ESPE Abstracts

Background: Height references have been available for decades, although only related to chronological age and not considering the broad individual variation in the timing and tempo of pubertal maturation and growth. Therefore, growth references and growth charts for the adolescent period have been of limited usefulness both for monitoring growth in individuals and for research. To fill this gap, we recently developed a new type of height reference based on growth curves aligned for onset of pubertal growth.

Aim: To explore the usefulness of this new type of pubertal height reference allowing alignment of individuals' growth curves based on timing of pubertal growth spurt.

Methods: References for total-height, specific-pubertal-height_SDS (P-function) and basic-height_SDS (QES-function) was constructed from QEPS (Quadratic-Exponential-Puberty-Stop)-function-estimated height curves aligned for time/age at onset of pubertal growth (defined as 5% P-function) from 1572 healthy GrowUp₁₉₉₀Gothenburg-cohort-children. Usefulness were explored using data from GrowUp₁₉₇₄Gothenburg-cohort children with different pubertal timing (early <-1.5yrs, average ±0.25yrs, late >+1.5yrs); tall/short stature; high/low BMI.

Results: When using height reference according to chronological age, the height curve was left-shifted for early and right-shifted for late maturers, high-lightening the minimal usefulness of ordinary references only considering age.

When using the new puberty-adjusted references, the variation in total pubertal height gain (early maturers gaining more, late maturers gaining less compared to average pubertal maturers) was owing to differences between the three groups in basic growth whereas height gained owing to the specific pubertal function did not differ between the three groups. Duration of pubertal growth was longer in early and shorter in late maturers and at adult height early matures were shorter whereas late male maturers were taller than those in the average group.

Tall children gain more height during puberty owing to more basic growth despite less specific pubertal growth, whereas short children gain less height during puberty due to less basic growth despite more specific pubertal growth (when compared to reference population).

Obese children have less specific pubertal height gain than thin children with an underlying low amount of specific P-function growth and more basic growth before puberty that was maintained during puberty (compared to reference population) whereas the opposite was found in thin children.

Conclusions: The new pubertal growth reference was able to identify differences in the underlying growth functions that translate into differences in total pubertal height gain for children of varying BMI, height, and different pubertal timings.