Bone mineralization in rhythmic gymnasts before puberty: associations with selected anthropometrical, body compositional and hormonal parameters
Date
2012-06-28
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Abstract
Osteoporoos on tõsine ülemaailmne terviseprobleem. On leitud, et parem luutihedus lapsena võib kanduda täiskasvanuikka ja nii on tulevikus suurem võimalus ennetada osteoporoosi. Lisaks geneetilistele faktorite ja toitumisele mõjutavad laste luutihedust kehamass, kehaline koormus, endokriinsüsteem ja puberteedi algusaeg. Kehamass mõjutab luutihedust mehaanilise koormuse ja hormoonide (sh leptiin, adiponektiin, greliin) vahendusel. Mainitud hormoonid mõjutavad luud aga läbi kehakoostise ja samuti kesknärvisüsteemi vahendusel. Viimastel andmetel peetakse lastel rasvavabamassi oluliseks luu mineraaltiheduse tõstjaks, samas on leitud, et rasvamass võib luutihedusele mõjuda nii positiivselt kui ka negatiivselt. Selgelt mõjub luu mineraaltihedusele positiivselt aga regulaarne ning intensiivne hüppeline ehk löögiline kehaline koormus. Iluvõimlemine on kindlasti löögilise spordiala esindajaks, kuna ühel treeningul võib iluvõimleja sooritada isegi kuni 400 maksimaalse pingutusega hüpet. Iluvõimlemisega alustatakse 3-4 aastaselt, treeningud on suhteliselt varakult intensiivsed ja mahukad langetades oluliselt võimlejate keha- ning rasvamassi. Kuigi puberteediealiste sportlaste luutiheduse seoseid mainitud faktoritega on korduvalt uuritud, on siiani vähem informatsiooni, kuidas intensiivne kehaline koormus on seotud prepuberteediealiste noorsportlaste luutihedusega, kelle kehamass on vähemaktiivsete eakaaslastega võrreldes madalam. Antud töö eesmärgiks oli seega hinnata prepuberteediealiste iluvõimlejate luutiheduse seoseid kehakoostise ja hormoonidega. Tulemused näitasid, et võimlejatel on tunduvalt suurem luu mineraalainete tihedus, madalam kehamass ning leptiini kontsentratsioon. Noortel iluvõimlejatel on luutihedus enim seotud rasvamassi, samaealistel regulaarselt spordiga mittetegevatel tüdrukutel aga eelkõige rasvavabamassi, leptiini ja ghreliiniga. Seega võib eeldada, et regulaarsel hüppelisel koormusel on luu mineraliseerumisele oluline positiivne mõju, olgugi, et võimlejate kehamass ja leptiini kontsentratsioon on inaktiivsete lastega võrreldes tunduvalt madalam.
Osteoporosis is a major global public health concern. Individuals who achieve a higher peak bone mass during childhood might prevent osteoporosis in later life. Factors predicting bone mineral density in children are genetic factors, lifestyle – diet, body composition, physical activity,endocrine status, and timing of pubertal maturation. Body composition affects bone by mechanical loading and hormones (leptin, adiponectin, ghrelin). These hormones predict bone mineral density by body composition and central nervous system. Fat free mass correlates positively with bone mineral density, but it is found that fat mass might be positive or negative independent determinant of bone mass. Regular high-impact weight-bearing physical activity is certainly one of the main factor for bone development. Rhythmic gymnastics seems to be especially osteogenic in children, probably due to high-volume, high impact training and the involvement at a relatively early age (3-4y). The relationships between athletes`bone mineral density and factors mentioned before are several times studied, but there is a little information how intensive physical activity is related to bone mineral density in prepubertal gymnasts whose body mass is lower than inactive controls. The aim of the current thesis was to investigate possible associations between specific anthropometric, body composition and hormonal values with bone mineral parameters in prepubertal rhythmic gymnasts and untrained controls. Gymnasts had significantly higher bone mineral density and lower body mass and leptin concentration than controls. In rhythmic gymnasts bone mineral density was related to fat mass and in untrained controls with fat free mass, leptin and ghrelin concentration. So it may assume that high-impact activity has strong impact to bone mineralization, although gymnasts have lower body mass and leptin concentration compared to untrained controls.
Osteoporosis is a major global public health concern. Individuals who achieve a higher peak bone mass during childhood might prevent osteoporosis in later life. Factors predicting bone mineral density in children are genetic factors, lifestyle – diet, body composition, physical activity,endocrine status, and timing of pubertal maturation. Body composition affects bone by mechanical loading and hormones (leptin, adiponectin, ghrelin). These hormones predict bone mineral density by body composition and central nervous system. Fat free mass correlates positively with bone mineral density, but it is found that fat mass might be positive or negative independent determinant of bone mass. Regular high-impact weight-bearing physical activity is certainly one of the main factor for bone development. Rhythmic gymnastics seems to be especially osteogenic in children, probably due to high-volume, high impact training and the involvement at a relatively early age (3-4y). The relationships between athletes`bone mineral density and factors mentioned before are several times studied, but there is a little information how intensive physical activity is related to bone mineral density in prepubertal gymnasts whose body mass is lower than inactive controls. The aim of the current thesis was to investigate possible associations between specific anthropometric, body composition and hormonal values with bone mineral parameters in prepubertal rhythmic gymnasts and untrained controls. Gymnasts had significantly higher bone mineral density and lower body mass and leptin concentration than controls. In rhythmic gymnasts bone mineral density was related to fat mass and in untrained controls with fat free mass, leptin and ghrelin concentration. So it may assume that high-impact activity has strong impact to bone mineralization, although gymnasts have lower body mass and leptin concentration compared to untrained controls.
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Keywords
iluvõimlejad, luutihedus, keha koostis, antropomeetria, hormoonid, füüsiline koormus, aesthetic gymnasts, bone density, body composition, anthropometry, hormones, physical load