objectively measured daily level of physical activity by accelerometer. All children reached above 60 minutes of moderate to intense daily physical activity per day, the international recommended level of daily physical activity according to the United Kingdom Expert Consensus Group. Conclusion: The everyday physical activity in these pre-pubertal children seems to be so high that the school transportation contributes little to their total level of physical activity. As a result, the choice of school transportation seems not to influence the accrual of bone mineral or gain in bone size during a I2-month follow-up period.
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| 4. |
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| 5. |
- Alwis, Gayani, et al.
(författare)
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Femoral Neck Bone Strength Estimated by Hip Structural Analysis (HSA) in Swedish Caucasians Aged 6-90 Years.
- 2012
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 90:3, s. 174-185
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Tidskriftsartikel (refereegranskat)abstract
- Dual-energy X-ray absorptiometry hip scans of 1,760 population-based Caucasians, 599 girls and 642 boys aged 6-19 years and 270 women and 249 men aged 20-90 years, were analyzed with the hip structural analysis (HSA) software to present age- and sex-specific normative HSA data of the femoral neck (FN). Measured traits included bone mineral density (BMD), cross-sectional area (CSA), section modulus (Z), periosteal diameter (PD), endosteal diameter (ED), cortical thickness (CT), and cross-sectional moment of inertia (CSMI). When plotting the measured traits versus age, the curves increased with higher ages until statistically significant break points were reached, for all traits at age 17 in girls and age 19 in boys. After the break points, PD and ED increased with higher ages but, as ED increased more than PD, BMD and CT decreased significantly with higher ages. The decline in BMD was counteracted by the increase in bone size so that there was only a nonstatistically significant decrease in bone strength, estimated as Z and CSMI, from break point to age 90. The partial preservation of bone strength was more obvious in men than in women as the decline in BMD was higher in women than in men, while the expansion in PD was larger in men than in women. The sex difference in the normative FN bone strength data seems to be related to sex discrepancies in the development of both bone mass and geometrical parameters during both growth and adulthood.
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| 6. |
- Alwis, Gayani, et al.
(författare)
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Normative Calcaneal Quantitative Ultrasound Data as an Estimation of Skeletal Development in Swedish Children and Adolescents.
- 2010
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 87, s. 493-506
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Tidskriftsartikel (refereegranskat)abstract
- We present age- and gender-specific normative bone status data evaluated by quantitative ultrasound (QUS) in the calcaneus with the Lunar Achilles device and compare these estimates with bone mineral content (BMC) and bone mineral density (BMD) estimated by dual X-ray absorptiometry (DXA). Included were a sample of 518 population-based collected Swedish girls and 558 boys aged 6-19 years. QUS measurements included speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index (SI) in the calcaneus. DXA measurements included BMC and BMD in the femoral neck (FN), lumbar spine (L2-L4), and total body (TB). Height and weight were measured with standard equipment. Age, height, and weight were significantly associated with SOS, BUA, and SI. Compared to SOS, in both girls and boys there was a higher correlation between BUA and FN BMC (r = 0.71 and r = 0.73, respectively), FN BMD (r = 0.68 and r = 0.67, respectively), L2-L4 BMC (r = 0.70 and r = 0.64, respectively), L2-L4 BMD (r = 0.69 and r = 0.64, respectively), TB BMC (r = 0.76 and r = 0.75, respectively), and TB BMD (r = 0.74 and r = 0.74, respectively). The correlations between SOS and FN BMC (r = 0.38 and r = 0.52, respectively), FN BMD (r = 0.41 and r = 0.52, respectively), L2-L4 BMC (r = 0.31 and r = 0.40, respectively), L2-L4 BMD (r = 0.32 and r = 0.41, respectively), TB BMC (r = 0.42 and r = 0.49, respectively), and TB BMD (r = 0.48 and r = 0.54, respectively) were lower, although still significant (all P < 0.001). BUA seems to be the QUS parameter that best resembles the changes in BMC during growth.
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| 7. |
- Alwis, Gayani, et al.
(författare)
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Normative dual energy X-ray absorptiometry data in Swedish children and adolescents.
