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

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

A one-year exercise intervention program in pre-pubertal girls does not influence hip structure

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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 <it>t</it>-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.</p> <p>Results</p> <p>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.</p> <p>Conclusion</p> <p>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.</p

The prevalence of gonarthrosis and its relation to meniscectomy in former soccer players

The prevalence of radiographic signs of gonarthrosis and its relation to knee injuries were studied in 286 former soccer players-215 nonelite and 71 elite players-and were compared with 572 age-matched controls with a mean age of 55 years. The prevalence of gonarthrosis among the nonelite players was 4.2%, among the elite players 15.5%, and among the controls 1.6%. Seven of the soccer players had known anterior cruciate ligament injuries, and 40 had had meniscectomies. Of the 32 nonelite players with knee injuries, 4 (13%) had gonarthrosis, and of the 183 without known knee injuries 5 (3%) had gonarthrosis. Among the elite players, the prevalence of gonarthrosis in knees without diagnosed injuries was 11%. We conclude that soccer, especially at an advanced level, is associated with an increased risk for gonarthrosis. After excluding subjects with known knee injuries, there was no difference between nonelite players and controls, but we found a higher rate of gonarthrosis among the elite players

Exercise, bone mass and bone size in prepubertal boys: one-year data from the pediatric osteoporosis prevention study.

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

Daily Physical Education in the School Curriculum in Prepubertal Girls during 1 Year is Followed by an Increase in Bone Mineral Accrual and Bone Width-Data from the Prospective Controlled Malmö Pediatric Osteoporosis Prevention Study.

Abstract The aim of this study was to evaluate a general school-based 1-year exercise intervention program in a population-based cohort of girls at Tanner stage I. Fifty-three girls aged 7–9 years were included. The school curriculum-based exercise intervention program included 40 minutes/school day. Fifty healthy age-matched girls assigned to the general school curriculum of 60 minutes physical activity/week served as controls. Bone mineral content (BMC, g) and areal bone mineral density (aBMD, g/cm2) were measured with dual X-ray absorptiometry (DXA) of the total body (TB), lumbar spine (L2–L4 vertebrae), third lumbar vertebra (L3), femoral neck (FN), and leg. Volumetric bone mineral density (g/cm3) and bone width were calculated at L3 and FN. Total lean body mass and total fat mass were estimated from the TB scan. No differences at baseline were found in age, anthropometrics, or bone parameters when the groups were compared. The annual gain in BMC was 4.7 percentage points higher in the lumbar spine and 9.5 percentage points higher in L3 in cases than in controls (both P < 0.001). The annual gain in aBMD was 2.8 percentage points higher in the lumbar spine and 3.1 percentage points higher in L3 in cases than in controls (both P < 0.001). The annual gain in bone width was 2.9 percentage points higher in L3 in cases than in controls (P < 0.001). A general school-based exercise program in girls aged 7–9 years enhances the accrual of BMC and aBMD and increases bone width