Does height and IGF-I determine pubertal timing in girls?

Area of Science:

• Pediatric Endocrinology
• Growth Hormone Axis
• Pubertal Development

Background:

• Pubertal timing is influenced by the growth hormone/insulin-like growth factor (GH/IGF) axis.
• Key IGF-regulating factors include pregnancy-associated plasma protein-A/A2 (PAPP-A/PAPP-A2) and stanniocalcin 2 (STC2).

Purpose of the Study:

• To investigate the association between height, IGF-I concentration, and genotypes of PAPPA, PAPPA2, and STC2 with the timing of female pubertal milestones.
• To determine if genetic variations in IGF-regulating factors influence pubertal onset.

Main Methods:

• Analysis of height, IGF-I levels, and genotypes in 1382 Danish girls.
• Inclusion of cohorts with tall stature (≥2 SD) and short stature (≤-2 SD).
• Assessment of pubertal milestones: thelarche (breast development) and menarche.

Main Results:

• Thelarche occurred significantly earlier in tall girls and later in short girls compared to normal-stature girls.
• Higher IGF-I levels were associated with earlier thelarche and menarche.
• No significant association was found between PAPPA, PAPPA2, or STC2 genotypes and age at thelarche or menarche, although PAPPA2 minor allele carriers were shorter.

Conclusions:

• Height and IGF-I levels, but not specific genotypes of PAPP-A, PAPP-A2, and STC2, are negatively associated with age at thelarche and menarche.
• Childhood growth and IGF-I levels may serve as biomarkers for predicting pubertal timing.