Natural history of idiopathic advanced bone age diagnosed in childhood: pattern of growth and puberty.
BACKGROUND
Significant idiopathic bone age (BA) advancement is defined as BA >2 SD above the mean chronological age (CA) with no underlying etiology. BA advancement due to endocrinopathies is associated with early puberty and compromised adult height (AHt), necessitating treatment. The natural history of idiopathic BA advancement is not well-established.


OBJECTIVE
to determine the pattern of growth and puberty, and validity of AHt prediction in idiopathic BA advancement.


METHODS
fifty-five prepubertal patients (20 boys aged 6.7 ± 2.2 years, 35 girls aged 6.4 ± 2.0 years) evaluated between 1985 and 2008 were found to have idiopathic BA advancement. Assessed during follow-up were: BA, height (Ht), weight (Wt), pubertal course and predicted AHt (PAHt). Attained AHt was compared to PAHt and to midparental Ht (MPHt).


RESULTS
throughout follow-up, BA-SDS (SD score) significantly declined (p < 0.001), Ht-SDS significantly decreased (p = 0.006) and Wt-SDS did not change. Pubertal onset, duration and growth were within the normal range. Attained AHts did not differ significantly from MPHts (boys: 172 ± 6.7 vs. 171 ± 6.1 cm; girls: 160.5 ± 6.5 vs. 159.0 ± 6.8 cm). PAHts using the 'accelerated' tables of Bayley and Pinneau were accurate.


CONCLUSIONS
idiopathic BA advancement differs from BA advancement with underlying endocrinopathy in evolution of BA progression (decline in BA-SDS), growth pattern, validity of AHt prediction and uncompromised AHt. This indicates that it requires minimal clinical monitoring and usually does not mandate treatment.
Lazar
Liora
L
The Jesse Z and Sara Lea Shafer Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.
Lebenthal
Yael
Y
Shalitin
Shlomit
S
Phillip
Moshe
M
D000293:Adolescent; D041923:Adolescent Development; D000365:Age Determination by Skeleton; D001827:Body Height / Q000235:genetics; D015992:Body Mass Index; D001848:Bone Diseases, Developmental / Q000503:physiopathology*; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006130:Growth Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D006225:Hand / Q000000981:diagnostic imaging; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008499:Medical Records; D010290:Parents; D011379:Prognosis; D011627:Puberty; D012189:Retrospective Studies