A school-curriculum-based exercise intervention program for two years in pre-pubertal girls does not influence hip structure

Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences, Lund University, Sweden.
Dynamic Medicine 02/2008; 7(1):8. DOI: 10.1186/1476-5918-7-8
Source: PubMed


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.
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).
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.
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.

Download full-text


Available from: Magnus K Karlsson
  • [Show abstract] [Hide abstract]
    ABSTRACT: Folding analog-to-digital converters, fold the input signal symmetrically in order to reduce the number of comparators required to amplitude analyze the signal (preprocessing). The optimum symmetrical number system (OSNS) formulation is a direct consequence of the need to extract the maximum amount of information from a symmetrically folded waveform. OSNS folding converters require the minimum number of comparator circuits for any desired resolution. Although there is a direct correspondence between the OSNS and the residue number system, the symmetrical residues cannot be converted to a binary value (e.g., using the Chinese Reminder Theorem) in a straightforward manner. This paper presents an efficient algorithm that converts the symmetrical residues within a three moduli (2<sup>k</sup>+1,2<sup>k</sup>,2<sup>k </sup>-1) OSNS to the equivalent binary representation. Also presented is a pipelined field programmable gate array (FPGA) realization of the algorithm
    No preview · Conference Paper · Jan 1998
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It is increasingly recognized that osteoporosis affects children as well as adults both as a primary problem and as secondary to various diseases, medications, and lifestyle issues. In this review, we emphasize the correct diagnosis of osteoporosis in children as opposed to adults, etiology, and pharmaceutical and non-pharmaceutical treatments. We especially focus on rheumatologic conditions associated with osteoporosis and management issues.
    Full-text · Article · Oct 2009 · Pediatric Rheumatology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this 7-year prospective longitudinal study was to examine whether the level and consistency of leisure-time physical activity (LTPA) during adolescence affected the bone mineral content (BMC) and bone mineral density (BMD) attained at early adulthood. The study subjects were 202 Finnish girls who were 10 to 13 years of age at baseline. Bone area (BA), BMC, and BMD of the total body (TB), total femur (TF), and lumbar spine (L(2)-L(4)) were assessed by dual-energy X-ray absorptiometry (DXA). Scores of LTPA were obtained by questionnaire. Girls were divided into four groups: consistently low physical activity (G(LL)), consistently high (G(HH)), and changed from low to high (G(LH)) and from high to low (G(HL)) during 7 years of follow-up. At baseline, no differences were found in BA, BMC, and BMD among the groups in any of the bone sites. Compared with the G(LL) group, the G(HH) group had higher BMC (11.7% in the TF, p < .05) and BMD at the TB (4.5%) and the TF (12.2%, all p < .05) at age 18. Those in the G(LH) group also had higher a BMC at each site (8.5% to 9.4%, p < .05) and a higher BMD in the TB (5.4%) and the TF (8.9%) than that of G(LL) (all p < 0.05) at the age 18. Our results suggest that long-term leisure-time physical activity has a positive effect on bone mass gain of multiple bone sites in girls during the transition from prepuberty to early adulthood. In addition, girls whose physical activity increases during adolescence also benefit from bone mass gain.
    Full-text · Article · Nov 2009 · Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research
Show more