- 2010
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Ingår i: Acta paediatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 99, s. 1091-1099
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To present normative dual energy X-ray absorptiometry data in healthy young Swedes. Methods: Included were 710 girls and 759 boys aged 6-30 years from southern Sweden. Bone mineral content, bone mineral density, bone size, lean body and fat mass were measured by dual energy X-ray absorptiometry in total body, lumbar spine, hip, arms and legs. Results: Swedish children had similar bone mass to children in the Netherlands but higher than children in Canada and Korea. Height, weight, bone mass, bone size and lean mass increased at a constant rate from age 6 until the rapid increase in all traits at puberty. The pubertal growth spurt started earlier in girls than in boys, while the spurt in boys was larger in magnitude and occurred for a longer period. Around one-quarter of the adult total body and lumbar spine peak bone mineral content was gained during the 2 years with the fastest gain in both genders. Conclusion: This study presents normative bone mass data in Swedish children, data that are similar to that in Dutch children but higher than in Canadian and Korean children. The gain in Swedish children seems to mimic the gain seen in children in other settings.
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| 8. |
- Daly, Robin, et al.
(författare)
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Muscle Determinants of Bone Mass, Geometry and Strength in Prepubertal Girls.
- 2008
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Ingår i: Medicine & Science in Sports & Exercise. - 1530-0315. ; 40:6, s. 1135-1141
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:: The aim of this study was to compare the relative contribution of peak muscle force (isokinetic peak torque) with surrogate estimates of muscle force, including leg lean tissue mass (LTM) and vertical jump height (VJH), on bone mass, geometry and strength in healthy prepubertal girls (n = 103). METHODS:: Total leg and FN BMC and leg LTM were measured by DXA; the hip strength analysis program was used to assess FN diameter, cross-sectional area (CSA) and section modulus (Z). Isokinetic peak torque of the knee extensors and flexors (60 degrees .s) were used as direct measures of peak muscle force. VJH was measured as an estimate of neuromuscular function. Total leg length or femoral length was used as a surrogate measure of moment arm length. RESULTS:: All estimates of muscle function, except VJH, were positively associated with leg BMC (r = 0.72 - 0.90) and FN BMC, geometry and strength (r = 0.35-0.65) (all, P < 0.001). Multiple linear regression analyses revealed that leg LTM and isokinetic peak torque were independently and equally predictive of leg BMC and FN BMC, bone geometry and strength, explaining 8 to 28% of the variance in each of the bone traits after accounting for moment arm length. When isokinetic peak torque was corrected for both leg LTM and moment arm length, it remained an independent predictor of BMC, CSA and Z, but only accounted for an additional 2 to 5% of the variance. CONCLUSION:: These data suggest that DXA-derived leg LTM can be used as a reasonable surrogate for isokinetic peak muscle forces when assessing bone strength in relation to muscular function in healthy pre-pubertal girls.
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| 9. |
- Fritz, Jesper, et al.
(författare)
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A 5-year exercise program in children improves muscle strength without affecting fracture risk.
- 2016
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Ingår i: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6327 .- 1439-6319. ; 116:4, s. 707-715
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Tidskriftsartikel (refereegranskat)abstract
- High level of physical activity (PA) is associated with great muscle strength and high fracture risk. This prospective controlled population-based study evaluated how a pediatric PA intervention program influenced muscle strength and fracture risk.
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| 10. |
- Lindén, Christian, et al.
(författare)
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Exercise, bone mass and bone size in prepubertal boys: one-year data from the pediatric osteoporosis prevention study.
- 2007
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Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 1600-0838 .- 0905-7188. ; 17:4, s. 340-347
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Tidskriftsartikel (refereegranskat)abstract
- This non-randomized prospective controlled study evaluates a daily school-based exercise intervention program of 40 min/school day for I year in a population-based cohort of 81 boys aged 7-9 years. Controls were 57 age-matched boys assigned to the general school curriculum of 60min/ week. Bone mineral content BMC; g) and areal bone mineral density (aBMD; g/cm(2)) were measured with dual X-ray absorptiometry (DXA) of the total body, the third lumbar vertebra (L3) and the femoral neck (FN). Bone width for L3 and FN was calculated from the lumbar spine and hip scan. No differences between the groups were found at baseline in age, anthropometrics or bone parameters. The mean annual gain in L3 BMC was 5.9 percentage points higher (P < 0.001), L3 aBMD a mean 2.1 percentage points higher (P = 0.01) and L3 width a mean 2.3 percentage points higher (P = 0.001) in the cases than in the controls. When all individuals were included in one cohort, the total duration of exercise including both school-based and spare-time training correlated with L3 BMC (r = 0.26, P = 0.003), L3 aBMD (r = 0.18, P = 0.04) and L3 width (r = 0.24, P = 0.006). The study suggests that exercise in pre-pubertal boys influences the accrual of bone mineral and bone width and that a 1-year school-based exercise program confers skeletal benefits, at least in the lumbar spine.
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