Preserved bone health in adolescent elite rhythmic gymnasts despite hypoleptinemia.
OBJECTIVE
Leptin is linked to hormonal disturbances occurring in anorexia and positively linked with bone mineral density. The aim of this study was to determine whether hypoleptinemia occurring in rhythmic gymnasts may affect bone health.


METHODS
Leptin, insulin, cortisol, IGF1 levels and bone markers were determined in 36 rhythmic gymnasts (EG) and 20 controls (C). Body composition, BMD at the whole body (WBBMD), lumbar spine (LSBMD) and bone ultrasound properties (SOS, BUA) were measured.


RESULTS
The rhythmic gymnasts had lower fat mass and leptin level than the controls. There was no difference for IGF1, cortisol and insulin levels. Bone turnover rate was higher in elite gymnasts. The uncoupling index showed that remodeling favored the bone formation. LSBMD, WBBMD, SOS and BUA were higher in elite gymnasts after adjustment for fat mass. Leptin correlated positively with fat mass and negatively with physical activity.


CONCLUSIONS
High impact training is able to counterbalance bone effects usually encountered in hormonally disturbed subjects. Our results suggest that hypoleptinaemia might be related to direct osteogenic effects and indirect hormonal mechanisms including preservation of IGF and cortisol levels.
Courteix
D
D
Laboratory of Bone Architecture and Physical Exercise (ATOSEP EA 3895), University of Orleans, Orleans, France. daniel.courteix@wanadoo.fr
Rieth
N
N
Thomas
T
T
Van Praagh
E
E
Benhamou
C L
CL
Collomp
K
K
Lespessailles
E
E
Jaffré
C
C
D000293:Adolescent; D000886:Anthropometry; D015519:Bone Density / Q000502:physiology; D001846:Bone Development / Q000502:physiology*; D001842:Bone and Bones / Q000033:anatomy & histology; D016022:Case-Control Studies; D002648:Child; D024042:Collagen Type I / Q000652:urine; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006173:Gymnastics / Q000502:physiology*; D006801:Humans; D020738:Leptin / Q000097:blood*; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000652:urine
D024042:Collagen Type I; D020738:Leptin; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin